Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D493/00—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system
  • C07D493/02—Heterocyclic compounds containing oxygen atoms as the only ring hetero atoms in the condensed system in which the condensed system contains two hetero rings
  • C07D493/10—Spiro-condensed systems
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D311/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only hetero atom, condensed with other rings
  • C07D311/02—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only hetero atom, condensed with other rings ortho- or peri-condensed with carbocyclic rings or ring systems
  • C07D311/78—Ring systems having three or more relevant rings
  • C07D311/80—Dibenzopyrans; Hydrogenated dibenzopyrans
  • C07D311/82—Xanthenes
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K5/00—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof
  • C07K5/04—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof containing only normal peptide links
  • C07K5/06—Dipeptides
  • C07K5/06191—Dipeptides containing heteroatoms different from O, S, or N
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K5/00—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof
  • C07K5/04—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof containing only normal peptide links
  • C07K5/08—Tripeptides
  • C07K5/0827—Tripeptides containing heteroatoms different from O, S, or N
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K5/00—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof
  • C07K5/04—Peptides containing up to four amino acids in a fully defined sequence; Derivatives thereof containing only normal peptide links
  • C07K5/10—Tetrapeptides
  • C07K5/1027—Tetrapeptides containing heteroatoms different from O, S, or N
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07K—PEPTIDES
  • C07K7/00—Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
  • C07K7/04—Linear peptides containing only normal peptide links
  • C07K7/06—Linear peptides containing only normal peptide links having 5 to 11 amino acids
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/14—Heterocyclic carbon compound [i.e., O, S, N, Se, Te, as only ring hetero atom]
  • Y10T436/142222—Hetero-O [e.g., ascorbic acid, etc.]

Definitions

• This invention is in the field of intracellular detection of enzymes using fluorogenic or fluorescent probes.
• the invention relates to novel fluorescent dyes and application of these dyes for the preparation of novel fluorogenic or fluorescent peptide or amino acid derivatives which are substrates of proteases and peptidases.
• the invention relates to novel fluorogenic or fluorescent peptide derivatives which are substrates of enzymes involved in apoptosis, such as caspases and the lymphocyte-derived serine protease
• the invention also relates to a process for measuring the activity of caspases and other enzymes involved in apoptosis in living or dead whole cells, cell lines or tissue samples derived from any healthy, diseased, infected or cancerous organ or tissue.
• the invention also relates to the use of the fluorogenic or fluorescent substrates in a novel assay system for discovering or detecting inhibitors or inducers of apoptosis in compound collections or compound libraries.
• the invention relates to the use of the fluorogenic or fluorescent substrates in determining the sensitivity of cancer cells to treatment with chemotherapeutic drugs.
• the invention also relates to novel fluorogenic or fluorescent peptide derivatives which are substrates of exopeptidases such as aminopeptidase A and N, methionine aminopeptidase and dipeptidyl-peptidase IV, endopetidases such as calpain, proteases such as HIV proteases, HCMV protease, HSV protease, HC ⁇ ' protease and adenovirus protease.
• exopeptidases such as aminopeptidase A and N, methionine aminopeptidase and dipeptidyl-peptidase IV
• endopetidases such as calpain
• proteases such as HIV proteases, HCMV protease, HSV protease, HC ⁇ ' protease and adenovirus protease.
• Organisms eliminate unwanted cells by a process variously known as regulated cell death, programmed cell death or apoptosis. Such cell death occurs as a normal aspect of animal development as well as in tissue homeostasis and aging (Glucksmann, A., Biol. Rev. Cambridge Philos. Soc. 26:59-86 (1951); Glucksmann, A., Archives de Biologie 7r5:419-437 (1965); Ellis et al, Dev. 772:591-603 (1991); Vaux et al, Cell 7(5:777-779 (1994)). Apoptosis regulates cell number, facilitates morphogenesis, removes harmful or otherwise abnormal cells and eliminates cells that have already performed their function. Additionally, apoptosis occurs in response to various physiological stresses, such as hypoxia or ischemia (PCT published application WO96/20721).
• Apoptotic bodies membrane enclosed particles containing intracellular material
• Apoptosis is achieved through an endogenous mechanism of cellular suicide (Wyllie, A. H., in Cell Death in Biology and Pathology, Bowen and Lockshin, eds., Chapman and Hall (1981), pp. 9-34).
• a cell activates its internally encoded suicide program as a result of either internal or external signals.
• the suicide program is executed through the activation of a carefully regulated genetic program (Wylie et al, Int. Rev. Cyt. 68:251 (1980); Ellis et al, Ann. Rev. Cell Bio. 7:663 (1991)).
• Apoptotic cells and bodies are usually recognized and cleared by neighboring cells or macrophages before lysis. Because of this clearance mechanism, inflammation is not induced despite the clearance of great numbers of cells (Orrenius, S., J. Internal Medicine 237:529-536 (1995)).
• IL-l ⁇ Mammalian interleukin-l ⁇ (IL-l ⁇ ) plays an important role in various pathologic processes, including chronic and acute inflammation and autoimmune diseases (Oppenheim, J.H., et al, Immunology Today, 7:45-56 (1986)).
• IL-l ⁇ is synthesized as a cell associated precursor polypeptide (pro- IL-l ⁇ ) that is unable to bind IL-1 receptors and is biologically inactive
• IL-1 is also a cytokine involved in mediating a wide range of biological responses including inflammation, septic shock, wound healing, hematopoiesis and growth of certain leukemias (Dinarello, C.A., Blood
• Interleukin-l ⁇ converting enzyme is a protease responsible for the activation of interleukin-l ⁇ (IL-l ⁇ ) (Thornberry, N.A., et al, Nature 356:768 (1992); Yuan, J., et al, Cell 75:641 (1993)).
• ICE is a substrate-specific cysteine protease that cleaves the inactive prointerleukin-1 to produce the mature IL-1.
• the genes that encode for ICE and CPP32 are members of the mammalian ICE/Ced-3 family of genes which presently includes at least twelve members: ICE, CPP32/Yama/Apopain, mICE2, ICE4, ICH1, TX/ICH- 2, MCH2, MCH3, MCH4, FLICE/MACH/MCH5, ICE-LAP6 and ICErellll.
• a death trigger such as Tumor Necrosis Factor, FAS-ligand, oxygen or nutrient deprivation, viruses, toxins, anti-cancer drugs etc.
• caspases can activate caspases within cells in a cascade-like fashion where caspases upstream in the cascade (e.g. FLICE/MACH/MCH5) can activate caspases further downstream in the cascade (e.g. CPP-32/Yama/Apopain). Activation of the caspase cascade leads to cell death.
• Caspases are also thought to be crucial in the development and treatment of cancer. There is mounting evidence that cancer cells, while containing caspases, lack parts of the molecular machinery that activate the caspase cascade (Los et al, Blood, Vol. 90, No 5:3118-3129 (1997)). This causes the cancer cells to lose their capacity to undergo cellular suicide and the cells become immortal — they become cancerous.
• chemotherapeutic drugs can trigger cancer cells to undergo suicide by re-activating the dormant caspase cascade. This may be a crucial aspect of the mode of action of most, if not all, known anticancer drugs (Los et al, Blood, Vol. 90, No 5:3118-3129 (1997); Friesen et al, Nat. Med. 2:574 (1996)). Chemotherapeutic drugs may differ in their capacity to activate the caspase system in different classes of cancers. Moreover, it is likely that anti-cancer drugs differ in their ability to activate the caspase cascade in a given cancer (e.g. lung cancer) and in different patients. In other words, there are differences from one patient to another in the chemosensitivity of, e.g. lung cancer cells, to various anti-cancer drugs.
• a given cancer e.g. lung cancer
• the excessive activation of the caspase cascade plays a crucial role in a wide variety of degenerative organ diseases, while a non- functioning caspase system is a hallmark of cancer cells.
• New drugs that inhibit or stimulate the caspase cascade are likely to revolutionize the treatment of numerous human diseases ranging from infectious, cardiovascular, endocrine, kidney, liver and brain diseases to diseases of the immune system and to cancer.
• HTCA assays In order to find drugs that either inhibit or stimulate the caspase cascade, it is necessary to develop high-throughput caspase activation (HTCA) assays. These HTCA assays must be able to monitor activation or inhibition of the caspase cascade inside living or whole cells. Ideally, HTCA assays should be versatile enough to measure the caspase cascade activity inside any living or whole cell regardless of the cell's origin. Furthermore, such HTCA assays should be able to measure— within living or whole cells— the activation or inhibition of any of the caspase enzymes or any other enzymes that are involved in the caspase cascade. Developing such versatile HTCA assays represents a substantial advance in the field of drug screening.
• HTCA assays do not permit inner cellular screening for compounds that can either activate or inhibit the caspase cascade.
• cell-free, high-throughput screening assays available that can measure the activity of individually isolated caspase enzymes, or assays that can measure the activity of caspases in dead cells which have been permeabilized by osmotic shock (Los et al, Blood, Vol. 90, No 5:3118-3129 (1997)).
• These cell-free enzyme assays cannot predict the effect of a compound on the caspase cascade in living cells for the following reasons:
• chemosensitivity testing has not found wide-spread use because the procedures involved have some inherent technical difficulties. The testing is very time consuming (six or more days per screen) and it requires culturing of the cells prior to screening. The cell culture leads to clonal selection of cells and the cultured cells are then no longer representative of the cancer in the patient.
• a HTCA assay system for quickly measuring intracellular caspase activity could be used to determine very rapidly the chemosensitivity profile of freshly excised cancer cells.
• the assay has a high throughput, it would be feasible to test chemosensitivity of multiple samples taken from the same patient, e.g. from different metastases. This information could then be used to design a treatment regimen using combinations of marketed anti-cancer drugs to which the cells showed greatest sensitivity.
• HTCA assays and reagents for such assays that can be employed in drug discovery or diagnostic procedures to quickly detect and measure the activity of compounds that activate or inhibit the caspase cascade or other enzymes involved in apoptosis in the interior of living or dead whole cells.
• a reagent for this type of cell assay ideally should meet the following conditions: a) there should be a big difference in fluorescence signal between peptide-reporter molecule and reporter molecule after the amide bond in peptide-reporter is cleaved by the caspases or other enzymes involved in apoptosis, preferably the peptide-reporter molecule should be non-fluorescent and most preferably the peptide-reporter molecule should be non-fluorescent and colorless; b) the peptide-reporter molecule should be cell permeable, therefore there should be minimum numbers of hydrophilic groups in the molecule and the size of the molecule should preferably be small; c) the peptide-reporter molecule should preferably not diffuse out of the cell once it permeates the cell membrane; d) the reporter molecule should preferably not diffuse out of the cell once it is liberated from the peptide.
• the method of screening apoptosis inhibitors or inducers in whole cells vs cell-free enzyme assay can also be used for the screening of inhibitors of enzymes other than caspases.
• enzyme inhibitors were first identified by cell-free enzyme assays. Cell cultures were then used for secondary assay to assess activity of the active compounds in intact cells.
• a cell permeable fluorogenic or fluorescent substrate will enable the screening of inhibitors of proteases and peptidases and other enzymes directly in living whole cells.
• AGM-1470 (also known as TNP-470) is an angiogenesis inhibitor in clinical trials for a variety of cancers.
• the mechanism of action of AGM-1470 was recently discovered by two independent research groups (Sin, N., et al. Proc. Natl. Acad. Sci. U.S.A. 94:6099-6103 (1997); Griffith, E.C., et al, Chem. Biol. :461-471 (1997)). They found that AGM-1470 and analogs are inhibitors of methionine animopeptidase type 2 (MetAP-2). The potency for inhibition of endothelial cell proliferation and inhibition of methiomne aminopeptidase activity was determined for a series of AGM-1470 analogs and a significant correlation between the two activities was found.
• angiogenesis inhibitors are known to be able to selectively kill cancer cells
• a cellular screening assay for inhibitors of MetAP-2 may result in novel anti-cancer drugs. Therefore cell permeable fluorogenic or fluorescent substrates for MetAP-2 can be used for the screening of inhibitors of MetAP-2 in endothelial cells which could lead to novel anticancer agents.
• HIV protease inhibitors such as ritonavir and viracept have been shown to be very effective in the treatment of patients infected with HIV. These inhibitors were designed based on the structure of the HIV protease substrate. The activities of these inhibitors were first determined against HIV protease. Active compounds were then tested for inhibition of HIV infection in cell cultures.
• a cell permeable fluorogenic or fluorescent substrate for HIV protease can be used for the screening of HIV protease inhibitors in HIV infected cells which could speed up the process for the discovery of novel HIV protease inhibitors and lead to new and better treatment for HIV infection.
• a cell permeable fluorogenic or fluorescent substrate for HIV protease also can be used to screen compounds which inhibit gene transcription or translation, viral entry, or other key proteins in the early stage of HIV infection.
• the fluorogenic or fluorescent substrates also could be used for diagnosis of HIV infection, which might be more sensitive than the currently available methods.
• cell permeable fluorogenic or fluorescent substrates for cathepsin B can be used for the screening of cathepsin B inhibitors.
• Cell permeable fluorogenic or fluorescent substrates for dipeptidyl- peptidase IV can be used for the screening of dipeptidyl-peptidase IV inhibitors.
• Cell permeable fluorogenic or fluorescent substrates for renin can be used for the screening of renin inhibitors and cell permeable fluorogenic or fluorescent substrates for adenovirus protease or other viral proteases can be used for the screening of adenovirus protease or other viral protease inhibitors.
• U.S. Patent Nos. 4,557,862 and 4,640,893 disclose Rhodamine 110 derivatives as fluorogenic substrates for proteinases of the formula:
• R, and R 2 which are the same or different, are selected from the group consisting of amino acids, amino acid derivatives, blocked amino acids, blocked amino acid derivatives, and peptides.
• Exemplary (AA) 2 -Rhodamines and (peptide) 2 -Rhodamines are (Z-Arg) 2 -Rhodamine 110, (Arg) 2 -Rhodamine 110, (Z-Ala-Arg) 2 -Rhodamine 110, (Z-Gln-Arg) 2 -Rhodamine 110, (Z-Glu- Arg) 2 -Rhodamine 110, (Z-Gly-Arg) 2 -Rhodamine 110, (Z-Leu-Arg) 2 - Rhodamine 110, (Z-Met-Arg) 2 -Rhodamine 110, (Z-Phe-Arg) 2 -Rhodamine 110, (Z-Pro-Arg) 2 -Rhodamine 110, (Z-Trp-Arg
• WO 96/36729 discloses compounds or their salts for assaying the activity of an enzyme inside a metabolically active whole cell.
• the assay compound is said to include a leaving group and an indicator group.
• the leaving group is selected from the group comprising amino acids, peptides, saccharides, sulfates, phosphates, esters, phosphate esters, nucleotides, polynucleotides, nucleic acids, pyrimidines, purines, nucleosides, lipids and mixtures.
• the indicator group is selected from compounds which have a first state when joined to the leaving group, and a second state when the leaving group is cleaved from the indicator group by the enzyme.
• Preferred indicator compounds are said to be Rhodamine 110, rhodol, and fluorescein and analogs of these compounds.
• U.S. patent 5,576,424 disclosed haloalkyl derivatives of reporter molecules used to analyze metabolic activity in cells of the Formula:
• -BLOCK is a group selected to be removable by action of a specific analyte, to give reporter spectral properties different from those of the substrate;
• -REPORTER- is a molecule that, when no longer bound to BLOCK by a BLOCK-REPORTER bond, has spectral properties different from those of the substrate;
• -SPACER- is a covalent linkage;
• XR- is a haloalkyl moiety that can covalently react with an intracellular thiol to form a thioether conjugate.
• Preferred reporter compounds are said to include Rhodamine- 110, rhodol, fluorescein and others.
• the present invention relates to fluorogenic or fluorescent reporter compounds of general Formula I:
• X is a peptide, amino acid or other structure such that the compound of Formula I is a substrate for caspases, or other proteases or peptidases or other enzymes; and wherein X-Y is the scissile bond.
• Z is a halo-substituted benzoyl blocking group and the Y-Z bond is not a scissile bond.
• Y is a fluorogenic or fluorescent moiety, preferably a Rhodamine including, but not limited to, Rhodamine 110, Rhodamine 116.
• Rhodamine 19 and sulforhodamine are Rhodamine 19 and sulforhodamine.
• Y is Rhodamine 110.
• Z is a multifluoro-substituted benzoyl group, and most preferably pentafluorobenzoyl and tetrafluorobenzoyl.
• R,-R 5 are independently hydrogen, fluoro. chloro, bromo, iodo, haloalkyl, aryl, cycloalkyl, alkyl, alkenyl, alkynyl. aralkyl, aralkenyl, aryl alkynyl, hydroxyalkyl, nitro, amino, cyano, acyl (alkanoyl), acylamino, hydroxy, acyloxy, alkoxy, alkylthio, or carboxy, provided that at least one of R,, R 3 or R 5 is fluoro or chloro.
• three of the R r R 5 are fluoro, more preferably, four of the R,-R 5 are fluoro, and most preferably, R,-R 5 are all fluoro.
• X and R,-R 5 are as defined previously; R 8 and R, are the same or different and are independently hydrogen, alkyl or aryl; and R 10 and R ⁇ are the same or different and are independently hydrogen or alkyl.
• R 8 and are hydrogen, methyl, or ethyl and R 10 and R ⁇ are hydrogen or methyl. Most preferably R 8 and R n are hydrogen.
• one class of the novel fluorogenic or fluorescent reporter compounds of this invention are of Formula IV:
• R,- R 5 are as defined previously in Formula II; and Rg is a N-terminal protecting group, e.g. t-butyloxycarbonyl, acyl, benzyloxycarbonyl and pentafluorobenzoyl.
• Each AA independently is any natural or non-natural amino acid or derivative of an amino acid.
• n is an integer from 0-5 and m is an integer from 0-3.
• Another class of the novel fluorogenic or fluorescent reporter compounds of this invention are of Formula V:
• R,-R 5 , AA, n and m are as defined previously in Formulae II and IV;
• R 7 is a N-terminal protecting group including t-butyloxycarbonyl, acyl, benzyloxycarbonyl and pentafluorobenzoyl. R 7 may also be H.
• the invention also relates to a method for the preparation of a Gly- containing compound of Formula IV, comprising the steps of:
• R,-R 5 are defined above and Q is halo, hydroxy or a group of Formula VII: where RpR-s defined above, to give the substituted benzoyl-Rhodamine of Formula VIII;
• the substituted benzoyl group is pentafluoro substituted.
• step introducing Gly may be omitted and a compound of general Formula IV can be obtained by a method comprising the steps of:
• the invention also relates to the novel fluorescent dyes of Formula VIII which are derivatives of Rhodamine by introducing a fluoro- or chloro-substituted benzoyl blocking group into one of the two amino groups of Rhodamine.
• the HN-R 8 group in Formula VIII provides the point of attachment for reaction with a potential enzyme substrate, such as the carboxylic group of a N-protected peptide, to form a peptide amide bond.
• the reaction will convert the fluorescent molecule of Formula VIII into a non- fluorescent peptide-reporter molecule of Formulae IV or V which is a substrate for proteases or peptidases. Cleavage of the scissile peptide-reporter amide bond in peptide-reporter by proteases or peptidases produces compound of Formula VIII or VIII' which is fluorescent.
• novel fluorescent dyes of this invention are of Formula VIII:
• R,-R 5 are as defined previously in Formula II; R 8 -R u are as defined previously in Formula III.
• three of the R,-R 5 are fluoro, more preferably, four of the R ⁇ -K 5 are fluoro, and most preferably, R,-R 5 are all fluoro.
• R 8 -R ⁇ are hydrogen or alkyl. Most preferably, R 8 -R, , are all hydrogen.
• Compounds of Formula VIII of the present invention may exist in tautomeric forms, particularly the ring opening form of Formula VIII'. The invention includes all tautomeric forms including, but not limited to, VIII and v ⁇ r.
• the invention also relates to a process of using the reporter compounds represented by Formula IV to measure the activity of intracellular caspases or other enzymes involved in apoptosis in living or dead whole cells or tissues.
• the invention also relates to methods of using the compounds represented by Formula IV and the assay processes described herein to measure the activation or inhibition of any of the caspase enzymes inside any living or dead whole cell or tissue (normal or cancerous) by a test substance or substances.
• the compounds represented by Formula IV are cell-permeable, that is they can be introduced into whole cells or tissue samples.
• the compounds are fluorogenic or fluorescent and can be designed to be specific for any of the known caspases or for any other intracellular enzymes involved in apoptosis.
• fluorogenic or fluorescent substrates for specific caspases can be synthesized by the procedures described herein.
• the fluorogenic or fluorescent substrates can also be designed to measure more than one enzyme at a time, by designing substrates that are recognized and cleaved by more than one of the enzymes involved in the caspase cascade. Fluorogenic or fluorescent substrates which are "promiscuous" for more than one caspase may be utilized using the assay process described herein to measure the activity of as yet unknown caspases.
• the fluorogenic or fluorescent reporter molecules described herein are cleaved and respond with a large increase in fluorescence emission.
• the change in fluorescence can be measured spectrofluorometrically.
• the reporter molecules can also be used to measure baseline caspase activity in cells that are not undergoing apoptosis.
• the method is easily adaptable to high throughput or ultra-high throughput screening assays.
• the assay system is very versatile. Examples of the extreme versatility of the assay system are given below:
• the assay can be used to screen a cell or tissue for baseline activity of any caspase enzyme or any other enzyme involved in apoptosis. 2)
• the assay can be used with equal ease to screen for compounds that can either activate or inhibit the caspase cascade. That means the assay can be used to screen for drugs against degenerative diseases or for drugs against cancer.
• the assay can be used to screen for caspase cascade activation or inhibition in any living or dead cells or cell lines derived from any organ system in the body including, but not limited to. hair, brain, peripheral nervous system, eye, ear, nose, mouth, tonsils, teeth, esophagus, lung, heart, blood, blood vessels, bone marrow, lymph nodes, thymus, spleen, immune system, liver, stomach, intestinal tract, pancreas, endocrine glands and tissues, kidney, bladder, reproductive organs and glands, joints, bones and skin.
• the assay can be used to screen for drugs with potential use in any disease of any organ system in the body that involves malfunction of the caspase cascade.
• the assay can be used to screen for drugs that might modulate the caspase cascade directly or indirectly, i.e. by modulating the caspases itself or by modulating cellular receptors and co-factors that influence the caspase cascade.
• the assay can be used to determine the site of action at which a caspase cascade modulator interferes. That is, the assay can help to pin down the molecular mechanism of action of a novel caspase cascade modulator drug.
• the invention also relates to the use of the fluorogenic or fluorescent substrates represented by Formula IV for finding new compounds or new uses for known compounds in reducing, preventing or treating maladies in which apoptotic cell death is either a causative factor or a result.
• uses for the present invention include screening for compounds that can protect the nervous system following focal ischemia and global ischemia; screening for compounds that can treat neurodegenerative disorders such as Alzheimer's disease, Huntington's Disease, prion diseases, Parkinson's Disease, multiple sclerosis, amyotrophic lateral sclerosis, ataxia, telangiectasia, and spinobulbar atrophy; screening for compounds that can treat heart disease including myocardial infarction, congestive heart failure and cardiomyopathy; screening for compounds that can treat retinal disorders; screening for compounds that treat autoimmune disorders including lupus erythematosus, rheumatoid arthritis, type I diabetes, Sj ⁇ gren's syndrome and glornerulonephritis; screening for compounds
• the present invention also relates to the use of the fluorogenic or fluorescent substrates represented by Formula IV in screening procedures where libraries of known drugs or combinatorial or other compound libraries are screened for compounds with anti-tumor or anti-cancer activity.
• the cancer cells or cell lines can be derived from any cancer of any internal or external organ system in the body including, but not limited to brain, peripheral nervous system, eye, ear, nose, mouth, tonsils, teeth, esophagus, lung, heart, blood, blood vessels, bone marrow, lymph nodes, thymus, spleen, immune system, liver, stomach, intestinal tract, pancreas, endocrine glands and tissues, kidney, bladder, reproductive organs and glands (e.g. prostate gland), joints, bones and skin.
• brain peripheral nervous system
• eye ear, nose, mouth, tonsils, teeth, esophagus, lung, heart, blood, blood vessels, bone marrow, lymph nodes, thymus, spleen, immune system, liver, stomach, intestinal
• the present invention also relates to the use of the fluorogenic or fluorescent substrates represented by Formula I in diagnostic procedures to determine the chemosensitivity or resistance of cancer cells taken from an animal or a human being to treatment with chemotherapeutic drugs.
• the cancer cells or cell lines can be derived from any cancer of any internal or external organ system in the body including, but not limited to brain, peripheral nervous system, eye, ear, nose, mouth, tonsils, teeth, esophagus, lung, heart, blood, blood vessels, bone marrow, lymph nodes, thymus, spleen, immune system, liver, stomach, intestinal tract, pancreas, endocrine glands and tissues, kidney, bladder, reproductive organs and glands (e.g. prostate gland), joints, bones and skin.
• the invention relates to a method for detecting an enzyme involved in the apoptosis cascade in one or more cells, comprising
• the invention also relates to a method for measuring the activity of an enzyme involved in the apoptosis cascade in one or more cells, comprising
• the invention also relates to a method for determining whether a test substance has an effect on an enzyme involved in the apoptosis cascade in one or more test cells, comprising
• test cells may be contacted with said test substance prior to, after, or substantially simultaneously with the reporter compound according to the invention.
• the method may be used to detect whether the test substance stimulates or inhibits the activity of the enzyme.
• the invention also relates to further contacting the test cells with a second test substance or mixture of test substances in the presence of the first test substance.
• the test cell is a cancer cell or cell line derived from a human in need of treatment with a chemotherapeutic drug and the test substance is a chemotherapeutic agent or a mixture of chemotherapeutic agents.
• the invention also relates to a method to determine the sensitivity of an animal with cancer to treatment with one or more chemotherapeutic agents, comprising
• the invention also relates to a method of monitoring the treatment of an animal with one or more chemotherapeutic drugs, comprising
• the animal may suffer from a malady in which apoptotic cell death is either a causative factor or a result.
• the invention also relates to a method for determining whether a test substance inhibits or prevents cell death in one or more test cells, comprising (a) contacting the test cell with the test substance and the reporter compound according to the invention under conditions whereby the test substance either interacts with an external membrane receptor or is taken into the cell and the reporter compound is taken into the cell, and (b) recording the fluorescence of the test cells, wherein a change in fluorescence, either of magnitude or of wavelength, within the test cells compared to control cells that have only been contacted with the reporter compound, is an indication that the test substance inhibits or prevents cell death.
• the invention also relates to a method for determining whether a test substance causes or enhances cell death in one or more test cells, comprising the steps of:
• test substance (a) contacting the test cells with the test substance and the reporter compound according to the invention under conditions whereby the test substance either interacts with an external membrane receptor or is taken into the cells and the reporter compound is taken into the cells,
• the invention also relates to a process of using the reporter compounds represented by Formula V to measure the activity of intracellular peptidases and proteases in living whole cells, including, but not limited to, type-2 methionine aminopeptidase in endothelial cells and HIV protease in HIV infected cells.
• the invention also relates to methods of using the compounds represented by Formula V and the assay processes described herein to measure the inhibition of enzymes inside living whole cell by a test compound or compounds.
• the reporter compounds represented by Formula V are cell- permeable, that is they can be introduced into whole cells.
• the compounds are fluorogenic or fluorescent and can be designed to be specific for the known enzymes of interest, such as methionine aminopeptidase or HIV protease.
• Fig. 1 depicts a graph showing the fluorescence of N- pentafluorobenzoyl-Rhodamine 110 (RI 10-PFB) compared to Rhodamine 110 (R110).
• Figs. 2A and 2B depict photographs showing the staining of cells with N-pentafluorobenzoyl-Rl 10 (2B) compared to RI 10 (2A).
• Fig. 3 depicts a bar graph showing the cleavage of N-Gly-R 110-PFB and N-Cbz-Gly-Rl 10-PFB by HL-60 Cell Lysates.
• Figs. 4A and 4B depict photographs showing the staining of HL-60 Cells with N-Gly-Rl 10-PFB (4A) compared to N-Cbz-Gly-Rl 10-PFB (4B).
• Fig. 5 depicts a graph showing the cleavage of N-Z-DEVD-R110-PFB
• Fig. 6 depicts a bar graph with the results of a cleavage assay of Ac- DEVD-R1 10-TFB (SEQ ID NO:5) by recombinant caspase-3.
• Fig. 7 depicts a graph showing the cleavage of Ac-DEVD-Rl 10-TFB (SEQ ID NO: 5) in staurosporine induced apoptotic cells.
• Fig. 8 depicts a graph showing the cleavage of Ac-DEVD-Rl 10-TFB (SEQ ID NO: 5) in Anti -Fas antibody induced apoptotic cells.
• Fig. 9 depicts a graph showing the cleavage of Ac-DEVD-Rl 10-TFB (SEQ ID NO:5) in staurosporine induced apoptotic cells and its inhibition by a pan-caspase inhibitor.
• the fluorogenic or fluorescent substrates of the present invention are compounds having the general Formula I:
• X is a peptide, amino acid or other structure such that compounds of Formula I is a substrate for a caspase or other proteases or peptidases or other enzymes; and wherein X-Y is a scissile bond.
• Y is a fluorogenic or fluorescent moiety, preferably a Rhodamine including, but not limited to, Rhodamine 110, Rhodamine 116, Rhodamine 19 and sulfonorhodamine and most preferably Rhodamine 110.
• Z is a halo-substituted benzoyl blocking group and the Y-Z bond is not a scissile bond.
• Z is a multifluoro-substituted benzoyl group and most preferably Z is a tetrafluoro or pentafluorobenzoyl group.
• Preferred compounds falling within the scope of Formula I include compounds wherein the first amino acid attached to Y is an Asp.
• X is a N-blocked tetrapeptide substrate of a caspase including
• WEHD SEQ ID NO:10 DELD SEQ ID NO:l l, DGPD SEQ ID NO:12, DEPD SEQ ID NO:13, DGTD SEQ ID NO:14, DLND SEQ ID NO: 15, DEED SEQ ID NO: 16, DSLD SEQ ID NO: 17, DVPD SEQ ID NO:
• X is a N-blocked peptide which corresponds to a carboxyterminal or aminoterminal fragment consisting of 1,2 or 3 amino acids of the tetrapeptide substrate of a caspase including WEHD SEQ ID NOT, YVAD SEQ ID NO:2, LEHD SEQ ID NO:3, DETD SEQ ID NO:4, DEVD SEQ ID NO:5, DEHD SEQ ID NO:6, VEHD SEQ ID NO:7, LETD SEQ ID NO:8, SHVD SEQ ID NO: 10, DELD SEQ ID NO: 11, DGPD SEQ ID NO: 12, DEPD SEQ ID NO:13, DG
• X is a N-blocked peptide which corresponds to a carboxyterminal or aminoterminal fragment consisting of 1, 2, 3 or 4 amino acids of the tetrapeptide substrate of a caspase including WEHD SEQ ID NOT, YVAD SEQ ID NO:2, LEHD SEQ ID NO:3, DETD SEQ ID NO:4, DEVD SEQ ID NO:5, DEHD SEQ ID NO:6, VEHD SEQ ID NO:7, LETD SEQ ID NO:8, SHVD SEQ ID NO: 10, DELD SEQ ID NOT 1, DGPD SEQ ID NO:12, DEPD SEQ ID NO:
• R,-R 5 are independently hydrogen, fluoro, chloro, bromo, iodo, haloalkyl, aryl, cycloalkyl, alkyl, alkenyl, alkynyl, aralkyl, aralkenyl, aralkynyl, hydroxyalkyl, nitro, amino, cyano, acylamino, acyl, hydroxy, acyloxy, alkoxy, alkylthio, or carboxy; provided that at least one of the R,, R 3 or R 5 is fluoro or chloro.
• three of the R ] -R 5 are fluoro, more preferably, four of the RrR 5 are fluoro, and most preferably, RpR- 5 a e a ll fluoro.
• X and R]-R 5 are as defined previously in Formulae I and II; and R 8 and Rg are the same or different and are independently hydrogen, alkyl or aryl; and R 10 and R ⁇ are the same or different and are independently hydrogen or alkyl.
• R 8 and are hydrogen, methyl or ethyl.
• R 10 and R n are hydrogen or methyl.
• R 8 and R, are hydrogen.
• the fluoro- or chloro-substituted benzoyl group in Formula III is introduced to block one of the two amino groups in a Rhodamine.
• the remaining HNR 8 group is used for reaction with a potential enzyme substrate X, to give a fluorogenic substrate of Formula III.
• a potential enzyme substrate X By blocking one of the two amino groups in a Rhodamine, the overall size of the substrate is reduced compared to a bis-substituted Rhodamine, such as a bis-peptide-Rhodamine.
• the fluoro- or chloro-substituted benzoyl group also increases the lipophilicity of the molecule, thus increasing cell permeability of the substrates of Formula III.
• a nucleophile inside the cells such as a thiol, amino or hydroxyl group from proteins or peptides.
• replacement of the fluoro or chloro group by a nucleophile also results in the replacement of the electron withdrawing fluoro or chloro group by an electron donating group such as sulfide, amino or ether, or the replacement of the fluoro or chloro group by a highly hydrophilic moiety such as glutathion, which can change the fluorescent intensity or wavelength of the fluorogenic or fluorescent moiety of the substrates.
• one class of the novel fluorogenic or fluorescent reporter compounds of this invention are of Formula IV:
• R,-R 5 are as defined previously in Formula II; and R 6 is a N-terminal protecting group, e.g., t-butyloxycarbonyl, acyl, benzyloxycarbonyl and pentafluorobenzoyl; each AA independently is a residue or derivative of any natural or non-natural amino acid; n is 0-5; and m is 0-3.
• Rg is t-butyloxycarbonyl, benzyloxycarbonyl, acetyl, octanoyl, dodecanoyl or pentafluorobenzoyl.
• Compounds of Formula IV are novel fluorogenic or fluorescent substrates for caspases or other enzymes related with apoptosis.
• cleavage of the amide bond between Asp and Rhodamine will convert the fluorogenic substrate into the fluorescent dye of Formula VIII.
• cleavage of the amide bond between Asp and (AA) m will leave the
• Rhodamine attached to NH 2 -(AA) m will then be removed by aminopeptidases present in the cells to give the fluorescent dye of Formula VIII.
• (AA) ra may be designed to correspond with the P' sequence of the cleavage site of substrates of caspases or apoptosis related enzymes. The incorporation of the P' sequence of known substrates of caspases or apoptosis related enzymes are expected to increase specificity and affinity of the fluorogenic substrates. Since aminopeptidases are widely present in cells, one can insert a (AA) m sequence in the design of substrates of Formula IV for whole cell assays. This is another advantage of whole cell assays over cell-free enzyme assays.
• pro-reporter molecule is the methyl or ethyl ester forms of carboxyl-containing amino acid residues comprising compounds of
• AM acetoxymethyl
• PM pivaloyloxymethyl
• AM esters of carboxyl-containing compounds are known to be cell permeable and can be hydrolyzed by esterases inside the cells. Once hydrolyzed, the carboxyl-containing compounds become cell impermeable and are trapped inside the cells (Adams et al, J. Am. Chem. Soc. 777:7957-7968 (1989)).
• AM esters can be prepared by reacting the corresponding carboxy-containing compounds with bromomethyl acetate.
• Another class of the novel fluorogenic or fluorescent reporter compounds of this invention are of Formula V:
• R,-R 5 and AA are as defined previously in Formula II and IV; n is 1-5; m is 0-3; R 7 is a H; or R 7 is a N-terminal protecting group, preferably t- butyloxycarbonyl, acyl, acetyl, octanoyl. dodecanoyl, benzyloxycarbonyl or pentafluorobenzoyl.
• (AA) n is designed to be an amino acid or a peptide which is recognized by a specific peptidase or protease as the sequence in the p side and will be cleaved by the targeted peptidase or protease.
• (AA) m is designed to be an amino acid or peptide which is recognized by a specific peptidase or protease as the sequence in the P' side, and which can be removed by aminopeptidases presented in the cells.
• R 7 is a N-terminal protecting group such as a t-butyloxycarbonyl, Cbz or acetyl
• compounds of Formula V are substrates for endopeptidases such as cathepsin D or protease such as HIV protease
• R 7 is H
• compounds of Formula V are substrates for exopeptidases such as methionine aminopeptidase.
• compounds of Formula V may be designed to be substrates of type 2 methionine aminopeptidase (MetAP-2).
• MetAP-2 was identified recently by two research groups (Griffith, E.C., et al, Chem. Biol.
• MetAP-2 is a bifunctional enzyme which also regulate protein synthesis by affecting the phosphorylaton state of eIF-2.
• AGM-1470 is reported to only inhibit the aminopeptidase activity of MetAP-2 and have no effect on the regulatory activity of MetAP-2 (Griffith, E.C., et al, Chem. Biol. 4:461-471 (1997)). Since angiogenesis inhibitor such as AGM-1470 is known to be able to selectively kill cancer cells, inhibitors of MetAP-2 are expected to have anti- angiogenic properties and to be potential novel anticancer agents.
• MetAP-2 is a cobalt-dependent enzyme that hydrolyzes the amino- terminal methionine from certain proteins. Its preferred substrates are Met-X- Y.
• X is an amino acid with small and uncharged side groups, such as Gly, Ala, Ser. Leu, Met, Arg and Tyr are known to result in inactive substrates.
• Y can be Ser, Met, Gly or other amino acids (Li, X. & Chang Y.-H., Biochem.
• Rhodamine is much larger than an amino acid, a compound with methionine directly attached to Rhodamine most probably will not be a substrate for MetAP-2. Taking advantage of the presence of aminopeptidase in whole cells, the insertion of a (AA) m sequence between methionine and Rhodamine will make a good substrate for MetAP-2. This type of substrate is expected to work well in a whole cell assay but otherwise will not work in a cell-free MetAP-2 enzyme assay.
• preferred R 7 is H
• preferred (AA) n is Met
• preferred (AA) m is Gly, Ala, Gly-Gly, Ala-Gly or Gly-Ala.
• the methionine will be cleaved by type 2 methionine aminopeptidase in endothelial cells to give the Rhodamine attached to (AA) m .
• Aminopeptidases present inside the cells will then remove the (AA) m to give the fluorescent dye of Formula VI.
• Compounds of Formula V will be used for the screening of inhibitors of MetAP-2 in endothelial cells, which is expected to lead to the identification of novel anti-cancer drugs.
• HIV protease is an aspartic protease which processes polypeptides transcribed from the gag and pol genes and is essential for the maturation of infectious virus. Therefore HIV protease has been one of the major targets for chemotherapeutic intervention of HIV.
• HIV protease inhibitors have shown great potential in the treatment of HIV and have been approved for marketing. Most of these HIV protease inhibitors were designed based on the structure of the substrates of the protease. Therefore these compounds are either peptides or peptidomimetics. The search for new and novel HIV protease inhibitors is expected to provide more efficacious drugs for the fight against this deadly disease.
• the preferred substrates of HIV protease are peptides with a scissile hydrophobic-hydrophobic or aromatic-proline peptide bond between the P,-P,' (West, M.L., and Fairlie, D.P., Trand. Pharm. Sci. 16:67-74 (1995)).
• the P 4 -P 3 ' sequences of these nine sites are Ser-Gln-Asn-Tyr-Pro-Ile- Val SEQ ID NO: 28, Ala-Arg-Val-Leu-Ala-Glu-Ala SEQ ID NO: 29, Ala- Thr-Ile-Met-Met-Gln-Arg SEQ ID NO: 30, Arg-Gln-Ala-Asn-Phe-Leu-Gly
• HIV protease substrates incorporating sequences from both the P side and P' side of the cleavage sites of HIV protease substrates have been developed, and these include the fluorogenic N-alpha-benzoyl-Arg-Gly-Phe-Pro-MeO-beta- naphthylamide SEQ ID NO: 37, which contains the Phe-Pro dipeptide bond recognized by HIV-1 protease (Tyagi, S.C., and Carter, C.A., Anal. Biochem. 200:143-148 (1992)); the radiolabeled heptapeptide substrate, [tyrosyl-3,5-
• Glu-Ser SEQ ID NO: 40 (Evans, D.B., et al, Anal. Biochem. 206:288-292 (1992)); the intramolecular fluorescence resonance energy transfer (FRET) substrate 4-(4-dimethylaminophenylazo)benzoic acid (DABCYL)-Ser- Gln-Asn-Tyr-Pro-Ile-Val-Gln-5-[(2-aminoethyl)amino]naphthalene-l-sulfonic acid (EDANS) SEQ ID NO:41, wherein Tyr-Pro is the cleavage site
• fluorogenic or fluorescent substrates of HIV protease of Formula V can be designed to incorporate amino acids from both the P side and P' side of HIV substrate for application in whole cell assays. It is expected that after the peptide sequence in the P side is cleaved by the HIV protease, the peptide sequence in the P' side will be removed by aminopeptidases presented in the cells.
• preferred R 7 is acetyl or Cbz
• preferred (AA) n is Thr-Ile-Nle
• preferred (AA) m is Phe-Gln-Arg, Phe-Gln, or Phe
• preferred (AA) n is Ser- Leu-Asn-Phe SEQ ID NO: 54 or Leu-Asn-Phe
• preferred (AA) m is Pro-Ile- Val, Pro-He, or Pro
• preferred (AA) n is Ser-Gln-Asn-Tyr SEQ ID NO: 45, or Gln-Asn-Tyr
• preferred (AA) m is Pro-Ile-Val-Gln SEQ ID NO: 46, Pro- Ile-Val, Pro-Val-Val-NH 2 , Pro-Val-NH 2 , Pro-He, or Pro
• preferred (AA) n is
• Arg-Gly-Phe, and preferred (AA) m is Pro; or preferred (AA) n is Lys-Ala-Arg- Val-Leu SEQ ID NO: 47, Ala-Arg-Val-Leu SEQ ID NO: 48, or Arg-Val-Leu, and preferred (AA) m is Phe-Glu-Ala-Met SEQ ID NO: 49, Phe-Glu-Ala, Phe- Glu, or Phe; or preferred (AA) n is Pro-Phe-His-Leu SEQ ID NO: 50, or Phe- His-Leu, and preferred (AA) m is Leu-Glu-Glu-Ser SEQ ID NO: 40, Leu-Glu-
• n Ser-Gln-Asn-Leu-Phe SEQ ID NO: 78, Gln-Asn-Leu-Phe SEQ ID NO: 51, Asn-Leu-Phe, Arg-Lys-Ile-Leu- Phe SEQ ID NO: 52, Lys-Ile-Leu-Phe SEQ ID NO: 53, or Ile-Leu-Phe, and preferred (AA) m is Leu-Asp-Gly-NH 2 , Leu-Asp-NH 2 , or Leu-NH 2 .
• More preferred (AA) n is Ser-Leu-Asn-Phe SEQ ID NO: 54, or Leu-Asn-Phe, and more preferred (AA) m is Pro-Ile-Val, Pro-He, or Pro; or more preferred (AA) n is Arg-Gly-Phe, and more preferred (AA) m is Pro.
• Substrates of HIV protease of Formula V are expected to work in whole cell assays but otherwise will not work in cell-free enzyme assays. Cleavage of the (AA) n -(AA) m amide bond by HIV protease in HIV infected cells will give the Rhodamine attached to (AA) m . Aminopeptidases present inside the cells will then remove the (AA) m to give the fluorescent dye of Formula VI. Compounds of Formula V will be used for the screening of inhibitors of HIV protease in HIV infected cells.
• HIV protease inhibitors processes viral precursor proteins at a late stage in viral replication
• a cell permeable fluorogenic or fluorescent substrate for an HIV protease also can be used to screen compounds which inhibit gene transcription or translation, viral entry, or other key proteins in the early stage of HIV infection. Therefore this method can lead to the identification of inhibitors of HIV infections with a novel mechanism, which could not be identified in a cell-free enzyme assay.
• substrates of Formula V also can be used for the diagnosis of HIV infection.
• Compounds of Formula V also can be designed to be substrates of adenovirus protease.
• Adenovirus are the cause of several diseases including sporatic respiratory disease and epidemic acute respiratory disease which can lead to preumonia.
• Adenovirus protease is a cysteine protease which cleaves several viral proteins and is required for virus maturation and infectivity (Weber, J.M., Curr. Top. Microbiol Immunol. 199/1:227-235 (1995)).
• the preferred substrates of adenovirus protease includes (M,L,I)XGX-G and (M,L,I)XGG-X.
• the specificity of the substrates are mainly determined by P 2 and P 4 amino acids (Diouri, M., et al, J. Biol. Chem. 277:32511-32514 (1996)). Hydrophobic amino acids such as Met, Leu and He are perferred in P 4 . Small amino acid such as Gly is preferred in P 2 . A small and hydrophobic amino acid is also preferred for P, and P,', such as Ala and Gly; while P 3 can accommodate almost any amino acid. These observations were supported by the recently determined crystal structure of human adenorivus proteinase with its 11 aminoacid cofactor and substrate modeling based on the crystal structure (Ding, J., et al., EMBO J. 75. 1778-1783 (1996)).
• fluorogenic or fluorescent substrates of adevovirus protease can be designed to incorporate amino acids either from the P side only, or from both the P side and P' side of adenovirus protease substrate for application in whole cell assays.
• R 7 is acetyl or Cbz
• preferred (AA) n is Leu-Arg-Gly-Gly SEQ ID NO: 55, Met-Arg-Gly-Gly SEQ ID NO: 56, Ile-Arg-Gly-Gly SEQ ID NO: 55
• Compounds of Formula V will be used for the screening of inhibitors of adenovirus protease in adenovirus infected cells.
• Compounds of Formula V also can be designed to be substrates of herpes simplex virus type 1 (HSV-1) protease.
• HSV-1 protease Human herpes simplex virus type 1 is responsible for herpes labialis (cold sores).
• the HSV-1 protease is a serine protease and is responsible for proteolytic processing of itself and ICP35 for assembly of viral capside (Gao, M., et al, J. Virol. 6 ' 5:3702-3712 (1994)).
• HSV-1 protease resides within the P 4 -P ] ' region of the cleavage sites (McCann, P.J., et al, J. Virol. (55:526-529 (1994)).
• fluorogenic or fluorescent substrates of HSV-1 protease are designed to incorporate amino acids either from the P 4 -P, only, or both from P 4 -P, and P' side of HSV-1 protease substrate for application in whole cell assays.
• preferred R 7 is acetyl or Cbz
• preferred (AA) n is Leu-Val-Leu-Ala SEQ ID NO: 62
• cleavage of (AA) n -Rhodamine amide bond by the HSV-1 protease will produce fluorescent dye of the Formula VIII.
• cleavage of the (AA) n -(AA) m amide bond by HSV-1 in the cells will give the Rhodamine attached to (AA) m .
• Aminopeptidases present inside the cells will then remove the (AA) m to give the fluorescent dye of Formula VIII.
• Formula V will be used for the screening of inhibitors of HSV-1 protease in HSV-1 infected cells.
• Compounds of Formula V also can be designed to be substrates of human cytomegalovirus (HCMV) protease.
• HCMV can cause life-threatening infections in congenitally infected infants, immunocompromised individuals and immunosuppressed cancer or transplant patients.
• Human cytomegalovirus (HCMV) encodes a protease that cleaves itself and the HCMV assembly protein and is essential for virus replication, therefore it is a potential target for therapeutic intervetion.
• the HCMV protease is a serine protease and two proteolytic processing sites within the protease were identified at Ala 256-Ser 257 (release site) and Ala 643-Ser 644 (maturation site).
• fluorogenic or fluorescent substrates of HCMV protease are designed to incorporate amino acids either from the P side only, or both from P side and P' side of HCMV protease substrate for application in whole cell assays.
• preferred R 7 is acetyl or Cbz
• preferred (AA) n is Val-Val-Asn-Ala SEQ ID NO: 64 or Tbg-Tbg-Asn-Ala SEQ ID NO: 65
• m cleavage of (AA) n -Rhodamine amide bond by the HCMV protease will produce fluorescent dye of the Formula VIII.
• HCV hepatitis C virus
• HCV hepatitis C virus
• HCV protease NS3 and its protein activator NS4A participate in the processing of the viral polyprotein, thus the NS3/4A protease complex is an attractive target for antiviral therapy against HCV.
• the HCV protease is a serine protease and Cys-Ser has been identified as a cleavage site.
• One of the substrate sequence is Asp-Asp-Ile-Val-Pro-Cys- Ser-Met-Ser-Tyr SEQ ID NO: 66, and P, Cys and P 3 Val were found to be critical (Zhang, R., et al, J. Virol. 77:6208-6213 (1997)).
• fluorogenic or fluorescent substrates of HCV protease are designed to incorporate amino acids both from the P side and P' side of HCV protease substrate for application in whole cell assays.
• preferred R 7 is acetyl or Cbz
• preferred (AA) n is Asp-Asp-Ile-Val- Pro-Cys SEQ ID NO: 67, Asp-Ile-Val-Pro-Cys SEQ ID NO: 68, or Ile-Val- Pro-Cys SEQ ID NO: 69
• cleavage of (AA) n - Rhodamine amide bond by the HCV protease will produce fluorescent dye of the Formula VIII.
• the invention also relates to the novel compound of Formula VIII which are derivatives of a Rhodamine obtained by introducing a fluoro- or chloro-substituted benzoyl blocking group into one of the two amino groups in a Rhodamine.
• the HNR g group in Formula VIII provides the point of attachment for the reaction with a potential enzyme substrate, such as the carboxylic group of a N-blocked peptide, to form a peptide amide bond.
• the reaction will convert the fluorescent molecule of Formula VIII into a non- fluorescent molecule of Formula IV or V and produce a peptide-reporter molecule which functions as a substrate for a protease or peptidase.
• the hydrophobic fluoro- or chloro-substituted benzoyl blocking group is designed to increase cell permeability of the substrates of Formula I.
• the fluoro- or chloro-substituted benzoyl group is also designed to react with nucleophiles presented inside the cells, thus resulting in an accumulation of the substrates of Formula I inside the cells, as well as an increase in retention of the fluorescent moiety inside the cells after cleavage by target enzymes.
• replacement of the fluoro or chloro group by a nucleophile is expected to increase fluorescent intensity of the fluorescence moiety of the substrate of Formula I.
• novel fluorescent dyes of this invention are of Formula VIII:
• Compounds of Formula VIII of the present invention may exist in tautomeric forms, particularly the ring opening form of Formula VIII'.
• the invention includes all tautomeric forms including VIII and VIII'.
• Preferred fluorogenic or fluorescent substrates of the present invention are compounds having Formula I and include, but are not limited to: N-(Z-WEHD)-N-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID ⁇ O:l N-(Z-YVAD)-N-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:2) N-(Z-LEHD)-N-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:3) N-(Z-DETD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:4) N-(Z-DEVD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(Z-VEHD)-N'-pentafluorobenzoyl-Rhodamine 110.
• N-(Z-LETD)-N-pentafluorobenzoyl-Rhodamine 110 N-(Z-LEHD)-N'-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID ⁇ O:3 N-(Z-IEPD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:23) N-(Z-VEPD)-N'-pentafluorobenzoyl-Rhodamine 110.
• N-(Z-SHVD)-7 ⁇ r-pentafluorobenzoyl-Rhodamine 110 N-(Z-SHVD)-7 ⁇ r-pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO: 10) N-(Z-DELD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:l 1) N-(Z-DGPD)-N'-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 12 N-(Z-DEPD)-N-pentafluorobenzoyl-Rhodamine 110
• SEQ ID NO: 13 N-(Z-DGTD)-N'-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 14 N-(Z-DLND)- ⁇ T-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 15 N-(Z-DEED)-N-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 16 N-(Z-DSLD)-N-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 17 N-(Z-DVPD)-N-pentafluorobenzoyl-Rhodamine 110.
• SEQ ID NO: 18 N-(Z-DEAD)-N'-pentafluorobenzoyl-Rhodamine 110.
• N-(Z-TD)-N-pentafluorobenzoyl-Rhodamine 110 N-(Z-AD)-N-pentafluorobenzoyl-Rhodamine 110, N-(Z-VAD)-N , -pentafluorobenzoyl-Rhodamine 110, N-(Z-DEVDG)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:76) N-(Z-EVDG)-N-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:71)
• N-(PFB-DEVDG)-N-pentafluorobenzoyl-Pvhodamine 110 (SEQ ID ⁇ O:76) N-(PFB-EVDG)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:71) N-(PFB-DEVD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(Octanoyl-DEVD)-N'-pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(PFB-EVD)-N -pentafluorobenzoyl-Rhodamine 110,
• N-(Boc-WEHD)-N-pentafluorobenzoyl-Rhodamine 110 (SEQ ID NO: 1) N- Boc-YVAD N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:2) N- Ac-LETD ⁇ N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:8) N-(Ac-DEVD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(Ac-IETD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:24)
• N-(Ac-LQTD)-iV -pentafluorobenzoyl-Rhodamine 110 (SEQ ID ⁇ O:72) N-(Ac-EETD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:73) N-(Ac-LEVD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:9) ⁇ (Ac-AEHD)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:74) N-(Ac-WEHD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:l)
• N-iAc-YNAOyW -pentafluorobenzoyl-Rhodamine 110 N-(Ac-D(OEt)E(OEt)VD(OEt))-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(Ac-LEHD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:3) N-(Z-DEVD)-N'-(2, 3, 4, 5-tetrafluorobenzoyl)-Rhodamine 110, (SEQ ID NO:2) N-(Ac-D(OEt)E(OEt)VD(OEt))-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:5) N-(Ac-LEHD)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O
• N-(MG)-N -pentafluorobenzoyl-Rhodamine 110 N-(MA)-N -pentafluorobenzoyl-Rhodamine 110,
• N-G-N -pentafluorobenzoyl-Rhodamine 110 N-(MG)-N'-(2,3,4,5-tetrafluorobenzoyl)-Rhodamine 110,
• N-(Z-LNFPI)-_V -pentafluorobenzoyl-Rhodamine 110 N-(Z-LNFPI)-_V -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:84) N-(Z-LNFP)-N' -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:85) 7V-(Z-RGFP)-7V -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:37) TV-CZ-RQANFLG)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:31) N-(Z-RQANFL)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:86)
• N-(Z-RQANF)-N -pentafluorobenzoyl-Rhodamine 110 (SEQ ID NO:87) N-(Z-RKVLFLD)-yV -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:36) N Z-RKVLF)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:89) 7V-(Z-ARVLFLG)-.V -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:90)
• N-(Ac-RGFP)-N'-(2,3,4,5-tetrafluorobenzoyl)-Rhodamine 110 (SEQ ID ⁇ O:37) N-(Ac-SLNFPIV)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110, (SEQ ID ⁇ O:80) N-(Ac-SLNFPI)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110, (SEQ ID ⁇ O:81)
• N-(Ac-SLNFP)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110 (SEQ ID ⁇ O:82) N-(Ac-RGFP)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110, (SEQ ID ⁇ O:37) ⁇ (Ac-MRGGG)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:96)
• N-(Ac-IRGGG)-N " -pentafluorobenzoyl-Rhodamine 110 (SEQ ID ⁇ O:97) N- Ac-LVGGG)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:98) N-(Ac-MVGGG)-N' -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:99) N-(Ac-IVGGG)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ OTOO) N-(Ac-LRGGG)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ OT01)
• N-(Ac-LRGGA)- ⁇ r -pentafluorobenzoyl-Rhodamine 110 (SEQ ID ⁇ OT02) N-(Ac-LRGG)-N " -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:55) N-(Z-LRGGG)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ OT01) N-(Z-LRGGA)-N " -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ OT02) N-(Z-LRGG)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:55)
• N-(Ac-LRGG)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110 (SEQ ID ⁇ O:55) N Ac-LVLASSS)- ⁇ -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO: 103) N-(Ac-LVLASS)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ OT04) N-(Ac-LVLAS)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO: 105) N-(Ac-LVLA)-N -pentafluorobenzoyl-Rhodamine 110, (SEQ ID ⁇ O:62) N-(Z-LVLASSS)-iV -pentafluorobenzoyl-Rhodamine 110, (SEQ ID NO:103)
• N-(Z-Tbg-Tbg-NA)-N -pentafluorobenzoyl-Rhodamine 110 (SEQ ID NO: 110) N-(Ac-Tbg-Tbg-NASS)-N'-(2,3,4,5-tetrafluorobenzoyl)-Rhodamine 110,
• N-(Z-IVPCSMS)-N' -pentafluorobenzoyl-Rhodamine 110 (SEQ ID ⁇ O:l 14)
• N- Z-IVPCSMyN -pentafluorobenzoyl-Rhodamine 110 (SEQ ID ⁇ O:l 15)
• N-(Ac-IVPCS)-N'-(2,4,6-trifluorobenzoyl)-Rhodamine 110 (SEQ ID NOT 16) where Z is benzyloxycarbonyl, BOC is tert.-butoxycarbonyl, Ac is acetyl, PFB is pentafluorobenzoyl, Tbg is t-butylglycine, and AM is acetoxy methyl.
• Preferred novel fluorescent dyes of the present invention are compounds having Formula VIII and include, but are not limited to:
• N-(2,3,4,5-tetrafluorobenzoyl)-Rhodamine 110 N-(2,4,6-trifluorobenzoyl)-Rhodamine 110,
• N-(2,4,5-trifluorobenzoyl)-Rhodamine 110 N-(3,4,5-trifluorobenzoyl)-Rhodamine 110,
• Useful aryl groups are C 6 . 14 aryl, especially C 6 . 10 aryl.
• Typical C W4 aryl groups include phenyl, naphthyl, phenanthryl, anthracyl, indenyl, azulenyl, biphenyl, biphenylenyl and fluorenyl groups.
• Useful cycloalkyl groups are C 3.8 cycloalkyl groups, preferably cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.
• Useful alkyl groups include straight-chained and branched C M2 alkyl groups, preferably C,. 10 alkyl groups, more preferably, C,. 6 alkyl groups.
• Typical C,. 12 alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, 3-pentyl, hexyl and octyl groups.
• Useful acyl (alkanoyl) groups are C 2-10 alkanoyl groups such as acetyl, propionyl, butanoyl, pentanoyl, hexanoyl and the like as well as the branched chain isomers.
• Useful alkenyl groups are C 2.6 alkenyl groups, including ethenyl, propenyl, isopropenyl, butenyl, and sec-butenyl.
• Useful alkynyl groups are C 2.6 alkynyl groups, including ethynyl, propynyl, butynyl, and 2-butynyl groups.
• Useful aralkyl groups include any of the above-mentioned C,. I0 alkyl groups substituted by any of the above-mentioned C 6 . 14 aryl groups.
• Particularly useful groups include benzyl, phenethyl and naphthylmethyl.
• Useful aralkenyl groups include any of the above-mentioned C 2 . 4 alkenyl groups substituted by any of the above-mentioned C 6 . 14 aryl groups.
• Useful aralkynyl groups include any of the above-mentioned C 2 . 4 alkynyl groups substituted by any of the above-mentioned C 6 . 14 aryl groups.
• Particularly useful groups include phenylethynyl and phenylpropynyl.
• Useful haloalkyl groups include any of the above mentioned C,. 10 alkyl groups substituted by one or more fluorine, chlorine, bromine or iodine atoms, e.g. fluoromethyl, difluoromethyl, trifluoromethyl, pentafluoroethyl, 1,1-difluoroethyl, chloromethyl, chlorofluoromethyl and trichloromethyl groups.
• Useful hydroxyalkyl groups include any of the above mentioned C,. 10 alkyl groups substituted by hydroxy, e.g. hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxy butyl groups.
• Useful alkoxy groups include oxygen substituted by one of the C,. I0 alkyl groups mentioned above.
• Useful alkylthio groups include sulphur substituted by one of the C,. 10 alkyl groups mentioned above.
• Useful acylamino groups are any of the above mentioned C,. 6 acyl
• alkanoyl groups attached to an amino nitrogen, e.g. acetamido, propionamido, butanoylamido, pentanoylamido, hexanoylamido as well as aryl-substituted C 2 _ 6 acyl groups.
• acyloxy groups are any of the above mentioned C,. 6 acyl (alkanoyl) groups attached to an oxy (-O-) group, e.g. acetoxy, propionoyloxy, butanoyloxy, pentanoyloxy, hexanoyloxy and the like.
• Useful amino groups include -NH 2 , -NHR 14 and -NR 14 R ]5 , wherein R 14 and R 15 are C 0 alkyl or C 3 . 8 cycloalkyl groups as defined above.
• Certain of the compounds of the present invention may be in tautomeric forms, particularly in the Y-portion of Formula I.
• the invention includes all such tautomers.
• the invention also includes stereoisomers, the racemic mixtures of such stereoisomers as well as the individual entantiomers that may be separated according to methods that are well known to those of ordinary skill in the art.
• the compounds of this invention may be prepared using methods known to those skilled in the art. Specifically, compounds of Formula VIII can be prepared as illustrated by the exemplary reactions in Scheme 1.
• the invention also relates to a method for the preparation of a compound of Formula IV, comprising the steps of:
• R R 5 are defined above and Q is halo, hydroxy or a group of Formula VII:
• -(AA) n is WEH, YVA, LEH, DET, DEV, DEH, VEH, LET, SHV, DEL, DGP, DEP, DGT, DL ⁇ , DEE, DSL, DVP, DEA, DSY, ELP, VED, IEP or IET.
• Compounds of Formula IV also can be prepared using an anhydride in place of an acyl (alkanoyl) chloride, or an acid with a coupling reagent such as
• EDC in place of acyl (alkanoyl) chloride.
• Other reagents can be used in place of pentafluorobenzoyl chloride include, but are not limited to, 2,3,4,5- tetrafluorobenzoyl chloride, 2,4,5-trifluorobenzoyl chloride, and 2,3,4- trifluorobenzoyl chloride.
• the reaction is carried out in the presence of a base, such as (Et) 3 ⁇ , (i-Pr) 2 -NEt or pyridine, and the preferred solvent is DMF.
• the reaction is generally carried out at room temperature.
• the ratio of acyl chloride to Rhodamine is about 1 :1.
• the condensation reaction may be carried out using any conventional condensing agent that is used for peptide synthesis.
• the condensing agent is EDC, EEDQ. IBCF or other known condensing agents for peptide synthesis
• the solvent for the reaction is pyridine or dimethylformamide (DMF).
• the reaction is generally carried out at room temperature.
• the ratio of condensing agent to N-pentafluorobenzoyl- Rhodamine is about 3:1 to 1.1 :1 and the ratio of protected amino acid or peptide to N-pentafluorobenzoyl-Rhodamine or N-Gly -N-pentafluorobenzoyl- Rhodamine is about 3:1 to 1.1 :1.
• N-substituted benzoyl-Rhodamine Condensing N-substituted benzoyl-Rhodamine with a peptide such as Z-(AA) n -Asp(OBu-t) to give N-(Z-(AA) n -Asp(OBu-t))-N' -substituted benzoyl- Rhodamine in an one-step reaction is a preferred procedure.
• compounds of Formula VIII provide fluorescent dyes which can be condensed with any peptide or other structure for the preparation of fluorogenic or fluorescent compounds which are substrates for proteases or peptidases.
• compounds of Formula IV also can be prepared by first condensing a peptide with a Rhodamine to give N-peptide-Rhodamine, then reacting the N-peptide-Rhodamine with pentafluorobenzoyl chloride or other acylating reagent to give for example, N-pentafluorobenzoyl-N'-peptide- Rhodamine.
• a) peptides in general are much more expensive than acyl chlorides or anhydrides
• the condensation reaction between peptide and Rhodamine is not an efficient reaction. For these reasons it is preferred to attach the peptide to N-pentafluorobenzoyl-Rhodamine rather than attach the acyl group to N-peptide-Rhodamine.
• the invention relates to a method for determining whether a test substance has an effect on an enzyme involved in the apoptosis cascade in a test cell, comprising
• test substance either interacts with an external membrane receptor or is taken into said cell and the reporter compound is taken into the cell
• Activators either by direct or indirect mechanisms, of enzymes involved in the apoptosis cascade include but are not limited to known chemotherapeutic agents, such as etoposide (Yoon, H.J., et al, Biochim Biophys Acta 1395:110- 120 (1998)) and doxorubicin (Gamen, S., et al, FEBS Lett 417:360-364 (1997)) which are topoisomerase II inhibitors; cisplatin (Maldonado, V., et al,
• Inactivators either by direct or indirect mechanisms, of enzymes involved in the apoptosis cascade include but are not limited to endogenous proteins including Bcl-2 (Joensuu, H., et al, Am. J. Pathol 5:1191-1198 (1994)), the viral produced agent p35 (Miller, L.K., J.
• the invention relates to the use of the reporter compounds having Formulae I-IV in whole-cell assays using live or dead whole cells or tissue samples to screen for compounds that inhibit either directly or indirectly an enzyme or enzymes involved in apoptosis (programmed cell death).
• These screening assays using compounds having Formulae I-IV are expected to lead to discovery of new drugs or new uses for known drugs that slow or block cell death in a variety of clinical conditions in which the loss of cells, tissues or entire organs occurs.
• the reporter compounds having Formulae I-IV and the screening assays of the present invention can be used to identify drugs that reduce or prevent cell death in the nervous system (brain, spinal cord, and peripheral nervous system) under various conditions of ischemia and excitotoxicity, including, but not limited to, focal ischemia due to stroke and global ischemia due to cardiac arrest.
• the screening assays can also be used to identify compounds that reduce or prevent cell death in the nervous system due to traumatic injury (such as head trauma or spinal cord injury), viral infection or radiation-induced nerve cell death (for example, as a side-effect of cancer radiotherapy) or environmental toxicity (e.g. by certain halogenated hydrocarbons).
• the screening assays can also be used to identify cell death inhibitors which are useful to reduce or prevent cell death in a range of neurodegenerative disorders, including but not limited to Alzheimer's disease,
• Huntington's Disease Huntington's Disease, Parkinson's Disease, multiple sclerosis, amyotrophic lateral sclerosis, and spinobulbar atrophy.
• the screening assays of this invention can be used to identify compounds that prevent cell death in any condition which potentially results in the death of cardiac muscle. This includes myocardial infarction, congestive heart failure and cardiomyopathy.
• One particular application of the screening assay is to identify compounds which reduce or prevent myocardial cell death that occurs in certain viral infections of the heart.
• the screening assays of the invention can be used to identify compounds which prevent cell death of retinal neurons that occurs in disorders associated with increased intraocular pressure (such as glaucoma) or retinal disorders associated with the aging process (such as age-related macular degeneration).
• the assays can also be used to identify compounds which treat hereditary degenerative disorders of the retina, such as retinitis pigmentosa.
• the screening assays of the invention can also be used to identify cell death inhibitors that can be used to reduce or prevent premature death of cells in the immune system, and are particularly useful in identifying inhibitors which are useful in treating immune deficiency disorders, such as acquired immune deficiency syndrome (AIDS), severe combined immune deficiency syndrome (SCIDS) and related diseases.
• the screening assays can also be used to identify cell death inhibitors that can be used to treat radiation-induced immune suppression.
• the screening assays of the invention can also be used to identify drugs useful in organ transplantation procedures. Transplantation of human organs and tissues is a common treatment for organ failure. However, during the transplantation process, the donor organ or tissue is at risk for cell death since it is deprived of its normal blood supply prior to being implanted in the host. This ischemic state can be treated with cell death inhibitors by infusion into the donor organ or tissue, or by direct addition of the cell death inhibitors to the organ/tissue storage medium. Such cell death inhibitors can be identified using the screening assays described in this invention. Cell death inhibitors may also be used to reduce or prevent cell death in the donor organ/tissue after it has been transplanted to protect it from the effects of host immune cells which kill their targets by triggering apoptosis.
• the screening assays described in this invention can be used to identify cell death inhibitors useful in protecting transplanted organs from rejection.
• the cytoprotective effects of cell death inhibitors can also be used to prevent the death of human or animal sperm and eggs used in in vitro fertilization procedures. These inhibitors can be used during the harvesting process and can also be included in the storage medium.
• Cell death inhibitors useful for application in fertilization procedures can be identified using the screening assay methods described in this invention.
• Mammalian cell lines and yeast cells are commonly used to produce large amounts of recombinant proteins (such as antibodies, enzymes or hormones) for industrial or medicinal use.
• the lifespan of some of these cell lines is limited due to growth conditions, the nature of the recombinant molecule being expressed (some are toxic) and other unknown factors.
• the lifespans of industrial cell lines can be extended by including cell death inhibitors in the growth medium.
• Cell death inhibitors useful in extending the life span of cell lines can be identified using the screening assay procedures described in this invention.
• hair follicle regression (referred to as catagen) may be due at least partially to apoptosis. Therefore, it is possible that cell death inhibitors can be used to treat hair loss that occurs due to various conditions, including but not limited to male-pattern baldness, radiation-induced or chemotherapy-induced hair loss, and hair loss due to emotional stress. There is also evidence that apoptosis may play a role in the loss of hair color. Therefore, it is possible that cell death inhibitors can also be used in treating cases of premature graying of the hair. Cell death inhibitors useful in treating or preventing hair loss or graying of the hair can be identified using the screening assay procedures described in this invention.
• the death of skin epithelial cells can occur after exposure to high levels of radiation, heat or chemicals. It is possible that cell death inhibitors can be used to reduce or prevent this type of skin damage. In one particular application, cell death inhibitors can be applied in an ointment to treat acute over-exposure to the sun and to prevent blistering and peeling of the skin. Cell death inhibitors useful in treating or preventing death of skin cells can be identified using the screening assay procedures described in this invention.
• Another important aspect of the present invention is use of the reporter compounds having Formulae I-IV in whole-cell assays using live or dead whole cells or tissue samples to screen for compounds that stimulate, either directly or indirectly, an enzyme or enzymes involved in apoptosis. Therefore, these screening assays using compounds having Formulae I-IV are expected to lead to discovery of new drugs or new uses for known drugs that act as anti- cancer agents in diseases such as cancers, tumors and cell hyperplasias etc.
• Compounds that may be found using the screening assays and reagents described herein are useful for treatment of cancers, tumors or tissue hyperplasias including but not limited to cancers or tumors of the brain, peripheral nervous system, eye, ear, nose, mouth, tonsils, teeth, esophagus, lung, heart, blood, blood vessels, bone marrow, lymph nodes, thymus, spleen, immune system, liver, stomach, intestinal tract, pancreas, endocrine glands and tissues, kidney, bladder, reproductive organs and glands, joints, bones and skin.
• reporter compounds having Formulae I-IV in whole-cell assays using yeast and other fungi, and bacteria to screen compound libraries for anti-fungal or antibacterial drugs that act by inducing, either directly or indirectly, the caspase cascade or other enzymes involved in apoptosis in those cells.
• Another important aspect of the invention is to use the reporter compounds having Formulae I-IV to monitor the therapeutic effects of therapeutic agents or treatments given to patients with the aim of reducing, preventing or treating maladies in which apoptotic cell death is either a cause or a result.
• Another important aspect of the present invention is to use the reporter compounds having Formulae V to screen for HIV protease inhibitors in HIV infected cells, comprising
• test substance either interacts with an external membrane receptor or is taken into said cell and the reporter compound is taken into the cell
• Yet another important aspect of the present invention is to use the reporter compounds having Formulae V to diagnose HIV infection, comprising (a) contacting a test cell from a patient suspected of having HIV infection with the reporter compound according to the invention under conditions whereby the reporter compound is taken into the cell, and
• the reporter compounds having Formula V of the present invention can be used to screen for adenovirus protease inhibitors in adenovirus infected cells.
• the reporter compounds having Formula V of the present invention also can be used to screen for herpes simplex virus type-
• HSV-1 HSV-1 infected cells.
• HCV hepatitis C virus
• MetalAP-2 methionine aminopeptidase (MetAP-2) inhibitors in endothelial cells are two methionine aminopeptidase (MetAP-2) inhibitors in endothelial cells.
• the reporter compounds having Formula V of the present invention also can be used to diagnose adenovirus, herpes simplex virus type-1, human cytomegalovirus and hepatitis C virus.
• compositions within the scope of this invention include all compositions wherein the fluorogenic or fluorescent compounds of the present invention are contained in an amount which are effective to achieve its intended purpose. While amounts may vary from assay to assay, determination of optimal ranges of effective amounts of each component is within the skill of the art.
• the fluorogenic or fluorescent substrate compounds may be applied to cells or cell lines from mammals, e.g. humans, or other animals by incubating the cells or tissues containing the cells with the fluorogenic or fluorescent substrate at a concentration of about 0.01 nanomolar to about 1 molar, or an equivalent amount of a salt or proreporter molecule thereof in a physiologically compatible buffer.
• Such buffers include cellular growth medias, an example for leukemia derived cancer cells being RPMI- 1640 with or without 10% fetal bovine serum.
• Other known cellular incubation buffers could involve isotonic solutions buffered with either phosphate or HEPES.
• One of ordinary skill in the art can identify other suitable buffers with no more than routine experimentation.
• the cells can be derived from any organ or organ system for which it is desirable to find—by means of the screening assays-drugs that could be useful in treating apoptosis- mediated disorders, e.g., neuronal cell death, heart disease, liver disease, retinal disorders, kidney, joint and bone diseases, immune system disorders, cancers, tumors and tissue hyperplasias etc.
• Suitable solubilizers may be used for presenting the fluorogenic or fluorescent compounds of the present invention to tissues, cells or cell lines.
• Suitable solubilizers include aqueous solutions of the active compounds in water-soluble form, for example, water-soluble salts and alkaline solutions.
• suspensions of the compounds as appropriate oily suspensions may be presented to the cells or tissues.
• Suitable lipophilic solvents or vehicles include fatty oils, for example, sesame oil, or synthetic fatty acid esters, for example, ethyl oleate or triglycerides or polyethylene glycol-400 (the compounds are soluble in PEG-400) or dimefhylsulfoxide (DMSO) or another suitable solubilizer.
• the suspension or solution may also contain stabilizers.
• electroporation or presentation of the reporter molecules in liposomes or detergents may be used to enhance the cell permeability of the fluorogenic or fluorescent reporter molecules.
• the cells are contacted with the reporter compounds of the invention and the test substance for about 30 minutes to about 5 hours, most preferably, about 1 hour.
• the invention also relates to the pro-reporter derivatives of the compounds of the invention.
• pro-reporter derivatives include compounds which are cleaved in situ by endogenous enzymes to give the compounds of Formulae I-V.
• pro-reporter derivatives include lower alkyl esters of carboxyl-containing amino acid residues such as Asp and Glu.
• Especially preferred pro-reporter derivatives include the methyl or ethyl esters and acetoxymethyl (AM) or pivaloyloxymethyl esters of Asp- and Glu- containing compounds.
• the following examples demonstrate the usefulness of the invention in measuring the activity of caspases and other enzymes involved in apoptosis in cells and tissues.
• the examples also demonstrate usefulness of the invention in drug screening assays that can be utilized to find enhancers or inhibitors of apoptosis.
• These examples are illustrative, but not limiting, of the method and compositions of the present invention.
• Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in in vitro assays, drug screening procedures or diagnostic procedures which are obvious to those skilled in the art are within the spirit and scope of the invention.
• Rhodamine 110 (1500 mg, 4.1 mmol) in dimefhylformamide (40 mL) at -42 °C was added N,N-diisopropylethylamine (635.5 mg, 4.9 mmol). Then pentafluorobenzoyl chloride (1131 mg, 4.9 mmol) was added dropwise to the above solution. The reaction solution was stirred for 10 min at -42 °C and was then warmed to room temperature and kept stirring for 2 h. It was diluted with 200 mL of ice-water and extracted with ethyl acetate (3 x 50 mL).
• N-(Z-Gly)-N'-pentafluorobenzoyl-Rhodamine 110 (30 mg, 0.042 mmol)
• Rhodamine 110 (19 mg, 0.015 mmol)
• N' -pentafluorobenzoyl-Rhodamine 110 HBr (18 mg, 0.028 mmol) was obtained 29 mg (78 %) of the title compound as a solid.
• Rhodamine 110 (11 mg, 0.008 mmol) and 50% trifluoroacetic acid in methylene chloride (1 mL) was obtained 8.5 mg (91 %) of the title compound.
• N-pentafluorobenzoyl-Rhodamine 110 (25 mg, 0.045 mmol) was obtained 33 mg (92%) of the title compound as a solid.
• N-fAc-Asp(OBut)-Glu(OBut)-Val-Asp(OBut)J-N'-(2,3,4,5- tetrafluorobenzoyl)-Rhodamine 110 (SEQ ID NO:5)
• Rhodamine 110 22 mg, 0.018 mmol
• methylene chloride 1 ml
• trifluoroacetic acid 1 mL
• Rhodamine 110 SEQ ID NO:5
• Rhodamine 110 (48 mg, 0.092 mmol) was obtained 27 mg (21%) of title compound as a solid.
• Rhodamine 110 (18 mg, 0.013 mmol) in methylene chloride (1 ml) was added trifluoroacetic acid (0.07 mL), the solution was stirred at room temperature for 10 min. It was neutralized with N-methylmorpholine (NMM), concentrated and purified by column chromatography, yielded 14 mg (78%) of the title compound. ! H NMR (CD 3 OD) 10.36 (bs, IH), 9.45 (s, IH), 9.33 (s, IH), 8.20-7.38 (m, 8H), 6.92-
• Rhodamine 110 7 mg, 0.0058 mmol
• N- succinimidyl caprylate 2.78 mg, 0.01 lmmol
• 4-methyl morpholine 0.59 mg
• ethyl acetate 1.1 ml
• N-(Pentafluorobenzoyl-Asp-Glu-Val-Asp)-N'-pentafluorobenzoyl- Rhodamine 110 SEQ ID NO:5
• Rhodamine 110 (3.0 mg, 0.0022 mmol) and 50% trifluoroacetic acid in methylene chloride (0.5 mL) was obtained 0.9 mg (35%) of the title compound.
• N- pentafluorobenzoyl-Rhodamine 110 is a weaker fluorescent dye compared to Rhodamine 110.
• HL-60 cells (about 2xl0 6 ) were placed in 50 ⁇ L of Iscove's medium, without serum or phenol-red, containing 10 ⁇ M N-pentafluorobenzoyl-
• Rhodamine 110 A parallel sample was placed in the same medium containing 10 ⁇ M Rhodamine 110. The cells were incubated for 2 hours at 37°C in a CO 2 incubator, recovered by centrifugation, and resuspended in 50 ⁇ L of fresh medium without N-pentafluorobenzoyl-Rhodamine 110 or Rhodamine 110. Aliquots of each cell suspension were placed in microslides and viewed on a
• N- pentafluorobenzoyl-Rhodamine 110 can stain cells as intensely as Rhodamine 110, but that, unlike Rhodamine 110, the N-pentafluorobenzoyl-Rhodamine 110 signal remains strong over time.
• N-Gly-Rl 10-PFB was incubated with a lysate made from HL-60 cells, and the amount of fluorescence was measured at various times after incubation at 37°C. Parallel samples were run using the control substrate, N-Cbz-Gly- RI 10-PFB. Samples incubated with N-Gly-Rl 10-PFB together with cell lysate gave a strong fluorescent signal which was linear over the incubation times tested. The data for the 2 hour timepoint is shown in Fig. 3. Samples incubated with N-Gly-Rl 10-PFB and buffer only (no lysate) gave a very weak fluorescent signal.
• N-Cbz-Gly-Rl 10-PFB did not give a signal when incubated with cell lysate or buffer, indicating that this compound cannot be cleaved by aminopeptidases, as expected.
• N-Gly-Rl 10- PFB is a suitable fluorogenic substrate for aminopeptidases. It has a low background in its uncleaved state and a strong fluorescent signal in its cleaved state.
• HL-60 cells (about 2x10 6 ) were incubated with 10 ⁇ M of N-Gly-Rl 10- PFB for 2 hours at 37°C in a CO 2 incubator. Parallel samples were similarly incubated with the amino terminal-blocked compound, N-Cbz-Gly-Rl lO. At the end of the incubation, the cells were harvested by centrifugation and resuspended in 50 ⁇ L of fresh medium without substrate. Aliquots of each cell suspension were placed in microslides and viewed on a Nikon inverted microscope with epifluorescent illumination. Cells incubated with N-Gly- Rl 10-PFB exhibited a strong, homogeneously distributed, yellowish-green fluorescence.
• N-Gly- Rl 10-PFB can be used to detect aminopeptidase activity in whole cells and that it gives an intense signal which is well-retained and not subject to quick fading or leaching.
• Z-DEVD-R110-PFB (SEQ ID NO:5) was readily cleaved by recombinant caspase-3, resulting in a greater than 10-fold increase in fluorescence over the uncleaved substrate.
• a lysate from apoptotic HL-60 cells also readily cleaved Z-DEVD-R110-PFB (SEQ ID NO:5), as did lysate from control cells, although to a lesser extent ( Figure 5).
• Jurkat T leukemia cells were grown in RPMI 1640 media (Life Technologies, Inc.) + 10% FCS (Sigma Chemical Company) in a 5% CO 2 - 95% humidity incubator at 37°C, and maintained at a cell density between 4 and 8 x 10 5 cells/ml.
• Cells were harvested at 200xg and resuspended at lx 10 6 cells/ml into RPMI 1640 media containing 10% FCS and 1 ml each were dispensed in 2-wells of a 6-well plate.
• the apoptosis inducer staurosporine was added at 0.5 ⁇ g/ml concentration and the plate was incubated for 2 hrs at 37°C in a 5% CO 2 -95% humidity incubator.
• Fig. 7 shows that induction of apoptosis in Jurkat cells by staurosporine leads to cleavage of the caspase-3 substrate Ac-DEVD-Rl 10-TFB (SEQ ID NO:5) under whole cell assay conditions.
• Jurkat T leukemia cells were grown and harvested in a way similar to
• Example 60 The apoptosis inducer anti-Fas antibody (CH-11; MBL) was added at 200ng/ml concentration and the plate was incubated for 2hrs at 37°C in a 5% CO 2 -95% humidity incubator. Cells were pelleted and incubated with 50 ⁇ M of substrate Ac-DEVD-Rl 10-TFB (SEQ ID NO:5) for 2hrs at 37°C in serum-free RPMI medium. 500 ⁇ l PBS was added and samples were analyzed by flow cytometry. Fig. 8 showed that induction of apoptosis in Jurkat cells by anti-Fas antibody leads to cleavage of the caspase-3 substrate Ac-DEVD- Rl 10-TFB (SEQ ID NO:5) under a whole cell assay conditions.
• CH-11 apoptosis inducer anti-Fas antibody
• Jurkat T leukemia cells were grown and harvested in a way similar to Example 60.
• a pan-caspase inhibitor cbz-Val-Asp-fmk(see W099/18781) was added to one of the wells.
• the apoptosis inducer staurosporine was added with and without the caspase inhibitor at 0.5 ⁇ g/ml concentration and the plate was incubated for 2hrs at 37°C in a 5% CO 2 -95% humidity incubator.
• Cells were pelleted and incubated with 50 ⁇ M of substrate Ac-DEVD-Rl 10-TFB (SEQ ID NO:5) for 2hr at 37°C in serum-free RPMI medium.
• 500 ⁇ l PBS was added and samples were analyzed by flow cytometry.
• PARP cleavage is widely used as a biochemical marker for caspase-mediated apoptosis.
• the ability of a cytoprotective drug to block PARP cleavage is considered to be an indication of the drug's ability to inhibit the caspase proteolytic cascade and, in particular, CPP-32 (caspase-3), the main PARP protease. Measuring PARP cleavage is a slow and tedious process that is not suitable for HTCA assays and it is very incovenient for drug screening and diagnostic procedures.
• the activity of CPP-32 inside cells may be assayed by the fluorescence assays described in herein by using, for example, the fluorogenic CPP-32 substrate Ac-DEVD-Rl 10-TFB (SEQ ID NO: 5), and incubating, for example, Jurkat cells, a human T-cell line, with substrate Ac-DEVD-Rl 10-TFB (SEQ ID NO: 5) during Fas-mediated apoptosis.
• This cell culture model of apoptosis is well-characterized and is known to involve activation of at least two caspases, caspase-3 (CPP32) and caspase-8 (FLICE/MACH).
• Jurkat cells may be seeded at a density of, for example, 10,000 cells per well in 96-well multidishes in RPMI 1640 medium containing 10% FBS, or another suitable medium. Dishes containing larger numbers of wells (e.g. 300-3,000 wells per dish) may also be used (with appropriately adjusted volume and number of cells). The cells may be pre-incubated with e.g. O.OlnM-lM of Ac-DEVD-Rl 10-TFB (SEQ ID
• a test compound or compounds in the presence or absence of a test compound or compounds at a concentration of e.g. O.OlnM-lM for 2 hours at 37°C in a CO 2 incubator.
• Baseline fluorescence emission may be recorded with a suitable fluorescence recorder prior to, at the time of, or after adding Ac-DEVD-Rl 10-TFB (SEQ ID NO:5) and test compound or compounds.
• a monoclonal antibody to Fas may then be added at a final concentration of 500 ng/ml.
• Incubation at 37°C in a CO 2 incubator may be continued for an additional 4 hours.
• fluorescence may be recorded in the wells with a suitable plate reader or any other suitable instrument that can detect fluorescence.
• the increase in enzyme activity caused by stimulating the caspase cascade with Fas ligand may be calculated by subtracting the fluorescence measured at baseline from the fluorescence measured after stimulation of apoptosis enzyme with Fas ligand antibody.
• Specificity of the fluorescence emission as an indicator of caspase cascade activation may be determined by adding a known caspase inhibitor such as Z-DEVD-fmk (SEQ ID NO: 1
• any other caspase cascade inhibitor to the incubation mixture.
• the preincubation time and the total incubation time may be varied as appropriate to be shorter or longer than is indicated in this example.
• the optimal incubation time may be determined experimentally in each cell, cell line line or tissue in which caspase activity is to be measured.
• Ac-DEVD- Rl 10-TFB SEQ ID NO:5
• any other fluorogenic or fluorescent substrate of this invention may used.
• Jurkat cells any other cells or cell lines be they normal, diseased, infected or cancerous may be used.
• cells or cell lines may be derived from any tissue or internal or external organ or from any tumor or tumors or cancers.
• the cells or cell lines can be in form of suspensions, clusters, isolated cells, tissue fragments, biopsies, or cells grown in culture in form of monolayers or in suspension.
• Drugs that stimulate the caspase cascade in the absence of Fas ligand may be useful, for example, as anti-cancer chemotherapeutic agents.
• the assay described in Example 63 may be used to screen for drugs that stimulate the caspase cascade by carrying out the assay under similar conditions as in Example 63, except that a known or unknown compound with known or unknown anti-cancer or anti-tumor activity replaces the Fas ligand reagent.
• fluorescence assay in screening for drugs that inhibit or potentiate the caspase cascade stimulated with Fas ligand or another apoptosis inducer.
• Drugs that inhibit the caspase cascade may be useful in treating degenerative and other diseases caused by or associated with an inadequate activation of the caspase cascade.
• Drugs that potentiate the action of another caspase stimulator such as e.g. Fas ligand or an anti-cancer drug or agent, may be suitable to treat cancers or tumors caused by or associated with an inappropriate function of the caspase cascade.
• the assays and reagents described in this invention may be used to screen for drugs that either inhibit or potentiate the caspase cascade in cells by performing the assay as described in Example 63, using Fas ligand or any other agent that stimulates the caspase cascade or other apoptosis pathway in the presence of a test substance that inhibits or potentiates or acts synergistically with the action of the first apoptosis or caspase cascade inducer.
• Example 66 Use of fluorescence assay in testing samples cancer cells from patients for chemosensitivity to anti-cancer drugs
• the fluorescence assays described in this invention permit chemosensitivity or drug resistance testing of cancer or tumor cells or tissue samples taken from individual cancer or tumor patients.
• a fluorescence assay using a cancer cell or tissue sample taken from a patient may be conducted as described Example 65.
• different drugs with known or unknown chemotherapeutic activity can be tested for their capacity to stimulate the caspase cascade.
• the results from this assay provide information that can be used to design an optimal chemotherapeutic drug treatment regimen for the patient.

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• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
• Medicines That Contain Protein Lipid Enzymes And Other Medicines (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
• Investigating Or Analysing Biological Materials (AREA)

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• 1999
  • 1999-07-21 AU AU51160/99A patent/AU5116099A/en not_active Abandoned
  • 1999-07-21 DE DE69920473T patent/DE69920473T2/de not_active Expired - Fee Related
  • 1999-07-21 WO PCT/US1999/016423 patent/WO2000004914A1/en active IP Right Grant
  • 1999-07-21 EP EP99935751A patent/EP1100520B1/en not_active Expired - Lifetime
  • 1999-07-21 AT AT99935751T patent/ATE276754T1/de not_active IP Right Cessation
  • 1999-07-21 US US09/357,952 patent/US6248904B1/en not_active Expired - Lifetime
• 2002
  • 2002-05-06 US US10/138,375 patent/US6984718B2/en not_active Expired - Fee Related

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