CN115246872A - Conotoxin mutant and preparation method and application thereof - Google Patents

Conotoxin mutant and preparation method and application thereof Download PDF

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CN115246872A
CN115246872A CN202110225081.5A CN202110225081A CN115246872A CN 115246872 A CN115246872 A CN 115246872A CN 202110225081 A CN202110225081 A CN 202110225081A CN 115246872 A CN115246872 A CN 115246872A
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于日磊
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Ocean University of China
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Abstract

The method discloses a conotoxin mutant, the amino acid sequence of the mutant is SEQ ID NO:1GCCX 1 X 2 X 3 ACX 4 X 5 X 6 X 7 X 8 X 9 X 10 C X 11 (ii) a Wherein, X 1 Selected from S, T, A, R, alg, dap or Dab; x 2 Selected from H, R,W, A or N; x 3 Selected from P or Hyp; x 4 Selected from S, L, V, A, D, K, T, dab, dap or Y; x 5 Selected from V, L, A, Y, R, cit, dap, dab, D or K; x 6 Selected from N, Q or A; x 7 Selected from N, H or A; x 8 Is P or A; x 9 Selected from D, E, S or A; x 10 Is I or A; x 11 Is C-terminal amidation, or is selected from Y, L or R. The invention also provides a preparation method and application. The conotoxin mutant provided by the invention has an obvious analgesic effect and no addiction.

Description

Conotoxin mutant and preparation method and application thereof
Technical Field
The invention belongs to the technical field of biological medicines, and relates to a series of conotoxin mutants with strong inhibition effect on alpha 9 alpha 10 acetylcholine receptors, and a preparation method and application thereof.
Background
Acetylcholine receptors are pentameric ion channel proteins, located on cell membranes and composed of different subunits, that can regulate the neuromuscular junction and synaptic transmission between the central and peripheral nervous systems. The receptors can be classified into α 9 α 10 acetylcholine receptors (α 9 α 10 nAChR), neuronal acetylcholine receptors such as α 7 nAChR and α 3 β 2 nAChR, and muscle acetylcholine receptors such as α 1 β 1 γ δ, depending on the subunit constituting the receptor. Abnormalities in acetylcholine receptor structure and function are closely associated with a range of pathophysiological processes, and α 9 α 10 nachrs are newly discovered targets for the treatment of pain in recent years. Molecules with inhibitory effects on α 9 α 10 nachrs have potential analgesic activity. In addition, α 9 α 10 nachrs were found to be overexpressed in tumor cells, α 9 α 10 nachrs were also considered as targets for tumor drug studies (Pharmacol ther.2020 Dec 10 222. The conus which selectively targets the alpha 9 alpha 10nAChR also has the potential of being developed into antitumor drugs.
Conotoxin (CTX) is secreted by the carnivorous mollusk Conus living in tropical sea, and is a small peptide toxoid used for anaesthetizing prey, which is usually a short peptide consisting of 10-40 amino acids, rich in disulfide bonds, and has many pharmacological activities. It mainly takes membrane protein as target, especially ion channel receptor, membrane receptor and transport protein. According to the difference of pharmacological activity and molecular targets, conotoxins can be divided into a plurality of different families such as alpha, mu and the like. Wherein the alpha-conotoxin (alpha-CTxs) can specifically act on an acetylcholine receptor to play an inhibiting role. alpha-CTxs are usually short peptides consisting of 12-19 amino acids and containing two pairs of disulfide bonds, and the disulfide bond is Cys Ⅰ -Cys Ⅲ ，Cys Ⅱ -Cys Ⅳ The connection mode of (3). Mr1.1 is a novel alpha-4/7 conotoxin obtained by PCR amplification of the cDNA sequence of the venom duct of Conus marmoreus. Can Peng.et.al, showed that Mr1.1 specifically acts on mouse α 7 nAChR in vitro and is able to inhibit 40% of acetylcholine-induced α 6 α 3 β 2 nAChR amperage at 1 μmol levelIn vivo experiments also showed analgesic activity.
Disclosure of Invention
The invention finds that specific mutation on Mr1.1 amino acid residue can have specificity aiming at alpha 9 alpha 10nAChR and shows obvious analgesic activity when deeply researching alpha-conotoxin.
The technical problem of the invention can be solved by the following technical scheme:
a conotoxin mutant has an amino acid sequence of SEQ ID NO 1GCCX 1 X 2 X 3 ACX 4 X 5 X 6 X 7 X 8 X 9 X 10 C X 11 ；
Wherein X 1 Any one selected from S, T, A, R, (S) -2-amino-3-guanidinopropionic acid (Alg), L-2,3-diaminopropionic acid (Dap), or L-2,4-diaminobutyric acid (Dab); x 2 Selected from H, R, W, A or N; x 3 Any one selected from P or Hyp; x 4 Selected from any one of S, L, V, A, D, K, T, dab, dap or Y; x 5 Selected from any one of V, L, A, Y, R, cit, dap, dab, D or K; x 6 Selected from any one of N, Q or A; x 7 Selected from any one of N, H or A; x 8 Is P or A; x 9 Any one selected from D, E, S or A; x 10 Is I or A; x 11 Is C-terminal acylation, or is selected from any one of Y, L or R.
In one embodiment according to the invention, the mutant amino acid sequence is SEQ ID NO 2GCCSHPACSVNNPDICX 11 (ii) a Wherein, X 11 Any one selected from Y, L or R.
In one embodiment according to the invention, the N-terminus of the mutant amino acid sequence is methylated or acetylated.
In one embodiment according to the invention, the mutant amino acid sequence is SEQ ID NO 3GCCSHPACSVNNPDIC (representing C-terminal amidation) or SEQ ID NO 4GCC (Dap) HPACSVNNPDIC (representing C-terminal amidation).
In one embodiment according to the present invention, characterized in that the cysteines at positions 2 and 8 form an intrachain disulfide bond and the cysteines at positions 3 and 16 form an intrachain disulfide bond in the mutant.
The invention further provides a preparation method of the conotoxin mutant, which comprises the following steps:
1) Activating the resin with dichloromethane and N, N-dimethylformamide, and then obtaining a linear peptide SEQ ID NO. 1 according to a solid phase synthesis method;
2) Cutting the resin by using a mixed solution of trifluoroacetic acid, water, phenol and triisopropylsilane, removing the trifluoroacetic acid by rotary evaporation, and then adding glacial ethyl ether until a white solid is separated out; dissolving the white solid into a re-solution by water through centrifugation, and then freeze-drying the re-solution to obtain solid powder;
3) Protecting the sulfydryl of cysteine at 2-position and 8-position in the sequence SEQ ID NO. 1 by a first sulfydryl protecting group; protecting cysteines at positions 3 and 16 in the sequence SEQ ID NO. 1 with a second thiol protecting group;
4) Disulfide bonds from 2-8 and 3-16 are respectively constructed according to a disulfide bond construction method for the first thiol-protecting group and the second thiol-protecting group.
In one embodiment according to the present invention, the resin is activated in step 1) with a volume ratio of dichloromethane to N, N-dimethylformamide of 1:1.
in one embodiment according to the invention, the volume ratio of trifluoroacetic acid, water, phenol, triisopropylsilane in step 2) is 80:3-7:3-7:1-5.
in one embodiment according to the present invention, the first thiol-protecting group and the second thiol-protecting group in step 3) are trityl or acetamidomethyl, respectively, and the first thiol-protecting group and the second thiol-protecting group are not the same;
preferably, when the first thiol-protecting group or the second thiol-protecting group is trityl, an air oxidation method is used to construct the disulfide bond; further preferably, the air oxidation process is carried out by a process comprising the steps of: dissolving the solid powder in 0.2mg/mL ammonium bicarbonate aqueous solution of 0.2M, stirring and reacting for 48h at room temperature, and freeze-drying after reaction to obtain the solid powder;
when the first or second thiol-protecting group is an acetamidomethyl group, the disulfide is constructed by a method comprising the steps of:
water, acetonitrile and TFA were mixed in a volume ratio of 5:5:0.01, mixing to prepare a reaction solvent, weighing a proper amount of white solid powder, dissolving the white solid powder in the reaction solvent, adding 1-5mg/mL iodine/acetonitrile solution, uniformly mixing until the polypeptide concentration in the mixed solution is 1-3mg/mL, and freeze-drying to obtain the polypeptide-containing solid polypeptide preparation; further preferably, the iodine/acetonitrile solution is 2.5mg/mL and the aqueous ascorbic acid solution is 5mg/mL.
The invention further provides application of the conotoxin mutant in preparing an alpha 9 alpha 10nAChR inhibitor, a molecular probe or a reagent for researching the structure and the function of an ion channel receptor, a medicament for treating neuralgia-related diseases or a medicament or an auxiliary medicament for treating tumors, wherein preferably, the neuralgia-related diseases are selected from peripheral neuropathic pain or central pain; preferably, the peripheral neuropathic pain is selected from trigeminal neuralgia, sphenopalatine ganglion pain, winged canal neuralgia, geniculate ganglion pain, occipital neuralgia, intercostal neuralgia, cervicobrachial neuralgia, brachial plexus neuritis, ulnar neuralgia, median neuralgia, lateral femoral neuralgia, sciatica, coccygodynia, causalgia, herpes zoster, cancer pain; the central pain is spinal pain, thalalgia, pono, medullary pain, cerebral cortex pain.
The invention has the beneficial effects that:
compared with the alpha 7 nAChR, the conotoxin mutant Mr1.1 provided by the invention has stronger inhibitory activity on the alpha 9 alpha 10nAChR, is a specific inhibitor of the alpha 9 alpha 10nAChR, finds the Mr1.1 mutant with stronger inhibitory activity on the alpha 9 alpha 10nAChR in further research, and finds that the mutant has better analgesic activity and does not have obvious addictive property through in vivo experiments on the Mr1.1[ S4Dap ].
Drawings
FIG. 1 is a schematic diagram of a process for preparing a conotoxin mutant according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing the inhibitory activity of Mr1.1 and the mutant provided by the present invention on human α 9 α 10nAChR (h α 9 α 10 nAChR).
FIG. 3 is a graph of the test results for mechanical pain tested 1h after administration, showing that Mr1.1 mutant (S4 Dap) has significantly higher analgesic activity than morphine and RgIA4 (Proc Natl Acad Sci U S.2017 Mar 7 (114 (10): E1825-E1832.);
FIG. 4 is a graph of the test results for hot pain after 1h of administration, showing that Mr1.1[ S4Dap ] analgesic activity is much higher than that of morphine and RgIA4;
FIG. 5 is a graph of the results of mechanical pain measurements taken 24h after administration, showing that Mr1.1[ S4Dap ] analgesic activity is far greater than that of RgIA4, and that the duration of analgesia is 24h;
FIG. 6 is a graph of the results of testing thermal pain 24h after administration, showing that Mr1.1[ S4Dap ] analgesic activity is far greater than that of RgIA4, and that the duration of analgesia is 24h;
FIG. 7 is a graph of the results of evaluation of addiction (CPP experiment) showing that Mr1.1[ S4Dap ] is not addictive with RgIA4. Morphine, however, has significant addiction as a positive control;
FIG. 8 is a schematic structural diagram of a part of Mr1.1 mutant.
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
Example 1 polypeptide Synthesis
The experiment adopts an Fmoc solid-phase polypeptide synthesis technology, rink MBHA resin, piperidine as an Fmoc protective group removing reagent and HCTU and DIPEA as coupling conditions.
Preparation method
The active polypeptide of the present invention may be a natural polypeptide (or a wild-type polypeptide), a recombinant polypeptide or a synthetic polypeptide. The polypeptides of the invention may be isolated, chemically synthesized, or recombinant. Accordingly, the polypeptide of the present invention can be produced by a conventional isolation and extraction method, or can be artificially synthesized by a conventional method, or can be produced by a recombinant method. Preferably, the active polypeptides of the invention are synthesized by solid phase Fmoc chemistry.
For example, the active polypeptide Mr1.1[ S4Dap ] of the present invention can be synthesized by the method shown in the scheme of FIG. 1, which specifically comprises the steps of:
(1) Using a mixture of 1:1, activating the resin by dichloromethane and N, N-dimethylformamide, and then obtaining a linear peptide shown by SEQ ID NO 4GCC (Dap) HPACSVNNPDIC (. Beta. Represents C-terminal amidation) by following a solid phase synthesis method;
(2) The resin was cleaved using a mixed solution of trifluoroacetic acid, water, phenol, and triisopropylsilane, trifluoroacetic acid: water: phenol: triisopropylsilane =88:5:5:2 (V/V), removing trifluoroacetic acid by rotary evaporation, adding glacial ethyl ether, separating out white solid, adding water to dissolve the centrifuged solid, and freeze-drying the solid by using a freeze dryer to obtain solid powder;
(3) Constructing two pairs of disulfide bonds, wherein the thiol protecting groups selected for 2-position cysteine and 8-position cysteine are trityl, and the thiol protecting groups selected for 3-position cysteine and 16-position cysteine are acetamidomethyl;
the disulfide bond at position 2 and 8 was constructed:
50mg of the solid powder was dissolved in 150mL of 0.2M ammonium bicarbonate aqueous solution at a concentration of 0.2mg/mL by air oxidation, and reacted in a 250mL eggplant-shaped bottle under electromagnetic stirring at room temperature for 48 hours to obtain white solid powder using a freeze dryer.
The disulfide bond at position 16 of 3 was constructed:
10mg of white solid powder was weighed and dissolved in the reaction solvent, wherein water: acetonitrile: TFA =5:5:0.01, V/V, adding 3mL of iodine/acetonitrile solution into the reaction solvent to keep the solution in a yellow state, wherein the concentration of the iodine/acetonitrile solution is 5mg/mL; stirring and reacting in a 50mL eggplant-shaped bottle at room temperature for 30 minutes, adding an ascorbic acid aqueous solution with the concentration of 5mg/mL, uniformly mixing to ensure that the solution is colorless and clear, and freeze-drying to obtain the final product, namely white solid powder.
Fig. 8 is a partial structural view of conotoxin prepared according to the above-described procedure.
Example 2 electrophysiological Activity assay
cRNA for human α 9 α 10 acetylcholine receptor was prepared using an in vitro transcription kit and its concentration was calculated as OD at UV260 m. Xenopus laevis oocytes were dissected and harvested, and cRNA from both subunits was injected into frog eggs on the first and second days in an amount of 5ng each, and cultured in ND-96. Oocytes expressing the α 9 α 10 acetylcholine receptor are used for electrophysiological activity testing 1-4 days after injection. The specific test method comprises the following steps: 1 Xenopus oocytes injected with cRNA were placed in a 30uL Sylgard recording chamber 4mm in diameter and 2mm in depth, and ND96 perfusate (96.0 mM NaC1,2.0mM KC1,1.8mM CaCl) containing 0.1mg/ml Bovine Serum Albumin (BSA) was gravity-perfused 2 1.0mM MgCl 2 5mM HEPES, pH 7.1-7.5). All conotoxin solutions also contained 0.1mg/mL BSA to reduce non-specific adsorption, free switching between perfusing toxin or acetylcholine was possible with a switching valve, ACh-gated current was set at "slow" by a two-electrode voltage clamp amplifier, and on-line recordings were made with clamp gain at the maximum (× 2000) position. The glass electrode was drawn with a glass capillary having an outer diameter of 1mm and an inner diameter of 0.75mm and filled with 3M KCl as a voltage and current electrode. The membrane voltage is clamped at-70 mV, and the whole system is controlled by a computer and records data. The ACh pulse was automatically infused for 1s of ACh every 5min at a concentration of 6 μ M. At least 6 oocytes were recorded for each polypeptide and the current data tested were statistically analyzed using GraphPad Prism software.
The results are shown in FIG. 2 Vc1.1 (1. Mu.M), mr1.1 and its mutant (100 nM) for the inhibitory activity of human α 9 α 10nAChR (h α 9 α 10 nAChR). (Whole cell currents of h α 9 α 10nAChR were activated by 6 μ M acetylcholine). S4Dap was shown to have the strongest h α 9 α 10nAChR inhibitory activity, and S4Dab, S9Dap, V10R, etc. also showed higher inhibitory activity. In addition, S4A, S A, S9G, P O, I L, I Y, 17R, N terminal methylated polypeptide, N terminal acetylated polypeptide substantially retain the activity of wild Mr1.1. Combinations of the above variants are expected to have better activity
Example 3 characterization of analgesic activity in animals:
the analgesic activity was measured using the ischial bones of ratsChronic Compression Injury (CCI) model of nerves. Purchasing 24 rats 120-150g in a Jinanping yue animal breeding center, dividing the rats into four groups for adaptive training, after the rats are trained for one week to adapt to the environment, modeling two groups of the rats, wherein the modeling process comprises the following steps: after a rat is anesthetized by intraperitoneal injection of 2% pentobarbital sodium, right leg rat hair is removed, the skin of the right lower limb is cut by 1-2cm under an aseptic condition, muscles and fascia are separated bluntly, the sciatic nerve trunk is exposed, four knots are tied by 4-0 chromium catgut at the interval of 1mm, the tightness degree of the four knots is required until the toes of the rat slightly twitch, the blood circulation of the nerve adventitia is not influenced, the wound is cleaned by forty thousand units of penicillin sodium after the ligation is finished, and finally the four knots are sutured, and the infection is prevented by injecting 4 ten thousand units of penicillin sodium into the affected limb muscle for three consecutive days after the operation. Of the remaining two groups, one was used as a blank control and one was used as a sham group, exposing only the sciatic nerve trunk without ligation compression, simulating the effect of the wound on the pain threshold of the rats. After the threshold values of two groups of modeling rats are reduced to the minimum value after one week, in-situ intramuscular injection is carried out for two consecutive weeks, one group is injected with normal saline every day, and the other group is injected with Mr1.1[ S4Dap ]]The dosage is 1.6X 10 -4 mg/mg, measuring a mechanical pain threshold of the rat by an IITC electronic pain measuring instrument 24 hours after the administration every day, measuring a thermosensitive pain threshold of the rat by an IITC plantar hotspot pain measuring instrument, wherein in a thermal pain test, the working light intensity is set to be 025, the standby light intensity is set to be 010, the preset time is set to be 20, and the obtained data are subjected to statistical analysis by GraphPad Prism software.
FIG. 3 is a graph of the test results of mechanical pain testing 1h after administration, showing that Mr1.1[ S4Dap ] (Mr1.1 mutant in the figure) has significantly higher analgesic activity than that of morphine and RgIA4 (Proc Natl Acad Sci U S A.2017 Mar 114 (10): E1825-E1832..
FIG. 4 is a graph of the results of the test for hot pain after 1h of administration, showing that Mr1.1[ S4Dap ] (Mr1.1 mutant in the figure) has significantly higher analgesic activity than morphine and RgIA4.
FIG. 5 is a graph of the results of mechanical pain measurements taken 24h after administration, showing that Mr1.1[ S4Dap ] (Mr1.1 mutant in the figure) has greater analgesic activity than RgIA4, and that the duration of analgesia is 24h.
FIG. 6 is a graph of the results of testing thermal pain 24h after administration, showing that Mr1.1[ S4Dap ] (Mr1.1 mutant in the figure) has an analgesic activity far greater than that of RgIA4, and the duration of analgesia lasts 24h.
Example 4 evaluation of addiction:
the study carried out evaluation of rat addiction using a conditional preference (CPP) experiment. The device that conditional position preferred experiment adopted in this experiment is three casees CPP systems, and left incasement portion is totally black, and right incasement side is black and white equidistance spaced stripe, and two case sizes are 30cm apart from spaced stripe, and two casees are big, and the middle incasement side is grey white, and the size is 30cm white, and the size is for the size, respectively has shuttle door one between middle case and the left and right sides two casees, for respectively some dome shape entrance to a cave between the 10cm case, and the shuttle door accessible manual movement baffle comes control switch. When carrying out the CPP experiment, to guarantee that light is soft, noiselessness on every side, whole experiment divide into preprocessing stage, training stage and test stage three stage and go on:
a pretreatment stage: and (3) taking away the partition plate of the CPP box to open the shuttle door on the 1 st day after the rat is adapted to the environment, allowing the rat to enter from the middle box, and allowing the rat to freely shuttle in the three boxes for 15min without recording data. And on days 2-3, recording the residence time of the rat in each box body within 15min, taking the average value of experimental data of two days, selecting the rat with unobvious preference for subsequent experiments, and taking the non-preference box of the rat as a companion medicine box in the subsequent experiments.
A training stage: rats were divided into four groups, 6 rats in each group, i.e., a morphine administration group using a black box as a concomitant drug box, a morphine administration group using a black and white box as a concomitant drug box, a Mr1.1 mutant (i.e., mr1.1[ S4Dap ]) administration group using a black box as a concomitant drug box, and a Gex-2 administration group using a black and white box as a concomitant drug box. The 1/3/4/7 th day of the training phase was 9 am and the 2/4/6/8 th day was 15 pm, and the morphine group and the mr1.1 mutant group were each intramuscularly injected with the corresponding drugs. In the training process, the dosage of morphine lessens is gradually increased from 5mg/kg to 10mg/kg, the Mr1.1 mutant group is continuously injected with 1nM, the control group is injected with normal saline, the injection amount of the drug is 200 injections, and only one patient is put into a companion medicine box immediately after the injection of the drug is finished, and the rat freely moves for 40min. On the other hand, on the 1/3/4/7 th day, 15 pm and on the 2/4/6/8 th day, 9 am, three groups were each intramuscularly injected with an equal amount of physiological saline, and the rats were placed in a non-concomitant drug box and allowed to freely move for 40min.
And (3) a testing stage: the first day after training, testing of rat CPP score was performed. The specific method comprises the following steps: taking out the partition plate of the CPP box to open the shuttle door, putting the rat into the middle box to freely shuttle among different boxes, recording the waiting time of the rat in the different boxes within 15min, and observing the preference change of the rat; on the 2 nd day after training, each rat is injected with 0.01mg/kg naloxone to promote withdrawal reaction, the rat is placed in the middle box to freely shuttle among different boxes, the waiting time of the rat in the different boxes within 15min is recorded, and the change of preference of the rat is observed. During the test, the experimenter performed the double-blind principle.
FIG. 7 is a graph showing the results of evaluation of addiction (CPP test) showing that Mr1.1 mutant (i.e., mr1.1[ S4Dap ]) and RgIA4 do not have addiction. Morphine as a positive control showed significant addiction, however.
The above examples are provided for illustrative purposes only and are not intended to limit the scope of the present invention; it should be noted that various changes and modifications can be made by those skilled in the art without departing from the scope of the inventive concept, which falls within the scope of the invention; therefore, all equivalent changes and modifications within the scope of the claims of the present invention should be covered by the claims of the present invention.
Sequence listing
<110> China oceanic university
<120> conotoxin mutant and preparation method and application thereof
<160> 16
<170> SIPOSequenceListing 1.0
<210> 1
<211> 17
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> VARIANT
<222> (4)..(4)
<223> S, T, A, R, alg, dap or Dab
<220>
<221> VARIANT
<222> (5)..(5)
<223> selected from H, R, W, A or N
<220>
<221> VARIANT
<222> (6)..(6)
<223> P or Hyp
<220>
<221> VARIANT
<222> (9)..(9)
<223> S, L, V, A, D, K, T, dab, dap or Y
<220>
<221> VARIANT
<222> (10)..(10)
<223> V, L, A, Y, R, cit, dap, dab, D or K
<220>
<221> VARIANT
<222> (11)..(11)
<223> is selected from N, Q or A
<220>
<221> VARIANT
<222> (12)..(12)
<223> N, H or A
<220>
<221> VARIANT
<222> (13)..(13)
<223> P or A
<220>
<221> VARIANT
<222> (14)..(14)
<223> selected from D, E, S or A
<220>
<221> VARIANT
<222> (15)..(15)
<223> I or A
<220>
<221> VARIANT
<222> (17)..(17)
<223> selected from Y, L or R, or C-terminal amidation
<220>
<221> DISULFID
<222> (2)..(8)
<223> cysteine formation of intrachain disulfide bond
<220>
<221> DISULFID
<222> (3)..(16)
<223> cysteine formation of intrachain disulfide bond
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Ser, Thr, Ala, Arg, Alg, Dap or Dab.
<220>
<221> UNSURE
<222> (5)..(5)
<223> The 'Xaa' at location 5 stands for His、Arg、Trp、Ala or Asn.
<220>
<221> UNSURE
<222> (6)..(6)
<223> The 'Xaa' at location 6 stands for Pro or Hyp.
<220>
<221> UNSURE
<222> (9)..(9)
<223> The 'Xaa' at location 9 stands for Ser, Leu, Val, Ala, Asp, Lys, Thr, Dab, Dap or Tyr.
<220>
<221> UNSURE
<222> (10)..(10)
<223> The 'Xaa' at location 10 stands for Val, Leu, Ala, Tyr, Arg, Cit, Dap, Dab, Asp or Lys.
<220>
<221> UNSURE
<222> (11)..(11)
<223> The 'Xaa' at location 11 stands for Asn, Gln or Ala.
<220>
<221> UNSURE
<222> (12)..(12)
<223> The 'Xaa' at location 12 stands for Asn, His or Ala.
<220>
<221> UNSURE
<222> (13)..(13)
<223> The 'Xaa' at location 13 stands for Pro or Ala.
<220>
<221> UNSURE
<222> (14)..(14)
<223> The 'Xaa' at location 14 stands for Asp, Glu，Ser or Ala.
<220>
<221> UNSURE
<222> (15)..(15)
<223> The 'Xaa' at location 15 stands for Ile or Ala.
<220>
<221> UNSURE
<222> (17)..(17)
<223> The 'Xaa' at location 17 stands for Tyr, Leu, Arg or amidation.
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (5)..(5)
<223> The 'Xaa' at location 5 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (6)..(6)
<223> The 'Xaa' at location 6 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (9)..(9)
<223> The 'Xaa' at location 9 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (10)..(10)
<223> The 'Xaa' at location 10 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (11)..(11)
<223> The 'Xaa' at location 11 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (12)..(12)
<223> The 'Xaa' at location 12 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (13)..(13)
<223> The 'Xaa' at location 13 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (14)..(14)
<223> The 'Xaa' at location 14 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (15)..(15)
<223> The 'Xaa' at location 15 stands for Gln, Arg, Pro, or Leu.
<220>
<221> UNSURE
<222> (17)..(17)
<223> The 'Xaa' at location 17 stands for Gln, Arg, Pro, or Leu.
<400> 1
Gly Cys Cys Xaa Xaa Xaa Ala Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Cys
1 5 10 15
Xaa
<210> 2
<211> 17
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> VARIANT
<222> (17)..(17)
<223> selected from Y, L or R
<220>
<221> UNSURE
<222> (17)..(17)
<223> The 'Xaa' at location 17 stands for Tyr, Leu, or Arg.
<220>
<221> UNSURE
<222> (17)..(17)
<223> The 'Xaa' at location 17 stands for Gln, Arg, Pro, or Leu.
<400> 2
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
Xaa
<210> 3
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 3
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 4
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> MUTAGEN
<222> (4)..(4)
<223> X = 4-diaminosuccinic acid (Dap)
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Dap.
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Gln, Arg, Pro, or Leu.
<400> 4
Gly Cys Cys Xaa His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 5
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> MUTAGEN
<222> (4)..(4)
<223> X = diaminosuccinic acid (Dap)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Dap.
<220>
<221> UNSURE
<222> (4)..(4)
<223> The 'Xaa' at location 4 stands for Gln, Arg, Pro, or Leu.
<400> 5
Gly Cys Cys Xaa His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 6
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> MUTAGEN
<222> (9)..(9)
<223> X = diaminosuccinic acid (Dap)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<220>
<221> UNSURE
<222> (9)..(9)
<223> The 'Xaa' at location 9 stands for Dap.
<220>
<221> UNSURE
<222> (9)..(9)
<223> The 'Xaa' at location 9 stands for Gln, Arg, Pro, or Leu.
<400> 6
Gly Cys Cys Ser His Pro Ala Cys Xaa Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 7
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 7
Gly Cys Cys Ser His Pro Ala Cys Ser Arg Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 8
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 8
Gly Cys Cys Ala His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 9
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 9
Gly Cys Cys Ser His Pro Ala Cys Ala Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 10
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 10
Gly Cys Cys Ser His Pro Ala Cys Gly Val Asn Asn Pro Asp Ile Cys
1 5 10 15
<210> 11
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 11
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Ala Asp Ile Cys
1 5 10 15
<210> 12
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 12
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Leu Cys
1 5 10 15
<210> 13
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> AMIDATION
<222> (16)..(16)
<223> amidation
<400> 13
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Tyr Cys
1 5 10 15
<210> 14
<211> 17
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 14
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Ile Cys
1 5 10 15
Arg
<210> 15
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> FORMYLATION
<222> (1)..(1)
<223> N-terminal methylation
<220>
<221> AMIDATION
<222> (16)..(16)
<223> C-terminal amidation
<400> 15
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Tyr Cys
1 5 10 15
<210> 16
<211> 16
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<220>
<221> ACETYLATION
<222> (1)..(1)
<223> acetylation of N-terminal
<400> 16
Gly Cys Cys Ser His Pro Ala Cys Ser Val Asn Asn Pro Asp Tyr Cys
1 5 10 15

Claims (10)

1. The conotoxin mutant is characterized in that the amino acid sequence of the mutant is SEQ ID NO:1GCCX 1 X 2 X 3 ACX 4 X 5 X 6 X 7 X 8 X 9 X 10 C X 11 ；
Wherein, X 1 Any one selected from S, T, A, R, (S) -2-amino-3-guanidinopropionic acid (Alg), L-2,3-diaminopropionic acid (Dap), or L-2,4-diaminobutyric acid (Dab); x 2 Selected from H, R, W, A or N; x 3 Any one selected from P or Hyp; x 4 Selected from any one of S, L, V, A, D, K, T, dab, dap or Y; x 5 Selected from any one of V, L, A, Y, R, cit, dap, dab, D or K; x 6 Selected from any one of N, Q or A; x 7 Selected from any one of N, H or A; x 8 Is P or A; x 9 Any one selected from D, E, S or A; x 10 Is I or A; x 11 Is C-terminal amidation, or, is selected from any one of Y, L or R.
2. A conotoxin mutant according to claim 1, wherein the mutant amino acid sequence is SEQ ID NO 2GCCSHPACSVNNPDICX 11 ；
Wherein X 11 Any one selected from Y, L or R.
3. A conotoxin mutant according to claim 1, wherein the N-terminus of the mutant amino acid sequence is methylated or acetylated; preferably, the mutant amino acid sequence is SEQ ID NO 3GCCSHPACSVNNPDIC and the C-terminal is amidated; or SEQ ID NO 4GCC (Dap) HPACSVNNPDIC with the C-terminal amidated.
4. A conotoxin mutant according to any of claims 1 to 3, wherein the 2 nd and 8 th cysteines form an intra-chain disulfide bond and the 3 rd and 16 th cysteines form an intra-chain disulfide bond.
5. A method of producing a conotoxin mutant according to any of claims 1 to 4, comprising:
1) Activating the resin with dichloromethane and N, N-dimethylformamide, and then obtaining linear peptide SEQ ID NO 1 according to a solid phase synthesis method;
2) Cutting the resin by using a mixed solution of trifluoroacetic acid, water, phenol and triisopropylsilane, removing the trifluoroacetic acid by rotary evaporation, and then adding glacial ethyl ether until a white solid is separated out; dissolving the white solid into a re-solution by water through centrifugation, and then freeze-drying the re-solution to obtain solid powder;
3) Protecting the sulfydryl of the 2 nd and 8 th cysteines in the sequence SEQ ID NO. 1 by using a first sulfydryl protecting group; protecting cysteines at positions 3 and 16 in the sequence SEQ ID NO. 1 with a second thiol protecting group;
4) Disulfide bonds from 3 rd position to 16 th position and from 2 nd position to 8 th position are respectively constructed according to a disulfide bond construction method for the first thiol-protecting group and the second thiol-protecting group.
6. The method of claim 5, wherein the resin is activated in step 1) with a volume ratio of dichloromethane to N, N-dimethylformamide of 1:1.
7. the method according to claim 5, wherein the volume ratio of trifluoroacetic acid, water, phenol, triisopropylsilane in step 2) is 80:3-7:3-7:1-5.
8. the method according to claim 5, wherein the first mercapto-protecting group and the second mercapto-protecting group in step 3) are each trityl or acetamidomethyl, and the first mercapto-protecting group and the second mercapto-protecting group are different.
9. The method according to claim 5, wherein in step 3), when the first thiol-protecting group or the second thiol-protecting group is trityl, a disulfide bond is formed by an air oxidation method; further preferably, the air oxidation process is carried out by a process comprising the steps of: dissolving the solid powder in 0.2mg/mL ammonium bicarbonate aqueous solution of 0.2M, stirring and reacting for 48h at room temperature, and freeze-drying after reaction to obtain the solid powder;
when the first or second thiol-protecting group is an acetamidomethyl group, the disulfide is constructed by a method comprising the steps of:
mixing water, acetonitrile and TFA in a volume ratio of 5:5:0.01, mixing and preparing a reaction solvent, weighing a proper amount of white solid powder, dissolving the white solid powder in the reaction solvent, and then adding 1-5mg/mL iodine/acetonitrile solution, wherein the concentration of the polypeptide in the mixed solution is 1-3mg/mL; stirring at room temperature for reaction for 30 min, adding appropriate amount of ascorbic acid water solution, mixing to make the solution colorless and clear, and lyophilizing to obtain the final product; further preferably, the iodine/acetonitrile solution is 5mg/mL and the aqueous ascorbic acid solution is 5mg/mL.
10. Use of a conotoxin mutant according to any one of claims 1 to 4 in the preparation of an α 9 α 10nAChR inhibitor, in the preparation of a molecular probe or reagent for studying the structure and function of ion channel receptors, in the preparation of a medicament for treating neuralgia-related diseases, preferably selected from peripheral neuropathic pain or central pain, or in the preparation of a medicament or adjuvant for treating tumors;
preferably, the peripheral neuropathic pain is selected from trigeminal neuralgia, sphenopalatine ganglion pain, winged canal neuralgia, geniculate ganglion pain, occipital neuralgia, intercostal neuralgia, cervicobrachial neuralgia, brachial plexus neuritis, ulnar neuralgia, median neuralgia, lateral femoral neuralgia, sciatica, coccygodynia, causalgia, herpes zoster, cancer pain; the central pain is spinal pain, thalalgia, pono, medullary pain, and cerebral cortex pain.
CN202110225081.5A 2021-04-27 2021-04-27 Conotoxin mutant and preparation method and application thereof Pending CN115246872A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115260292A (en) * 2022-08-29 2022-11-01 中国海洋大学 Novel analgesic polypeptide

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108218971A (en) * 2016-12-21 2018-06-29 海南大学 Alpha-conotoxin peptides TxID new mutants, its pharmaceutical composition and purposes
CN108359001A (en) * 2018-04-11 2018-08-03 华南农业大学 Conotoxin mutant polypeptides lv1c-AA and application and preparation method
CN108864268A (en) * 2017-05-09 2018-11-23 同济大学 The preparation method and application of NTD structural domain and its optimization in conotoxin α D-GeXXA
CN112010959A (en) * 2019-05-31 2020-12-01 海南大学 Novel alpha O-conotoxin GeXIVA mutant, and pharmaceutical composition and application thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108218971A (en) * 2016-12-21 2018-06-29 海南大学 Alpha-conotoxin peptides TxID new mutants, its pharmaceutical composition and purposes
CN108864268A (en) * 2017-05-09 2018-11-23 同济大学 The preparation method and application of NTD structural domain and its optimization in conotoxin α D-GeXXA
CN108359001A (en) * 2018-04-11 2018-08-03 华南农业大学 Conotoxin mutant polypeptides lv1c-AA and application and preparation method
CN112010959A (en) * 2019-05-31 2020-12-01 海南大学 Novel alpha O-conotoxin GeXIVA mutant, and pharmaceutical composition and application thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115260292A (en) * 2022-08-29 2022-11-01 中国海洋大学 Novel analgesic polypeptide

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