WO2013133032A1

WO2013133032A1 - Dipeptidyl peptidase-iv inhibitor

Info

Publication number: WO2013133032A1
Application number: PCT/JP2013/054292
Authority: WO
Inventors: 明男山田; 琢磨桜井; 越智　大介
Original assignee: 森永乳業株式会社
Priority date: 2012-03-09
Filing date: 2013-02-21
Publication date: 2013-09-12
Also published as: JPWO2013133032A1; JP5976004B2

Abstract

　Provided are a superior dipeptidyl peptidase-IV inhibitor and the like.　Specifically provided are a dipeptidyl peptidase-IV inhibitor, a hypoglycemic agent and a vascular endothelial dysfunction inhibitor, each comprising, as an active ingredient, one or more peptides selected from among peptides comprising one of the amino acid sequences represented by (a)-(d): (a) Ser-Pro-Ala-Gln (SEQ ID NO: 1), (b) Gly-Pro-Val-Arg (SEQ ID NO: 2), (c) His-Pro-His-Pro-His (SEQ ID NO: 3), and (d) Ala-Pro-Lys (SEQ ID NO: 4).　Also provided are new peptides comprising any one of the amino acid sequences represented by (a)-(c): (a) Ser-Pro-Ala-Gln (SEQ ID NO: 1), (b) Gly-Pro-Val-Arg (SEQ ID NO: 2), and (c) His-Pro-His-Pro-His (SEQ ID NO: 3).

Description

Dipeptidyl peptidase-IV inhibitor

The present invention relates to a dipeptidyl peptidase-IV inhibitor and the like.

Dipeptidyl peptidase-IV (di- peptidyl peptidase-IV: hereinafter also referred to as “DPP-4”) is a multifunctional transmembrane glycoprotein having N-terminal dipeptidase activity. It is present on most mammalian cells and is present in various tissues such as the liver, kidney, small intestine, salivary gland, blood cells and plasma, so it is assumed that it has a broad role in vivo and is created. It is an enzyme that has recently attracted attention as a drug target.

Dipeptidyl peptidase-IV is known to be a degrading enzyme of glucagon-like peptide 1 (hereinafter referred to as “GLP-1”) and glucose-dependent insulinotropic polypeptide (hereinafter referred to as “GIP”) of incretin. ing. This GLP-1 is released after a meal and is glucose-induced stimulation of insulin biosynthesis and secretion, suppression of glucagon secretion, regulation of gene expression, nutritional effect on sputum cells, suppression of food intake, And multifaceted action including slowing of gastric emptying. By inhibiting dipeptidyl peptidase-IV, the degradation of incretins GLP-1 and GIP is suppressed, and these concentrations in blood increase. As a result, it is known that insulin secretion is promoted and the blood glucose level is lowered. The promotion of insulin secretion by incretin is an operating condition that the blood glucose level is high. Therefore, it can be said that inhibition of dipeptidyl peptidase-IV in type 2 diabetes due to decreased insulin secretion has a low risk of side effects such as hypoglycemia caused by conventional insulin secretagogues.

Thus, the dipeptidyl peptidase-IV inhibitor having an action of inhibiting dipeptidyl peptidase-IV activity is expected to be used as an antidiabetic agent. However, dipeptidyl peptidase-IV inhibitors are still a new genre of therapeutic agents compared to insulin secretion inhibitors, glucose absorption inhibitors, etc., and many new substances having dipeptidyl peptidase-IV inhibitory activity can be found. It is desired. Furthermore, the first step in the treatment of diabetes is diet therapy and exercise therapy, and when the blood glucose level cannot be controlled even now, pharmaceuticals for treating diabetes are currently used. Therefore, if it is possible to provide a substance having dipeptidyl peptidase-IV inhibitory activity as a supplement or food additive, it is considered that it can contribute widely to the improvement of blood glucose level.

For example, Patent Document 1 discloses that a bicyclic pyrimidine is used as a dipeptidyl peptidase-IV inhibitor for treating or preventing diabetes.
In addition, for example, in Patent Document 2, casein is subjected to alkaline decomposition by adjusting pH and temperature, and then various peptides such as proteases are further adjusted to separate and purify various peptides from hydrolyzed products. Furthermore, it has been disclosed that a dipeptidyl peptidase-IV inhibitory action has been found among them. In addition, there are disclosures about dipeptidyl peptidase-IV inhibitors derived from food (see, for example, Patent Documents 3 to 5).
Further, for example, in Table 2 of Patent Document 6, isolated peptides obtained by isolating only one peptide from casein or whey hydrolyzate are IPI, LPL, KVLP, LPVPQK, VPLGTQ, VPYPQ, PLLQ, GPFP, LPVPQ, LPQYL, MPLW, YVPEPF, PQSVLS, PFP, LPVP, EMPFPK, LPLP, GPFPIIV, APFPE, HPIK and AFPPEVF are described, and dipeptidyl peptidase-IV inhibition test results of these isolated peptides are disclosed.

Special table 2008-527011 US Patent Application Publication No. 2008/0075904 JP 2011-144167 A JP 2007-039424 A JP 2008-280291 A International Publication 2006/068480 Pamphlet

Thus, although dipeptidyl peptidase-IV inhibitors have been disclosed in the past, for example, in Patent Document 1, an organic synthetic compound requires a complicated synthesis process, and future verification is necessary regarding safety. Any dipeptidyl peptidase-IV inhibitor should be studied, and the current situation is that the search for dipeptidyl peptidase-IV inhibitors is not sufficient.
In addition, since peptides may have beneficial physiological activity, search for novel peptides and various physiological activity of peptides have been conducted. However, if the amino acids in the peptide increase or decrease or some of the amino acids are different, the physiological activity may be reduced or eliminated, and countless peptides even in the hydrolyzate of milk-derived proteins such as casein Therefore, it is difficult to find a new or known peptide having the desired physiological activity.
Therefore, the present invention is to provide an excellent dipeptidyl peptidase-IV inhibitor.

As a result of intensive studies to solve the above problems, the present inventor has found that SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 1) in a casein hydrolyzate obtained by hydrolyzing casein with a specific enzyme. 2) a peptide consisting of 3 to 5 amino acid residues of HPPHPH (SEQ ID NO: 3) and APK (SEQ ID NO: 4) (hereinafter also referred to as “the 3-5 peptide of the present disclosure” or “the 3-5 peptide”) ) Has been found to have a dipeptidyl peptidase-IV inhibitory action, and the present invention has been completed. SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 2), and (SEQ ID NO: 3) were novel peptides.

Moreover, since tetrapeptide SPAQ (SEQ ID NO: 1), tetrapeptide GPVR (SEQ ID NO: 2), pentapeptide HPPHP (SEQ ID NO: 3) and tripeptide APK (SEQ ID NO: 4) are food-derived components, they are highly safe. As contemplated, the 3-5 peptides of the present disclosure can also be provided as supplements or food additives. Therefore, it is considered that the peptide of the present disclosure can widely contribute to the improvement of blood glucose level.
From the above, it can be said that the 3-5 peptides of the present disclosure are more effective substances with added value.

That is, the present invention provides a dipeptidyl peptidase-IV inhibitor containing as an active ingredient one or more peptides selected from peptides consisting of any of the following amino acid sequences (a) to (d): is there.
(A) Ser-Pro-Ala-Gln (SPAQ: SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (GPVR: SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (HPPHPH: SEQ ID NO: 3)
(D) Ala-Pro-Lys (APK: SEQ ID NO: 4)

In addition, the peptide comprising the amino acid sequence of any of the following (a) to (c) of the present invention is a novel peptide.
(A) Ser-Pro-Ala-Gln (SPAQ: SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (GPVR: SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (HPPHPH: SEQ ID NO: 3)

The present invention provides a dipeptidyl peptidase-IV inhibitor, a blood glucose level increase inhibitor, a hyperglycemia improving agent, and a vascular endothelial disorder inhibitor because the 3-5 peptides of the present disclosure have an excellent dipeptidyl peptidase-IV inhibitory action. Etc. can be provided.

It is a figure which shows the result of the MS / MS analysis of peptide SPAQ (sequence number 1) of this indication. It is a figure which shows the result of the MS / MS analysis of peptide GPVR (sequence number 2) of this indication. It is a figure which shows the result of the MS / MS analysis of peptide HPPHPH (sequence number 3) of this indication. It is a figure which shows the result of the MS / MS analysis of peptide APK (sequence number 4) of this indication.

The peptide of the present disclosure is a peptide having an amino acid sequence represented by SEQ ID NOs: 1 to 5 having a dipeptidyl peptidase-IV inhibitory action.
Examples of the peptide comprising 3 to 5 amino acid residues of the present disclosure include the following.
As tetrapeptides, a peptide consisting of Ser-Pro-Ala-Gln (SEQ ID NO: 1) (hereinafter referred to as “SPAQ”): and a peptide consisting of Gly-Pro-Val-Arg (SEQ ID NO: 2) (hereinafter referred to as “GPVR”). ”);
As a pentapeptide, a peptide composed of His-Pro-His-Pro-His (SEQ ID NO: 3) (hereinafter referred to as “HPPHP”);
Examples of the tripeptide include a peptide composed of Ala-Pro-Lys (SEQ ID NO: 4) (hereinafter referred to as “APK”).
One or two or more selected from peptides consisting of the amino acid sequences shown in SEQ ID NOs: 1 to 4 can be used.
SPAQ, GPVR and APK are peptides containing one L-proline residue, and HPPHPH is a peptide containing two L-proline residues.
Here, in the present disclosure, Ser (S) is an L-serine residue, Pro (P) is an L-proline residue, Ala (A) is an L-alanine residue, and Gln (Q) is an L-glutamine residue. , Gly (G) is L-glycine residue, Val (V) is L-valine residue, Arg (R) is L-arginine residue, His (H) is L-histidine residue, Lys (K) is L-lysine residues are indicated.

Further, the 3-5 peptide of the present disclosure may be a salt of this peptide. Examples of the salts include alkali metals such as potassium and sodium; alkaline earth metals such as calcium and magnesium, and one or more of them may be used as appropriate.

About the manufacturing method of the peptide of this indication, it can carry out according to a method as described in international publication 2003/044044 pamphlet [reference reference 1] etc., for example, The following methods are illustrated, This is not particularly limited.
For example, a protein comprising one or more amino acid sequences selected from the amino acid sequences represented by SEQ ID NO: 1 (SPAQ), SEQ ID NO: 2 (GPVR), SEQ ID NO: 3 (HPPHP), and SEQ ID NO: 4 (APK) Or peptides obtained by hydrolyzing the peptide and separating and purifying it from the resulting degradation product; after synthesizing 3 to 5 peptides of the present disclosure by the chemical synthesis method of the peptide, A method of separating and purifying the disclosed 3 to 5 peptide; a method of extracting from a plant, animal or microorganism producing the 3 to 5 peptide of the present disclosure and a peptide containing the peptide, and separating and purifying from the obtained extract, etc. Is mentioned.

The 3-5 peptide of the present disclosure can be produced, for example, by appropriately hydrolyzing a protein such as casein with an acid alkali or an enzyme.
A method for obtaining the peptide by hydrolyzing a raw material protein with a hydrolase is exemplified.
First, before hydrolyzing a raw material protein with an enzyme, the protein is dissolved, dispersed or suspended in water.
The starting protein is a protein containing at least one of the amino acid sequences represented by SEQ ID NOs: 1 to 4, and can produce the 3-5 peptides of the present disclosure when appropriately digested with a hydrolase. There is no particular limitation. Examples of the protein include those derived from animals and microorganisms, and casein that is available in large quantities is preferable.
At this time, the treatment method varies depending on the properties of the raw protein, but if the raw protein is soluble, the raw protein may be dispersed and dissolved in water or warm water, and if it is poorly soluble, the protein will be dissolved in hot water. May be homogenized by mixing and stirring.

Then, an alkaline agent or an acid agent may be added to the solution containing the protein to adjust the pH. This pH is preferably adjusted to the optimum pH of the hydrolase used or in the vicinity thereof.
It does not specifically limit as said alkali agent or acid agent, What is necessary is just to use what is accept | permitted by a foodstuff or a pharmaceutical. Examples of the alkali agent include hydroxides such as sodium hydroxide and calcium hydroxide; carbonates such as potassium carbonate, and the like, and these may be alkali metal salts or alkaline earth metal salts. Examples of the acid agent include inorganic acids such as hydrochloric acid and phosphoric acid; organic acids such as citric acid, acetic acid, and formic acid. Of these, one or more may be used as appropriate.
In addition, it is desirable from the viewpoint of preventing deterioration due to contamination with various bacteria that the protein-containing solution is sterilized by heating at 70 to 90 ° C. for about 15 seconds to 10 minutes.

Next, a predetermined amount of hydrolase is added to the solution containing the protein and reacted at a temperature of about 10 to 85 ° C. for 0.1 to 48 hours to obtain a hydrolyzate.
At this time, after adding the hydrolase, the solution is maintained at an appropriate temperature according to the type of the enzyme, for example, 30 to 60 ° C., preferably 45 to 55 ° C. to start protein hydrolysis. Is desirable.
The hydrolysis reaction time may be continued until the desired decomposition rate is reached while monitoring the decomposition rate of the enzyme reaction. In order to obtain the 3-5 peptide of the present disclosure, the degradation rate of the raw protein is preferably 20-60%. Furthermore, when obtaining each peptide consisting of 4 to 5 amino acid residues of SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 2), and HPPHPH (SEQ ID NO: 3) of the present disclosure, the degradation rate of the starting protein is 20 ~ 30% is desirable. In addition, when obtaining a peptide comprising three amino acid residues of APK (SEQ ID NO: 4) of the present disclosure, it is desirable that the degradation rate of the raw material protein is 40 to 60%.
The hydrolase reaction is stopped, for example, by deactivation of the enzyme in the hydrolyzate, and can be performed by a heat deactivation treatment by a conventional method. The heating temperature and holding time of the heat deactivation treatment can be appropriately set in consideration of the thermal stability of the enzyme used, and can be set as appropriate under conditions that can be sufficiently deactivated, for example, at a temperature range of 80 to 130 ° C. for 30 minutes. It can be performed with a holding time of ˜2 seconds.

The hydrolase is not particularly limited, but is preferably an enzyme that can hydrolyze the raw protein to produce the peptide of the present disclosure. Specifically, the enzyme that can be produced is preferably an endopeptidase.

Examples of the endopeptidases include those derived from microorganisms and animals. Specific examples include proteases derived from bacteria belonging to the genus Bacillus, bacteria derived from Aspergillus, and proteases derived from animal pancreas. . A commercially available protease can be used.
Examples of commercially available proteases include proteases derived from Bacillus bacteria such as biopulase sp-20 (manufactured by Nagase Seikagaku) and protease N (manufactured by Amano Enzyme); PTN 6.0S (manufactured by Novozymes Japan), etc. Animal pancreatic proteases and the like can be exemplified as preferable ones. Further, for example, proteases derived from Aspergillus bacteria such as protease A (manufactured by Amano Enzyme); animal pancreatic proteases such as pancreatin (manufactured by Amano Enzyme) and the like can be exemplified as preferable examples.
For example, when a protease derived from a bacterium belonging to the genus Bacillus is used, it is preferably added at a rate of 100 to 5000 active units per gram of protein. In addition, when using a protease derived from animal pancreas, it is desirable to add it at a rate of 3000 to 8000 active units per gram of protein.

You may use the hydrolase used in this indication individually or in combination of 2 or more types. When using 2 or more types of enzymes, you may perform each enzyme reaction simultaneously or separately.
In the present disclosure, in order to obtain a peptide consisting of the amino acid sequence shown in SEQ ID NOs: 1 to 3 (specifically, SPAQ, GPVR or HPPHP), it is necessary to use biopase sp-20, protease N and PTN 6.0S in combination. It is particularly preferable to use a mixture of these three enzymes.
In the present disclosure, when obtaining a peptide (specifically, APK) having the amino acid sequence shown in SEQ ID NO: 4, it is preferable to use pancreatin and protease together, and these two enzymes may be used in combination. Particularly preferred.

The method for calculating the decomposition rate of the raw material protein was determined by measuring the total amount of nitrogen in the sample by the Kjeldahl method (edited by the Japan Food Industry Association, “Food Analysis Method”, page 102, Korin Co., Ltd., 1984). Measure the amount of formol nitrogen in the sample by the titration method (Matsuda et al., “Food Engineering Experiments”, Volume 1, Page 547, Yokendo, 1970), and calculate the decomposition rate from these measurements using the following formula To do.
Decomposition rate (%) = (formol nitrogen amount / total nitrogen amount) × 100

It is preferred to isolate or purify the 3-5 peptides of the present disclosure from the hydrolyzate.
The purification of the 3-5 peptide of the present disclosure is usually performed in the same manner as that used for the purification of oligopeptide, such as ion exchange chromatography, adsorption chromatography, reverse phase chromatography, partition chromatography, gel filtration chromatography. It can be carried out by appropriately combining various types of chromatography such as chromatography, solvent precipitation, salting out, and distribution between two liquid phases.

In the isolation or purification of the 3-5 peptide of the present disclosure, the fraction containing the target substance can be determined using the dipeptidyl peptidase-IV inhibitory action described below as an index. Moreover, the active ingredient of those fractions can be identified by mass spectrometry.

The proteolytic product obtained by hydrolase is one or more selected from SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 2), HPPHP (SEQ ID NO: 3) and APK (SEQ ID NO: 4). What is included is preferable.

The 3-5 peptides of the present disclosure can also be produced by chemical synthesis.
The chemical synthesis of 3-5 peptides of the present disclosure can be performed by a liquid phase method or a solid phase method generally used for oligopeptide synthesis. The synthesized peptide is deprotected as necessary, and unreacted reagents and by-products can be removed to isolate the 3-5 peptides of the present disclosure.
Such peptide synthesis can be performed using a commercially available peptide synthesizer. The fact that the target peptide was obtained can be confirmed using the dipeptidyl peptidase-IV inhibitory action described later as an index.

The 3-5 peptides of the present disclosure have a dipeptidyl peptidase-IV inhibitory action, as shown in Examples below.
Dipeptidyl peptidase-IV may cause various diseases and symptoms by decomposing compounds involved in physiological functions in vivo. For this reason, inhibition of dipeptidyl peptidase-IV takes advantage of dipeptidyl peptidase-IV by utilizing the fact that the life span of compounds involved in physiological functions in vivo that have been degraded by dipeptidyl peptidase-IV is extended. Prevention, amelioration, or treatment of the disease or symptom that occurs.
Examples of the compound involved in the physiological function include glucagon-like peptide 1 (GLP-1) of incretin and glucose-dependent insulinotropic polypeptide (GIP). And by inhibiting the degradation of glucagon-like peptide 1 of this incretin, glucose-induced stimulation of insulin biosynthesis and secretion, glucagon secretion inhibition, regulation of gene expression, nutritional effects on sputum cells, suppression of food intake, In addition, it is possible to achieve various actions such as slowing of gastric emptying. This can contribute to normalization of the elevated blood glucose level and improvement / adjustment of hunger and body weight.

It is also known that dipeptidyl peptidase-IV reduces the function of vascular endothelial cells and damages vascular endothelial cells. This decrease in blood vessel endothelial function or damage causes vascular disorders such as vasoconstriction, arteriosclerosis, and thrombus formation due to increased vascular tension, and these causes cause organ blood flow disorders, organ dysfunction, and diabetes. Complications will be induced.
In recent years, there have been many reports on the effect of improving endothelial function by administration of dipeptidyl peptidase-IV inhibitors (for example, see References 2 to 5 [Reference 2] Endocrine Journal 2011, 58 (1), 69-73. [Reference 3] J Am Coll Cardiol. 2012, 59 (3), 265-76; [Reference 4] Diabetes Care. 2011, 34 (9), 2072-7; [Reference 5] Cardiovascular Diabetology 2011, 10 (85) (http://www.cardiab.com/content/10/1/85)).
These effects are considered to be mediated by the protective action of blood vessels by incretin in addition to the improvement by simply lowering the blood glucose level. When blood sugar decreases and blood vessel suppleness is lost due to hyperglycemia, the blood pressure rises, and the increased blood pressure further damages the blood vessels, causing adverse effects on organs such as the heart, kidney, and brain appear. In order to break this vicious circle, a combination of dipeptidyl peptidase-IV inhibitors and angiotensin converting enzyme inhibitors has been tried, and dipeptidyl peptidase-IV inhibitors also play an important role in the treatment of cardiovascular system It is considered a thing.

That is, since the 3-5 peptide of the present disclosure has a dipeptidyl peptidase-IV inhibitory action, the blood sugar level elevation inhibiting action, the hyperglycemia improving action, the vascular endothelial function lowering inhibiting action, the vascular endothelial disorder inhibiting action, the vascular disorder inhibiting action And vascular endothelial cell protective effect and appetite suppression effect.
In addition, the 3-5 peptides of the present disclosure are considered to be capable of suppressing appetite and protecting vascular endothelial cells. Note that “suppressing the increase in blood glucose level” here means including a decrease in blood glucose level, and particularly means “being able to lower a blood glucose level that is higher than a normal value or higher than necessary”. The determination of the normal value of the blood glucose level may be based on the 2010 diagnostic criteria of the Japan Diabetes Society.
Furthermore, it is considered that the diseases and symptoms caused by dipeptidyl peptidase-IV can be prevented, ameliorated, or treated by inhibiting dipeptidyl peptidase-IV with the peptides 3 to 5 of the present disclosure. Therefore, the peptides 3 to 5 of the present disclosure are used in a method for preventing, ameliorating, and / or treating diseases and symptoms caused by dipeptidyl peptidase-IV by ingesting or administering to animals including humans. be able to.
Examples of various diseases and symptoms caused by dipeptidyl peptidase-IV of the present disclosure include hyperglycemia, diabetes, diabetic complications, vascular endothelial disorder, and vascular disorder. The various diseases caused by dipeptidyl peptidase-IV may be various diseases mediated by dipeptidyl peptidase-IV.
Furthermore, various diseases caused by hyperglycemia, diabetes and hyperglycemia conditions include, for example, diabetic microangiopathy (eg retinopathy, nephropathy, neuropathy, etc.) and macrovascular complications (eg angina) Ischemic heart disease such as symptom / myocardial infarction, cerebral infarction, obstructive arteriosclerosis, gangrene, etc.).

The fact that the dipeptidyl peptidase-IV inhibitor can be used as a prophylactic or therapeutic agent for the above-mentioned various diseases is as disclosed in the aforementioned Patent Documents 1 to 5 and Reference Documents 2 to 5. It goes without saying that the disclosed 3-5 peptides can also be implemented as preventive and therapeutic agents for the various diseases.
Therefore, the 3-5 peptide of the present disclosure may be used for dipeptidyl peptidase-IV inhibition, blood glucose level increase suppression, hyperglycemia improvement, vascular endothelial disorder suppression, anti-diabetes and the like as described above, In addition, it can be used in various preparations intended for use as described above, such as dipeptidyl peptidase-IV inhibitors, blood sugar level increase inhibitors, vascular endothelial disorder inhibitors, and antidiabetic agents. Can be used to

Therefore, the 3-5 peptide of the present disclosure and the above-mentioned various preparations containing this as an active ingredient (hereinafter also referred to as “the dipeptidyl peptidase-IV inhibitor etc.”) are ingested or administered to animals including humans. Thus, prevention, improvement and / or treatment of hyperglycemia, diabetes (especially type 2 diabetes) and diabetic complications (for example, diabetic vascular endothelial disorder and nephropathy), vascular endothelial disorder, vascular disorder, etc. Can be used in a method for
Further, the present disclosure 3-5 peptide and the above-mentioned various preparations containing this as an active ingredient are for humans or animals for the prevention, improvement and / or treatment of hyperglycemia, diabetes, vascular disorders and the like as described above. It can be used as an active ingredient of pharmaceuticals, quasi-drugs, external preparations for skin, cosmetics and foods.
When blended in a pharmaceutical product, it can be an oral or parenteral agent. In addition, when formulated in foods, prevention, improvement or treatment of the above-mentioned various diseases caused by dipeptidyl peptidase-IV and various diseases caused by hyperglycemic conditions, dipeptidyl peptidase-IV inhibition, blood glucose level increase It can be applied to functional foods based on physiological functions such as suppression and improvement of hyperglycemia, foods for the sick, and foods for specified health use.
The dipeptidyl peptidase-IV inhibitor, etc., as described above, is a human or veterinary drug, quasi-drug, or external skin for the prevention, improvement and / or treatment of hyperglycemia, diabetes, vascular disorders, etc. It can be blended and used as an active ingredient of agents, cosmetics, foods and the like.

The present disclosure 3-5 peptide and the above-mentioned various preparations containing this as an active ingredient may be either oral administration or parenteral administration, but oral administration is desirable. Parenteral administration includes intravenous injection, rectal administration, inhalation and the like. Examples of the dosage form for oral administration include tablets, capsules, troches, syrups, granules, acid agents, ointments and the like.
In formulating, in addition to milk protein hydrolyzate and 3-5 peptides of the present disclosure, it is possible to use components such as excipients, pH adjusters, colorants, corrigents and the like that are usually used for formulation. it can.

In addition, the 3-5 peptide of the present disclosure may be used in combination with a drug having a dipeptidyl peptidase-IV inhibitory action and / or angiotensin converting enzyme inhibitory action, an antidiabetic drug, a hypoglycemic drug, etc. that are known or will be found in the future Is also possible.
A person who is diabetic or a reserve group thereof (the reserve group refers to a person who has not yet been diabetic but has a high blood glucose level) needs to pay attention to hypertension. However, in general, it cannot be said that blood pressure can be lowered even if the increase in blood glucose level can be suppressed with a blood glucose level increase suppressant, while blood glucose level can be increased even if blood pressure is decreased with a blood pressure lowering drug. It cannot be said that it can be suppressed. For this reason, diabetic and hypertensive humans are often prescribed both blood glucose level-inhibiting drugs and antihypertensive drugs, and there is a concern of side effects due to the combination of drugs. However, since the 3-5 peptides of the present disclosure are considered to be highly safe because they are peptides that can be separated from the casein enzymatic degradation product, reduction of side effects can be expected even when other drugs are combined.

Further, 3 to 5 peptides of the present disclosure are contained in a food as an active ingredient, and one embodiment of the above-described various preparations containing the 3 to 5 peptides of the present disclosure and this as an active ingredient has a dipeptidyl peptidase-IV action. It can also be processed as food.
Examples of such foods include liquids, pastes, solids, powders, etc. In addition to tablet confectionery, liquid foods, feeds (including for pets), etc., for example, flour products, instant foods, processed agricultural products, Processed marine products, processed livestock products, milk / dairy products, fats and oils, basic seasonings, compound seasonings / foods, frozen foods, beverages, and other commercial products.

For example, examples of the flour product include bread, macaroni, spaghetti, noodles, cake mix, fried flour, bread crumbs and the like. Examples of the instant foods include instant noodles, cup noodles, retort / cooked food, cooking canned food, microwave food, instant soup / stew, instant miso soup / soup, canned soup, freeze-dried food, and other instant foods.
Examples of the processed agricultural products include canned agricultural products, canned fruits, jams and marmalades, pickles, boiled beans, dried agricultural products, cereals (cereal processed products), and the like. Examples of the processed fishery products include canned fishery products, fish hams and sausages, fish paste products, marine delicacies, and tsukudani. Examples of the processed livestock products include canned livestock, pastes, livestock ham, sausages and the like.
Examples of the milk / dairy products include processed milk, milk beverages, yogurts, lactic acid bacteria beverages, cheese, ice creams, prepared powdered milks, creams, and other dairy products. Examples of the fats and oils include butter, margarines, and vegetable oils.
For example, the basic seasonings include soy sauce, miso, sauces, tomato processed seasonings, mirins, vinegars, etc., and the combined seasonings and foods include cooking mixes, curry ingredients, sauces, Examples include dressings, noodle soups, spices, and other complex seasonings.
Examples of the frozen food include raw material frozen food, semi-cooked frozen food, cooked frozen food, and the like.
Examples of the confectionery include caramel, candy, chewing gum, chocolate, cookies, biscuits, cakes, pie, snacks, crackers, Japanese confectionery, rice confectionery, bean confectionery, dessert confectionery, and other confectionery.
For example, the beverages include carbonated beverages, natural fruit juices, fruit juice beverages, soft drinks with fruit juices, fruit drinks, fruit drinks with fruits, vegetable drinks, soy milk, soy milk drinks, coffee drinks, tea drinks, powdered drinks, concentrated drinks Sports drinks, nutritional drinks, alcoholic drinks, other taste drinks, and the like.
For example, examples of commercially available foods other than the above include baby foods, sprinkles, and tea paste.

In the dipeptidyl peptidase-IV inhibitor and the like of the present disclosure, the blending amount of the 3-5 peptide of the present disclosure is preferably at least 0.001% by mass with respect to the final composition of the preparation.
The dose of the 3-5 peptide of the present disclosure varies depending on age, symptoms, etc., but is usually 0.001 to 3000 mg / day, preferably 0.01 to 30 mg / day, and is once to three times a day. May be administered separately.

Hereinafter, specific examples and the like will be described, but the present invention (the present disclosure) is not limited thereto.

Production Example 1: Production of tetrapeptide SPAQ, tetrapeptide GPVR, pentapeptide HPPHPH and tripeptide APK by enzymatic degradation of casein <Enzymatic degradation of casein 1>
900 g of water is added to 100 g of commercially available casein (manufactured by New Zealand Daily Board), well dispersed, sodium hydroxide is added to adjust the pH of the solution to 7.0, and the casein is completely dissolved. An aqueous casein solution was prepared. The casein aqueous solution was sterilized by heating at 85 ° C. for 10 minutes, adjusted to a temperature of 50 ° C., sodium hydroxide was added to adjust the pH to 9.5, and then biolase sp-20 (manufactured by Nagase Seikagaku Corporation) 100 , 800 active units (1,200 active units per gram of protein), protease N (manufactured by Amano Enzyme) 168,000 active units (2,000 active units per gram of protein), and PTN 6.0S (manufactured by Novozymes Japan) The hydrolysis reaction was initiated by adding 588,000 active units (7,000 active units per gram of protein). When the degradation rate of casein reached 25.0%, the enzyme reaction was stopped by heating at 80 ° C. for 6 minutes to deactivate the enzyme, and then cooled to 10 ° C. This hydrolyzed solution was ultrafiltered through an ultrafiltration membrane (manufactured by Asahi Kasei Co., Ltd.) having a molecular weight cut-off of 10,000, concentrated and freeze-dried to obtain 87 g of a freeze-dried product (casein enzyme degradation product 1).

<Peptide separation by HPLC>
The casein hydrolyzate was separated by reverse phase HPLC. The HPLC conditions are shown in the following HPLC condition 1.
[HPLC condition 1]
Column: Cadenza CD-C18
10 mmI. D. × 250mm (manufactured by Intact Corporation)
Detection: UV 215nm
Flow rate: 3 ml / min Eluent A: Aqueous solution containing 0.2% FA Eluent B: Acetonitrile solution containing 0.2% FA From 98% of Eluent A, 75% after 30 minutes, 50% after 40 minutes The hydrolyzate was separated under a gradient condition of 20% after 43 minutes, and the eluate was fractionated every 0.75 ml. When the dipeptidyl peptidase-IV inhibitory ability of the eluted fraction was measured, a strong inhibitory activity ability was recognized in the fraction eluted at a retention time of 10 to 15 minutes.
Furthermore, in order to refine | purify, it refine | purified by HPLC of another condition. The conditions at this time are shown in the following HPLC condition 2. At this time, the eluents A and B of the condition 1 were changed to the eluents A and B of the condition 2, respectively, and the other conditions were the same as the condition 1.
[HPLC condition 2]
Column: Cadenza CD-C18
10 mmI. D. × 250mm (manufactured by Intact Corporation)
Detection: UV 215nm
Flow rate: 3 ml / min Eluent A: Aqueous solution containing 0.1% TFA B: Acetonitrile solution containing 0.1% TFA

Under the same gradient conditions, the hydrolyzate was separated, and the eluate was fractionated every 0.75 ml. When the elution fraction was measured for its ability to inhibit dipeptidyl peptidase-IV, a strong inhibitory activity was observed in the fraction eluted at a retention time of 16.0 minutes. The 50% inhibitory concentration of enzyme activity in this fraction was 10-30 μg / ml.
Compound 1 having the above active peak was identified by a protein sequencer (PPSQ-23A) manufactured by Shimadzu Corporation. As a result, it was found to have a novel structure called SPAQ (SEQ ID NO: 1). These amino acid residues were L-type.
Furthermore, as shown in FIG. 1, as shown in FIG. 1, m / z = 147 by MS / MS analysis using ThermoQuest Corporation mass spectrometer LTQ with a molecular weight of 401.2 and m / z = 402.2 (MH +) as a precursor ion. Product ions such as .2, 218.2, 256.1 were detected.
Thus, it was revealed that the structure of active peak compound 1 of the peptide having dipeptidyl peptidase-IV inhibitory ability was SPAQ. Also, the 50% inhibitory concentration in the synthetic peptide SPAQ obtained in Production Example 2 described later Was 16 μg / ml, consistent with the value of the purified fraction.

Further, by performing the same operation, from the above "casein enzyme degradation product 1", in addition to the tetrapeptide SPAQ (SEQ ID NO: 1), as a peptide having dipeptidyl peptidase-IV inhibitory activity, compounds 2 to 3 having active peaks were obtained. This was identified. As a result of this identification, it was confirmed that the tetrapeptide GPVR (SEQ ID NO: 2) and the pentapeptide HPPHPH (SEQ ID NO: 3) were contained in the “casein enzyme degradation product 1”. The amino acid residues of these compounds 2 to 3 were all L-type.
In addition, when the active peak compound 2 was identified, the molecular weight was 427.3, and m / z = 428.3 (MH +) by MS / MS analysis using a precursor ion, as shown in FIG. Product ions such as 175.2 and 254.2 were detected. As a result, this compound was found to have a novel structure called GPVR (SEQ ID NO: 2).
Moreover, when the active peak compound 3 was identified, its molecular weight was 623.3, and m / z = 624.3 (MH +) was analyzed by MS / MS analysis using a precursor ion, as shown in FIG. Product ions such as 235.2, 372.3, and 390.3 were detected. As a result, this compound was found to have a structure of HPPHPH (SEQ ID NO: 3).
Thus, it was revealed that the structures of active peak compounds 2 to 3 of the peptide having dipeptidyl peptidase-IV inhibitory ability are GPVR and HPPHPH.

<Enzymatic degradation of casein 2>
Commercially available casein (manufactured by New Zealand Daily Board) To 900 g of water, 900 g of water was added and well dispersed, and sodium hydroxide was added to adjust the pH of the solution to 7.0 to completely dissolve casein. The aqueous casein solution was sterilized by heating at 85 ° C. for 10 minutes, adjusted to 50 ° C., sodium hydroxide was added to adjust the pH to 9.0, 2 g of pancreatin (manufactured by Amano Enzyme), protease A 4 g (Amano Enzyme Co., Ltd.) was added to initiate the hydrolysis reaction. When the decomposition rate of casein reached 55.0%, the enzyme reaction was stopped by heating at 80 ° C. for 6 minutes to deactivate the enzyme, and then cooled to 10 ° C. This hydrolyzed solution was filtered through diatomaceous earth, concentrated and freeze-dried to obtain 79 g of a freeze-dried product (casein enzyme degradation product 2).
The obtained “casein enzymatic degradation product 2” was measured for dipeptidyl peptidase-IV inhibitory activity according to the above-mentioned <Peptide separation by HPLC> and was eluted at a retention time of 8.5 minutes for the first HPLC separation. Further, the fraction eluted at the retention time of 16.25 minutes of the second HPLC separation showed a strong dipeptidyl peptidase-IV inhibitory activity. The 50% inhibitory concentration of enzyme activity in this fraction was 11 μg / ml.
Further, the active peak compound 4 was obtained from the above-mentioned fraction in which the strong dipeptidyl peptidase-IV inhibitory activity was recognized. As a result, the molecular weight was found to be 314.2, m / z = 315.2 (MH +). As shown in FIG. 4, product ions such as m / z = 147.1, 169.1, 244.2 and the like were detected by MS / MS analysis using as a precursor ion. As a result, this compound 4 was found to have a structure of tripeptide APK (SEQ ID NO: 4). All amino acid residues of Compound 4 were L-type.
Thus, it was revealed that the structure of active peak compound 4 of the peptide having dipeptidyl peptidase-IV inhibitory ability is APK.

Production Example 2: Chemical synthesis of 3 to 5 peptides of SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 2), HPPH (SEQ ID NO: 3), APK (SEQ ID NO: 4) Peptide synthesizer (Model 433A, Applied Biosystems) ), Fmoc-Val (Peptide Research Laboratories)), Fmoc-Pro (Peptide Research Laboratories), Fmoc-Ala (Peptide Research Laboratories), Fmoc-Gln-Wang-PEG Resin Peptide SPAQ was synthesized by solid phase synthesis using (Watanabe Chemical Co., Ltd.) as a raw material.
The operation was performed according to the manual of Applied Biosystems and then deprotected. This peptide was purified by the above HPLC condition 1.
The obtained peptide SPAQ has a molecular weight (M) of 401.2 measured by mass spectrometry, and is similar to the spectrum in the purified fraction by MS / MS analysis using m / z = 402.2 (MH +) as a precursor ion. Spectrum was obtained (see FIG. 1).

Further, GPVR, HPPHPH, and APK were obtained by the solid phase synthesis method as described above, and spectra similar to the spectra in the respective purified fractions were obtained by MS / MS analysis (see FIGS. 2 to 4).
In addition, Val-Pro-Pro (VPP: SEQ ID NO: 5), Ile-Pro-Pro (IPP: SEQ ID NO: 6), and Leu-Tyr (LY: SEQ ID NO: 7) were chemically synthesized.

Test Example 1: Dipeptidyl peptidase-IV inhibitory activity confirmation test of each peptide The dipeptidyl peptidase-IV inhibitory activity confirmation test of each peptide obtained in Production Example 2 shown in Table 1 was conducted, and the results are shown in Table 1. .

Tetrapeptide SPAQ, tetrapeptide GPVR, pentapeptide HPPHP and tripeptide APK had dipeptidyl peptidase-IV inhibitory action. Furthermore, the enzymatic degradation product of casein including SPAQ (SEQ ID NO: 1), GPVR (SEQ ID NO: 2), HPPHH (SEQ ID NO: 3) and APK (SEQ ID NO: 4) is a material having a dipeptidyl peptidase-IV inhibitory action or the like It is considered that it can be used for food, medicine, etc. as food.
As a result of searching for commercially available casein degradation products containing these 3 to 5 peptides, SPAQ, GPVR and HPPHP were found in Morinaga Milk Peptide MKP (manufactured by Morinaga Milk Industry Co., Ltd.). Moreover, APK was recognized by CU5000 (made by Morinaga Milk Industry Co., Ltd.).
The 50% inhibitory concentration of Morinaga Milk Peptide MKP (manufactured by Morinaga Milk Industry) for dipeptidyl peptidase-IV inhibition was 356 μg / ml. SPAQ, GPVR and HPPHP are thought to contribute to the dipeptidyl peptidase-IV inhibitory action of Morinaga Milk Peptide MKP (manufactured by Morinaga Milk Industry).
The 50% inhibitory concentration of CU5000 (manufactured by Morinaga Milk Industry Co., Ltd.) for dipeptidyl peptidase-IV inhibition was 84 μg / ml. APK is considered to contribute to the dipeptidyl peptidase-IV inhibitory action of the casein degradation product of CU5000 (manufactured by Morinaga Milk Industry Co., Ltd.).

<Method for measuring DPP-4 inhibitory activity>
Measurement of dipeptidyl peptidase (DPP-4) inhibition was performed according to the method of Kato et al. “Kato, T. et al. Biochem. Med. 19, p351, 1978”.
Specifically, the enzyme reaction was performed using Recombinant Human DPPIV / CD26 (R & D Systems, Inc.) as the enzyme (DPP-4) and H-Gly-Pro-AMC (Biomol GmbH) as the substrate.
To each well of a 96-well microplate (nunc 137101), add water or an aqueous solution of each concentration of the test substance or HPLC fraction, and add 20 μl of Tris-HCl (0.25 M, pH 8.0). The total volume was adjusted to 80 μl. After stirring, the plate was warmed in a 37 ° C. incubator for about 10 minutes, 10 μl of DPP-4 solution and 10 μl of substrate solution were added (total volume 100 μl), and the reaction was started by stirring. A well to which water was added instead of the enzyme was used as a control.
The enzyme reaction was measured using a microplate reader (SH-9000, Corona Electric Co., Ltd.) under the condition where the internal temperature was maintained at 37 ° C. (5 minute interval, ex360 nm / em460 nm).
Vildagliptin (JS Research Chemicals Trading) was used as a positive target whose inhibitory activity was calculated from the fluorescence intensity value during a period in which the increase in fluorescence intensity over time was linear (within 30 minutes from the start of the reaction).

Inhibition rate (%) = 100% − [(Yb) / (Xa)] × 100%
X: water + enzyme + substrate Y: test substance + enzyme + substrate a: water + substrate b: test substance + substrate <How to determine the concentration of IC ₅₀ >
The concentration of the test substance was diluted stepwise (10 to 2000 μg / ml) and the inhibition rate was determined. Based on the results, a relational expression between the logarithm (log ₁₀ ) of the addition concentration of the test substance and the inhibition rate was obtained. From this relational expression, IC ₅₀ was calculated by calculating back the concentration at which the inhibition rate of the enzyme was 50%.

Since 3-5 peptides (specifically SPAQ, GPVR, HPPHPH, APK) of the present disclosure can be isolated from casein hydrolyzate, they are highly safe and can be used for pharmaceuticals, foods, skins. It can be used in a wide range of fields such as external preparations and functional foods.

Further, the present technology can also take the following configurations.
[1] A dipeptidyl peptidase-IV inhibitor, comprising a peptide having any one of the following amino acid sequences (a) to (d) as an active ingredient, and an increase in blood glucose level An inhibitor, an antihyperglycemic agent, an antidiabetic agent, a vascular endothelial disorder inhibitor or a blood vessel improving agent.
(A) Ser-Pro-Ala-Gln (SPAQ: SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (GPVR: SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (HPPHPH: SEQ ID NO: 3)
(D) Ala-Pro-Lys (APK: SEQ ID NO: 4)

[2] One or two selected from SPAQ, GPVR, HPPH and APK for the production of a dipeptidyl peptidase-IV inhibitor, a blood glucose level increase inhibitor, an antidiabetic agent, a vascular endothelial disorder inhibitor or a vascular amelioration agent Use of more than one species of peptide.
[3] Selected from SPAQ, GPVR, HPPHPH, and APK for the production of dipeptidyl peptidase-IV foods for inhibiting IV, blood sugar level rising foods, anti-diabetic foods, vascular endothelial disorder inhibiting foods, or blood vessel improving foods Use of one or more peptides.

[4] A dipeptidyl peptidase-IV inhibitor, a blood glucose level increase inhibitor, an antidiabetic agent, a vascular endothelial disorder inhibitor, or a blood vessel ameliorating agent of one or more peptides selected from SPAQ, GPVR, HPPHPH and APK Use for.
[5] Food for inhibiting dipeptidyl peptidase-IV, food for lowering blood sugar, food for anti-diabetic, food for suppressing vascular endothelial injury or blood vessel of one or more peptides selected from SPAQ, GPVR, HPPHPH and APK Use in food for improvement.
[6] SPAQ, GPVR, HPPHPH for prevention, amelioration, or treatment of diseases caused by dipeptidyl peptidase-IV, diseases caused by hyperglycemia, diabetes, vascular endothelial disorders or diseases caused by vascular disorders One or more peptides selected from APK.
[7] One or more peptides selected from SPAQ, GPVR, HPPHP and APK are used as active ingredients, diseases caused by dipeptidyl peptidase-IV, diseases caused by hyperglycemia, diabetes, vascular endothelial disorder or A method for preventing, improving or treating a disease caused by a vascular disorder.
[8] SPAQ, GPVR, for use in the prevention, amelioration or treatment of diseases caused by dipeptidyl peptidase-IV, diseases caused by hyperglycemia, diabetes or diseases caused by vascular endothelial or vascular disorders, One or more peptides selected from HPPHP and APK.
[9] SPAQ, GPVR, HPPHH, and the like for prevention, amelioration, or treatment of diseases caused by dipeptidyl peptidase-IV, diseases caused by hyperglycemia, diabetes, or diseases caused by vascular endothelial disorder or vascular injury Use of one or more peptides selected from APK.
Preferably, the disease and / or symptom caused by the dipeptidyl peptidase-IV is selected from hyperglycemia, diabetes, diabetic complications, vascular endothelial disorder and vascular disorder.

[10] A peptide comprising the amino acid sequence of any one of the following (a) to (c).
(A) Ser-Pro-Ala-Gln (SPAQ: SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (GPVR: SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (HPPHPH: SEQ ID NO: 3)
[11] One or more peptides selected from SPAQ, GPVR, HPPHH and APK obtained by hydrolyzing casein and a method for producing the same.
[12] One or more peptides selected from SPAQ, GPVR, HPPHPH and APK obtained by separating and purifying casein in the following steps and a method for producing the same.
(A) Performing with a hydrolase (preferably endopeptidase). It is preferably carried out under conditions of 10 to 85 ° C. and 0.1 to 48 hours.
(B) Separating and purifying the hydrolyzate by chromatography. Preferably, one or two kinds selected from ion exchange chromatography, reverse phase chromatography, partition chromatography and the like are used.

Claims

A dipeptidyl peptidase-IV inhibitor comprising as an active ingredient one or more peptides selected from peptides consisting of any of the following amino acid sequences (a) to (d):
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
A blood glucose level increase inhibitor comprising as an active ingredient one or more peptides selected from peptides consisting of the amino acid sequences of any of the following (a) to (d):
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
A vascular endothelial disorder inhibitor comprising, as an active ingredient, one or more peptides selected from peptides consisting of any of the following amino acid sequences (a) to (d):
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
A peptide comprising the amino acid sequence of any one of (a) to (c) below.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
A peptide comprising any one of the following amino acid sequences (a) to (d) for producing a dipeptidyl peptidase-IV inhibitor, a hypoglycemic agent, an antidiabetic agent, a vascular endothelial disorder inhibitor or a vascular ameliorating agent Use of one or more selected peptides.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
Any of the following amino acids (a) to (d) for the production of a dipeptidyl peptidase-IV-inhibiting food, a blood sugar-lowering food, an anti-diabetic food, a vascular endothelial disorder-suppressing food, or a vascular ameliorating food Use of one or more peptides selected from peptides consisting of sequences.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
A dipeptidyl peptidase-IV inhibitor, a hypoglycemic agent, an antidiabetic agent, a vascular endothelial disorder of one or more peptides selected from peptides consisting of any of the following amino acid sequences (a) to (d) Use as an inhibitor or vascular remedy.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
A dipeptidyl peptidase-IV-inhibiting food, a blood glucose-lowering food, an anti-diabetic food, of one or more peptides selected from peptides consisting of any of the following amino acid sequences of (a) to (d): Use in foods for suppressing vascular endothelial injury or foods for improving blood vessels.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
The following (a) to (a) for use in the prevention, amelioration or treatment of a disease caused by dipeptidyl peptidase-IV, a disease caused by a hyperglycemic condition, diabetes or a disease caused by vascular endothelial disorder or vascular disorder 1 type, or 2 or more types of peptides chosen from the peptide which consists of any amino acid sequence of d).
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
The following (a) to (d) for the prevention, amelioration or treatment of diseases caused by dipeptidyl peptidase-IV, diseases caused by hyperglycemia, diabetes or diseases caused by vascular endothelial or vascular disorders Use of 1 type or 2 or more types of peptides chosen from the peptide which consists of one of these amino acid sequences.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)
One or more peptides selected from peptides consisting of any of the following amino acid sequences (a) to (d) as active ingredients, diseases caused by dipeptidyl peptidase-IV and hyperglycemic conditions A method for preventing, ameliorating, or treating a disease, diabetes, or a disease caused by vascular endothelial disorder or vascular disorder.
(A) Ser-Pro-Ala-Gln (SEQ ID NO: 1)
(B) Gly-Pro-Val-Arg (SEQ ID NO: 2)
(C) His-Pro-His-Pro-His (SEQ ID NO: 3)
(D) Ala-Pro-Lys (SEQ ID NO: 4)