CN112646022B

CN112646022B - Bioactive peptide PKCPKCDKEVYFAERV, and preparation method and application thereof

Info

Publication number: CN112646022B
Application number: CN202011481235.9A
Authority: CN
Inventors: 张少辉; 洪志骏; 栾媛媛; 李锡安; 占文静; 陈承余; 肖珊珊; 石毅; 梁世排; 梁世赞
Original assignee: Zhejiang Huitai Life Health Technology Co ltd; Panda Dairy Group Co ltd
Current assignee: Zhejiang Huitai Life Health Technology Co ltd; Panda Dairy Group Co ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-03-29
Anticipated expiration: 2040-12-16
Also published as: CN112646022A

Abstract

The invention relates to the field of protein, and in particular relates to a bioactive peptide PKCPKCDKEVYFAERV, a preparation method and application thereof, wherein the amino acid sequence of the bioactive peptide PKCPKCDKEVYFAERV is Pro-Lys-Cys-Pro-Lys-Cys-Asp-Lys-Glu-Val-Tyr-Phe-Ala-Glu-Arg-Val. In vitro immune function regulating experiments prove that the bioactive peptide PKCPKCDKEVYFAERV has better immune regulating function. The bioactive peptide PKCPKCDKEVYFAERV can promote the phagocytosis of neutral red by macrophages, effectively inhibit inflammation, regulate immune response, improve the capability of an organism for resisting infection of external pathogens, reduce the morbidity of the organism, improve the quality of life and have very important significance for developing foods, health-care products and medicines with immune regulation functions.

Description

Bioactive peptide PKCPKCDKEVYFAERV, and preparation method and application thereof

Technical Field

The invention relates to the field of protein, in particular to a bioactive peptide PKCPKCDKEVYFAERV, and a preparation method and application thereof.

Background

In recent years, bioactive peptides have become a word of great energy in the ear. Because of its many potential biological functions, it attracts more and more attention and becomes one of the hot spots of scientific research. The beneficial effects of many bioactive peptides, such as anti-cancer, blood pressure lowering, antibacterial, cholesterol lowering, anti-diabetic, etc., are well documented. Currently more than 3000 different bioactive peptides have been reported in the most authoritative bioactive peptide database BIOPEP-UMW.

Currently, the research on bioactive peptides is mostly focused on food-derived bioactive peptides, and the research and report on non-food-derived bioactive peptides are less. And it has been confirmed from the research results that non-food-derived bioactive peptides have higher affinity and can effectively exert their bioactive functions, compared to food-derived bioactive peptides.

Immunomodulatory peptides are a class of bioactive peptides that were first obtained from milk following opioid peptide discovery and demonstrated their physiological activity. Jolles et al found in 1981 for the first time that a hexapeptide with an amino acid sequence Val-Glu-Pro-Ile-Pro-Tyr can be obtained by hydrolyzing human milk protein with trypsin, and in vitro experiments prove that the hexapeptide can enhance the phagocytosis of mouse abdominal cavity macrophages to sheep erythrocytes. Migliore-Samour et al found that the casein-derived hexapeptide Thr-Thr-Met-Pro-Leu-Trp was able to stimulate phagocytosis of murine peritoneal macrophages by sheep red blood cells and to enhance resistance to Klebsiella pneumoniae, with anti-inflammatory properties. Lemna hexandra et al, fed rats with synthetic mouse bone marrow macrophages and a source peptide (PGPIPN), found that phagocytosis of rat peritoneal macrophages and red blood cell-related anti-inflammatory function were significantly enhanced. Bowdis et al, in studying the immune function of the 13 amino acid peptide indolicidin derived from bovine neutrophils, found that the polypeptide indolicidin inhibits LPS-induced TNF- α production in a macrophage-like cell line.

Research shows that the immunoregulation peptide can enhance the immunity of the organism, stimulate the proliferation of lymphocytes of the organism, enhance the phagocytic function of macrophages, promote the release of cytokines, promote the increase of the induced amount of nitric oxide of the macrophages, improve the capability of the organism for resisting the infection of external pathogens, reduce the morbidity of the organism and cannot cause the immune rejection reaction of the organism.

The immunomodulatory peptides presently disclosed are generally small peptides with specific immunomodulatory activity, isolated enzymatically from proteins or synthesized chemically. However, when these small peptides are not enzymatically separated from the protein, the protein itself often has no immunomodulatory activity. It is one of the directions in the field of protein research to find bioactive peptides with specific functions from a wide variety of proteins whose amino acid sequences are known, and to study the functions of these polypeptides.

The amino acid sequence of Cysteine-rich protein 1 is shown in SEQ ID NO: 2, respectively. At present, there is no research on the related functions of polypeptide fragments of Cysteine-rich protein 1 protein in the prior art.

Disclosure of Invention

The invention aims to provide a bioactive peptide PKCPKCDKEVYFAERV, and a preparation method and application thereof.

The purpose of the invention can be realized by the following technical scheme:

in a first aspect of the invention, a bioactive peptide PKCPKCDKEVYFAERV is provided, having an amino acid sequence of Pro-Lys-Cys-Pro-Lys-Cys-Asp-Lys-Glu-Val-Tyr-Phe-Ala-Glu-Arg-Val as shown in SEQ ID NO: 1 is shown.

Preferably, the bioactive peptide is mouse spleen derived lymphocyte peptide. Specifically, the protein is derived from Cysteine-rich protein 1, and is the amino acid residue at the 2 nd to 17 th positions of the Cysteine-rich protein 1. The amino acid sequence of Cysteine-rich protein 1 is shown as SEQ ID NO: 2, respectively.

The amino acid sequence and the corresponding nucleotide sequence of the Cysteine-rich protein 1 protein are the prior art, and the nucleotide fragment for coding the 2 nd to 17 th amino acid residues of the Cysteine-rich protein 1 protein can code mature bioactive peptide PKCPKCDKEVYFAERV.

Preferably, the bioactive peptide has anti-inflammatory and immunoregulatory functions.

The present invention also provides polynucleotides encoding the biologically active peptide PKCPKCDKEVYFAERV.

In the second aspect of the present invention, there is provided a method for preparing the bioactive peptide PKCPKCDKEVYFAERV, which can be artificially synthesized by genetic engineering methods, can be directly obtained from cells by separation and purification methods, and can be directly prepared by chemical synthesis.

The artificial synthesis of the bioactive peptide PKCPKCDKEVYFAERV by genetic engineering is a technical solution that can be realized by those skilled in the art, and for example, the synthesis of the sequence of the polypeptide can be controlled by a suitable DNA template based on DNA recombination technology.

The method for directly obtaining the cell by the separation and purification method can be as follows: based on the amino acid sequence of the given bioactive peptide PKCPKCDKEVYFAERV, the bioactive peptide PKCPKCDKEVYFAERV is obtained from mouse spleen-derived lymphocytes by a conventional enzymolysis and purification method in biological technology.

In a third aspect of the present invention, there is provided a use of the bioactive peptide PKCPKCDKEVYFAERV in the preparation of a medicament or a cosmetic having an anti-inflammatory function.

Further, the use of the bioactive peptide PKCPKCDKEVYFAERV in the manufacture of a medicament for inhibiting inflammation due to oxidation.

In a fourth aspect of the present invention, there is provided a use of the bioactive peptide PKCPKCDKEVYFAERV in the preparation of food or medicine with immunoregulatory function.

Further, the use of the bioactive peptide PKCPKCDKEVYFAERV in the preparation of a food or a medicament for promoting the ability of macrophages to phagocytose neutral red.

In a fifth aspect of the invention, there is provided an anti-inflammatory product comprising said biologically active peptide PKCPKCDKEVYFAERV or a derivative of said biologically active peptide PKCPKCDKEVYFAERV; the anti-inflammatory product comprises anti-inflammatory food, anti-inflammatory health product, anti-inflammatory drug or anti-inflammatory cosmetic.

In a sixth aspect of the present invention, there is provided a product having an immunoregulatory function, comprising said biologically active peptide PKCPKCDKEVYFAERV or a derivative of said biologically active peptide PKCPKCDKEVYFAERV; the product with immunoregulatory function comprises food with immunoregulatory function or medicine with immunoregulatory function.

Derivatives of the bioactive peptides PKCPKCDKEVYFAERV are meant to have the same activity or better activity than the bioactive peptides PKCPKCDKEVYFAERV.

The derivative of the bioactive peptide PKCPKCDKEVYFAERV refers to a bioactive peptide derivative obtained by modifying the amino acid side chain group, amino terminal or carboxyl terminal of the bioactive peptide PKCPKCDKEVYFAERV by hydroxylation, carboxylation, carbonylation, methylation, acetylation, phosphorylation, esterification or glycosylation.

The bioactive peptide PKCPKCDKEVYFAERV has the beneficial effects that: the bioactive peptide PKCPKCDKEVYFAERV has good anti-inflammatory activity; the bioactive peptide PKCPKCDKEVYFAERV can promote the phagocytosis of neutral red by macrophages, effectively inhibit inflammation, regulate immune response, improve the capability of an organism for resisting infection of external pathogens, reduce the morbidity of the organism, improve the quality of life and have very important significance for developing foods, health-care products and medicines with immune regulation functions.

Drawings

FIG. 1: a primary mass spectrum of a fragment with a mass to charge ratio of 676.0016 (m/z = 676.0016);

FIG. 2: a secondary mass spectrum of a segment with the mass-to-charge ratio of 676.0016 and the breaking conditions of the bioactive peptides az and by;

Detailed Description

Before the present embodiments are further described, it is to be understood that the scope of the invention is not limited to the particular embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition to the specific methods, devices, and materials used in the examples, any methods, devices, and materials similar or equivalent to those described in the examples may be used in the practice of the invention in addition to the specific methods, devices, and materials used in the examples, in keeping with the knowledge of one skilled in the art and with the description of the invention.

Unless otherwise indicated, the experimental methods, detection methods, and preparation methods disclosed herein all employ techniques conventional in the art of molecular biology, biochemistry, chromatin structure and analysis, analytical chemistry, cell culture, recombinant DNA technology, and related arts. These techniques are well described in the literature, and may be found in particular in the study of the MOLECULAR CLONING, Sambrook et al: a LABORATORY MANUAL, Second edition, Cold Spring Harbor LABORATORY Press, 1989 and Third edition, 2001; ausubel et al, Current PROTOCOLS IN MOLECULAR BIOLOGY, John Wiley & Sons, New York, 1987 and periodic updates; the series METHODS IN ENZYMOLOGY, Academic Press, San Diego; wolffe, CHROMATIN STRUCTURE AND FUNCTION, Third edition, Academic Press, San Diego, 1998; (iii) METHODS IN ENZYMOLOGY, Vol.304, Chromatin (P.M.Wassarman and A.P.Wolffe, eds.), Academic Press, San Diego, 1999; and METHODS IN MOLECULAR BIOLOGY, Vol.119, chromatography Protocols (P.B.Becker, ed.) Humana Press, Totowa, 1999, etc.

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1 Artificial Synthesis of active peptide PKCPKCDKEVYFAERV

Synthesis of bioactive peptide

Biologically active peptide PKCPKCDKEVYFAERV was synthesized.

Confirmation of biologically active peptides

1) UPLC analysis

UPLC conditions were as follows:

the instrument comprises the following steps: waters ACQUITY UPLC ultra-high performance liquid phase, electrospray, quadrupole and time-of-flight mass spectrometer

Specification of chromatographic column: BEH C18 chromatographic column

Flow rate: 0.4mL/min

Temperature: 50 deg.C

Ultraviolet detection wavelength: 210nm

Sample introduction amount: 2 μ L

Gradient conditions: solution A: water containing 0.1% formic acid (v/v), liquid B: acetonitrile containing 0.1% formic acid (v/v)

Time(min) %A %B

0 95.0 5.0

1.50 80.0 20.0

3.50 60.0 40.0

5.00 40.0 60.0

7.00 15.0 85.0

8.00 0.0 100.0

11.00 0.0 100.0

11.50 95.0 5.0

13.00 95.0 5.0

2) Mass spectrometric analysis

The mass spectrometry conditions were as follows:

ion mode: ES +

Mass range (m/z): 100. 1000A

Capillary voltage (Capillary) (kV): 3.0

Sampling cone (V): 35.0

Ion source temperature (. degree. C.): 115

Desolvation temperature (. degree. C.): 350

Desolventizing gas stream (L/hr): 700.0

Collision energy (eV): 4.0

Scan time (sec): 0.25

Inner scan time (sec): 0.02

According to the above analysis method, the bioactive peptide PKCPKCDKEVYFAERV was subjected to chromatographic analysis and mass spectrometric analysis using ultra high performance liquid, electrospray, quadrupole, time-of-flight mass spectrometry. The primary mass spectrum of the bioactive peptide PKCPKCDKEVYFAERV is shown in figure 1, the secondary mass spectrum of the extracted peak and the az and by breaking conditions are shown in figure 2, the mass-to-charge ratio of the bioactive peptide of the peak is 676.0016, and the retention time is 17.33 min.

3) Results

As can be seen from fig. 2, the fragment sequence of mass-to-charge ratio 676.0016 obtained from az and by cleavage was Pro, Lys, Cys, Asp, Lys, Glu, Val, Tyr, Phe, Ala, Glu, Arg, Val (PKCPKCDKEVYFAERV) and was represented by SEQ ID NO: 1. the fragment corresponds to the 2 nd to 17 th residue sequences of Cysteine-rich protein 1 protein, the GenBank number of the amino acid sequence of the Cysteine-rich protein 1 protein is BAB25566.1, and the sequence is shown in SEQ ID NO: 2.

example 2 immunological Activity assay of bioactive peptides

First, experiment of macrophage phagocytosis neutral red promoting ability of biological active peptide PKCPKCDKEVYFAERV

1. Experimental reagents and instruments:

reagent: experimental animals balb/c mice (male 6-8 weeks old) were collected at the animal Experimental center of the college of agriculture and biology of Shanghai university of transportation; the mouse spleen lymphocyte-derived bioactive peptide PKCPKCDKEVYFAERV obtained in example 1; LPS, purchased from Sigma; neutral red staining solution, produced by Biyuntian biotechnological research institute.

The instrument equipment comprises: LRH-250F Biochemical incubator Shanghai Hengshi Co., Ltd; GL-22M high speed refrigerated centrifuge Shanghai Luxiang apparatus centrifuge Instrument Co., Ltd; hera cell 150 CO₂Culture boxHeraeus corporation; dragon Wellscan MK3 microplate reader Labsystems.

2. The experimental method comprises the following steps:

the number of the added cells was 2X 10⁶100 mul/well of cell suspension per ml, adding 200 mul/well of RPMI1640 complete culture solution (10% FBS) containing active peptide PKCPKCDKEVYFAERV (1 mg/ml) after adherent purification as experimental group, adding 200 mul/well of RPMI1640 complete culture solution (10% FBS) containing no active peptide for culture as blank group; and LPS is added into the experimental group and the blank group when the culture time reaches 24h to reach the final concentration of 10 mug/ml; after further culturing for 48h, the cell culture solution was aspirated. After washing the bottom of the well with PBS, 80. mu.l/well of neutral red dye solution at 37 ℃ was added, and after 10 minutes the dye solution was aspirated and washed twice with PBS, 150. mu.l of cell lysate (glacial acetic acid: absolute ethanol =1:1, v/v) was added to each well. After overnight dissolution at 4 ℃ the absorbance value (OD 540) was determined at a wavelength of 540 nm.

3. Experimental results and analysis:

TABLE 2 determination of the ability of the bioactive peptide PKCPKCDKEVYFAERV to promote phagocytosis of neutral Red by macrophages

Experiment grouping	Absorbance value (OD 540)
		Blank group	0.1075±0.0284
Experimental group	0.1328±0.0239**

Note: significant difference compared to negative control (P < 0.05)

The difference in the negative control group was very significant (P <0.01)

The experimental results are shown in table 2, compared with the blank cell group, the macrophage phagocytosis ability of the inflammatory group added with 1mg/ml bioactive peptide PKCPKCDKEVYFAERV is obviously increased, and compared with the blank cell group, the macrophage phagocytosis ability of the inflammatory group added with the bioactive peptide PKCPKCDKEVYFAERV has a very significant difference (P is less than 0.01). The biological active peptide PKCPKCDKEVYFAERV is proved to have obvious promotion effect on the ability of phagocytizing neutral red by macrophages in vitro under the condition of inflammation.

Second, experiment of action of bioactive peptide PKCPKCDKEVYFAERV on immunocytokines in serum

1. Experimental reagents and instruments:

reagent: experimental animal ICR mouse (male 5 weeks old), experimental animal center in shanghai city; d-gal, national pharmaceutical group chemical reagents, Inc.; paraformaldehyde, chemical reagents of the national drug group, ltd; sodium chloride, national pharmaceutical group chemical reagents ltd; the mouse spleen lymphocyte-derived bioactive peptide PKCPKCDKEVYFAERV obtained in example 1; BCA protein kit, Nanjing Kaikyi Biotech Co., Ltd; ELISA cytokine Rapid kits (TNF-. alpha.and IL-6), Wuhan Dr bioengineering, Inc.

The instrument equipment comprises: model CM-230 Mohr super Water, Shanghai Mole scientific instruments, Inc.; millipore Milllex GP0.22 μm membrane filter, Millipore USA; GL-22M high-speed refrigerated centrifuge, Shanghai Luxiang apparatus centrifuge instruments Inc.

2. The experimental method comprises the following steps:

(1) model for animal aging

After one week of adaptive ICR mouse feeding, 4 groups of 6 mice were divided. Group 1 was a low dose intragastric group, mice were injected subcutaneously in the neck and back with D-gal at a dose of 500mg/kg daily and bioactives PKCPKCDKEVYFAERV at a dose of 1 mg/day; group 2 was a high dose intragastric group, mice were injected subcutaneously in the neck and back with D-gal at a dose of 500mg/kg per day, and 3 mg/mouse with bioactive peptide PKCPKCDKEVYFAERV administered intragastric at a daily dose; group 3 was blank, mice grew normally; group 4 was an animal model group, and mice were injected subcutaneously into the neck and back with D-gal at a dose of 500mg/kg daily, and gavage with 0.9% normal saline; the injection period of the D-gal and the gavage period of the bioactive peptide are both 42 days. The bedding is replaced every 3 days and the feed and distilled water supply is ensured. The weight of the mice was weighed once every five days, D-gal injection was prepared according to the weight of the mice, and the D-gal injection was filtered through a 0.22 μm syringe filter to ensure sterility.

(2) Obtaining animal viscera and serum

After the experiment period is finished, blood of the mouse is obtained by an eyeball-picking blood-taking method, the mouse is killed by breaking the neck after the blood is obtained, then the body of the mouse is placed on a low-temperature ice box, the blood of the mouse is stood for 1 hour at room temperature, and then is centrifuged for 15min at 3000g, and serum is separated. The serum was stored in a freezer at-80 ℃ for testing. All procedures in the procedure of treating the experimental animals followed the guidance comments on the animals being treated in good care published by the department of scientific technology in 2006. The spleen of the mouse is directly soaked in a prepared 4% paraformaldehyde solution to fix the shape. The paraformaldehyde powder is relatively insoluble, and a trace amount of sodium bicarbonate can be added to adjust the pH value to be alkaline so as to aid dissolution. The preparation of the paraformaldehyde solution needs to be completed in a fume hood.

(3) Sample detection

According to the instruction of the kit, firstly, a standard curve is drawn, standard powder is prepared into a solution of 1000pg/mL by using a standard diluent, and then the solution is continuously diluted into different concentrations of 500 pg/mL, 250 pg/mL, 125 pg/mL, 62.5 pg/mL, 31.3pg/mL, 15.6 pg/mL and the like. Each concentration gradient solution was pipetted at 100. mu.L in an antibody-coated microplate. And (3) sucking 100 mu L of mouse serum sample, and adding the mouse serum sample into the same enzyme label plate (if the serum sample is insufficient, the mouse serum sample can be diluted properly and then needs to be converted proportionally when being detected and calculated). The plate was covered and incubated at 37 ℃ for 90 min. After the reaction is finished, carefully throwing off the liquid in the ELISA plate, placing the ELISA plate on absorbent paper, carefully beating the absorbent paper, and removing the redundant liquid. Adding preheated biotin anti-antibody working solution into each hole of the ELISA plate according to 100 mu L of each hole, and reacting for 60min at 37 ℃. After the reaction was completed, the reaction solution was washed 3 times with 0.01M PBS, 100. mu.L of PBS was added to each well, and the solution was removed after soaking for 1min, and the reaction was repeated 3 times. The preheated ABC working solution is added into each hole according to the volume of 0.1ml in turn, and the reaction is carried out for 30min at the temperature of 37 ℃. After the reaction, the reaction mixture was washed with 0.01M PBS for 5 times, and soaked for about 1min each time. Adding TMB color development solution which is balanced at 37 ℃ for 30min in turn according to 90 mu L per hole, and reacting for 8-12min at 37 ℃ in a dark place. TMB stop solution was added in an amount of 0.1ml per well in this order, and the color blue was immediately changed to yellow, and the OD value was measured at 450nm using a microplate reader. The standard protein of the cell factor is serially diluted in known concentration, an OD value is measured, a standard curve is drawn, and the content of the cell factor in the specimen can be calculated according to the standard curve.

3. Experimental results and analysis:

TABLE 6 cytokine profile in serum of groups of mice

	TNF-α(pg/mL)	IL-6 (pg/mL)
			Group 1	2.37±0.17**	75.37±14.34**
Group 2	2.53±0.63**	89.01±12.31**
			Group 3	2.26±0.27**	64.28±11.37**
Group 4	5.38±0.28	158.39±21.75

From Table 6, it can be found that the IL-6 and TNF-alpha contents in the mice of the model group in the experiment are 158.39 + -21.75 pg/mL and 5.38 + -0.28 pg/mL respectively, which show a significant increase (P <0.01) compared with the normal group, so that the mice of the model group are considered to have symptoms of aging inflammation at the cytokine level due to continuous injection of the aging-causing factor, and the IL-6 and TNF-alpha contents in the serum of the mice of the bioactive peptide gavage group are effectively controlled. According to the experimental result of the cell factors, the secretion levels of serum inflammatory cell factors IL-6 and TNF-alpha of the mice in the bioactive peptide gavage group are lower than those of the mice in the animal model group, and the oxidation damage of the mice caused by free radical attack and peroxidation product accumulation can be inhibited to a certain degree from the perspective of the oxidation damage; from the viewpoint of inflammation, the inflammation caused by oxidation of the mice is effectively inhibited; from the aging point of view, a series of senile diseases of mice caused by aging caused by long-term injection of D-gal are likely to be controlled. Therefore, PKCPKCDKEVYFAERV can be determined to effectively inhibit the inflammation caused by oxidation of mice, has a certain immunoregulation effect, and can be used for research and development of health care products.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Sequence listing

<110> panda milk group GmbH, Zhejiang ghui peptide Life health science & technology, Inc

<120> bioactive peptide PKCPKCDKEVYFAERV, and preparation method and application thereof

<160> 2

<170> SIPOSequenceListing 1.0

<210> 1

<211> 16

<212> PRT

<213> Artificial Sequence (Artificial Sequence)

<400> 1

Pro Lys Cys Pro Lys Cys Asp Lys Glu Val Tyr Phe Ala Glu Arg Val

1 5 10 15

<210> 2

<211> 77

<212> PRT

<213> Artificial Sequence (Artificial Sequence)

<400> 2

Met Pro Lys Cys Pro Lys Cys Asp Lys Glu Val Tyr Phe Ala Glu Arg

1 5 10 15

Val Thr Ser Leu Gly Lys Asp Trp His Arg Pro Cys Leu Lys Cys Glu

20 25 30

Lys Cys Gly Lys Thr Leu Thr Ser Gly Gly His Ala Glu His Glu Gly

35 40 45

Lys Pro Tyr Cys Asn His Pro Cys Tyr Ser Ala Met Phe Gly Pro Lys

50 55 60

Gly Phe Gly Arg Gly Gly Ala Glu Ser His Thr Phe Lys

65 70 75

Claims

1. A bioactive peptide PKCPKCDKEVYFAERV, characterized in that its amino acid sequences are Pro-Lys-Cys-Pro-Lys-Cys-Asp-Lys-Glu-Val-Tyr-Phe-Ala-Glu-Arg-Val, respectively.

2. A polynucleotide encoding the biologically active peptide PKCPKCDKEVYFAERV of claim 1.

3. The method of claim 1, wherein the bioactive peptide PKCPKCDKEVYFAERV is produced directly by chemical synthesis.