CN110950929A

CN110950929A - Polypeptides having thrombolytic activity

Info

Publication number: CN110950929A
Application number: CN201911369003.1A
Authority: CN
Inventors: 赵树民; 鲍勇刚; 石松传; 周方
Original assignee: Beijing Botai Jukang Biotechnology Co ltd
Current assignee: BEIJING PEPNOCH BIOTECH Corp.,Ltd.
Priority date: 2017-08-25
Filing date: 2017-08-25
Publication date: 2020-04-03
Anticipated expiration: 2037-08-25
Also published as: CN107586316B; CN107586316A; WO2019037482A1; CN110950929B

Abstract

The invention relates to a thrombolytic polypeptide, the amino acid sequence of which is Ile-Thr-Met-Ala-Ala-Gln, Ile-Thr-Met-Ala-Ile-Lys, Ile-Thr-Met-Ala-Asp-Ser, Glu-Asp-Ser-Arg-Gln-His, Glu-Asp-Ser-Arg-Ile-Thr, Glu-Asp-Ser-Arg-Tyr-Gln.

Description

Polypeptides having thrombolytic activity

The invention is a divisional application with the original application number of 201710740956.9, the original application date of 8 months and 25 days in 2017, and the original invention name is as follows: a polypeptide having thrombolytic activity.

Technical Field

The invention belongs to the field of biological medicine, and particularly relates to a polypeptide with thrombolytic activity.

Background

With the continuous improvement of living standard of human, the incidence of cardiovascular and cerebrovascular diseases such as coronary heart disease is increasing year by year, and the cardiovascular and cerebrovascular diseases are high in leadership in the cause of death of the diseases at present. Especially the incidence, disability rate and mortality of acute thrombotic diseases of cerebral thrombosis in middle-aged and elderly people, researches show that cardiovascular and cerebrovascular diseases such as cerebral thrombosis have the tendency of being young and serious threat to human health. Thrombosis is the main cause of cardiovascular and cerebrovascular diseases, and refers to the pathological process in which blood tangible components form emboli in blood vessels (mostly small blood vessels) under certain conditions, so that the blood vessels are partially or completely blocked and the blood supply of corresponding parts is obstructed.

Anticoagulant therapy and thrombolytic therapy are the most promising treatment methods for ischemic cardiovascular and cerebrovascular diseases at present. The traditional anticoagulant drugs mainly comprise two types, namely a retardant and heparin. The bioavailability, half-life and anticoagulation effect of heparin vary from person to person, and the risk of postoperative bleeding is high. The direct thrombin inhibitors commonly used at present in the retardant class are hirudin and recombinant hirudin, which have short half-lives of 0.5-1 hour and are mainly cleared by the kidney, so that they should be used with caution in patients with renal insufficiency. And the safe dosage range of these two drugs is narrow, which must be monitored in the laboratory. In addition, the thrombolytic drugs used clinically at present can cause fatal bleeding complications due to too large dosage, and the thrombolytic therapeutic effect is affected due to too small dosage, so that the application of the thrombolytic drugs is greatly limited, and therefore, new anticoagulant drugs need to be continuously developed.

Polypeptide drugs are being researched in the future, and mainly aim at the key protein on the in vivo pathway to be combined as a target so as to change the protein structure to treat diseases. The polypeptide array technology platform is an advanced platform for screening polypeptide drugs in high throughput. The polypeptide with thrombolytic activity prepared by the invention can be developed into a novel polypeptide drug with thrombolytic activity.

Disclosure of Invention

In view of the above-mentioned drawbacks of thrombolytic drugs, the present invention provides a group of polypeptides having thrombolytic activity.

According to one aspect of the present invention, there is provided a polypeptide having thrombolytic activity, which has an amino acid sequence of: Ile-Thr-Met-Ala-X1-X2, wherein X1 is selected from Ala, Ile, Asp; x2 is selected from Gln, Lys, Ser.

Preferably, the amino acid sequence of the polypeptide is as shown in SEQ ID NO: 1. SEQ ID NO: 2 or SEQ ID NO: 3, specifically: Ile-Thr-Met-Ala-Ala-Gln, Ile-Thr-Met-Ala-Ile-Lys or Ile-Thr-Met-Ala-Asp-Ser.

According to another aspect of the present invention, there is provided a polypeptide having thrombolytic activity, which has the amino acid sequence: Glu-Asp-Ser-Arg-X3-X4, wherein X3 is selected from Gln, Ile and Tyr; x4 is selected from His, Thr, Gln.

Preferably, the amino acid sequence of the polypeptide is as shown in SEQ ID NO: 4. SEQ ID NO: 5 or SEQ ID NO: and 6, specifically Glu-Asp-Ser-Arg-Gln-His, Glu-Asp-Ser-Arg-Ile-Thr or Glu-Asp-Ser-Arg-Tyr-Gln.

According to another aspect of the invention, the invention provides the use of said polypeptide for the manufacture of a medicament for the treatment and/or prevention of thrombosis.

According to another aspect of the present invention, there is provided a pharmaceutical composition comprising an active ingredient polypeptide and a pharmaceutically acceptable carrier.

The pharmaceutical composition includes, but is not limited to, injection, tablet, granule, capsule, oral liquid, pill, etc.

The pharmaceutically acceptable carrier includes diluent, excipient, filler, binder, wetting agent, disintegrating agent, absorption enhancer, surfactant, adsorption carrier, lubricant, etc. which are conventional in the pharmaceutical field, and flavoring agent, sweetener, etc. may be added if necessary.

The polypeptide of the present invention should be present in an "effective amount" as an active ingredient, which refers to a non-toxic, but sufficient amount of a drug or agent that provides the desired effect. In the pharmaceutical compositions of the present invention, an "effective amount" of an ingredient refers to an amount of that ingredient which, when used in combination with other ingredients, is effective in providing the desired effect. The "effective amount" will vary from subject to subject, depending on age and general condition of the individual, the particular active agent, and the like. Thus, an exact "effective amount" cannot always be intended, however, a suitable "effective amount" in any individual case can be determined by one of ordinary skill in the art using routine experimentation.

The polypeptide of the present invention can be prepared by methods known to those skilled in the art (e.g., solid phase synthesis), and can be isolated and purified by separation and purification methods known to those skilled in the art (e.g., high performance liquid chromatography).

The research result of the invention shows that the six polypeptides can obviously prolong the time of forming the carotid artery thrombus of the rat, obviously shorten the length of the thrombus in vitro of the rat and reduce the weight of the thrombus, and shows that the polypeptides have good thrombolytic activity and can be used for preparing the medicine for thrombolysis.

Drawings

FIG. 1 is an image of a screened polypeptide chip;

FIG. 2 is a curve of an in vitro thrombolytic assay of a polypeptide;

FIG. 3 is an HPLC chromatogram of the polypeptide Pep 1;

FIG. 4 is an HPLC chromatogram of the polypeptide Pep 2;

FIG. 5 is an HPLC chromatogram of the polypeptide Pep 3;

FIG. 6 is an HPLC chromatogram of the polypeptide Pep 4;

FIG. 7 is an HPLC chromatogram of the polypeptide Pep 5;

FIG. 8 is an HPLC chromatogram of the polypeptide Pep 6;

FIG. 9 is an MS map of polypeptide Pep 1;

FIG. 10 is an MS map of polypeptide Pep 2;

FIG. 11 is an MS map of polypeptide Pep 3;

FIG. 12 is an MS map of polypeptide Pep 4;

FIG. 13 is an MS map of polypeptide Pep 5;

FIG. 14 is an MS map of the polypeptide Pep 6.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes or modifications can be made by those skilled in the art after reading the description of the present invention, and such equivalents also fall within the scope of the invention.

EXAMPLE 1 screening of thrombolytic Polypeptides

1. Design screening database

1) Establishing a complete random primary hexapeptide database: X-X-X-X-X-X. Wherein X is a mixture of equimolar amounts of Fmoc-protected D-Gly, D-Ala, D-Val, D-Leu, D-Ile, D-Phe, D-Pro, D-Tyr, D-Ser, D-Thr, D-Trp, D-Met, D-Glu, D-Gln, D-Asp, D-Asn, D-Lys, D-Arg, and D-His.

2) Establishing a secondary hexapeptide random database: Ile-Thr-X-X-X and Glu-Asp-X-X-X-X. Wherein X is a mixture of equimolar amounts of Fmoc-protected D-Gly, D-Ala, D-Val, D-Leu, D-Ile, D-Phe, D-Pro, D-Tyr, D-Ser, D-Thr, D-Trp, D-Met, D-Glu, D-Gln, D-Asp, D-Asn, D-Lys, D-Arg, and D-His.

3) Establishing a tertiary hexapeptide random database: Ile-Thr-Met-Ala-X-X-X-X and

Glu-Asp-Ser-Arg-X-X-X-X. Wherein X is a mixture of equimolar amounts of Fmoc-protected D-Gly, D-Ala, D-Val, D-Leu, D-Ile, D-Phe, D-Pro, D-Tyr, D-Ser, D-Thr, D-Trp, D-Met, D-Glu, D-Gln, D-Asp, D-Asn, D-Lys, D-Arg, and D-His.

4) A polypeptide combination database established according to 1), 2), 3). A polypeptide array synthesizer is utilized, a specially processed cellulose membrane is used as a substrate, the substrate of a synthesized polypeptide chip is an FMOC-PEG-cellulose membrane, the size of the polypeptide chip is 15cm x 11cm, each chip bears 198 polypeptide points, and each group of chips needs two chips with 361 polypeptide points. The method is realized by adopting in-situ synthesis and layer-by-layer synthesis. The synthesis parameters are that the loading amount of amino acid on each peptide point is 0.6ul, the diameter of the peptide point is 0.5cm, the distance between the peptide points is 0.1cm, the concentration of the amino acid is 0.25M, and the synthesis of the peptide points is repeated once. The synthesized screening chip is shown in FIG. 1.

The polypeptide chip synthesized in the steps 1) to 4) is used for screening the polypeptide with thrombolytic activity.

2. Activity screening

1) Screening the thrombolytic activity of each polypeptide compound on the chip, wherein the test adopts a determination method that: the synthesized chip was treated with saturated ammonia gas at room temperature for 12 hours, then 361 polypeptides synthesized on the chip were placed at the bottom of a 1.5ml EP tube by punching with a punch, 30ul of 50mM Tris Buffer at pH 8.0 was added to each tube and dissolved at room temperature for 2 hours, and 20ul of the solution was used for screening for thrombolytic activity.

2) Preparation of 1M CaCl₂50mM Tris Buffer, 1mg/ml carboxypeptidase inhibiting peptide solution, positive control peptide CPI-2ki, Thrombobodulin, Trombin/CaCl₂mixture：860ul Tris buffer+100ulCaCl₂The solution +40uldd Tris dissolves Trombin, 130 mu g/ml tPA and 1mg/ml of each polypeptide with thrombolytic activity obtained by the screening are used for in vitro thrombolytic determination experiments.

3) The 96-well plate was used for the experiment and reagents were added from top to bottom as follows:

the Plasma corresponding to the plate wells (as above) was preheated for 5min at the first 37 ℃ and then the corresponding amount of tPA was added to the system. OD value at 420nm was measured immediately: the first 5min, 1 measurement per minute, and the subsequent initial measurement 1 measurement every 5min for 2 h. And drawing a line graph according to the measured data. Finding out the polypeptide group with obvious thrombolytic activity (corresponding to one polypeptide spot on the chip, possibly a mixture of multiple polypeptides)

The screened polypeptide group with obvious thrombolytic activity, Ile-Thr-Met-Ala-Ala-Gln, Ile-Thr-Met-Ala-Ile-Lys, Ile-Thr-Met-Ala-Asp-Ser, Glu-Asp-Ser-Arg-Gln-His, Glu-Asp-Ser-Arg-Thr, Glu-Asp-Ser-Arg-Tyr-Gln and the screening result thereof, and the data curve of the polypeptide with thrombolytic activity is shown in figure 2 (note: Pep1 represents Ile-Thr-Met-Ala-Gln; Pep2 represents Ile-Thr-Met-Ala-Ile-Lys; Pep3 represents Ile-Thr-Met-Ala-Asp-Ser; Pep4 represents Glu-Asp-Ser-Arg-Gln-His; Pep5 represents Glu-Asp-Ser-Gln-His; Pep5 represents Glu-Asp-Ser-Gln-His; Pep4 represents Glu-Ser Arg-Ile-Thr; pep6 represents Glu-Asp-Ser-Arg-Tyr-Gln).

EXAMPLE 2 Synthesis and purification of Polypeptides

Synthesis Polypeptides were synthesized from C-terminus to N-terminus using solid phase synthesis. The synthesis is carried out by adopting a chemical synthesizer (AMS586Multiple Peptide synthesizer, ABIMED, Germany), amino acid protected by Fmoc is used as raw material, Fmoc-Rink linker resin is used as adhesion matrix, HOBT is used as condensing agent, DIC is used as activating agent, and polypeptide is synthesized layer by layer.

In the synthesis process, 2% of DMF solution of acetic anhydride is used as a side chain blocking reagent; after the Fmoc removal reagent was 20% piperidine, the synthesis was completed by TFA cleavage and side chain group removal. The synthesized crude product was collected by centrifugation and subjected to R-HPLC (Waters 741) and C₁₈-column(Waters Delta-pak^TM40 x 100mm, 15um, 100 angstroms) to obtain polypeptide with purity of more than 98%, and freeze-drying into powder.

The polypeptides Ile-Thr-Met-Ala-Ala-Gln (Pep1), Ile-Thr-Met-Ala-Ile-Lys (Pep2), Ile-Thr-Met-Ala-Asp-Ser (Pep3), Glu-Asp-Ser-Arg-Gln-His (Pep4), Glu-Asp-Ser-Arg-Ile-Thr (Pep5), Glu-Asp-Ser-Arg-Tyr-Gln (Pep6) have HPLC maps shown in figures 3-8 (the chromatographic conditions are shown in Table 1) and MS maps shown in figures 9-14.

TABLE 1 polypeptide HPLC chromatographic conditions

HPLC (high performance liquid chromatography) maps show that each polypeptide consists of a characteristic peak;

the molecular weights of the MS-analyzed polypeptides are shown in table 2.

TABLE 2 molecular weight of the polypeptide

	Theoretical Mr/g/mol	MS measurement of Mr/g/mol
			Ile-Thr-Met-Ala-Ala-Gln	633.77	634.05
Ile-Thr-Met-Ala-Ile-Lys	675.89	676.10
			Ile-Thr-Met-Ala-Asp-Ser	636.72	637.00
Glu-Asp-Ser-Arg-Gln-His	770.76	770.90
			Glu-Asp-Ser-Arg-Ile-Thr	719.76	720.00
Glu-Asp-Ser-Arg-Tyr-Gln	783.76	783.90

EXAMPLE 3 animal experiments on thrombolytic Activity of Polypeptides

1 in vivo thrombolysis test

The experimental method comprises the following steps: 200 Wistar rats are selected and randomly divided into 20 groups, each group comprises 10 rats, namely a blank control group, a positive control group, a low-dosage administration group, a medium-dosage administration group and a high-dosage administration group (experimental polypeptide samples are respectively 0.25 mg/kg, 0.5 mg/kg and 1.0mg/kg), the positive drug group is administered with urokinase 3000U/kg, and the control group is administered with physiological saline with the same volume. 45 minutes after intravenous administration of each group, 3% sodium pentobarbital (1ml/kg) was intraperitoneally injected for anesthesia, the carotid artery of the rat was injured by electrical stimulation to form a thrombus, and the thrombus formation time was observed with a thrombometer. The results are shown in Table 3.

TABLE 3 in vivo thrombolysis test results

^※The experimental group and the control group have statistical difference with P less than 0.05

The experimental results show that the administration of low, medium and high dose groups (the experimental polypeptide samples are 0.25, 0.5 and 1.0mg/kg respectively) can obviously prolong the time of carotid artery thrombosis of rats, and the effect of inhibiting thrombosis of the high dose group is stronger than that of the positive control drug urokinase. The experimental polypeptide sample is proved to have obvious inhibition effect on the electrical stimulation of the carotid thrombosis of the rat.

2 in vitro thrombolysis test

The experimental method comprises the following steps: 200 Wistar rats are selected and randomly divided into 20 groups, each group comprises 10 rats, namely a blank control group, a positive control group, a low-dosage administration group, a medium-dosage administration group and a high-dosage administration group (experimental polypeptide samples are respectively 0.25 mg/kg, 0.5 mg/kg and 1.0mg/kg), the positive drug group is administered with urokinase 3000U/kg, and the control group is administered with physiological saline with the same volume. After intravenous administration for 10 minutes, 3% sodium pentobarbital (1ml/kg) is injected into the abdominal cavity for anesthesia, the abdominal wall is cut along the abdominal midline, about 1.8ml of blood is taken from the abdominal aorta, the blood is injected into a silicified plastic tube, the two ends of the plastic tube are tightly butted and placed into an external thrombosis instrument, the temperature is kept constant at 37 ℃ for 15 minutes, the thrombus in the plastic tube is taken out and placed on filter paper, the surface blood stain is completely absorbed, the length, the wet weight and the dry weight of the thrombus are measured, and the record is recorded. The results are shown in Table 4.

TABLE 4 in vitro thrombolysis test results

^※The representative and blank controls were compared to P < 0.05,^※※represents that P is less than 0.01,^※※※represents P < 0.001

The experimental results show that the length of the thrombus in vitro of the rat can be obviously shortened by the polypeptide of the low, medium and high dose groups (the experimental polypeptide samples are respectively 0.25, 0.5 and 1.0mg/kg), and the weight of the thrombus can be reduced, wherein the action of the high dose group (the polypeptide sample amount is 1.0mg/kg) is better than that of the positive control (urokinase 3000U/kg).

Example 5

Taking 10g of any one polypeptide of Pep1-Pep6, adding appropriate adjuvants of injection (including lyophilized powder for injection and sterile packaged dry powder for injection), and making into thrombolytic injection by injection (including lyophilized powder for injection and sterile packaged dry powder for injection).

Example 6

Taking 10g of any one polypeptide of Pep1-Pep6, adding appropriate adjuvants into tablet (including sustained release tablet, matrix tablet, coated tablet, dispersible tablet, etc.), and making into thrombolytic tablet by tablet process (including sustained release tablet, matrix tablet, coated tablet, dispersible tablet, etc.).

Example 7

Adding appropriate adjuvant into 10g of any one polypeptide of Pep1-Pep6, and making into thrombolytic capsule by capsule process.

Example 8

Taking 10g of any one polypeptide of Pep1-Pep6, adding appropriate adjuvants of emulsion (including microemulsion, nanoemulsion, etc.), and preparing into thrombolytic emulsion by emulsion (including microemulsion, nanoemulsion, etc.) process.

Example 9

Taking 10g of any one polypeptide of Pep1-Pep6, adding appropriate adjuvants of the granule, and preparing into thrombolytic granule according to the granule process.

Example 10

10g of any polypeptide of Pep1-Pep6 is taken, added with proper auxiliary materials of the sustained-release controlled-release agent, and prepared into the thrombolytic sustained-release controlled-release agent according to the sustained-release controlled-release agent process.

Example 11

Taking 10g of any one polypeptide of Pep1-Pep6, adding proper auxiliary materials of the oral liquid, and preparing the thrombolytic oral liquid according to the oral liquid process.

Example 12

Adding appropriate adjuvants into 10g of any one polypeptide of Pep1-Pep6, and making into thrombolytic liposome by liposome process.

Sequence listing

<110> Beijing Bo peptide Polykang Biotech Ltd

<120> Polypeptides having thrombolytic Activity

<160>6

<170>PatentIn Version 3.3

<210>1

<211>6

<212>PRT

<213> Artificial sequence

<400>1

Ile Thr Met Ala Ala Gln 6

<210>2

<211>6

<212>PRT

<213> Artificial sequence

<400>2

Ile Thr Met Ala Ile Lys 6

<210>3

<211>6

<212>PRT

<213> Artificial sequence

<400>3

Ile Thr Met Ala Asp Ser 6

<210>4

<211>6

<212>PRT

<213> Artificial sequence

<400>4

Glu Asp Ser Arg Gln His 6

<210>5

<211>6

<212>PRT

<213> Artificial sequence

<400>5

Glu Asp Ser Arg Ile Thr 6

<210>6

<211>6

<212>PRT

<213> Artificial sequence

<400>6

Glu Asp Ser Arg Tyr Gln 6

Claims

1. A thrombolytic polypeptide, wherein the amino acid sequence of said polypeptide is:

Ile-Thr-Met-Ala-X1-X2, wherein X1 is selected from Ala, Ile, Asp; x2 is selected from Gln, Lys, Ser.

2. The polypeptide of claim 1, wherein the amino acid sequence of said polypeptide is as set forth in SEQ ID NO: 1. SEQ ID NO: 2 or SEQ ID NO: 3, respectively.

3. Use of a polypeptide according to claim 1 or 2 for the preparation of a medicament for the treatment and/or prevention of thrombosis.

4. A pharmaceutical composition comprising the polypeptide of claim 1 or 2 and a pharmaceutically acceptable carrier.

5. The pharmaceutical composition of claim 4, wherein the pharmaceutical composition comprises an injection, a tablet, a granule, a capsule, an oral liquid, or a pill.

6. A thrombolytic polypeptide, wherein the amino acid sequence of said polypeptide is:

Glu-Asp-Ser-Arg-X3-X4, wherein X3 is selected from Gln, Ile and Tyr; x4 is selected from His, Thr, Gln.

7. The polypeptide of claim 6, wherein the amino acid sequence of said polypeptide is as set forth in SEQ ID NO: 4. SEQ ID NO: 5 or SEQ ID NO: and 6.

8. Use of a polypeptide according to claim 6 or 7 for the preparation of a medicament for the treatment and/or prevention of thrombosis.

9. A pharmaceutical composition comprising the polypeptide of claim 6 or 7 and a pharmaceutically acceptable carrier.

10. The pharmaceutical composition of claim 9, wherein the pharmaceutical composition comprises an injection, a tablet, a granule, a capsule, an oral liquid, or a pill.