CN112724224A

CN112724224A - Keratin BD-15, preparation method, pharmaceutical composition and application thereof

Info

Publication number: CN112724224A
Application number: CN201911028705.3A
Authority: CN
Inventors: 庾石山; 王晓良; 李勇; 屈晶; 蔡杰; 徐少峰; 刘云宝; 张咪
Original assignee: Institute of Materia Medica of CAMS
Current assignee: Institute of Materia Medica of CAMS
Priority date: 2019-10-28
Filing date: 2019-10-28
Publication date: 2021-04-30
Anticipated expiration: 2039-10-28
Also published as: WO2021083205A1; CN112724224B

Abstract

The invention relates to a keratin BD-15, a nucleic acid molecule for coding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the expression vector or integrating the nucleic acid molecule with a genome, a preparation method of the keratin BD-15, a pharmaceutical composition containing the keratin BD-15, and application of the keratin BD-15, the nucleic acid molecule, the expression vector, the host cell or the pharmaceutical composition in preparing medicaments for relieving fever, easing pain, relieving cough, eliminating phlegm, resisting convulsion, resisting epilepsy, reducing blood pressure, resisting inflammation and resisting viruses.

Description

Keratin BD-15, preparation method, pharmaceutical composition and application thereof

Technical Field

The invention relates to a keratin BD-15, a nucleic acid molecule for coding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the expression vector or integrating the nucleic acid molecule with genome, a preparation method of the keratin BD-15, a pharmaceutical composition containing the keratin, and application of the keratin and the pharmaceutical composition in preparing medicines for relieving fever, easing pain, relieving cough, eliminating phlegm, resisting convulsion, resisting epilepsy, reducing blood pressure, resisting inflammation and resisting viruses.

Background

Keratin is a kind of protein, widely present in the epidermis of human and animals, and is a main component of hair, feather, hoof, shell, claw, horn, etc., and is an extremely important structural protein of connective tissue, playing a role in protecting the body.

Keratin is widely present in organisms, is a renewable resource, has great utilization value, and is not widely and effectively utilized. The main reason is that keratin is insoluble in various solvents and is generally more resistant to enzymatic degradation by proteases than other proteins. Therefore, the difficulty of extracting and preparing the natural keratin is very high.

With the rapid development of modern biotechnology such as genomics, proteomics, genetic engineering, microbial engineering and the like, more and more genes are discovered. The preparation and production of target protein by using protein expression system is an important means for researching biological function of gene or protein.

The protein expression system is utilized to prepare the target keratin, and the structure and the function of the target keratin are further researched, and the protein expression system is not reported in other documents and has novelty and creativity.

Disclosure of Invention

The invention aims to provide a keratin BD-15, a nucleic acid molecule for coding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the expression vector or integrating the nucleic acid molecule with a genome, a preparation method of the keratin BD-15, a pharmaceutical composition containing the keratin BD-15, and application of the keratin BD-15, the nucleic acid molecule, the expression vector, the host cell or the pharmaceutical composition in preparation of medicines for relieving fever and pain, relieving cough and eliminating phlegm, resisting convulsion, resisting epilepsy, reducing blood pressure, resisting inflammation and resisting viruses.

In order to solve the technical problem, the invention provides the following technical scheme:

in a first aspect of the technical solution of the present invention, a keratin BD-15 is provided, wherein the amino acid sequence of the keratin BD-15 is:

(1) an amino acid sequence shown as SEQ ID NO.1 in a sequence table;

(2) the amino acid sequence shown in SEQ ID NO.1 in the sequence table is formed by replacing, deleting or adding 1-35 amino acids, and the amino acid sequence basically keeps the same biological function.

Further, conventional modifications can be made on the keratin BD-15; or the keratin BD-15 is also connected with a label for detection or purification.

Further, the conventional modification includes acetylation, amidation, cyclization, glycosylation, phosphorylation, alkylation, biotinylation, fluorophore modification, polyethylene glycol (PEG) modification, immobilization modification, sulfation, oxidation, methylation, deamination, disulfide bond formation or disulfide bond cleavage; the tags comprise His6, GST, EGFP, MBP, Nus, HA, IgG, FLAG, c-Myc and definition eXact.

In a second aspect of the present invention, there is provided a nucleic acid molecule encoding the keratin BD-15 of the first aspect.

Further, the nucleotide sequence of the nucleic acid molecule is:

(1) a nucleotide sequence shown as SEQ ID NO.2 in the sequence table;

(2) a nucleotide sequence obtained by optimizing the sequence based on the nucleotide sequence shown in SEQ ID NO. 2;

(3) a nucleotide sequence complementary to the nucleotide sequence in (1) or (2) above.

In a third aspect of the present invention, there is provided an expression vector comprising the nucleic acid molecule of the second aspect.

Further, the expression vector may be pET series, pUC series, pQE series, pBV series, pMAL series, pPIC9, pPIC9K, pHIL-S1, pPICZ α/A, pYAM75P, pHIL-D2, pA0815, pPIC3K, pPICZ, pHWO10, pGAPZ, pGAPZa, pPIC3.5K, etc.; the preferred expression vector is a pET series vector; the most preferred expression vector is pET-28a (+).

In a fourth aspect of the present invention, there is provided a host cell comprising the expression vector of the third aspect or having the nucleic acid molecule of the second aspect integrated into its genome.

Further, the host cell includes a bacterium, a yeast, an aspergillus, a plant cell, or an insect cell.

Further, the bacterium includes Escherichia coli or yeast.

The competent host cell may be BL21 series, Transetta series, Rosetta series, DH5 α series, JM series, Top series, Orgami series, Trans1-T1, TG1, TB 1; y11430, MG1003, GS115(AOX1), KM71, SMD1168, etc.; preferred expression competent cells are BL21(DE3), Transetta (DE 3).

In a fifth aspect of the present invention, there is provided a method for preparing the keratin BD-15 of the first aspect, comprising the steps of:

A. synthesizing a nucleic acid molecule corresponding to the keratin BD-15 of the first aspect, linking the nucleic acid molecule to a corresponding expression vector, transforming the expression vector into a host cell, culturing the host cell with the expression vector in a fermentation device under certain conditions, and inducing the expression of the keratin BD-15 to obtain a crude protein solution containing the keratin BD-15;

B. and D, separating, purifying and drying the crude protein solution expressed in the step A to obtain the keratin BD-15.

Further, in step A, the host cell is mainly selected from Escherichia coli, the keratin BD-15 is expressed in an inclusion body of the Escherichia coli, and the fermentation equipment comprises a shake flask or a fermentation tank.

Further, in the step A, after the induction expression of the keratin BD-15, impurities can be washed by using a cleaning agent, and a crude protein solution can be obtained by dissolving the impurities by using a solution.

Further, the culture medium in the step A can be LB culture medium, TB culture medium, SB culture medium, SOB culture medium, SOC culture medium, PDA culture medium, YPD culture medium, Bengal culture medium, high salinity culture medium, DOBA culture medium, Miqu culture medium and modified formula thereof; the shake flask fermentation is preferably an LB culture medium and a TB culture medium, and most preferably a TB culture medium; the fermentation tank is preferably LB culture medium and its modified formula.

Further, the inducer in the step A can be IPTG, lactose, arabinose and the like; preferably IPTG or lactose.

Further, in the step A, centrifuging the obtained zymophyte liquid, and removing the supernatant; suspending the precipitate in buffer solution, crushing thallus, centrifuging again, and discarding supernatant; and cleaning the precipitate with a cleaning agent, and dissolving with a urea solution to obtain a BD-15 crude protein solution.

Wherein the buffer solution is preferably buffer A, and the dosage of the buffer A is as follows: volume of fermentation liquid: the volume of the buffer A is 1-100: 1, preferably 10: 1;

the cleaning agent may be a urea solution, guanidine hydrochloride solution, Triton, buffer a, etc., preferably a urea solution, most preferably a 2M urea solution (which may contain 1% Triton) in amounts of: volume of fermentation liquid: the volume of the 2M urea is 0.2-100: 1, preferably 1-15: 1;

the urea solution is preferably an 8M urea solution, in the amounts: volume of fermentation liquid: the volume of the 8M urea is 0.2-100: 1, preferably 2-15: 1.

Further, in the step B, the separation and purification method comprises an ultrafiltration microfiltration membrane technology purification method, a column chromatography purification method, a salting-out method and a dialysis method.

Further, in the step B, the separation and purification method comprises the following steps:

(1) and (3) a dialysis method, namely purifying the crude protein solution obtained in the step A by a dialysis method to obtain the BD-15 solution of the target protein.

The dialysis bag may have a molecular weight cut-off of 0.5-10kD, preferably the dialysis bag has a molecular weight cut-off of 3.5-10kD, most preferably the dialysis bag has a molecular weight cut-off of 10 kD.

(2) And D, the ultrafiltration and microfiltration method is to purify the crude protein solution obtained in the step A by using membrane technologies such as an ultrafiltration membrane or a microfiltration membrane and the like to obtain the target protein BD-15 concentrated solution.

Preferably, the microfiltration membrane purification is carried out twice, wherein the first membrane aperture is 1000-1500 nm, and the second membrane aperture is 20-50 nm.

(3) The column chromatography method is that the crude protein solution obtained in the step A is separated and purified by column chromatography, such as various exchange columns or exclusion column chromatography, to obtain the target protein BD-15.

Preferred exclusion columns are sephadex columns, Superdex 30Increase, Superdex 75Increase, Superdex 200Increase, Superose 6Increase, etc.; preferred columns are ion exchange resin columns: anion exchange resin columns, HiTrap Q FF, HiTrap Capto Q Impres, HiTrap Capto Q, HiTrap DEAE, Toyopearl Q-650M, Toyopearl SuperQ-650M, and the like; cation exchange resin column, HiTrap SP FF, HiTrap Capto SP ImpRes, HiTrap Capto SP, Toyopearl SP-650M, Toyopearl Super SP-650M. Most preferred is an anion exchange resin column.

As the eluent, those commonly used in the art can be used, for example, water, salt solutions including sodium chloride solution, sodium dihydrogen phosphate solution, disodium hydrogen phosphate solution, sodium acetate, acetic acid and the like.

(4) And (3) the salting-out method is to purify the crude protein solution obtained in the step A by using a salting-out method to obtain a target protein BD-15 suspension.

The salting-out agent can be ammonium sulfate, sodium chloride, magnesium chloride, aluminum sulfate, ammonium nitrate, ammonium chloride, magnesium sulfate, etc. Preferred salting-out agents are ammonium sulfate and aqueous solutions thereof. Adding saturated ammonium sulfate water solution to make the final concentration of ammonium sulfate reach 10-50%, preferably 20-30%, more preferably 25%.

The salting-out frequency is 1 to 3 times, preferably 2 times.

And adding pure water into the precipitate after salting out for cleaning, wherein the cleaning time is 2-5 times, and preferably 3 times.

Further, the target protein BD-15 solution purified in the step B can be dried into dry powder by freeze drying or vacuum drying, or the concentrated solution can be directly spray dried into dry powder.

In a sixth aspect of the present invention, there is provided a pharmaceutical composition comprising the keratin BD-15 of the first aspect or the nucleic acid molecule of the second aspect or the expression vector of the third aspect or the host cell of the fourth aspect, and a pharmaceutically acceptable carrier or excipient.

The keratin obtained in the steps of the invention can be dried into dry powder by freeze drying or vacuum drying, or the concentrated liquid can be directly sprayed and dried into dry powder and then made into various dosage forms.

The invention relates to a pharmaceutical composition, which comprises any one of the keratin obtained in the steps and a pharmaceutically acceptable carrier.

The invention also relates to pharmaceutical compositions containing the keratin of the invention as active ingredient, together with conventional pharmaceutical excipients or adjuvants. Usually, the keratin of the invention accounts for 0.1-100.0% of the total weight of the pharmaceutical composition.

The invention also provides a pharmaceutical composition comprising a pharmaceutically effective amount of a protein as an active ingredient and a pharmaceutically acceptable carrier.

The pharmaceutical compositions of the present invention may be prepared according to methods well known in the art. For this purpose, the proteins of the invention can, if desired, be combined with one or more solid or liquid pharmaceutical excipients and/or adjuvants, in a suitable administration form or dosage form for use as a human or veterinary medicine.

The keratin of the present invention or the pharmaceutical composition containing it can be administered in unit dosage form, and the administration route can be intestinal or parenteral, such as oral, intramuscular, subcutaneous, nasal, oral mucosa, eye, lung, skin, vagina, peritoneum, rectum, etc., preferably oral administration.

The route of administration of the keratin of the invention or of the pharmaceutical compositions containing it may be by injection. The injection includes intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection, intraperitoneal injection, acupoint injection, etc.

The dosage form for administration may be a liquid dosage form, a solid dosage form, or a semi-solid dosage form. The liquid dosage forms can be solution (including true solution and colloidal solution), emulsion (including oil-in-water type, water-in-oil type and multiple emulsion), suspension, injection (including water injection, powder injection and infusion), eye drop, nose drop, lotion and liniment. The solid dosage form can be tablet (including common tablet, enteric coated tablet, buccal tablet, dispersible tablet, chewable tablet, effervescent tablet, orally disintegrating tablet), capsule (including hard capsule, soft capsule, and enteric coated capsule), granule, powder, pellet, dripping pill, suppository, pellicle, patch, aerosol (powder), spray, etc.; semisolid dosage forms can be ointments, gels, pastes, and the like.

The keratin of the invention can be prepared into common preparations, sustained release preparations, controlled release preparations, targeting preparations and various particle drug delivery systems.

To form the unit dosage form into a tablet, a wide variety of excipients well known in the art can be used, including diluents, binders, wetting agents, disintegrants, lubricants, glidants. The diluent can be starch, dextrin, sucrose, glucose, lactose, mannitol, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, calcium hydrogen phosphate, calcium carbonate, etc.; the humectant can be water, ethanol, isopropanol, etc.; the binder can be starch slurry, dextrin, syrup, Mel, glucose solution, microcrystalline cellulose, acacia slurry, gelatin slurry, sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcellulose, ethyl cellulose, acrylic resin, carbomer, polyethylene pyrrolidone, polyethylene dipropyl alcohol, etc.; the disintegrant may be dry starch, microcrystalline cellulose, low-substituted hydroxypropyl cellulose, crosslinked polyvinylpyrrolidone, crosslinked sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate, citric acid, calcium carbonate, polyoxyethylene sorbitol fatty acid ester, and sodium dodecyl sulfate; the lubricant and glidant may be talc, silicon dioxide, stearate, tartaric acid, liquid paraffin, polyethylene glycol, and the like.

The tablets may be further formulated into coated tablets, such as sugar-coated tablets, film-coated tablets, enteric-coated tablets, or double-layer and multi-layer tablets.

For making the administration units into pills, a wide variety of carriers well known in the art can be used. Examples of the carrier are, for example, diluents and absorbents such as glucose, lactose, starch, cacao butter, hydrogenated vegetable oil, polyvinylpyrrolidone, glycerol laureth glycol, kaolin, talc and the like; binding agent such as acacia, xanthan gum, gelatin, ethanol, honey, liquid sugar, rice paste or batter, etc.; disintegrating agents, such as agar powder, dried starch, alginate, sodium dodecylsulfate, methylcellulose, ethylcellulose, etc.

For making the administration unit into a suppository, various carriers well known in the art can be widely used. As examples of the carrier, there may be mentioned, for example, polyethylene glycol, lecithin, cacao butter, higher alcohols, esters of higher alcohols, gelatin, semisynthetic glycerides and the like.

To encapsulate the administration units, the active ingredient keratin of the invention is mixed with the various carriers mentioned above and the mixture thus obtained is placed in hard gelatin capsules or soft capsules. The effective component of the keratin of the invention can also be prepared into microcapsules, and the microcapsules are suspended in aqueous medium to form suspension, or can be filled into hard capsules or prepared into injection for application.

For example, the keratin of the present invention may be formulated into injectable preparations such as solutions, suspensions, emulsions, lyophilized powders, which may be aqueous or non-aqueous, and may contain one or more pharmaceutically acceptable carriers, diluents, binders, lubricants, preservatives, surfactants or dispersants. For example, the diluent may be selected from water, ethanol, polyethylene glycol, l, 3-propanediol, ethoxylated isostearyl alcohol, polyoxylated isostearyl alcohol, polyoxyethylene sorbitol fatty acid ester, etc. In addition, for the preparation of isotonic injection, sodium chloride, glucose or glycerol may be added in an appropriate amount to the preparation for injection, and conventional cosolvents, buffers, pH adjusters and the like may also be added. These adjuvants are commonly used in the art.

In addition, colorants, preservatives, flavors, flavorings, sweeteners or other materials may also be added to the pharmaceutical preparation, if desired.

For the purpose of administration, enhancing the therapeutic effect, the keratin or pharmaceutical composition of the present invention can be administered by any known administration method.

The dose of the keratin pharmaceutical composition of the present invention to be administered depends on many factors such as the nature and severity of the disease to be prevented or treated, the sex, age, body weight, character and individual response of the patient or animal, the administration route, the number of administrations, the therapeutic purpose, and thus the therapeutic dose of the present invention can be widely varied. Generally, the dosage of the pharmaceutical ingredients of the present invention used is well known to those skilled in the art. The prophylactic or therapeutic objectives of the invention can be achieved by appropriate adjustment, depending on the actual amount of drug contained in the final formulation of the keratin composition of the invention, to achieve the desired therapeutically effective amount. Suitable daily dosage ranges for the keratin of the invention are: the amount of keratin used in the present invention is 0.01 to 500mg/kg body weight, preferably 0.5 to 100mg/kg body weight, more preferably 1 to 50mg/kg body weight, and most preferably 2 to 30mg/kg body weight. The above-described dosage may be administered in a single dosage form or in divided dosage forms, e.g., two, three or four dosage forms, depending on the clinical experience of the administering physician and the dosage regimen including the use of other therapeutic agents. The total dose required for each treatment can be divided into multiple doses or administered as a single dose. The protein or the pharmaceutical composition of the present invention can be taken alone, or in combination with other therapeutic agents or symptomatic drugs and the dosage is adjusted.

The seventh aspect of the present invention provides the use of the keratin BD-15 of the first aspect, or the nucleic acid molecule of the second aspect, or the expression vector of the third aspect, or the host cell of the fourth aspect, or the pharmaceutical composition of the sixth aspect, in the preparation of a medicament for relieving fever, alleviating pain, relieving cough, eliminating phlegm, resisting convulsion, resisting epilepsy, lowering blood pressure, resisting inflammation, and resisting viruses.

In order to accomplish the object of the present invention, the present invention adopts the following technical solution, and specifically, the present invention prepares the keratin BD-15, comprising the steps of:

(1) synthesizing nucleotide sequences and determining the accuracy of the sequences;

the preferred nucleotide sequence is shown in SEQ ID No. 2.

(2) Transferring the nucleotide sequence into an expression vector;

the expression vector can be pET series, pUC series, pQE series, pBV series, pMAL series, pPIC9, pPIC9K, pHIL-S1, pPICZ alpha/A, pYAM75P, pHIL-D2, pA0815, pPIC3K, pPICZ, pHWO10, pGAPZ, pGAPZa, pPIC3.5K and the like; the preferred expression vector is a pET series vector; the most preferred expression vector is pET-28a (+).

(3) Transfecting the expression vector into a host cell;

the host cell may be E.coli or yeast; preferred host cells are E.coli;

the competent cells can be BL21 series, Transetta series, Rosetta series, DH5 alpha series, JM series, Top series, Orgami series, Trans1-T1, TG1, TB 1; y11430, MG1003, GS115(AOX1), KM71, SMD1168, etc.; preferred expression competent cells are BL21(DE3), Transetta (DE 3).

(4) Fermenting and culturing host cells under proper conditions to induce and express the target protein BD-15;

the fermentation equipment can adopt a shake flask or a fermentation tank;

the culture medium can be LB culture medium, TB culture medium, SB culture medium, SOB culture medium, SOC culture medium, PDA culture medium, YPD culture medium, Bengal culture medium, high-salinity Chaudhuri culture medium, DOBA culture medium, Miqu culture medium and modified formula thereof; the shake flask fermentation is preferably an LB culture medium and a TB culture medium, and most preferably a TB culture medium; the fermentation tank is preferably LB culture medium and its modified formula.

The inducer can be IPTG, lactose, arabinose, etc.; preferably IPTG or lactose.

(5) Enriching the target protein BD-15 product;

centrifuging the zymophyte liquid obtained in the step (4), and removing supernatant; suspending the precipitate in buffer solution, crushing thallus, centrifuging again, and discarding supernatant; and cleaning the precipitate with a cleaning agent, and dissolving with a urea solution to obtain a BD-15 crude protein solution.

(6) Separating and purifying the target protein BD-15:

and (5) purifying the crude protein solution obtained in the step (5) to obtain the target protein BD-15. The purification may be performed by dialysis, or ultrafiltration microfiltration, or column chromatography, or a salting-out step.

A. And (3) a dialysis step, namely purifying the crude protein solution obtained in the step (5) by a dialysis method to obtain the target protein BD-15 solution.

B. And (3) an ultrafiltration microfiltration step, namely purifying the crude protein solution obtained in the step (5) by using membrane technologies such as an ultrafiltration membrane or a microfiltration membrane and the like to obtain a target protein BD-15 concentrated solution.

C. And (3) a column chromatography step, namely, separating and purifying the crude protein solution obtained in the step (5) by column chromatography, such as various exchange columns or exclusion column chromatography to obtain the target protein BD-15.

D. And (3) a salting-out step, namely purifying the crude protein solution obtained in the step (5) by using a salting-out method to obtain a target protein BD-15 suspension.

The salting-out frequency is 1 to 3 times, preferably 2 times.

And D, freeze drying or vacuum drying the target protein BD-15 solution obtained by purification in the steps A to D to obtain dry powder, or directly spray drying the concentrated solution to obtain dry powder.

The invention has the beneficial technical effects that:

1. the protein is keratin obtained for the first time, and the preparation method has the characteristics of high yield and high sample purity.

2. The protein BD-15 can obviously inhibit the body temperature rise at most time points after yeast molding and has strong effect through the pharmacodynamic test research of the protein BD-15 on a yeast and lipopolysaccharide induced SD rat fever model;

3. the invention respectively proves that the protein BD-15 can obviously prolong the III-level and IV-level seizure latency of the mice epilepsy through the pharmacodynamic test research of the protein BD-15 on the mice convulsion and epilepsy caused by Pilocarpine (PLO) and Pentylenetetrazol (PTZ);

4. the protein BD-15 is proved to have the tendency of increasing the excretion amount of phenol red and the potential of the effect of eliminating phlegm through the research of the protein BD-15 on the efficacy test of eliminating phlegm by the excretion method of the phenol red of mice;

5. the protein BD-15 is proved to be capable of obviously reducing cough times through the pharmacodynamic test research of the protein BD-15 on the cough relieving by the mouse ammonia water induced cough method, and has a remarkable cough relieving effect;

6. the invention proves that the protein BD-15 can obviously reduce the frequency of mouse writhing and has obvious analgesic effect through the pharmacodynamic test research of the protein BD-15 on ICR mouse acetic writhing.

Drawings

FIG. 1: analysis of the expressed protein BD-15 by reduced SDS Polyacrylamide gel electrophoresis (SDS-PAGE)

(M: protein molecular weight Standard; S: expression protein BD-15)

FIG. 2 Effect of protein BD-15 on Yeast-induced rat fever model

(compared with normal control group, # P <0.01, # P < 0.001; compared with model group, # P <0.05, # P <0.01, # P <0.001)

FIG. 3 Effect of protein BD-15 on Lipopolysaccharide (LPS) -induced fever model in rats

(compared with normal control group, # P < 0.001; compared with model group, # P <0.01, # P <0.001)

Detailed Description

The following examples and pharmacological activity test examples are intended to further illustrate the present invention, but are not intended to limit the present invention in any way.

The experimental methods in the following examples and pharmacological activity test examples are conventional methods unless otherwise specified; the experimental materials used, unless otherwise specified, were purchased from conventional biochemicals.

EXAMPLE 1 preparation of crude solution A of protein BD-15 by Shake flask fermentation (TB Medium)

Synthesizing a nucleotide sequence shown as SEQ ID No.2, and transferring the nucleotide sequence into a pET-28a (+) vector; sequencing to obtain an expression vector containing a correct sequence; the expression vector was transfected into BL21(DE3) cells to obtain expression competent host cells containing the nucleotide sequence of interest. Adding into LB culture medium, culturing in shaker at 37 deg.C and 220rpm for 1 hr to obtain recombinant strain.

The recombinant strain was streaked on LBA plates containing Kanamycin, and the plates were placed upside down in a 37 ℃ incubator overnight for 16 hours.

400ml of TB medium is prepared and is subpackaged into 2 bottles of 200 ml. Kanamycin (final concentration 50. mu.g/ml) was added to each flask (200ml) of TB medium, and a single colony on the plate was added to TB medium and subjected to amplification culture overnight at 37 ℃ and 220rpm in a shaker to obtain a seed solution.

28.8L of TB medium was prepared and dispensed into 144 flasks, 200ml each. Kanamycin (final concentration 50. mu.g/ml) was added to each flask (200ml) of TB medium, and 2ml of seed solution was added thereto, followed by culturing in a shaker at 37 ℃ and 220rpm for 2-3 hours. Monitoring OD₆₀₀When OD is reached₆₀₀When the protein reaches about 1.0, adding an inducer, and inducing and expressing the protein in a shaking table under the inducing conditions selected from the following table.

Combining the bacterial liquids in the bottles, centrifuging at 7000rpm for 5 minutes, and removing the supernatant after sterilizing; the precipitate was suspended in about 3L of buffer, filtered through a 80-100 mesh screen, and the filtrate was disrupted by a high pressure disrupter at a pressure of 800-1000bar 2 times for 2 minutes each. The crushed bacteria liquid is centrifuged at 7000rpm for 30 minutes, and the supernatant is discarded to obtain a precipitate (i.e., inclusion bodies). Adding 1L cleaning agent into the precipitate, cleaning for 2 times, centrifuging, and discarding supernatant. The precipitate was dissolved in urea solution for 4 times (800 ml, 600ml, 400ml, respectively). The 4 solutions are combined, centrifuged at 7000rpm for 30 minutes, and the precipitate is discarded, and the supernatant is the crude protein solution A.

Analyzing the crude solution A of the protein BD-15 by using reduced SDS-PAGE, wherein the concentration of a separation gel is 12.5 percent, and staining is carried out by a Coomassie brilliant blue R250 method; a blue band was clearly observed around a molecular weight of 53 kD.

EXAMPLE 2 Shake flask fermentation preparation of crude protein BD-15 solution B (other Medium)

In the embodiment 1, synthesizing and sequencing to obtain an expression vector containing a sequence shown as SEQ ID No. 2; the expression vector was transfected into BL21(DE3) cells to obtain expression competent host cells containing the nucleotide sequence of interest.

Prepare 20ml LB medium, take 800 u l, add containing target coding sequence of host cells 50 u l, in the shaking table, at 37 degrees C, 220rpm under the conditions of 1 hours.

The above-mentioned bacterial solution was dipped and streaked on LBA plates containing kanamycin, and the plates were placed upside down in a 37 ℃ incubator overnight and cultured for 16 hours.

10ml of LB medium was added with Kanamycin (final concentration 50. mu.g/ml), and a single colony on the plate was added to LB medium and amplified overnight at 37 ℃ and 220rpm for 15 hours in a shaker to obtain a seed solution.

1L of the medium shown in the following table was prepared and dispensed into 10 bottles of 100ml each. Kanamycin (final concentration 50. mu.g/ml) was added to each flask (100ml) of the medium, and 1ml of the seed solution was added thereto, followed by culturing in a shaker at 37 ℃ and 220rpm for 2 to 3 hours. Monitoring OD₆₀₀When OD is reached₆₀₀When the concentration reached about 1.0, the inducer IPTG (final concentration: 0.5mM) was added thereto, and the protein was expressed by induction in a shaker at 37 ℃ and 220 rpm.

Culture medium

LB medium, SOB medium, SOC medium

Combining the bacterial liquids in the bottles, centrifuging at 10000rpm for 10 minutes, and removing the supernatant after sterilizing; the pellet was suspended in about 100mL of buffer, filtered through a 80-100 mesh screen, and the filtrate was disrupted using a high pressure disrupter at a pressure of 800 and 1000bar 2 times for 2 minutes each. And centrifuging the crushed bacteria liquid at 10000rpm for 30 minutes, and removing the supernatant.

Adding 40mL of cleaning agent buffer A into the precipitate, cleaning for 3 times, centrifuging, and removing the supernatant; adding 40mL of cleaning agent 2M urea solution into the precipitate, cleaning for 2 times, centrifuging, and removing supernatant; adding 40mL of 4M urea solution into the precipitate, cleaning for 2 times, centrifuging, and removing supernatant; dissolving the precipitate in 8M urea solution (containing 50mM Tris/HCl buffer) for 3 times (40 ml, 30 ml); the solution is combined, centrifuged at 7000rpm for 30 minutes, and the precipitate is discarded, and the supernatant is the crude protein solution B.

Analyzing the crude solution B of the protein BD-15 by using reduced SDS-PAGE, wherein the concentration of the separation gel is 12.5 percent, and staining is carried out by a Coomassie brilliant blue R250 method; a blue band was clearly observed around a molecular weight of 53 kD.

EXAMPLE 3 fermenter preparation of crude solution C of protein BD-15

In the embodiment 1, synthesizing and sequencing to obtain an expression vector containing a sequence shown as SEQ ID No. 2; the expression vector was transfected into BL21(DE3) cells to obtain expression competent host cells containing the nucleotide sequence of interest. Adding into LB culture medium, culturing in shaker at 37 deg.C and 220rpm for 1 hr to obtain recombinant strain.

To the LBA plate containing Kanamycin, 100. mu.l of the recombinant strain was added, the spreader was spread to dry uniformly, and the plate was inverted and incubated overnight in a 37 ℃ incubator. Taking three single colonies respectively, streaking on a plate containing kanamycin, culturing the plate overnight, after three batches of shake flask fermentation expression verification, preserving the strains with 15% glycerol, subpackaging into 0.8ml each to obtain a working cell bank, and freezing and storing in a refrigerator at-80 ℃ for later use.

1 glycerol strain was taken out from the working cell bank, 100. mu.l of the glycerol strain was added to 40ml of LB medium, Kanamycin (final concentration: 50. mu.g/ml) was added thereto, and the mixture was cultured in a shaker at 37 ℃ and 220rpm for 6 hours to obtain a primary seed solution.

Taking 1.2ml of the primary seed solution, adding into 120ml of LB culture medium, adding Kanamycin (final concentration is 50 mug/ml), and culturing in a shaker at 37 ℃ and 220rpm for 7 hours to obtain a secondary seed solution.

3L of the modified LB medium was added to a 5L fermenter, and then 120ml of the secondary seed solution and 3ml of Kanamycin (final concentration 50. mu.g/ml) were added and cultured at 37 ℃ for about 8 hours in the presence of dissolved oxygen at 30% (tandem rotation speed). OD was monitored at around 20, 3g of lactose was used as an inducer, induction was carried out at 20 ℃ and feeding was carried out at a rate of 30 ml/hr, and incubation was carried out at 20 ℃ for 24 hours.

Centrifuging the bacterial liquid at 7000rpm for 5 minutes, and removing the supernatant after sterilizing; the precipitate was suspended in about 200ml of buffer A, filtered through a 80-100 mesh screen, and the filtrate was crushed using a high pressure crusher at a pressure of 800-. The disrupted bacterial liquid is centrifuged at 7000rpm for 30 minutes, and the supernatant is discarded.

Adding 2M urea solution (containing 1% Triton) into the precipitate, and washing for 2 times, 1L each time; then 1L of 2M urea solution is added for cleaning for 1 time, and the supernatant is discarded after centrifugation. The precipitate was dissolved 4 times in 8M urea solution (400 ml, 300ml, 200ml, 100ml, respectively). And combining the four solutions, centrifuging at 7000rpm for 30 minutes, and discarding the precipitate to obtain a supernatant, namely the crude protein solution C.

Analyzing the crude solution C of the protein BD-15 by using reduced SDS-PAGE, wherein the concentration of the separation gel is 12.5 percent, and staining is carried out by a Coomassie brilliant blue R250 method; a blue band was clearly observed around a molecular weight of 53 kD.

EXAMPLE 4 crude protein solution A protein BD-15 was prepared by dialysis

The crude protein solution A obtained in example 1 was filtered through a 0.45. mu.ml filter and the filtrates were combined. Dialyzing the filtrate with water, intercepting the molecular weight of 10kD in a dialysis bag, dialyzing for 72 hours, and freeze-drying the inner liquid to obtain the target protein BD-15; the purity was determined by electrophoresis to be 93.2%.

And (3) confirming the structure of the protein BD-15:

1. analysis by reduced SDS-polyacrylamide gel electrophoresis (SDS-PAGE)

The instrument comprises the following steps: protein electrophoresis apparatus (Bio-Rad).

The method and the result are as follows: the BD-15 protein solution was analyzed by reduced SDS-PAGE and the gel concentration was 12.5% and stained by Coomassie Brilliant blue R250. The molecular weight of the BD-15 band is around 53 kD.

2. LC-MS/MS-based protein complete sequence analysis

The main materials are as follows: acetonitrile, formic acid, ammonium bicarbonate, Dithiothreitol (DTT), Iodoacetamide (IAA), trypsin, chymotrypsin, Glu-C, Asp-N;

the main apparatus is as follows: capillary HPLC (Thermo Ultimate model 3000), electrospray-combinatorial ion trap Orbitrap Mass Spectrometers (Thermo Q active Hybrid Quadrupole-Orbitrap Mass Spectrometers).

The method and the result are as follows:

carrying out pretreatment such as dissolving replacement, reductive alkylation, multiple proteolysis and the like on the protein BD-15 to obtain an enzyme digestion peptide segment; and (3) performing liquid chromatography tandem mass spectrometry on the enzyme-digested peptide fragment solution, searching protein database analysis data by using Maxquant (1.6.2.10) in a mass spectrometry original file, and determining that the enzyme-digested peptide fragment solution is consistent with a target sequence SEQ ID No.1 according to an identification result.

EXAMPLE 5 crude protein solution A protein BD-15 prepared by other methods of purification

The crude protein solution a obtained in example 1 was purified by the following two methods:

the first method comprises the following steps: salting out;

placing the crude protein solution A in a container with stirring for salting out twice: slowly adding saturated solution of ammonium sulfate along the wall to make final concentration of ammonium sulfate be 25% or 50%, precipitating protein in salting-out process, and filtering after salting-out is completed to complete first salting-out; adding 400ml pure water into the precipitate for suspension, slowly adding saturated solution of ammonium sulfate along the wall again to make the final concentration of ammonium sulfate be 25%, performing salting-out for the second time, and filtering to obtain the precipitate as crude protein extract. The crude protein extract was washed three times with water: adding 200ml of pure water for suspension, stirring, standing and filtering; repeating the steps for three times, and freeze-drying the precipitate to obtain the target protein BD-15.

The second method comprises the following steps: column chromatography;

the crude protein solution A is purified by passing through anion exchange resin columns such as HiTrap Q FF 16/10, HiTrap Capto Q ImpRes, HiTrap Capto Q, HiTrap DEAE, etc., respectively. The eluent is NaCl solution gradient elution, 20mM NaH is added₂PO₄/Na₂HPO₄Buffer (pH 8.0). Detecting and combining the elution fractions by SDS-PAGE electrophoresis, and centrifuging the combined eluent at 7000rpm for 2 times for 1 hour each time; the supernatant was filtered through a 0.45 μm filter and the filtrates were combined. And (3) dialyzing the filtrate with water, concentrating, cutting off the molecular weight of 10kD by a dialysis bag, and freeze-drying the internal liquid to obtain the target protein BD-15.

The protein BD-15 obtained in both methods was confirmed to have the same amino acid sequence as the protein prepared in example 4 by the same structure confirmation method as in example 4.

EXAMPLE 6 purification of crude protein solution B to prepare protein BD-15

The crude protein solution B obtained in example 2 was purified by the following three methods:

the first method comprises the following steps: dialyzing;

and (3) filtering the crude protein solution B by using a 0.45-micron membrane, dialyzing the filtrate by using water for over 72 hours, and carrying out internal liquid cooling and freeze drying to obtain the target protein BD-15.

Dialysis bag

Molecular weight cut-off: 0.5kD, 3.5kD, 5kD, 10kD

The second method comprises the following steps: column chromatography;

the crude protein solution B is purified by passing through anion exchange resin columns such as HiTrap Q FF 16/10, HiTrap Capto Q ImpRes, HiTrap Capto Q, HiTrap DEAE, etc. The eluent is NaCl solution gradient elution, 20mM NaH is added₂PO₄/Na₂HPO₄Buffer (pH 8.0). Detecting and combining the elution fractions by SDS-PAGE electrophoresis, and centrifuging the combined eluent at 7000rpm for 2 times for 1 hour each time; the supernatant was filtered through a 0.45 μm filter and the filtrates were combined. And (3) dialyzing the filtrate with water, concentrating, cutting off the molecular weight of 10kD by a dialysis bag, and freeze-drying the internal liquid to obtain the target protein BD-15.

The third method comprises the following steps: salting out;

placing the crude protein solution B in a container with stirring for salting out twice: slowly adding saturated solution of ammonium sulfate along the wall to make final concentration of ammonium sulfate be 25% or 50%, precipitating protein in salting-out process, and filtering after salting-out is completed to complete first salting-out; adding 400ml pure water into the precipitate for suspension, slowly adding saturated solution of ammonium sulfate along the wall again to make the final concentration of ammonium sulfate be 25%, performing salting-out for the second time, and filtering to obtain the precipitate as crude protein extract. The crude protein extract was washed three times with water: adding 200ml of pure water for suspension, stirring, standing and filtering; repeating the steps for three times, and freeze-drying the precipitate to obtain the target protein BD-15.

The protein BD-15 produced by the three methods was confirmed to have the same amino acid sequence as the protein produced in example 4 by the same structure confirmation method as in example 4.

EXAMPLE 7 purification of crude protein solution C to prepare protein BD-15

The crude protein solution C obtained in example 3 was purified by the following two methods:

the first method comprises the following steps: microfiltration membrane technology;

and (3) purifying the crude protein solution C by using a microfiltration membrane technology: firstly, performing solid-liquid separation by using a 1500nm or 1000nm ceramic membrane core; discarding the inner solution, and repeatedly microfiltering the outer solution with 20nm or 50nm ceramic membrane core to remove urea; and (5) freeze-drying the secondary microfiltration internal liquid to obtain the target protein BD-15.

The second method comprises the following steps: salting out;

placing the crude protein solution C in a container with stirring for salting out twice: slowly adding saturated solution of ammonium sulfate along the wall to make final concentration of ammonium sulfate be 25%, precipitating protein in salting-out process, filtering after salting-out is completed, and completing the first salting-out; adding 400ml pure water into the precipitate for suspension, slowly adding saturated solution of ammonium sulfate along the wall again to make the final concentration of ammonium sulfate be 25%, performing salting-out for the second time, and filtering to obtain the precipitate as crude protein extract. The crude protein extract was washed three times with water: adding 200ml of pure water for suspension, stirring, standing and filtering; repeating the steps for three times, and freeze-drying the precipitate to obtain the target protein BD-15.

Pharmacological test

Experimental example 1 pharmacodynamic test of BD-15 protein (example 4 protein) on Yeast-induced SD rat fever model

Animals: male SD rat 230-260 g;

medicine preparation: yeast (OXOID LP0021), aspirin (SIGMA a2093), protein BD-15;

the instrument comprises the following steps: an electronic balance (model SARTORIUS BP 121S), and an electronic thermometer (model CITIZEN CT-513W).

Grouping experiments:

a normal control group;

model group: a yeast fever model;

positive control group: aspirin (Aspirin)300mg/kg group;

protein BD-15, 10mg/kg group, 50mg/kg group.

The method comprises the following steps:

preparation of experimental animals: after the experimental animals are adapted for 1 day in the experimental environment (the temperature is 22 ℃ plus or minus 2 ℃, and the relative humidity is 50 percent plus or minus 2 percent), the operation of pre-adapting and measuring the anal temperature is respectively carried out at 8:00 and 15:00, the animals are fasted without water prohibition before the experiment for 12 hours, and the animals are allowed to empty the excrement before the anal temperature is measured. Before measuring the temperature each time, the probe of the electronic thermometer is smeared with vaseline, the rat rectum is inserted for 2cm (the insertion depth can be marked at the position of 2cm, and the consistency of the insertion depth each time is ensured), and the body temperature value is recorded after the reading is stable.

Subcutaneous injection of dry yeast replicates the rat fever model: measuring the body temperature of rats before modeling, screening out qualified rats with the body temperature of 36.2-37.3 ℃, and randomly grouping 8 rats in each group. Aspirin and different doses of protein BD-15 were administered orally and immediately after subcutaneous injection of 20% yeast suspension (10ml/kg), normal control group was injected subcutaneously with equal volume of normal saline, and rat body temperature was monitored 2 hours later, 1 time every 2 hours, for 8 hours. And (3) data statistics:

calculating the body temperature mean value, standard deviation and standard error of each group of rats according to the body temperature value of each time point measured on the same day of the experiment, and comparing each group of data by using TTEST, wherein the difference of significance is considered when P is less than 0.05.

The experimental results are as follows:

after aspirin (300mg/kg) and protein BD-15(10mg/kg, 50mg/kg) were orally administered, 20% yeast was immediately injected subcutaneously for molding, and the body temperature of the animals was monitored at 2 hours, 4 hours, 6 hours, and 8 hours after molding, respectively. The results are shown in Table 1 and FIG. 2.

TABLE 1 influence of test drugs on Yeast-induced fever model in rats

(P <0.01, P <0.001 compared to normal control group; P <0.05, # P <0.01, # P <0.001 compared to model group) conclusions of the experiment:

after aspirin (300mg/kg) and protein BD-15(10mg/kg, 50mg/kg) were orally administered, 20% yeast was immediately injected subcutaneously for molding, and the body temperature of the animals was monitored at 2 hours, 4 hours, 6 hours, and 8 hours after molding, respectively. The results show that:

1) the body temperature of the model group rats is obviously increased within 2 hours, 4 hours, 6 hours and 8 hours of model building, compared with the normal group, P is less than 0.05, the statistical difference exists, and the model building is successful, stable and reliable.

2) The positive tool medicine aspirin group can effectively inhibit the body temperature rise of a model rat within 2 hours, 4 hours, 6 hours and 8 hours of molding, compared with the model group, P is less than 0.05, statistical difference exists, and the positive tool medicine aspirin is stable in performance.

3) The temperature rise of the model rat can be inhibited to different degrees by the protein BD-15 with different doses after the model is made; the 50mg/kg dose group has stronger effect, can inhibit the body temperature rise of a model rat within 2 hours, 4 hours, 6 hours and 8 hours after the model is made, and has statistical difference when P is less than 0.05 compared with the model group; the 10mg/kg dose group can inhibit the body temperature rise of model rats at 2 hours, 6 hours and 8 hours after the model is made, and compared with the model group, the P is less than 0.05 and has statistical difference.

Experimental example 2 pharmacodynamic test of protein BD-15 (example 4 protein) on Lipopolysaccharide (LPS) -induced SD rat fever model

Animals: male SD rat 230-260 g;

medicine preparation: lipopolysaccharide (LPS, SIGMA L-2880), aspirin (SIGMA A2093), protein BD-15;

Grouping experiments:

a normal control group;

model group: a lipopolysaccharide fever model;

positive control group: aspirin (Aspirin)300mg/kg group;

protein BD-15, 10mg/kg group, 50mg/kg group.

The method comprises the following steps: the method for replicating the rat fever model by injecting lipopolysaccharide into the abdominal cavity comprises the following steps:

preparation of experimental animals: after the experimental animals are adapted to the experimental environment (the temperature is 22 +/-2 ℃, and the relative humidity is 50% +/-2%) for 1 day, the operation of pre-adapting and measuring the anal temperature is carried out respectively at 8:00 and 15:00, the animals are fasted without water prohibition before the experiment for 12 hours, and the animals are allowed to empty excrement before the anal temperature is measured. Before measuring the temperature each time, the probe of the electronic thermometer is smeared with vaseline, the rat rectum is inserted for 2cm (the insertion depth can be marked at the position of 2cm, and the consistency of the insertion depth each time is ensured), and the body temperature value is recorded after the reading is stable.

Intraperitoneal injection of lipopolysaccharide replicates rat fever model: measuring the body temperature of rats before modeling, screening out qualified rats with the body temperature of 36.2-37.3 ℃, and randomly grouping 8 rats in each group. Immediately after oral administration of aspirin and various doses of protein BD-15, lipopolysaccharide (20. mu.g/kg, 2ml/kg) was intraperitoneally injected, an equal volume of normal saline was intraperitoneally injected to a normal control group, and the body temperature of rats was monitored 2 hours later and 8 hours in total.

And (3) data statistics:

The experimental results are as follows:

after aspirin (300mg/kg) and protein BD-15(10mg/kg and 50mg/kg) were orally administered, 20. mu.g/kg lipopolysaccharide was immediately intraperitoneally injected to mold, and the body temperatures of the animals were monitored at 2 hours, 4 hours, 6 hours, and 8 hours after molding, respectively. The results are shown in Table 3 and FIG. 3.

TABLE 2 Effect of test drugs on Lipopolysaccharide (LPS) -induced fever model in rats

And (4) experimental conclusion:

after aspirin (300mg/kg) and protein BD-15(10mg/kg and 50mg/kg) were orally administered, respectively, immediately after the injection of 20. mu.g/kg Lipopolysaccharide (LPS) into the abdominal cavity, the animal body temperature was monitored at 2 hours, 4 hours, 6 hours, and 8 hours after the molding, and the results showed that:

1) the temperature of the rats can be successfully induced to rise by injecting 20 mu g/kg of lipopolysaccharide into the abdominal cavity, the body temperature of the rats in the model group is obviously raised in 2 hours, 4 hours, 6 hours and 8 hours after model building, compared with the normal group, P is less than 0.05, statistical difference exists, and the model is stable.

2) The positive tool medicine aspirin group can effectively inhibit the body temperature rise of a model rat within 2 hours, 4 hours, 6 hours and 8 hours of molding, compared with the model group, P is less than 0.05, statistical difference exists, and the positive tool medicine is stable in performance.

3) The BD-1550 mg/kg dose group tended to lower body temperature in model rats 2 hours and 4 hours after molding, but was not statistically significant.

EXAMPLE 3 pharmacodynamic test of the protein BD-15 (example 4 protein) against convulsion-induced epilepsy in mice by Pilocarpine (PLO)

Animals: male ICR mice;

medicine preparation: pilocarpine HCl (PLO, Pilocarpine hydrochloride), Diazepam (Diazepam tablets), protein BD-15.

Grouping experiments:

a model group;

diazepam (Diazepam)2mg/kg group;

protein BD-15, 50mg/kg group, 200mg/kg group.

The method comprises the following steps:

model preparation and administration:

the medicine is taken once in the afternoon before the molding, the PLO-225mg/kg (molding agent) is injected into the abdominal cavity 1 hour after the test medicine is filled into the stomach on the molding day, and the positive medicine is taken once 20 minutes before the molding. Observations were continued for 30 minutes after PLO injection.

Observation indexes are as follows: (ii) seizure status: attack time from class II to class IV; ② death time.

Attack level: reference Racine grading standards: level 0: no reaction is carried out; stage I: as twitching of facial muscles or corners of the mouth; II stage: the head can be nodded; grade III: convulsion of one limb; stage IV: spasticity or general limb convulsions; and V stage: generalized grand mal epilepsy (generalized tonic convulsive seizures).

Data processing:

counting the number of IV-grade outbreaks and death cases of each group of mice in the experiment; the level II, III and IV latencies, with the latency of mice that did not develop to level IV scored a maximum of 1800 seconds. Case statistics are counted by chi-square test. Calculating the mean value and standard error of the latency, applying TTEST, comparing the model group with other groups, and considering that the P is less than 0.05, the difference is significant.

The experimental results are as follows: see tables 3 and 4.

TABLE 3 Experimental on PLO induced epilepsy in mice with test drugs-statistics of number of cases

Group of	Number of experimental examples	Number of cases in stage IV	Grade IV attack rate	Number of death cases	Mortality rate
						Model set	10	9	90％	0	0
Diazepam 2mg/kg	10	1**	10％**	0	0
						BD-15-50mg/kg	10	7	70％	0	0
BD-15-200mg/kg	10	8	80％	1	10％

(comparison with model group, P <0.05, P <0.01)

TABLE 4 test drug for PLO induced epilepsy in mice-seizure in grade II, III and IV (mean + -SEM)

Group of	Class II onset latency(s)	Class III onset latency(s)	Latent stage IV attack(s)
				Model set	86±3	145±7	672±131
Diazepam 2mg/kg	94±7	176±13*	1691±109**
				BD-15-50mg/kg	84±4	149±10	1207±163*
BD-15-200mg/kg	84±4	152±8	869±164

(comparison with model group, P <0.05, P <0.01)

And (4) experimental conclusion:

1) the experimental results showed that the grade IV attack rate of the model group was 90%. 1 out of 40 mice died.

2) The positive medicine can completely inhibit the seizure rate of the epilepsy level IV and obviously prolong the seizure latency of the mice level III and level IV.

3) In the epilepsy class IV latency comparison, the BD-1550 mg/kg group was statistically different from the model group.

EXAMPLE 4 pharmacodynamic test of protein BD-15 (example 4 protein) against Pentylenetetrazol (PTZ) -induced epilepsy in mice

Animals: male ICR mice;

medicine preparation: pentylenetetrazole (PTZ), retigabine, protein BD-15.

Grouping experiments:

a model group;

retigabine 60mg/kg group;

protein BD-15, 50mg/kg group, 200mg/kg group.

The method comprises the following steps:

model preparation and administration:

the medicine is taken once in the afternoon before the molding, PTZ-65mg/kg (modeling agent) is injected into the abdominal cavity 1 hour after the test medicine is filled into the stomach on the molding day, and the positive medicine is taken once half an hour before the molding. Observations were continued for 15 minutes after PTZ injection. Observation indexes are as follows: (ii) seizure status: attack time from class III to VI; ② death situation

Attack level: reference Racine grading standards: level 0: no reaction is carried out; stage I: as twitching of facial muscles or corners of the mouth; and II, stage: the head can be nodded; grade III: convulsion of one limb; IV stage: spasticity or general limb convulsions; and V stage: generalized grand mal epilepsy (generalized tonic convulsive seizures).

Data processing:

counting the number of attack and death cases of each group of mice in the experiment; the latencies of class III and IV, the latency of mice that did not develop to class IV, were recorded as a maximum of 900 seconds. Case statistics are counted by chi-square test. Calculating the mean value and standard error of the latency, applying TTEST, comparing the model group with other groups, and considering that the P is less than 0.05, the difference is significant.

The experimental results are as follows: see tables 5 and 6.

TABLE 5 Experimental on PTZ induced epilepsy in mice-statistics of the number of cases

(comparison with model group, P <0.05, P <0.01)

TABLE 6 test drugs for PTZ induced epilepsy in mice-seizure latency of grade III and IV (mean + -SEM)

Group of	Class III latency to attack (second)	Episode of IVIncubation period (seconds)
			Model set	66±4	205±81
Retigabine 60mg/kg	106±16*	722±94**
			BD-15-50mg/kg	79±5	214±83
BD-15-200mg/kg	92±8*	420±131

(comparison with model group, P <0.05, P <0.01)

And (4) experimental conclusion:

2) The positive medicine can reduce the seizure rate of the epilepsy level IV and obviously prolong the seizure latency of the mice level III and level IV.

3) In the class III latency comparison for epilepsy, the BD-15200 mg/kg group was statistically different from the model group.

Experimental example 5 protein BD-15 (example 4 protein) efficacy test animals against mouse phenol Red excretion expectoration: male ICR mice;

drugs and reagents: musultan (ambroxol hydrochloride tablets), phenol red, sodium bicarbonate and protein BD-15;

the instrument comprises the following steps: centrifuge (Sigma-3K15 type), balance (XS105DU type), enzyme-labeling tester (BIO-TEK type).

Grouping experiments:

a solvent control group;

mushutan 30mg/kg group;

protein BD-15, 20mg/kg group, 50mg/kg group.

The method comprises the following steps:

model preparation and administration:

animals were fasted 16 hours before the experiment without water deprivation. Orally administering Mushutan and different doses of protein BD-15 (administration volume is 10ml/kg) according to groups, administering distilled water with the same volume to a solvent control group, injecting 2.5% phenol red solution into abdominal cavity after 1 hour, removing neck after 30 minutes, killing mice, taking from the lower part of thyroid cartilage to the front section of trachea before trachea branching, and placing 3ml of 5% NaHCO into the trachea₃The solution was allowed to stand for 3 hours, 1ml of the supernatant was taken, and after centrifugation at 3000rpm for 5 minutes, the absorbance at 546nm was measured and recorded. And calculating the excretion of the phenol red according to the standard curve of the phenol red.

Data processing:

respectively recording the time point of oral administration and the time point of intraperitoneal injection of 2.5% phenol red solution, and taking the time point of a trachea; and measuring at 546nm of the microplate reader to obtain the absorbance of each group of samples, and calculating the excretion of the phenol red according to the standard curve of the phenol red. Calculating the mean value and standard error of each group of data, applying TTEST, comparing the solvent control group with other groups, and considering that P <0.05 has significant difference.

The experimental results are as follows:

administering Musultan (30mg/kg) and different doses of protein BD-15(20mg/kg, 50mg/kg), injecting 2.5% phenol red solution into abdominal cavity after 1 hr, removing neck after 30 min, killing mouse, taking the trachea from the lower part of thyroid cartilage to the front section of trachea branch, placing 3ml of 5% NaHCO into the trachea₃The solution was allowed to stand for 3 hours, 1ml of the supernatant was taken, and after centrifugation at 3000rpm for 5 minutes, the absorbance at 546nm was measured and recorded. And calculating the excretion of the phenol red according to the standard curve of the phenol red. The results are shown in Table 7.

TABLE 7 test drug effect on mouse phenol Red excretion for eliminating phlegm (X + -SEM)

Group of	N	Phenol Red excretion (μ g/ml)	P
				Solvent control group	10	0.715±0.087	---
Musultan 30mg/kg	10	1.169±0.109**	0.004
				BD-15-20mg/kg	10	0.948±0.096	0.089
BD-15-50mg/kg	10	0.935±0.095	0.104

(comparison with solvent control group, P <0.05, P <0.01)

And (4) experimental conclusion:

1) the experimental result shows that when the Musultan 30mg/kg group is compared with the solvent control group, the excretion amount of phenol red is obviously increased, P is less than 0.05, and the statistical significance is achieved.

2) Protein BD-15 showed an increased but not statistically significant excretion of phenol red compared to the solvent control.

Experimental example 6 protein BD-15 (protein in example 4) drug effect test animals on mouse ammonia induced cough (AMH) to relieve cough: male ICR mice;

drugs and reagents: dextromethorphan hydrobromide, ammonia water, 0.2% of CMC-Na and protein BD-15;

the instrument comprises the following steps: a compression nebulizer (model 403T), a balance (model XS105 DU).

Grouping experiments:

a solvent control group;

dextromethorphan 15 mg/kg;

protein BD-15, 20mg/kg group, 50mg/kg group.

The method comprises the following steps:

model preparation and administration:

dextromethorphan and different doses of protein BD-15 (administration volume is 10ml/kg) are orally administered according to groups, distilled water with the same volume is administered to a solvent control group, the solvent control group is placed in a sealed box after 1 hour, 10 seconds of ammonia water with 10% concentration is introduced, and then the cough latency and the cough frequency within 2 minutes of the mice are observed and recorded.

Data processing:

the time points for oral administration, nebulization experiments, mice cough latency and number of coughs within 2 minutes were recorded separately. Cough latency refers to the time from the onset of ammonia nebulization to the number of seconds required for a cough to occur. The cough in mice was manifested by contraction of the abdominal muscles (chest contraction) with the mouth enlarged. Calculating the mean value and standard error of each group of data, applying TTEST, comparing the model group with other groups, and considering that P is less than 0.05, the difference is significant.

The experimental results are as follows:

dextromethorphan (15mg/kg) and different doses of protein BD-15(20mg/kg and 50mg/kg) were administered in advance, placed in a sealed box after 1 hour, and atomized with 10% ammonia water for 10 seconds, and then the cough latency and the number of coughs within 2 minutes were observed and recorded. The results are shown in Table 8.

TABLE 8 antitussive effect test (X + -SEM) of test drugs on mouse ammonia induced cough

Group of	N	Incubation period (seconds)	P	Number of coughs	P
						Solvent control group	9	25.3±1.9	---	66.8±3.9	---
Dextromethorphan 15mg/kg	9	38.0±2.57**	0.001	33.4±3.8**	0.001
						BD-15-20mg/kg	9	27.8±2.1	0.401	55.8±3.1*	0.042
BD-15-50mg/kg	9	30.2±3.3	0.213	55.8±5.7	0.130

(comparison with solvent control group, P <0.05, P <0.01)

And (4) experimental conclusion:

1) the experimental result shows that compared with a solvent control group, the dextromethorphan group has obvious improvement effect on the incubation period and the cough frequency, the P is less than 0.05, and the statistical significance is achieved.

2) Compared with a solvent control group, the BD-1520 mg/kg dose group has obvious improvement effect on cough frequency, and has statistical significance, wherein P is less than 0.05.

Experimental example 7 pharmacodynamic test of protein BD-15 (example 4 protein) on ICR mouse acetate writhing animals: male ICR mice;

drugs and reagents: aspirin, normal saline, glacial acetic acid and protein BD-15.

Grouping experiments:

a model group;

aspirin (Aspirin)300mg/kg group;

protein BD-15, 50mg/kg group, 200mg/kg group.

The method comprises the following steps:

after the experimental animal is adapted to the environment for one day, aspirin is taken 300mg/kg, protein BD-1550 mg/kg and protein BD-200 mg/kg are taken orally one hour in advance, and the administration volume is 10 ml/kg; then, 0.6% acetic acid solution is injected into the abdominal cavity, and the animal writhing latency (seconds) and times are observed within 15 minutes.

Data processing:

the mean and standard error were calculated for each group and statistical differences were considered to be present when P <0.05 compared to the model group using TTEST.

The experimental results are as follows:

after aspirin was orally administered at 300mg/kg and various doses of protein BD-15(50mg/kg, 200mg/kg) for one hour, 0.6% acetic acid solution was intraperitoneally injected, and the incubation period and frequency of writhing were observed in ICR mice. The results are shown in Table 9.

TABLE 9 Effect of test Agents on ICR mouse acetate writhing experiments

(comparison with model group, P <0.01)

And (4) experimental conclusion:

the injection of 0.6% acetic acid solution into the abdominal cavity of the mouse causes large area and long-term pain stimulation in the deep part, which causes the mouse to generate writhing reaction (the abdomen contracts into an S shape, the trunk and the hind legs stretch, the buttocks rise and wriggle). And (3) judging whether the tested sample has the analgesic effect by taking the latency time and the frequency of the mice starting to generate writhing as the pain response indexes. The experimental result shows that:

1) the aspirin 300mg/kg can obviously prolong the torsion latency and reduce the torsion times, has obvious analgesic effect, and has statistical significance when compared with a model group, wherein P is less than 0.05.

2) The BD-1550 mg/kg dose group can obviously reduce the times of mouse writhing, and compared with the model group, the P is less than 0.05, and the statistical significance is achieved.

Sequence listing

<110> institute of medicine of Chinese academy of medical sciences

<120> a keratin BD-15, its preparation method, its pharmaceutical composition and application

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<170> SIPOSequenceListing 1.0

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<211> 493

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Met Ala Ser His Ser Tyr Asn Ser Ser Ser Tyr Arg Val Arg Asp Phe

1 5 10 15

Ser Ser Cys Ser Ala Val Val Pro Lys Pro Gly Val His Gly Phe Ala

20 25 30

Asn Gly Leu Ala Phe His Gly Gly Ser Pro Gly Gly Pro Gly Tyr Arg

35 40 45

Arg Leu Gly Gly Phe Gly Ser Arg Ser Leu Cys Ala Val Gly Ser Pro

50 55 60

Arg Ile Ala Val Ser Tyr Ala Trp Pro Leu Arg Gly Gly Gly Ser Phe

65 70 75 80

Gly Tyr Gln Ala Gly Gly Leu Tyr Gly Pro Ile Pro Pro Cys Ile Thr

85 90 95

Thr Val Ser Val Asn Glu Ser Leu Leu Ala Pro Leu Asn Leu Glu Ile

100 105 110

Asp Pro Lys Ala Gln Cys Val Lys His Glu Glu Lys Glu Gln Ile Lys

115 120 125

Gly Leu Asn Asn Lys Phe Ala Ala Phe Ile Asp Lys Val Arg Phe Leu

130 135 140

Glu Gln Gln Asn Lys Leu Leu Glu Thr Lys Leu Gln Phe Tyr Gln Asn

145 150 155 160

His Gln Cys Cys Glu Ser Asn Leu Glu Pro Leu Phe Asn Gly Tyr Ile

165 170 175

Glu Thr Leu Arg Arg Glu Ala Glu Cys Val Glu Ala Asn Ser Gly Arg

180 185 190

Leu Ala Ser Glu Leu Asn His Val Glu Glu Val Leu Glu Gly Tyr Lys

195 200 205

Lys Lys Tyr Glu Glu Glu Val Ala Leu Lys Thr Thr Ala Glu Asn Glu

210 215 220

Phe Val Val Leu Lys Lys Asp Ile Asp Cys Ala Tyr Leu Arg Lys Ala

225 230 235 240

Asp Leu Glu Ala Asn Val Glu Ala Leu Lys Glu Glu Met Ser Phe Leu

245 250 255

Gln Ser Leu Tyr Asp Glu Glu Ile Tyr Leu Leu Gln Ser Gln Ile Ser

260 265 270

Asp Thr Ser Val Val Val Lys Met Asp Asn Ser Arg Glu Leu Asn Met

275 280 285

Asp Ser Val Val Ala Glu Ile Lys Ala Gln Tyr Asp Gly Ile Ala Ser

290 295 300

Arg Ser Arg Ala Glu Val Glu Ser Trp Tyr Gln Thr Lys Cys Glu Glu

305 310 315 320

Met Lys Val Thr Val Thr Gln Gln Gly Glu Asn Leu Arg Arg Thr Lys

325 330 335

Glu Glu Ile Asn Glu Leu Asn Arg Met Ile Gln Arg Leu Thr Ala Glu

340 345 350

Val Glu Asn Ala Lys Gln Gln Arg Cys Lys Leu Glu Thr Ala Leu Ala

355 360 365

Glu Ala Glu Gln Gln Gly Glu Ala Ala Leu Asn Asp Ala Lys Cys Lys

370 375 380

Leu Ala Gly Leu Glu Glu Ala Leu Gln Lys Ala Lys Gln Asp Met Ala

385 390 395 400

Cys Leu Leu Lys Glu Tyr Gln Glu Val Met Asn Ser Lys Leu Gly Leu

405 410 415

Asp Val Glu Ile Ala Thr Tyr Arg Lys Leu Leu Glu Gly Glu Glu Ser

420 425 430

Arg Leu Cys Glu Gly Val Gly Ser Ile Asn Ile Cys Val Ser Arg Ser

435 440 445

Gln Gly Gly Val Ile Cys Gly Asp Leu Asp Ser Thr Val Pro Arg Gly

450 455 460

Leu Gly Gly Thr Ala Ile Ser Ser Ser Ala Leu Cys Ser Pro Ser Val

465 470 475 480

Gly Gly Phe Cys Ser Ser Val Arg Ser Val Arg Phe Ala

485 490

<210> 2

<211> 1482

<212> DNA

<213> Bos taurus

<400> 2

atggcttccc actcgtacaa ctctagctcg taccgggtcc gtgatttctc gtcgtgcagc 60

gcggtcgtac caaaacctgg ggtgcatggg ttcgccaacg gtctggcgtt tcacggtggg 120

tcgcctggtg gccctgggta ccgccgtctg ggcggctttg gcagccgtag cctgtgcgcc 180

gtcggctcgc cgcgtattgc ggttagctac gcgtggccgt tgcgtggcgg tggttcattc 240

gggtaccagg ccggtgggct ttacgggccc attcccccct gcatcacaac cgtctcagtt 300

aacgagtcac tgcttgcacc tctgaactta gagatagatc ctaaggccca atgtgtgaag 360

catgaagaaa aggaacagat caagggtctt aacaacaagt tcgctgcgtt catcgacaaa 420

gtgcgctttt tagagcagca aaacaaactt ttggagacca agttgcagtt ttaccagaat 480

catcaatgct gtgagagtaa cctggagcct ctgttcaatg ggtacataga gaccttacgt 540

cgtgaggcgg agtgcgttga ggccaactcc ggacgccttg cgtccgagtt gaatcatgtc 600

gaggaagtgt tagaaggcta caaaaagaaa tacgaagagg aggttgcgct taagacgaca 660

gctgagaatg agtttgtcgt cctgaaaaag gatattgact gcgcatattt acggaaggca 720

gacctggaag cgaacgtcga ggcgttaaaa gaagagatgt ccttcttaca gagcctttac 780

gacgaagaaa tctacctgtt acaaagtcaa atatcggaca cctcagtagt ggtgaagatg 840

gacaattcac gcgagttaaa catggattcc gtggtggctg agataaaagc acagtacgat 900

gggatcgcct cccgctctcg cgcggaggtc gagtcgtggt atcagacgaa atgcgaggaa 960

atgaaagtga ccgtcacaca gcagggcgag aatcttcgcc gtacgaagga ggagatcaac 1020

gagcttaatc ggatgatcca acgcttgacc gcagaagtcg aaaacgctaa acaacagcgg 1080

tgtaagctgg aaactgcgct ggcggaagcg gaacagcaag gggaggccgc actgaatgac 1140

gcgaagtgca agttagcggg cctggaggag gcacttcaga aggccaaaca ggacatggct 1200

tgcttactta aggagtatca ggaggtcatg aactcgaagc tggggcttga cgtggaaata 1260

gccacttacc ggaagttatt agagggtgag gagtcgcggt tatgtgaggg cgttggctcg 1320

ataaacattt gcgtctcccg gtcccaggga ggtgtgatat gcggtgattt ggactccacg 1380

gtcccgcgtg gtttaggcgg cacggcaatt agcagcagcg ccctttgcag cccgtcggtt 1440

gggggattct gctcatcggt gcgttcggta cggttcgcat aa 1482

Claims

1. A keratin BD-15, wherein the amino acid sequence of the keratin BD-15 is:

(1) an amino acid sequence shown as SEQ ID NO.1 in a sequence table;

2. Keratin BD-15 according to claim 1, characterized in that a conventional modification can be made on keratin BD-15; or the keratin BD-15 is also connected with a label for detection or purification.

3. The keratin BD-15 according to claim 2, wherein the conventional modifications include acetylation, amidation, cyclization, glycosylation, phosphorylation, alkylation, biotinylation, fluorophore modification, polyethylene glycol PEG modification, immobilization modification, sulfation, oxidation, methylation, deamination, disulfide bond formation or disulfide bond cleavage; the tags comprise His6, GST, EGFP, MBP, Nus, HA, IgG, FLAG, c-Myc and definition eXact.

4. A nucleic acid molecule encoding the keratin BD-15 of any one of claims 1-3.

5. The nucleic acid molecule of claim 4, wherein said nucleic acid molecule has the nucleotide sequence:

(1) a nucleotide sequence shown as SEQ ID NO.2 in the sequence table;

6. An expression vector comprising the nucleic acid molecule of any one of claims 4 to 5.

7. A host cell comprising the expression vector of claim 6 or having the nucleic acid molecule of any one of claims 4 to 5 integrated into its genome.

8. The host cell of claim 7, wherein said host cell comprises a bacterium, a yeast, an aspergillus, a plant cell, or an insect cell.

9. The host cell of claim 8, wherein said bacterium comprises E.coli.

10. A process for the preparation of a BD-15 keratin protein according to any one of claims 1 to 3, comprising the steps of:

A. synthesizing a nucleic acid molecule corresponding to the keratin BD-15 of any one of claims 1 to 3, linking the nucleic acid molecule to a corresponding expression vector, transforming the expression vector into a host cell, culturing the host cell with the expression vector in a fermentation device under certain conditions, and inducing the expression of the keratin BD-15 to obtain a crude protein solution containing the keratin BD-15;

11. The method according to claim 10, wherein in step a, said host cell is selected from the group consisting essentially of e.coli, said BD-15 keratin is expressed in e.coli inclusion bodies, and said fermentation device comprises a shake flask or a fermentor.

12. The method according to claim 10, wherein in the step a, after the induction of the expression of the keratin BD-15, the impurities are washed with a detergent and dissolved with a solution to obtain a crude protein solution.

13. The method according to claim 10, wherein in step B, the separation and purification method comprises ultrafiltration microfiltration membrane purification, column chromatography purification, salting out method, dialysis method.

14. A pharmaceutical composition comprising the keratin BD-15 of any one of claims 1 to 3 and a pharmaceutically acceptable carrier or excipient.

15. Use of the keratin BD-15 of any one of claims 1 to 3 or the nucleic acid molecule of any one of claims 4 to 5 or the expression vector of claim 6 or the host cell of claims 7 to 9 or the pharmaceutical composition of claim 14 for the preparation of a medicament for antipyretic, analgesic, antitussive, expectorant, anticonvulsant, antiepileptic, hypotensive, anti-inflammatory, antiviral.