CN112724224B

CN112724224B - Keratin BD-15, its preparation method, its pharmaceutical composition and use

Info

Publication number: CN112724224B
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: 2023-09-26
Anticipated expiration: 2039-10-28
Also published as: CN112724224A; WO2021083205A1

Abstract

The invention relates to a keratin BD-15, a nucleic acid molecule encoding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the expression vector or genome integrated with the nucleic acid molecule, 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 antipyretic analgesic drugs, antitussive expectorant drugs, anticonvulsant drugs, antiepileptic drugs, antihypertensive drugs, anti-inflammatory drugs and antiviral drugs.

Description

Keratin BD-15, its preparation method, its pharmaceutical composition and use

Technical Field

The invention relates to a keratin BD-15, a nucleic acid molecule encoding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the expression vector or a genome integrated with the nucleic acid molecule, 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 antipyretic analgesic, antitussive, expectorant, anticonvulsant, antiepileptic, antihypertensive, anti-inflammatory and antiviral drugs.

Background

Keratin is a kind of protein, widely existing in human and animal epidermis, and is a major component of hair, feathers, hooves, shells, paws, horns, etc., and is a structural protein that is extremely important for connective tissues, and plays a role in protecting the body.

Keratin is widely available in organisms and is a renewable resource with great utility value, but is not widely and effectively utilized. The main reasons are that keratin is insoluble in various solvents and that keratin is generally more resistant to enzymatic hydrolysis by proteases than other proteins. The difficulty of extraction and preparation of natural keratin is thus very great.

With the rapid development of modern biotechnology such as genomics, proteomics, genetic engineering, microbial engineering, etc., more and more genes are discovered. The use of protein expression systems for the production of proteins of interest is an important tool for the study of the biological functions of genes or proteins.

The protein expression system is used for preparing the target keratin, so that the structure and the function of the target keratin are researched, and no other documents report the target keratin, and the target keratin has novelty and creativity.

Disclosure of Invention

The technical problem solved by the invention is to provide a keratin BD-15, a nucleic acid molecule for encoding the keratin BD-15, an expression vector containing the nucleic acid molecule, a host cell containing the nucleic acid molecule or a genome integrated with the nucleic acid molecule, 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 antipyretic analgesic, antitussive, expectorant, anticonvulsant, antiepileptic, antihypertensive, antiinflammatory and antiviral drugs.

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

according to a first aspect of the present invention, there is provided a keratin BD-15, wherein the keratin BD-15 has an amino acid sequence of:

(1) An amino acid sequence shown as SEQ ID NO.1 in the sequence table;

(2) The amino acid sequence shown in SEQ ID No.1 in the sequence table basically maintains the same biological function through substitution, deletion or addition of 1-35 amino acids.

Further, conventional modifications may be made on the keratin BD-15; or a label for detection or purification is further attached to the keratin BD-15.

Still further, such 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 tag comprises His6, GST, EGFP, MBP, nus, HA, igG, FLAG, c-Myc and proficiency eXact.

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

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

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

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

(3) A nucleotide sequence complementary to the nucleotide sequence of (1) or (2) above.

According to 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, pPIC9K, pHIL-S1, pPICZ alpha/A, pYAM P, pHIL-D2, pA0815, pPIC3K, pPICZ, pHWO10, pGAPZ, pGAPZa, pPIC3.5K, etc.; preferred expression vectors are pET series vectors; the most preferred expression vector is pET-28a (+).

According to a fourth aspect of the present invention there is provided a host cell comprising an expression vector according to the third aspect or a nucleic acid molecule according to the second aspect integrated into the genome.

Further, the host cell includes bacteria, yeast, aspergillus, plant cells, or insect cells.

Still further, the bacteria include E.coli or yeast.

Competent host cells can be BL21 series, transetta series, rosetta series, DH 5. Alpha. Series, JM series, top series, orgami series, trans1-T1, TG1, TB1; y11430, MG1003, GS115 (AOX 1), KM71, SMD1168, etc.; a preferred expression competent cell is BL21 (DE 3), transetta (DE 3).

A fifth aspect of the present invention provides a method for preparing the keratin BD-15 according to the first aspect, comprising the steps of:

A. synthesizing a nucleic acid molecule corresponding to the keratin BD-15 in the first aspect, connecting the nucleic acid molecule into a corresponding expression vector, transforming the expression vector into a host cell, culturing the host cell with the expression vector in fermentation equipment 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 C, separating, purifying and drying the crude protein solution expressed in the step A to obtain the keratin BD-15.

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

Further, in the step A, after the induced expression of the keratin BD-15, impurities may be washed with a detergent, and dissolved with a solution to obtain a crude protein 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-salt Zolla culture medium, DOBA culture medium, rice koji culture medium, modified formula thereof and the like; shake flask fermentation is preferably performed on LB medium and TB medium, and most preferably TB medium; the fermentation tank is preferably LB culture medium and its improved 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, the obtained fermentation broth is centrifuged, and the supernatant is discarded; suspending the precipitate in buffer solution, crushing thallus, centrifuging, and discarding supernatant; and (3) cleaning the precipitate by using a cleaning agent, and then dissolving the precipitate by using a urea solution to obtain a BD-15 crude protein solution.

Wherein, buffer is preferably buffer A, and the dosage is as follows: volume of fermentation broth: buffer a volume=1 to 100:1, preferably 10:1;

the cleaning agent can be urea solution, guanidine hydrochloride solution, triton, buffer A, etc., preferably urea solution, most preferably 2M urea solution (which may contain 1% Triton), and the amount thereof is as follows: volume of fermentation broth: 2M urea volume=0.2-100:1, preferably 1-15:1;

The urea solution is preferably an 8M urea solution, and the dosage of the urea solution is as follows: volume of fermentation broth: 8M urea volume=0.2-100:1, preferably 2-15:1.

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

Further, in the step B, the separation and purification method is as follows:

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

The dialysis bag cut-off molecular weight may be from 0.5 to 10kD, with a preferred dialysis bag cut-off molecular weight of from 3.5 to 10kD, and a most preferred dialysis bag cut-off molecular weight of 10kD.

(2) The ultrafiltration and microfiltration method is characterized in that the crude protein solution obtained in the step A is purified by using ultrafiltration membranes or microfiltration membranes and other membrane technologies to obtain the target protein BD-15 concentrated solution.

Preferably, the method comprises two times of microfiltration membrane purification, wherein the first membrane has a pore diameter of 1000-1500 nm and the second membrane has a pore diameter of 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, so as to obtain the target protein BD-15.

Preferred exclusion columns are sephadex columns, superdex 30Increase,Superdex 75Increase,Superdex 200Increase,Superose 6Increase, etc.; the preferred exchange column is an ion exchange resin column: anion exchange resin column, hiTrap Q FF, hiTrap Capto Q Impres, hiTrap Capto Q, hiTrap DEAE, toyopearl Q-650M,Toyopearl SuperQ-650M, etc.; 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.

The eluent may be used as an eluent commonly used in the art, such as water, a salt solution including sodium chloride solution, sodium dihydrogen phosphate solution, disodium hydrogen phosphate solution, sodium acetate, acetic acid, etc.

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

The salting-out agent may be ammonium sulfate, sodium chloride, magnesium chloride, aluminum sulfate, ammonium nitrate, ammonium chloride, magnesium sulfate, etc. The preferred salting-out agent is ammonium sulfate and an aqueous solution thereof. The saturated aqueous ammonium sulfate solution is added to achieve a final concentration of ammonium sulfate of 10 to 50%, preferably 20 to 30%, more preferably 25%.

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

Adding pure water into the precipitate after salting out for cleaning for 2-5 times, preferably 3 times.

Furthermore, the target protein BD-15 solution obtained by purification in the step B can be freeze-dried or vacuum-dried to form dry powder, or the concentrated solution can be directly spray-dried to form dry powder.

According to 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 above steps of the present invention may be freeze-dried or vacuum-dried to form a dry powder, or the concentrated liquid may be directly spray-dried to form a dry powder, and then made into various dosage forms.

The invention relates to a pharmaceutical composition comprising any one of keratins obtained in the above steps and a pharmaceutically acceptable carrier.

The invention also relates to pharmaceutical compositions containing as active ingredient the keratin of the invention and conventional pharmaceutical excipients or auxiliaries. The keratin of the invention generally represents 0.1 to 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 may, if desired, be combined with one or more solid or liquid pharmaceutical excipients and/or auxiliaries, in the form of suitable administration forms or dosage forms which can be used as human or veterinary medicines.

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

The administration route of the keratin of the present invention or the pharmaceutical composition containing the same may be injection administration. The injection includes intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection, intraperitoneal injection, acupoint injection, etc.

The dosage form may be a liquid, solid or semi-solid dosage form. The liquid dosage forms can be solutions (including true solution and colloidal solution), emulsions (including oil-in-water, water-in-oil, and multiple emulsions), suspensions, injections (including water injections, powder injections, and infusions), eye drops, nasal drops, lotions, liniments, and the like. The solid dosage forms can be tablets (including common tablets, enteric coated tablets, buccal tablets, dispersible tablets, chewable tablets, effervescent tablets, orally disintegrating tablets), capsules (including hard capsules, soft capsules and enteric coated capsules), granules, powder, micropills, dripping pills, suppositories, films, patches, aerosol (powder) and sprays; the semisolid dosage form may be an ointment, gel, paste, or the like.

The keratin of the invention can be prepared into common preparations, slow release preparations, controlled release preparations, targeted preparations and various microparticle administration systems.

For the purpose of tableting unit dosage forms, various excipients known in the art, including diluents, binders, wetting agents, disintegrants, lubricants, glidants, may be widely used. The diluent can be starch, dextrin, sucrose, glucose, lactose, mannitol, sorbitol, xylitol, microcrystalline cellulose, calcium sulfate, calcium hydrogen phosphate, calcium carbonate, etc.; the wetting agent can be water, ethanol, isopropanol, etc.; the binder may be starch slurry, dextrin, syrup, mel, glucose solution, microcrystalline cellulose, acacia slurry, gelatin slurry, sodium carboxymethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, ethyl cellulose, acrylic resin, carbomer, polyvinylpyrrolidone, polyethylene glycol, etc.; the disintegrating agent can be dry starch, microcrystalline cellulose, low substituted hydroxypropyl cellulose, crosslinked polyvinylpyrrolidone, crosslinked sodium carboxymethyl cellulose, sodium carboxymethyl starch, sodium bicarbonate and citric acid, calcium carbonate, polyoxyethylene sorbitol fatty acid ester, and sodium dodecyl sulfonate; 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 bilayer and multilayer tablets.

For the preparation of the dosage unit into a pill, various carriers well known in the art can be widely used. Examples of carriers are, for example, diluents and absorbents such as glucose, lactose, starch, cocoa butter, hydrogenated vegetable oils, polyvinylpyrrolidone, polyethylene glycol glycerol laurate, kaolin, talc, etc.; binding agents such as acacia, huang Pujiao, gelatin, ethanol, honey, liquid sugar, rice paste or batter, etc.; disintegrants such as agar powder, dry starch, alginate, sodium dodecyl sulfate, methylcellulose, ethylcellulose, etc.

For preparing the dosage unit into suppositories, various carriers well known in the art can be widely used. Examples of carriers include polyethylene glycol, lecithin, cocoa butter, higher alcohols, esters of higher alcohols, gelatin, semisynthetic glycerides, and the like.

In order to capsule the administration unit, the keratin of the present invention is mixed with the above-mentioned various carriers, and the thus obtained mixture is placed in a hard gelatin capsule or a soft capsule. The keratin of the invention can be made into microcapsule, which is suspended in water medium to form suspension, or be made into hard capsule or injection.

For example, the keratin of the present invention is formulated into an injectable preparation such as a solution, suspension solution, emulsion, lyophilized powder for injection, which may be aqueous or nonaqueous, 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, polyoxy isostearyl alcohol, polyoxyethylene sorbitol fatty acid esters, and the like. In addition, in order to prepare an isotonic injection, an appropriate amount of sodium chloride, glucose or glycerin may be added to the preparation for injection, and further, a conventional cosolvent, a buffer, a pH adjuster, and the like may be added. These adjuvants are commonly used in the art.

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

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

The dosage 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, weight, character and individual response of the patient or animal, the administration route, the number of administrations, the purpose of treatment, and thus the therapeutic dosage of the present invention may vary widely. Generally, the dosages of pharmaceutical ingredients used in the present invention are well known to those skilled in the art. The actual amount of drug contained in the final formulation of the keratin composition according to the invention can be suitably adjusted to achieve the therapeutically effective amount thereof, thus achieving the preventive or therapeutic purpose of the present invention. Daily suitable dosage range of keratin according to the invention: the keratin of the present invention is used in an amount of 0.01 to 500mg/kg body weight, preferably 0.5 to 100mg/kg body weight, more preferably 1 to 50mg/kg body weight, most preferably 2 to 30mg/kg body weight. The above-mentioned dosages may be administered in a single dosage form or in divided dosage forms, for example, two, three or four dosage forms, depending on the clinical experience of the administering physician and the dosage regimen involving the use of other therapeutic means. The total dose required for each treatment may be divided into multiple or single doses. The protein or pharmaceutical composition of the invention may be taken alone or in combination with other therapeutic or symptomatic agents and adjusted in dosage.

According to a seventh aspect of the present invention, there is provided 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 for the preparation of an antipyretic, analgesic, antitussive, expectorant, anticonvulsant, antiepileptic, antihypertensive, antiinflammatory, antiviral drug.

In order to achieve the purpose of the invention, the following technical scheme is adopted, in particular to the preparation of the keratin BD-15, which comprises the following steps:

(1) Synthesizing a nucleotide sequence and determining the accuracy of the sequence;

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, pPIC9K, pHIL-S1, pPICZ alpha/A, pYAM P, pHIL-D2, pA0815, pPIC3K, pPICZ, pHWO, pGAPZ, pGAPza, pPIC3.5K, etc.; preferred expression vectors are pET series vectors; the most preferred expression vector is pET-28a (+).

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

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

Competent cells can be BL21 series, transetta series, rosetta series, DH 5. Alpha. Series, JM series, top series, orgami series, trans1-T1, TG1, TB1; y11430, MG1003, GS115 (AOX 1), KM71, SMD1168, etc.; a preferred expression competent cell is BL21 (DE 3), transetta (DE 3).

(4) Fermenting and culturing the host cells under proper conditions to induce the expression of 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, bengalia red culture medium, high-salt Boehringer's culture medium, DOBA culture medium, rice yeast culture medium, and its modified formula; shake flask fermentation is preferably performed on LB medium and TB medium, and most preferably TB medium; the fermentation tank is preferably LB culture medium and its improved formula.

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

(5) Enrichment of the target protein BD-15 product;

centrifuging the fermentation broth obtained in the step (4), and discarding the supernatant; suspending the precipitate in buffer solution, crushing thallus, centrifuging, and discarding supernatant; and (3) cleaning the precipitate by using a cleaning agent, and then dissolving the precipitate by using a urea solution to obtain a BD-15 crude protein solution.

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

and (3) 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 using a dialysis method to obtain the target protein BD-15 solution.

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

C. The 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 times are 1 to 3 times, preferably 2 times.

The target protein BD-15 solution obtained by purification in the steps A-D can be freeze-dried or vacuum-dried to form dry powder, or the concentrated solution can be directly spray-dried to form dry powder.

The beneficial technical effects of the invention are as follows:

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

3. according to the invention, through the pharmacodynamic test research of the protein BD-15 on mice convulsion and epilepsy caused by Pilocarpine (PLO) and Pentatetrazole (PTZ), the protein BD-15 can obviously prolong the stage III and stage IV seizure incubation periods of the mice;

4. According to the invention, through the pharmacodynamic test research of protein BD-15 on eliminating phlegm by a mouse phenol red excretion method, the protein BD-15 has the trend of increasing the phenol red excretion amount and has the potential of eliminating phlegm;

5. according to the invention, through the pharmacodynamic test research of the protein BD-15 on the cough relieving method of the ammonia water of the mice, the protein BD-15 is proved to be capable of obviously reducing the times of cough and has obvious cough relieving effect;

6. according to the invention, through the pharmacodynamic test research of the protein BD-15 on ICR mouse acetic acid torsion, the protein BD-15 can obviously reduce the number of times of mouse torsion, and has an obvious analgesic effect.

Drawings

Fig. 1: SDS polyacrylamide gel electrophoresis (SDS-PAGE) analysis of expressed protein BD-15 reduction type

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

FIG. 2 influence of protein BD-15 on yeast-induced fever model in rats

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

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

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

Detailed Description

The following examples and pharmacological activity test examples are provided to further illustrate the present invention, but are not meant 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 all purchased from conventional biochemistry reagents.

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

Synthesizing a nucleotide sequence shown as SEQ ID No.2, and transferring the nucleotide sequence into a pET-28a (+) vector; sequencing and determining to obtain an expression vector containing a correct sequence; the expression vector is transfected into BL21 (DE 3) cells to obtain expression competent host cells containing the nucleotide sequence of interest. Added into LB medium, cultured in a shaker at 37 ℃ and 220rpm for 1 hour to obtain recombinant strain.

Dip recombinant strain streaked on Kana mycin containing LBA plates, the plates were placed upside down in a 37℃incubator overnight for 16 hours.

400ml of TB medium was prepared and 2 bottles of 200ml each were dispensed. Kanamycin (final concentration 50. Mu.g/ml) was added to each bottle (200 ml) of TB medium, and single colonies on the plates were added to the TB medium, and subjected to amplification culture overnight in a shaker at 37℃and 220rpm to obtain seed solutions.

28.8L of TB medium was prepared, and the culture medium was dispensed into 144 flasks of 200ml each. Kanamycin (final concentration 50. Mu.g/ml) was added to each bottle (200 ml) of TB medium, and 2ml of seed solution was added thereto, and the mixture was cultured in a shaker at 37℃and 220rpm for 2-3 hours. Monitoring OD ₆₀₀ When OD ₆₀₀ When the temperature reaches about 1.0, an inducer is added to induce the expressed protein in a shaking table, and the induction conditions are selected from the following table.

Mixing the bacterial solutions, centrifuging at 7000rpm for 5 minutes, sterilizing the supernatant, and discarding; the precipitate was suspended in about 3L of buffer, filtered through a 80-100 mesh screen, and the filtrate was broken with a high pressure breaker at a pressure of 800-1000bar for 2 times, each for 2 minutes. After disruption, the bacterial liquid was centrifuged at 7000rpm for 30 minutes, and the supernatant was discarded to obtain a pellet (i.e., inclusion body). The precipitate was washed 2 times with 1L of a washing agent, centrifuged, and the supernatant was discarded. The precipitate was dissolved 4 times by adding urea solution, 800ml, 600ml, 400ml respectively. Combining the 4 times of solutions, centrifuging at 7000rpm for 30 minutes, discarding the precipitate, and obtaining the supernatant as the crude protein solution A.

Crude protein BD-15 solution A was stained with Coomassie Brilliant blue R250 method, at a concentration of 12.5% as a separating gel by reducing SDS-PAGE; a distinct blue band was shown around molecular weight 53 kD.

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

The expression vector containing the sequence shown as SEQ ID No.2 was synthesized and sequenced as determined in example 1; the expression vector is transfected into BL21 (DE 3) cells to obtain expression competent host cells containing the nucleotide sequence of interest.

20ml of LB medium was prepared, 800. Mu.l of host cells containing the target coding sequence were added thereto, and cultured in a shaker at 37℃and 220rpm for 1 hour.

Dip the bacterial liquid in Kanamycin containing LBA plate streak, plate was placed in 37 degrees C constant temperature incubator overnight culture 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 the LB medium, and the mixture was subjected to amplification culture in a shaker at 37℃and 220rpm overnight to obtain a seed solution.

1L of the medium shown in the following table was prepared, and the medium was dispensed into 10 bottles of 100ml each. Kanamycin (final concentration 50. Mu.g/ml) was added to each flask (100 ml) of the medium, followed by 1ml of the seed solution, and the mixture was cultured in a shaker at 37℃and 220rpm for 2-3 hours. Monitoring OD ₆₀₀ When OD ₆₀₀ When reaching about 1.0, the inducer IPTG (final concentration 0.5 mM) was added, and the protein was induced in a shaker at 37℃and 220 rpm.

Culture medium

LB medium, SOB medium and SOC medium

Mixing the bacterial solutions, centrifuging at 10000rpm for 10 min, sterilizing the supernatant, and discarding; the precipitate was suspended in about 100mL of buffer, filtered through a 80-100 mesh screen, and the filtrate was broken with a high pressure breaker at a pressure of 800-1000bar for 2 times, each for 2 minutes. After disruption, the bacterial liquid was centrifuged at 10000rpm for 30 minutes, and the supernatant was discarded.

Adding 40mL of cleaning agent buffer A into the precipitate, cleaning for 3 times, centrifuging, and removing supernatant; adding 40mL of cleaning agent 2M urea solution into the precipitate to clean for 2 times, centrifuging, and discarding 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 solution) for 3 times, 40ml, 30ml respectively; and combining the solutions, centrifuging at 7000rpm for 30 minutes, discarding the precipitate, and obtaining the supernatant as the crude protein solution B.

Crude protein BD-15 solution B was stained with Coomassie Brilliant blue R250 method, at a concentration of 12.5% as a separating gel by reducing SDS-PAGE; a distinct blue band was shown around molecular weight 53 kD.

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

The expression vector containing the sequence shown as SEQ ID No.2 was synthesized and sequenced as determined in example 1; the expression vector is transfected into BL21 (DE 3) cells to obtain expression competent host cells containing the nucleotide sequence of interest. Added into LB medium, cultured in a shaker at 37 ℃ and 220rpm for 1 hour to obtain recombinant strain.

In the Kanamycin containing LBA plate, adding recombinant strain 100 u l, the applicator to even dry, plate was placed in 37 degrees C constant temperature incubator overnight culture. Respectively streaking three single colonies in a plate containing Kana mycin, culturing the plate overnight, after confirming that the expression is correct through three shake flask fermentation, preserving the strain with 15% glycerol, subpackaging into 0.8ml each, and obtaining a working cell bank, and freezing the working cell bank in a refrigerator at the temperature of minus 80 ℃ for later use.

Taking out 1-branch glycerol bacteria from the working cell library, adding 100 μl into 40ml LB culture medium, adding Kana mycin (final concentration 50 μg/ml), and culturing in a shaker at 37deg.C and 220rpm for 6 hr to obtain primary seed solution.

1.2ml of the primary seed solution was taken, and added to 120ml of LB medium, kana mycin (final concentration: 50. Mu.g/ml) was added, and the mixture was cultured 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, followed by 120ml of a secondary seed solution and 3ml of Kana-mycin (final concentration: 50. Mu.g/ml) and cultured at 37℃under a condition of 30% dissolved oxygen (serial rotation speed) for about 8 hours. OD was monitored to be about 20, 3g lactose was used as inducer, induction was performed at 20℃and feed was performed at a rate of 30 ml/hr, and incubation was performed at 20℃for 24 hours.

Centrifuging the bacterial liquid at 7000rpm for 5 minutes, sterilizing the supernatant, and discarding the supernatant; the precipitate was suspended in about 200ml buffer A, filtered through a 80-100 mesh screen, and the filtrate was crushed with a high pressure crusher at a pressure of 800-1000bar for 2 times each for 2 minutes. After disruption, the bacterial liquid was centrifuged at 7000rpm for 30 minutes, and the supernatant was discarded.

The precipitate was washed 2 times with 1L each of 2M urea solution (1% Triton); then, 1L of 2M urea solution was added thereto and washed 1 time, followed by centrifugation, and the supernatant was discarded. The precipitate was dissolved 4 times by adding 8M urea solution, 400ml, 300ml, 200ml, 100ml respectively. Combining the four solutions, centrifuging at 7000rpm for 30 minutes, discarding the precipitate, and obtaining the supernatant as the crude protein solution C.

Crude protein BD-15 solution C was stained with Coomassie Brilliant blue R250 method at a concentration of 12.5% by reducing SDS-PAGE; a distinct blue band was shown around molecular weight 53 kD.

EXAMPLE 4 preparation of crude protein solution A protein BD-15 by dialysis

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

Protein BD-15 structure confirmation:

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

Instrument: protein electrophoresis apparatus (Bio-Rad).

Method and results: protein BD-15 solution was stained with Coomassie Brilliant blue R250 method, at a concentration of 12.5% as a separating gel by reducing SDS-PAGE. BD-15 band molecular weight was 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 instrument is as follows: capillary high performance liquid chromatograph (Thermo Ultimate 3000 type), electrospray-combined ion trap Orbitrap mass spectrometer (Thermo Q Exative Hybrid Quadrupole-Orbitrap Mass Spectrometer).

Method and results:

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

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

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

the first method is as follows: salting out;

the crude protein solution A is placed in a container with stirring for salting out twice: slowly adding an ammonium sulfate saturated solution along the wall to ensure that the final concentration of the ammonium sulfate is 25% or 50%, separating out protein in the salting-out process, and filtering after salting-out is completed to finish the first salting-out; adding 400ml of pure water into the precipitate for suspension, slowly adding ammonium sulfate saturated solution along the wall again to make the final concentration of ammonium sulfate be 25%, salting out for the second time, and filtering to obtain the 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, precipitating, freeze drying and obtaining the target protein BD-15.

The second method is as follows: column chromatography;

the crude protein solution A is purified by anion exchange resin columns such as HiTrap Q FF 16/10,HiTrap Capto Q ImpRes,Capto Q ImpRes,HiTrap Capto Q,HiTrap DEAE and the like. The eluent is NaCl solution for gradient elution, and 20mM NaH is added ₂ PO ₄ /Na ₂ HPO ₄ Buffer (pH 8.0). The eluate fractions were pooled by SDS-PAGE electrophoresis, and the pooled eluate was centrifuged 2 times at 7000rpm for 1 hour each; the supernatant was filtered through a 0.45 μm filter, and the filtrates were combined. Concentrating the filtrate by water dialysis, intercepting the molecular weight of 10kD by a dialysis bag, and freeze-drying the inner liquid to obtain the target protein BD-15.

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

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

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

the first method is as follows: dialyzing;

filtering the crude protein solution B with 0.45 μm membrane, dialyzing the filtrate with water, dialyzing for more than 72 hr, and lyophilizing the inner solution to obtain the target protein BD-15.

Dialysis bag

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

The second method is as follows: column chromatography;

The crude protein solution B is purified by anion exchange resin columns such as HiTrap Q FF 16/10,HiTrap Capto Q ImpRes,Capto Q ImpRes,HiTrap Capto Q,HiTrap DEAE and the like. The eluent is NaCl solution for gradient elution, and 20mM NaH is added ₂ PO ₄ /Na ₂ HPO ₄ Buffer (pH 8.0). The eluate fractions were pooled by SDS-PAGE electrophoresis, and the pooled eluate was centrifuged 2 times at 7000rpm for 1 hour each; the supernatant was filtered through a 0.45 μm filter, and the filtrates were combined. Concentrating the filtrate by water dialysis, and retaining molecular weight of 10kD in dialysis bagAnd (5) freeze-drying the solution to obtain the target protein BD-15.

The third method is as follows: salting out;

the crude protein solution B is placed in a container with stirring for salting out twice: slowly adding an ammonium sulfate saturated solution along the wall to ensure that the final concentration of the ammonium sulfate is 25% or 50%, separating out protein in the salting-out process, and filtering after salting-out is completed to finish the first salting-out; adding 400ml of pure water into the precipitate for suspension, slowly adding ammonium sulfate saturated solution along the wall again to make the final concentration of ammonium sulfate be 25%, salting out for the second time, and filtering to obtain the 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, precipitating, freeze drying and obtaining the target protein BD-15.

The protein BD-15 obtained in the three methods had the same amino acid sequence as the protein prepared in example 4, as confirmed by the same structure confirmation method as in example 4.

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

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

the first method is as follows: microfiltration membrane technology;

protein crude solution C, purified by microfiltration membrane technology: firstly, carrying out solid-liquid separation by using a 1500nm or 1000nm ceramic membrane core; discarding the inner liquid, and repeatedly micro-filtering the outer liquid by using a 20nm or 50nm ceramic membrane core to remove urea; and freeze-drying the secondary microfiltration inner liquid to obtain the target protein BD-15.

The second method is as follows: salting out;

the crude protein solution C is placed in a container with stirring for salting out twice: slowly adding an ammonium sulfate saturated solution along the wall to ensure that the final concentration of the ammonium sulfate is 25%, separating out protein in the salting-out process, and filtering after the salting-out is completed to finish the first salting-out; adding 400ml of pure water into the precipitate for suspension, slowly adding ammonium sulfate saturated solution along the wall again to make the final concentration of ammonium sulfate be 25%, salting out for the second time, and filtering to obtain the 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, precipitating, freeze drying and obtaining the target protein BD-15.

Pharmacological test

Experimental example 1 test of the efficacy of protein BD-15 (protein of example 4) on a model of yeast-induced SD rat fever

Animals: 230-260 g of male SD rat;

medicine: saccharomycetes (OXOID LP 0021), aspirin (SIGMA A A2093), protein BD-15;

instrument: an electronic balance (SARTORIUS BP121S type), and an electronic thermometer (CITIZEN CT-513W type).

Experimental grouping:

normal control group;

model group: a yeast heating 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 in an experimental environment (the temperature is 22+/-2 ℃ and the relative humidity is 50+/-2%) for 1 day, pre-adaptation measurement of the anal temperature is carried out at the early time of 8:00 and 15:00 respectively, no water is forbidden after feeding for 12 hours before the experiment, and the animals are emptied of excrement before the anal temperature is measured. Before each temperature measurement, the probe of the electronic thermometer is smeared with vaseline, and is inserted into the rectum of a rat for 2cm (the mark can be arranged at the position of 2cm to ensure that the insertion depth is consistent each time), and the body temperature value is recorded after the reading number is stable.

Subcutaneous dry yeast replicate rat fever model: the body temperature of the rats is measured before molding, and qualified rats with the body temperature of 36.2-37.3 ℃ are screened out, randomly grouped, and 8 rats are selected from each group. Immediately after oral administration of aspirin and different doses of protein BD-15, a 20% yeast suspension (10 ml/kg) was subcutaneously injected, and normal control groups were subcutaneously injected with an equal volume of physiological saline, and after 2 hours, the body temperature of rats was monitored 1 time every 2 hours, for a total of 8 hours. Data statistics:

based on the temperature values measured at each time point on the day of the experiment, the average, standard deviation and standard error of the temperature of each group of rats are calculated, and the data of each group are compared among groups by using TTEST, wherein P <0.05 is considered to have significant difference.

Experimental results:

immediately after oral administration of aspirin (300 mg/kg), protein BD-15 (10 mg/kg, 50 mg/kg), 20% yeast was subcutaneously injected for molding, and animal body temperature 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 agents on the yeast-induced fever model of rats

(P <0.01, P <0.001 compared to normal control; P <0.05, #p <0.01, #p <0.001 compared to model group) experimental conclusion:

immediately after oral administration of aspirin (300 mg/kg), protein BD-15 (10 mg/kg, 50 mg/kg), 20% yeast was subcutaneously injected for molding, and animal body temperature 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 rats in the model group is obviously increased in 2 hours, 4 hours, 6 hours and 8 hours when the rats are molded, and compared with the rats in the normal group, the rats in the model group have the statistical difference, and the model is successfully, stably and reliably established.

2) The positive tool medicine aspirin group can effectively inhibit the body temperature rise of a model rat in 2 hours, 4 hours, 6 hours and 8 hours of modeling, and compared with the model group, the positive tool medicine aspirin group has a statistical difference, and the positive tool medicine aspirin group has stable performance.

3) The protein BD-15 with different dosages can inhibit the body temperature rise of the model rat to different degrees after the model is molded; the 50mg/kg dose group has stronger effect, can inhibit the body temperature rise of the model rat in 2 hours, 4 hours, 6 hours and 8 hours after the modeling, and has statistical difference when compared with the model group, the P is less than 0.05; the 10mg/kg dose group inhibited model rat body temperature elevation at 2 hours, 6 hours, 8 hours post-molding, and had a statistical difference in P <0.05 compared to the model group.

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

Animals: 230-260 g of male SD rat;

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

Experimental grouping:

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 intraperitoneal injection of lipopolysaccharide comprises the following steps:

preparation of experimental animals: after the experimental animals are adapted for 1 day in an experimental environment (the temperature is 22+/-2 ℃ and the relative humidity is 50% +/-2%), the operation of measuring the anal temperature is pre-adapted at 8:00 and 15:00, the operation is fasted for 12 hours before the experiment, water is not forbidden, and the animal is emptied of excrement before the anal temperature is measured. Before each temperature measurement, the probe of the electronic thermometer is smeared with vaseline, and is inserted into the rectum of a rat for 2cm (the mark can be arranged at the position of 2cm to ensure that the insertion depth is consistent each time), and the body temperature value is recorded after the reading number is stable.

Intraperitoneal injection of lipopolysaccharide replicates the rat fever model: the body temperature of the rats is measured before molding, and qualified rats with the body temperature of 36.2-37.3 ℃ are screened out, randomly grouped, and 8 rats are selected from each group. Immediately after oral administration of aspirin and different doses of protein BD-15, lipopolysaccharide (20. Mu.g/kg, 2 ml/kg) was injected intraperitoneally, and the normal control group was injected intraperitoneally with an equal volume of physiological saline, and after 2 hours, the body temperature of the rats was monitored for a total of 8 hours.

Data statistics:

Experimental results:

immediately after oral administration of aspirin (300 mg/kg), protein BD-15 (10 mg/kg, 50 mg/kg), 20. Mu.g/kg lipopolysaccharide was injected intraperitoneally 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 3 and FIG. 3.

TABLE 2 influence of test agents on Lipopolysaccharide (LPS) -induced fever model in rats

Conclusion of experiment:

immediately after oral administration of aspirin (300 mg/kg), protein BD-15 (10 mg/kg, 50 mg/kg), and molding by intraperitoneal injection of 20. Mu.g/kg lipopolysaccharide, animal body temperature was monitored at 2 hours, 4 hours, 6 hours, 8 hours after molding, and the results showed that:

1) The intraperitoneal injection of 20 mug/kg lipopolysaccharide can successfully induce the body temperature of rats to rise, the body temperature of rats in a model group is obviously raised in 2 hours, 4 hours, 6 hours and 8 hours when the rats are molded, and compared with a normal group, the rats have the P <0.05, have statistical differences and are stable in model.

2) The positive tool medicine aspirin group can effectively inhibit the body temperature rise of a model rat in 2 hours, 4 hours, 6 hours and 8 hours of modeling, and compared with the model group, the positive tool medicine aspirin group has the statistical difference, and the positive tool medicine has more stable performance.

3) BD-15 50mg/kg dose group had a tendency to lower body temperature of model rats at 2 hours and 4 hours after molding, but was not statistically significant.

Experimental example 3 test of the efficacy of protein BD-15 (example 4 protein) on convulsive agent Pilocarpine (PLO) in mice convulsive epilepsy

Animals: male ICR mice;

medicine: pilocarpine HCl (PLO, pilocarpine hydrochloride), diazepam (Diazepam tablet), protein BD-15.

Experimental grouping:

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 drug administration:

the drug is administered once in the afternoon before molding, PLO-225mg/kg (molding agent) is injected intraperitoneally 1 hour after the gastric administration of the test drug on the molding day, and the positive drug is administered once 20 minutes before molding. Observations were continued for 30 minutes after injection of PLO.

And (3) observing the indexes: (1) seizure condition: II-IV level attack time; (2) time to death.

Seizure level: reference is made to the Racine grading standard: level 0: without any reaction; stage I: expressed as facial muscle or mouth angle twitches; stage II: nodding can be performed; class III: a lateral limb tic; grade IV: tonic or generalized limb twitch; v level: general seizure (generalized tonic seizure) of epilepsy.

And (3) data processing:

counting IV grade attacks and death cases of each group of mice in the experiment; the latency of mice from no onset to stage IV was noted as maximum 1800 seconds for stage II, III and IV latencies. The statistics of the number of cases is counted by using a chi-square test. Mean and standard error were calculated at latency, and the model group was compared to the other groups using a TTEST, with P <0.05 considered significant differences.

Experimental results: see tables 3 and 4.

TABLE 3 experiment of the test agent on PLO induced mouse epilepsy-statistics of the number of cases

Group of	Number of experimental examples	Number of IV-level cases	Grade IV seizure rate	Number of deaths	Mortality rate of
						Model group	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％

(P <0.05, P <0.01 compared to model group)

TABLE 4 seizure incubation period (mean+ -SEM) of PLO induced mice with test agent

Group of	Stage II seizure incubation period(s)	Stage III seizure incubation period(s)	Stage IV seizure incubation period(s)
				Model group	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

(P <0.05, P <0.01 compared to model group)

Conclusion of experiment:

1) The experimental results show that the IV seizure rate of the model group is 90%. 1 out of 40 mice died.

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

3) In the comparison of latency to epileptic grade IV, the BD-15 50mg/kg group was statistically different from the model group.

Experimental example 4 pharmacodynamic test of protein BD-15 (example 4 protein) against Pentatetrazole (PTZ) induced mouse epilepsy

Animals: male ICR mice;

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

Experimental grouping:

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 drug administration:

the injection is administered once in the afternoon before molding, PTZ-65mg/kg (molding agent) is injected intraperitoneally 1 hour after the gastric administration of the test drug on the molding day, and the positive drug is administered once in the first half hour of molding. The observation was continued for 15 minutes after injection of PTZ. And (3) observing the indexes: (1) seizure condition: III-VI level attack time; (2) death condition

Seizure level: reference is made to the Racine grading standard: level 0: without any reaction; stage I: expressed as facial muscle or mouth angle twitches; stage II: nodding can be performed; III grade: a lateral limb tic; grade IV: tonic or generalized limb twitch; v level: general seizure (generalized tonic seizure) of epilepsy.

And (3) data processing:

counting the number of attacks and deaths of each group of mice in the experiment; the latency of mice from stage III and stage IV, which did not develop to stage IV, was noted as a maximum of 900 seconds. The statistics of the number of cases is counted by using a chi-square test. Mean and standard error were calculated at latency, and the model group was compared to the other groups using a TTEST, with P <0.05 considered significant differences.

Experimental results: see tables 5 and 6.

TABLE 5 test of the test agent on PTZ-induced mouse epilepsy-statistics of the number of cases

(P <0.05, P <0.01 compared to model group)

TABLE 6 test of PTZ induced mouse epilepsy-seizure latency of grade III and grade IV (mean+ -SEM)

Group of	Stage III seizure incubation period (seconds)	Stage IV seizure incubation period (seconds)
			Model group	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

(P <0.05, P <0.01 compared to model group)

Conclusion of experiment:

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

3) In the class III latency comparison of epilepsy, the BD-15 200mg/kg group was statistically different from the model group.

Experimental example 5 protein BD-15 (protein of example 4) efficacy test animal for eliminating phlegm by phenol red excretion method in mice: male ICR mice;

medicine and reagent: musultam (ambroxol hydrochloride tablet), phenol red, sodium bicarbonate, protein BD-15;

instrument: centrifuge (Sigma-3K 15 type), balance (XS 105DU type), enzyme-labeled tester (BIO-TEK type).

Experimental grouping:

a solvent control group;

a group of 30mg/kg of sultam;

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

The method comprises the following steps:

model preparation and drug administration:

animals were fasted for 16 hours prior to the experiment without water. Oral administration of sulbactam and different doses of protein BD-15 (administration volume 10 ml/kg) in groups, administration of equal volume of distilled water in solvent control group, intraperitoneal injection of 2.5% phenol red solution after 1 hr, neck removal to kill mice after 30 min, taking from the subungual cartilage to the tracheal branch before the tracheal branch,the trachea is taken in 3ml 5% NaHCO ₃ The solution was allowed to stand for 3 hours, and after 1ml of the supernatant was centrifuged at 3000rpm for 5 minutes, absorbance was measured and recorded at 546 nm. And calculating the excretion amount of the phenol red according to the standard curve of the phenol red.

And (3) data processing:

respectively recording the oral administration time point, the 2.5% phenol red solution intraperitoneal injection time point and the tracheal time point; and measuring at 546nm of the enzyme-labeled instrument 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. Mean and standard error were calculated for each group of data, and the solvent control group was compared to the other groups using the TTEST, with P <0.05 considered significant differences.

Experimental results:

administering sulbactam (30 mg/kg) and different doses of protein BD-15 (20 mg/kg, 50 mg/kg), intraperitoneally injecting 2.5% phenol red solution after 1 hr, removing neck after 30 min to kill mice, taking from the lower part of the thyroid cartilage to the first segment of trachea before branching, placing the trachea into 3ml of 5% NaHCO ₃ The solution was allowed to stand for 3 hours, and after 1ml of the supernatant was centrifuged at 3000rpm for 5 minutes, absorbance was measured and recorded at 546 nm. And calculating the excretion amount of the phenol red according to the standard curve of the phenol red. The results are shown in Table 7.

TABLE 7 test of efficacy of the test agent in eliminating phlegm by phenol Red excretion method of mice (X.+ -. SEM)

Group of	N	Phenol Red excretion (μg/ml)	P
				Solvent control group	10	0.715±0.087	---
Musultam 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

(P <0.05, < P <0.01 compared to the solvent control group)

Conclusion of experiment:

1) Experimental results show that compared with a solvent control group, the 30mg/kg compound of sulbactam has obviously increased phenol red excretion, and P is less than 0.05, thus having statistical significance.

2) Protein BD-15 showed an increasing trend in phenol red excretion compared to the solvent control, but was not statistically significant.

Experimental example 6 protein BD-15 (protein of example 4) against mice Ammonia-induced cough-relieving efficacy test animals: male ICR mice;

medicine and reagent: dextromethorphan hydrobromide, ammonia water, 0.2 percent CMC-Na and protein BD-15;

instrument: compression atomizer (403T), balance (XS 105 DU).

Experimental grouping:

a solvent control group;

dextromethorphan 15mg/kg group;

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

The method comprises the following steps:

model preparation and drug administration:

dextromethorphan and different doses of protein BD-15 (dosing volume 10 ml/kg) were orally administered in groups, an equal volume of distilled water was administered to the solvent control group, 1 hour later, placed in a sealed box, 10 seconds of 10% strength aqueous ammonia was nebulized, and then the cough latency and cough count in 2 minutes were observed and recorded in the mice.

And (3) data processing:

the oral dosing time points, the nebulization time points, the cough latency of the mice and the number of coughs in 2 minutes were recorded separately. Cough latency refers to the number of seconds required to atomize ammonia onset time to cough. The cough of the mice is manifested by contraction of the abdominal muscles (chest constriction) and simultaneous opening of the large mouth. The mean and standard error were calculated for each group of data, and the model group was compared to the other groups using the TTEST, with P <0.05 considered significant differences.

Experimental results:

dextromethorphan (15 mg/kg) and different doses of protein BD-15 (20 mg/kg, 50 mg/kg) were given in advance, 1 hour later put into a sealed box, 10 seconds of 10% strength ammonia was nebulized, and then it was pair-wise observed and recorded the cough latency and the number of coughs in 2 minutes of the mice. The results are shown in Table 8.

TABLE 8 cough-relieving efficacy experiment (X+ -SEM) of the test drug on the ammonia water cough-relieving method of mice

Group of	N	Latency (seconds)	P	Number of coughing times	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

(P <0.05, < P <0.01 compared to the solvent control group)

Conclusion of experiment:

1) Experimental results show that compared with the solvent control group, the dextromethorphan group has obvious improvement effect on latency and cough frequency, and the P is less than 0.05, thereby having statistical significance.

2) The BD-15 20mg/kg dose group showed significant improvement in cough count compared to the solvent control group, with P <0.05, which was statistically significant.

Experimental example 7 protein BD-15 (protein of example 4) efficacy test animal against ICR mouse acetic acid torsion: male ICR mice;

medicine and reagent: aspirin, physiological saline, glacial acetic acid, and protein BD-15.

Experimental grouping:

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 animals are adapted to the environment for one day, 300mg/kg of aspirin, 50mg/kg of protein BD-15 and 200mg/kg of protein BD-15 are orally administered in advance for one hour, wherein the administration volume is 10ml/kg; then, 0.6% acetic acid solution was injected intraperitoneally, and the number of times and the period of time of torsion latency of the animal were observed within 15 minutes.

And (3) data processing:

the mean and standard error were calculated for each set of data, using the TTEST, and P <0.05 was considered statistically different compared to the model set.

Experimental results:

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

TABLE 9 influence of test agents on ICR mouse acetic acid torsion experiments

(compared to model group, P < 0.01)

Conclusion of experiment:

the 0.6% acetic acid solution is injected into the abdominal cavity of the mouse, which causes deep and large-area pain stimulation for a long time, so that the mouse generates torsion reaction (the abdomen is contracted into an S shape, the trunk and the rear legs are stretched, the buttocks are raised and vermicular). The latency and the frequency of starting the torsion of the mice are used as pain response indexes to judge whether the tested sample has the analgesic effect. The experimental result shows that:

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

2) The BD-15 50mg/kg dose group can obviously reduce the twisting times of mice, and compared with a model group, the P is less than 0.05, thereby having statistical significance.

Sequence listing

<110> institute of medicine at the national academy of medical science

<120> a keratin BD-15, a process for its preparation, and its pharmaceutical compositions and uses

<160> 2

<170> SIPOSequenceListing 1.0

<210> 1

<211> 493

<212> PRT

<213> Bos taurus

<400> 1

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. An application of keratin BD-15 in preparing antipyretic, analgesic, antitussive, expectorant, anticonvulsant and antiepileptic drugs, characterized in that the amino acid sequence of the keratin BD-15 is as follows:

(1) The amino acid sequence shown in SEQ ID NO.1 of the sequence Listing.

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

The conventional modification comprises acetylation, amidation, cyclization, glycosylation, phosphorylation, alkylation, biotinylation, fluorescent group modification, polyethylene glycol PEG modification, immobilization modification, sulfation, oxidation, methylation and deamination; the tag comprises His6 and GST, EGFP, MBP, nus, HA, igG, FLAG, c-Myc, profinityeXact.

3. Use of a nucleic acid molecule encoding the keratin BD-15 as defined in any one of claims 1-2 for the preparation of a medicament for reducing fever, easing pain, relieving cough, eliminating phlegm, anticonvulsant, and antiepileptic.

4. Use according to claim 3, characterized in that 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 complementary to the nucleotide sequence of (1) above.

5. Use of an expression vector for the preparation of a medicament for reducing fever, easing pain, relieving cough, eliminating phlegm, anticonvulsant and antiepileptic, wherein the expression vector comprises the nucleic acid molecule according to any one of claims 3 to 4.

6. Use of a host cell comprising the expression vector of claim 5 or the nucleic acid molecule of any one of claims 3-4 integrated into the genome for the preparation of a medicament for reducing fever, pain, cough, phlegm, anticonvulsant, or antiepileptic.

7. The use according to claim 6, wherein the host cell comprises a bacterium, yeast, aspergillus, plant cell, or insect cell.

8. The use according to claim 7, wherein said bacteria comprise escherichia coli.

9. Use of a pharmaceutical composition for the preparation of a medicament for reducing fever, easing pain, relieving cough, eliminating phlegm, anticonvulsant and antiepileptic, characterized in that the pharmaceutical composition comprises the keratin BD-15 according to any one of claims 1-2 and a pharmaceutically acceptable carrier or excipient.