Antibacterial peptide J-133 and its antibacterial effect

Abstract

The application discloses an antibacterial peptide J-133 and antibacterial action thereof. The application belongs to the technical field of biology. The polypeptide of the application is a polypeptide with an amino acid sequence of MLSPYFYCLKPISSAINNRKANIQAYLRKGKKKSG. The medicine containing the polypeptide can be applied to the following aspects: 1) preparation of a product for inhibiting bacterial activity; 2) preparation of a product for inhibiting bacterial activity; 3) preparation of a product for treating bacterial infectious diseases; and 4) preparation of a product for treating bacterial infectious diseases.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to an antimicrobial peptide J-133 and its antimicrobial activity. Background Technology

[0002] With the widespread and even overuse of antibiotics, bacterial resistance has become an increasingly serious problem. The frequent emergence of multidrug-resistant bacteria and superbugs has posed a significant threat to global public health security. The World Health Organization has repeatedly warned that without effective alternatives, drug-resistant infections will become one of the major challenges facing human health in the future. Against this backdrop, the search for active substances with novel antibacterial mechanisms has become a research hotspot in the biomedical field.

[0003] Antimicrobial peptides (AMPs) are a class of small, bioactive polypeptides widely found in nature. They can be isolated from various organisms, including bacteria, fungi, plants, insects, and mammals, and are key effector molecules in the innate immune defense system. AMPs typically consist of 5 to 100 amino acid residues, with a molecular weight generally not exceeding 10 kDa. They possess broad-spectrum antimicrobial activity, inhibiting or killing bacteria, fungi, and some enveloped viruses. Due to their unique biological characteristics, low risk of inducing drug resistance, and relatively mild toxicity to host cells, antimicrobial peptides are considered important candidate molecules for developing next-generation anti-infective agents.

[0004] However, natural antimicrobial peptides still have limitations in practical applications, such as insufficient in vivo stability, susceptibility to protease degradation, and high preparation costs, which restrict their large-scale development and clinical translation. They urgently need to be improved and perfected through molecular design or delivery technology. Summary of the Invention

[0005] The main problem to be solved by this invention is how to obtain an antimicrobial peptide with broad-spectrum antibacterial activity and low toxicity.

[0006] To address the above problems, the present invention provides a polypeptide J-133.

[0007] The polypeptide J-133 provided by this invention is the polypeptide with the amino acid sequence of SEQ ID No:1 in the sequence listing.

[0008] The amino acid sequence of J-133 is: MLSPYFYCLKPISSAINNRKANIQAYLRKGKKKSG.

[0009] The aforementioned polypeptides can be synthesized artificially, or their encoding genes can be synthesized first and then expressed biologically.

[0010] Those skilled in the art can readily mutate the nucleotide sequence encoding the polypeptide of the present invention using known methods, such as directed evolution or point mutation. Any artificially modified nucleotides that have 75% or more identity with the nucleotide sequence of the polypeptide isolated according to the present invention, as long as they encode the polypeptide and have the polypeptide function, are derived from and equivalent to the nucleotide sequence of the present invention.

[0011] In this article, identity refers to the similarity between amino acid sequences or nucleotide sequences. The identity of amino acid or nucleotide sequences can be determined using homology search sites on the Internet, such as the BLAST page on the NCBI homepage. For example, in Advanced BLAST 2.1, using blastp as the procedure, setting the Expect value to 10, setting all filters to OFF, using BLOSUM62 as the matrix, setting the Gap existence cost, Per residue gap cost, and Lambda ratio to 11, 1, and 0.85 (default values) respectively, and performing a search to calculate the identity of a pair of amino acid or nucleotide sequences, then the identity value (%) can be obtained.

[0012] The pharmaceutical salts of the aforementioned polypeptides also fall within the scope of protection claimed in this invention.

[0013] The use of the aforementioned polypeptides in the preparation of drugs for inhibiting bacteria or treating bacterial infectious diseases also falls within the scope of protection claimed in this invention.

[0014] The use of the medicinal salts described above in the preparation of drugs for inhibiting bacteria or treating bacterial infectious diseases also falls within the scope of protection claimed by this invention.

[0015] The present invention also provides a medicament for inhibiting bacteria or treating bacterial infectious diseases, said medicament containing the polypeptides or pharmaceutical salts described above.

[0016] The pharmaceutical salts of the polypeptides of this invention are commonly used pharmaceutical salts in the prior art. These salts can be prepared using standard methods, such as by reacting a free acid with an organic or inorganic base. In the presence of a basic group such as an amino group, acidic salts such as hydrochloride, hydrobromide, acetate, pamoate, etc., can be used as dosage forms; in the presence of an acidic group (such as -COOH) or an alcohol group, pharmaceutically acceptable esters such as acetate, maleate, pivaloyloxymethyl, etc., as well as esters known in the literature for improving solubility and hydrolysis, can be used as sustained-release and prodrug formulations.

[0017] In addition to the polypeptide of SEQ ID No:1 or its pharmaceutically acceptable salt, the drug described above may also contain a suitable carrier or excipient. The carrier materials here include, but are not limited to, water-soluble carrier materials (such as polyethylene glycol, polyvinylpyrrolidone, organic acids, etc.), poorly soluble carrier materials (such as ethyl cellulose, cholesterol stearate, etc.), and enteric carrier materials (such as cellulose acetate phthalate and carboxymethyl ethyl cellulose, etc.). Water-soluble carrier materials are preferred.

[0018] These materials can be used to formulate various dosage forms, including but not limited to tablets, capsules, pellets, aerosols, pills, powders, solutions, suspensions, emulsions, granules, liposomes, transdermal preparations, lozenges, suppositories, and lyophilized powder injections. These can be conventional formulations, sustained-release formulations, controlled-release formulations, and various microparticle delivery systems.

[0019] The polypeptide is an antimicrobial peptide J-133, which has a molecular weight of 3.99 kDa, an isoelectric point of 10.591, and an average hydrophobicity of -0.571.

[0020] In this article, the bacteria referred to are either Gram-positive or Gram-negative bacteria.

[0021] Furthermore, the Gram-positive bacterium is *Bacillus stearothermii* (…). Bacillusspizizenii The Gram-negative bacteria mentioned are Escherichia coli (Escherichia coli). Escherichiacoli ), Pseudomonas aeruginosa ( Pseudomonas aeruginosa Acinetobacter baumannii ( Acinetobacter baumannii ) and Klebsiella pneumoniae subspecies of pneumonia ( Klebsiella pneumoniae subsp. pneumoniae ).

[0022] Furthermore, the concentration of the polypeptide used in the drug is 16-128 μg / mL.

[0023] In one specific embodiment, the antimicrobial peptide J-133 is effective against Acinetobacter baumannii (… Acinetobacter baumannii The minimum inhibitory concentration (MIC) of ATCC 19606 is 16 μg / mL; against Pseudomonas aeruginosa (… Pseudomonas aeruginosa The minimum inhibitory concentration (MIC) of ATCC 27853 is 64 μg / mL; against Escherichia coli (… Escherichia coli ATCC 25922, Bacillus stearothermia ( Bacillus spizizenii ATCC 6633 and Klebsiella pneumoniae subsp. pneumoniae ( Klebsiella pneumoniae subsp. pneumoniae The minimum inhibitory concentration (MIC) of ATCC 13883 is 128 μg / mL.

[0024] The present invention also provides the use of the foregoing drug in any of the following: 1) Application in the preparation of products that inhibit bacterial activity; 2) Applications in the preparation of products used to inhibit bacterial activity; 3) Application in the preparation of products for treating bacterial infectious diseases; 4) Application in the preparation of products for the treatment of bacterial infectious diseases.

[0025] The methods for preparing the antimicrobial peptides mentioned above include chemical synthesis or biosynthesis. The chemical synthesis method may be a solid-phase synthesis method; the biosynthesis method may include the following: 1) Biosynthetic method: Synthesizing antimicrobial peptides through microbial expression systems; 2) DNA synthesis method: such as using a DNA synthesizer to synthesize antimicrobial peptide genes and producing antimicrobial peptides in E. coli through fusion expression; 3) Amino acid residue substitution and chemical modification: By designing and modifying natural antimicrobial peptides, their antibacterial effect and hemolytic effect can be improved.

[0026] This invention also provides the following biomaterials: C1) A nucleic acid molecule encoding the polypeptide described above; C2) An expression cassette containing the nucleic acid molecule described in C1); C3) A recombinant vector containing the nucleic acid molecule described in C1) or a recombinant vector containing the expression cassette described in C2).

[0027] The nucleic acid molecules mentioned in this article can be DNA, such as cDNA, genomic DNA, or recombinant DNA; the nucleic acid molecules can also be RNA, such as gRNA, mRNA, siRNA, shRNA, sgRNA, miRNA, or antisense RNA.

[0028] The vectors described herein are known to those skilled in the art and include, but are not limited to: plasmids, bacteriophages (such as λ phage or M13 filamentous phage), granules (i.e., Cos plasmids), Ti plasmids, or viral vectors.

[0029] In one specific embodiment, the antimicrobial peptide is synthesized into a crude polypeptide by solid-phase synthesis; the polypeptide is then purified to obtain a purity greater than 95%. Attached Figure Description

[0030] Figure 1 The six-sided diagram is a prediction of the structure of the antimicrobial peptide J-133.

[0031] Figure 2 This is a schematic diagram of the HPLC detection results for the antimicrobial peptide J-133.

[0032] Figure 3 This is a schematic diagram of the MS detection results for the antimicrobial peptide J-133.

[0033] Figure 4 The results show the growth inhibition of various bacterial strains by the antimicrobial peptide J-133 at different concentrations.

[0034] Figure 5 The results of enzyme-linked immunosorbent assay (ELISA) analysis show the growth inhibition rate of antimicrobial peptide J-133 on various bacterial strains at different concentrations.

[0035] Figure 6 The results show the hemolytic effects of antimicrobial peptide J-133 on sheep erythrocytes.

[0036] Figure 7 The results show the hemolytic effects of antimicrobial peptide J-133 on mouse erythrocytes.

[0037] Figure 8 The results show the toxicity of antimicrobial peptide J-133 to human embryonic kidney cells. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0039] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0040] The following examples use statistical software to process the data. The experimental results are expressed as mean ± standard deviation. One-way ANOVA test was used. P < 0.05 (*) indicates a significant difference, and P < 0.001 (***) indicates a highly significant difference.

[0041] Example 1: Screening and physicochemical properties study of antimicrobial peptide J-133 1. Screening of antimicrobial peptide J-133 To obtain high-quality antimicrobial peptides, bovine intestinal metagenomic data were collected from the NCBI database. Bioinformatics tools were used to assemble, bin, and remove redundancy from the data to obtain high-quality metagenome blocks (MAGs). Species annotation was performed using tools such as GTDB-TK, and further, tools such as Prokka were used to predict open reading frames (ORFs) to identify hypothetical proteins with unknown functions, providing foundational data for subsequent antimicrobial peptide screening. Language models such as ESMFold were used to predict the structures of hypothetical proteins, obtaining their PDB structural information. Subsequently, software such as PyMOL was used to convert the structures into six-sided images, which were then used as input data for deep learning models to screen for novel antimicrobial peptides.

[0042] Protein sequences and their three-dimensional structural information from positive and negative samples were collected from the UniProt and PDB databases and converted into six-sided images. Based on this data, a DeepSeek-JanUS antimicrobial peptide screening model was constructed, and the model was trained and fine-tuned by combining image and sequence information to improve its antimicrobial peptide recognition ability.

[0043] The ORFs (and their corresponding image information) mined from the metagenomic data were input into a trained deep learning model for antimicrobial peptide screening. Based on the model's predictions, candidate sequences were scored using evaluation software, and sequence alignment was performed using BLAST. The candidate antimicrobial peptide sequence J-133 (full name: JMEPEELD_01133_hypothetical_protein) with the highest score was selected for subsequent experimental validation. The amino acid sequence of antimicrobial peptide J-133 is: MLSPYFYCLKPISSAINNRKANIQAYLRKGKKKSG (SEQ ID No:1).

[0044] The sequence alignment results of the antimicrobial peptide are shown in Table 1. The results show that the sequence has no highly homologous sequences in known antimicrobial peptide databases (APD3, dbAMP, DRAMP).

[0045] Table 1. Comparison results of antimicrobial peptide J-133 with antimicrobial peptide databases

[0046] The model prediction results for antimicrobial peptide J-133 are shown in Table 2. The prediction results of the trained model are similar to those of the online prediction website, with most models identifying the sequence as an antimicrobial peptide sequence.

[0047] Table 2. Prediction results of antimicrobial peptide J-133 model

[0048] 2. Physicochemical Properties Study of Antimicrobial Peptide J-133 The tertiary structure of the screened antimicrobial peptides was predicted using an online prediction tool, and the results are as follows: Figure 1 As shown, J-133 contains an α-helical structure. The physicochemical properties of the antimicrobial peptide J-133 are shown in Table 3, including the number of amino acids, extinction coefficient, molecular weight, isoelectric point, and average hydrophobicity.

[0049] Table 3. Physicochemical properties of antimicrobial peptide J-133

[0050] Example 2: Synthesis and purification of antimicrobial peptide J-133 Based on the designed amino acid sequence SEQ ID No:1, the crude polypeptide was synthesized by Shenyang Shengjing Biological Cell Research and Development Center Co., Ltd. using solid-phase synthesis; the polypeptide was then purified to obtain a purity greater than 95%.

[0051] The purity and molecular weight of the antimicrobial peptide J-133 were identified by a combination of high-performance liquid chromatography (HPLC) and mass spectrometry (MS). The HPLC results are as follows: Figure 2 As shown, HPLC detection was performed using a ChromCore 120 C18 5u column (4.6 × 250 mm) with gradient elution of 0.1% TFA aqueous solution (mobile phase A) and 0.1% TFA acetonitrile solution (mobile phase B) at a flow rate of 1.0 mL / min, a detection wavelength of 220 nm, and an injection volume of 10 μL. The detection results are as follows. Figure 2 As shown, the retention time of the target peak was 10.647 min, the peak shape was symmetrical and sharp, the area of ​​the main peak accounted for 95.3620% of the total peak area, and the content of impurity peaks was low, indicating that the purity of antimicrobial peptide J-133 was greater than 95%, which met the requirements of subsequent experiments for sample purity.

[0052] Mass spectrometry (MS) detection results as follows Figure 3 As shown, mass spectrometry was performed in ESI positive ion mode, and a series of multicharged protonated molecular ion peaks were acquired. Among them, m / z 571.00, 665.95, 798.95, 998.35 and 1330.80 were assigned to [M+7H].7+ [M+6H] 6+ [M+5H] 5+ [M+4H] 4+ and [M+3H] 3+ The molecular weights derived from the peaks of each charged ion state were highly consistent, with an average measured molecular weight of approximately 3989 Da, which is basically consistent with the theoretical molecular weight of antimicrobial peptide J-133 (Mw=3989.71 Da), and the error is within the allowable deviation range of the instrument. The combined HPLC and MS results confirm that the synthesized antimicrobial peptide J-133 has the correct molecular weight, correct structure, high purity, and meets the quality requirements for subsequent experiments.

[0053] Example 3: Antibacterial activity of antimicrobial peptide J-133 The experimental strains used for minimum inhibitory concentration (MIC) determination include: *Escherichia coli* (…). Escherichia coli ATCC 25922 (bio-52502), Pseudomonas aeruginosa ( Pseudomonas aeruginosa ATCC 27853 (bio-52506), Staphylococcus aureus subsp. aureus ( Staphylococcus aureus subsp aureus ATCC 25923 (bio-52504), Klebsiella pneumoniae subspecies of pneumonia ( Klebsiella pneumoniae subsp . pneumoniae ATCC 13883 (bio-107381), Acinetobacter baumannii ( Acinetobacter baumannii ATCC 19606 (bio-53250), Bacillus stearothermiae ( Bacillus spizizenii ATCC 6633 (bio-52499), all of the above strains were purchased from Beijing BioBio Biotechnology Co., Ltd., Aeromonas vera ( Aeromonas veronii (Source: This laboratory)

[0054] The glycerol-preserved bacterial strains of the above six species were inoculated into cation-adjusted Mueller-Hinton broth (CaMHB) and cultured overnight at 37 ℃ with shaking at 180 rpm. The CaMHB medium used in the experiment was purchased from Qingdao HopeBio Co., Ltd. (product name: CAMHB broth, catalog number: HB6231-1). The medium was prepared according to the instructions: 22.0 g of medium powder was weighed, added to 1000 mL of distilled water, heated to dissolve, dispensed, and autoclaved at 116-121 ℃ for 10 min. After overnight culture, the bacterial suspension was diluted 1:100 with fresh CaMHB medium and cultured at 37 ℃ with shaking at 180 rpm until the exponential growth phase (OD200). 600 =0.6-0.8). The bacterial concentration was then adjusted to 1×10⁻⁶ using sterile CaMHB medium. 6 CFU / mL, used for subsequent experiments.

[0055] The dilution method for antimicrobial peptide J-133 is the two-fold dilution method. First, 5 mg of lyophilized antimicrobial peptide J-133 is dissolved in 1 mL of sterile enzyme-free water to prepare a 5 mg / mL antimicrobial peptide stock solution. Then, it is serially diluted with sterile enzyme-free water to obtain working solutions of different concentrations.

[0056] MIC determination was performed using the microbroth dilution method in 96-well plates. Well 1 contained 200 μL of sterile, enzyme-free water as a blank control; well 2 contained 200 μL of bacterial culture as a growth control; well 3 contained 100 μL of sterile, enzyme-free water and 100 μL of bacterial culture as a negative control; well 4 contained 100 μL of antibiotic solution and 100 μL of bacterial culture as a positive control, with the antibiotic being either kanamycin (KAN) or tetracycline (TET), both at a final concentration of 128 μg / mL. Wells 5 through 12 contained 100 μL of antimicrobial peptide solution at different concentrations and 100 μL of bacterial culture, respectively. The antimicrobial peptide was serially diluted twofold, with final concentrations of 512, 256, 128, 64, 32, 16, 8, and 4 μg / mL, respectively. The final bacterial concentration in each well was 5 × 10⁻⁶. 5 CFU / mL. After incubating 96-well plates at 37 °C for 16-18 h, bacterial growth was observed visually. The lowest concentration of antimicrobial peptide that completely inhibited visible bacterial growth was defined as the minimum inhibitory concentration (MIC). Figure 4 All experiments were performed with three technical replicates.

[0057] Simultaneously, the absorbance at 600 nm was measured using an enzyme-linked immunosorbent assay (ELISA) reader. The growth inhibition rate was calculated using the following formula: Inhibition rate (%) = 1 - [(OD200) / 200] 样品 -OD 空白对照 ) / (OD 阴性对照 -OD 空白对照 Growth inhibition rate ≥80% and the result is statistically significant are judged as having an inhibitory effect.

[0058] Experimental results are as follows Figure 4 and Figure 5 As shown: Antimicrobial peptide J-133 against Acinetobacter baumannii ( Acinetobacter baumannii The minimum inhibitory concentration (MIC) of ATCC19606 is 16 μg / mL; against Pseudomonas aeruginosa (… Pseudomonas aeruginosa The minimum inhibitory concentration (MIC) of ATCC 27853 is 64 μg / mL; against Escherichia coli (… Escherichia coli ATCC 25922, Bacillus stearothermia ( Bacillus spizizenii ATCC 6633 and Klebsiella pneumoniae subsp. pneumoniae ( Klebsiella pneumoniae subsp. pneumoniae The minimum inhibitory concentration (MIC) of ATCC 13883 is 128 μg / mL.

[0059] Within the experimental concentration range, antimicrobial peptide J-133 is effective against Staphylococcus aureus subsp. aureus (…). Staphylococcus aureus subsp. aureus ATCC 25923 did not show significant antibacterial activity (MIC>512 μg / mL).

[0060] Example 4: Biosafety of antimicrobial peptide J-133 To evaluate the biosafety of the antimicrobial peptide J-133, its hemolytic activity and mammalian cytotoxicity were detected using erythrocyte hemolysis assay and human embryonic kidney cell (HEK-293) toxicity assay. 4% sheep erythrocytes (catalog number: S9450) and 4% mouse erythrocytes (catalog number: S9551) were purchased from Beijing Solarbio Science & Technology Co., Ltd. Human embryonic kidney cells and HEK-293 (STR) (catalog number: FH0242) were purchased from Shanghai Fuheng Biotechnology Co., Ltd.

[0061] Fresh 4% sheep red blood cells and 4% mouse red blood cells were collected, washed with sterile PBS, and centrifuged three times at 1000×g at 4 ℃ until the supernatant was clear. The red blood cells were collected and prepared into a 2% red blood cell suspension with PBS. The red blood cell suspension was mixed with an equal volume of antimicrobial peptide J-133 solution at different final concentrations (2, 4, 8, 16, 32, 64, 128, 256 μg / mL). A negative control (equal volume of PBS, 0% hemolysis) and a positive control (equal volume of 2% Triton X-100) were also included. After incubation at 37 ℃ for 1 h, the mixture was centrifuged at 1000×g for 10 min, and the absorbance at 540 nm was measured using the supernatant. Hemolysis rate (%) = (OD sample) OD negative control / (OD positive control) (OD negative control) × 100%. Each group had 3 replicates.

[0062] The results are as follows Figure 6 (Sheep red blood cells) and Figure 7 (Mouse erythrocytes) As shown: at a concentration of 256 μg / mL, the hemolytic rate of antimicrobial peptide J-133 on sheep erythrocytes was 0.6%, and the hemolytic rate on mouse erythrocytes was 0.3%. The results indicate that within the effective antibacterial concentration range, the hemolytic activity of antimicrobial peptide J-133 is low, and its safety to mammalian erythrocytes at a concentration of 256 μg / mL is within acceptable limits.

[0063] The toxicity of antimicrobial peptide J-133 to human embryonic kidney 293 (HEK-293) cells was determined using the CCK-8 assay. HEK-293 cells in logarithmic growth phase were seeded at 5000 cells / well in 96-well plates and cultured at 37 ℃ in a 5% CO2 incubator for 24 h. After cell adhesion, the culture medium was discarded, and medium containing different final concentrations (16, 32, 64, 128, 256, 512 μg / mL) of antimicrobial peptide J-133 was added to each well. Control wells without antimicrobial peptide and blank wells without cells were also included. Cells were cultured for another 24 h. 10 μL of CCK-8 reagent was added to each well, and the cells were incubated at 37 ℃ in the dark for 2 h. The absorbance at 450 nm was then measured. Cell viability (%) = (OD) / (Cell viability (%) 样品 -OD 空白 ) / (OD 细胞对照 -OD 空白 () × 100%. Each group has 3 replicates.

[0064] The results are as follows Figure 8 As shown, HEK-293 cell viability remained above 70% at concentrations of 16-256 μg / mL. In summary, the results of both hemolysis and cytotoxicity assays indicate that the antimicrobial peptide J-133 exhibits low toxicity / hemolysis at low concentrations, which increases significantly with increasing concentration, thus providing a safe basis for its development as an antimicrobial drug.

[0065] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. Polypeptide J-133, characterized in that, The polypeptide is a polypeptide with the amino acid sequence MLSPYFYCLKPISSAINNRKANIQAYLRKGKKKSG.

2. The pharmaceutical salt of the polypeptide according to claim 1.

3. The use of the polypeptide of claim 1 in the preparation of a medicament for inhibiting bacteria or treating bacterial infectious diseases.

4. The use of the pharmaceutical salt according to claim 2 in the preparation of a medicament for inhibiting bacteria or treating bacterial infectious diseases.

5. A drug for inhibiting bacteria or treating bacterial infectious diseases, characterized in that, The drug contains the polypeptide of claim 1 or the pharmaceutical salt of claim 2.

6. The drug according to claim 3, characterized in that, The bacteria are either Gram-positive or Gram-negative.

7. The drug according to claim 4, characterized in that, The Gram-positive bacteria is Bacillus stearothermiae (Bacillus stearothermiae). Bacillusspizizenii The Gram-negative bacteria mentioned are Escherichia coli (Escherichia coli). Escherichiacoli ), Pseudomonas aeruginosa ( Pseudomonas aeruginosa Acinetobacter baumannii ( Acinetobacter baumannii Klebsiella pneumoniae subsp. pneumoniae Klebsiella pneumoniae subsp. pneumoniae ).

8. The drug according to any one of claims 5-7, characterized in that, The concentration of the polypeptide used in the drug is 16-128 μg / mL.

9. The use of the medicament according to any one of claims 5-7 in any of the following: 1) Application in the preparation of products that inhibit bacterial activity; 2) Applications in the preparation of products used to inhibit bacterial activity; 3) Applications in the preparation of products for treating bacterial infectious diseases; 4) Application in the preparation of products for the treatment of bacterial infectious diseases.

10. A biomaterial, characterized in that, The biomaterial is any one of the following: C1) A nucleic acid molecule encoding the polypeptide of claim 1; C2) An expression cassette containing the nucleic acid molecule described in C1); C3) A recombinant vector containing the nucleic acid molecule described in C1) or a recombinant vector containing the expression cassette described in C2).

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