Efficient and safe A beta 42 variant antibacterial peptide and application thereof

Abstract

The invention discloses an efficient and safe A beta 42 variant antibacterial peptide and application thereof. On the basis of an existing natural amyloid peptide sequence, a sequence (YNGK with strong beta-turn formation tendency and amyloid aggregation inhibition) with a specific structure and effect is inserted, a sequence (continuous 3 / 5 Arg capable of inhibiting amyloid aggregation) with a specific effect is added at two ends for modification, and the short peptide is obtained through artificial synthesis. Determining the antibacterial activity and other related physicochemical properties of the obtained series of oligopeptides so as to evaluate whether the series of oligopeptides are AMP and the activity intensity; on the basis of the existing amyloid peptide sequence and antibacterial activity information, rational design and transformation are performed on the amyloid peptide, and experiments verify that the antibacterial peptide can be efficiently and quickly screened, and the problems that the existing antibacterial peptide is high in acquisition difficulty, poor in antibacterial effect and the like are solved.

Description

Technical Field

[0001] The present invention belongs to the field of biotechnology, and in particular relates to an efficient and safe Aβ42 variant antimicrobial peptide and an application thereof. Background Art

[0002] Since the discovery of antibiotics, they have played an important role in the health of humans and animals, and have played an important role in promoting the production and growth of animals. However, due to the increasingly prominent problems of drug resistance and residues, more and more countries and regions have gradually banned the addition of antibiotics to animal feed, and have continuously regulated the use of clinical antibiotics. In recent years, the research on new medical drugs and alternative antibiotic substances in animal feed has become a hot topic of concern and research. Antimicrobial peptides (AMPs) are components of the innate immune system and a class of drugs with high potential for clinical application. They have been shown to have effective antibacterial activity against multidrug-resistant (MDR) strains. AMPs are key components of organisms in nature to fight pathogenic invasions and are found in all species. Antimicrobial peptides have multiple biological functions, and their wide distribution and diversity make them a rich source for the discovery of potential new lead drugs.

[0003] Due to the presence of a large number of hydrophobic amino acid residues, interaction with membranes is a characteristic of amyloid peptides. There is a certain relationship between the amyloidosis of peptides and their antimicrobial properties. Aβ amyloid peptides associated with Alzheimer's disease (AD) are produced in the brain and peripheral tissues and are cleaved from β precursor protein (APP) by proteolytic pathways into fragments of 39-43 amino acids in length. Among them, Aβ42 is more neurotoxic and more aggregative, forming the core of Aβ precipitation. Aβ42 aggregates show different structural features during the aggregation reaction, including changes in β-fold content and surface hydrophobicity, which are closely related to their cytotoxicity. Recent studies have shown that Aβ42 has antimicrobial and antibacterial activities and may function as an AMP in vivo, playing the role of an innate immune effector molecule. Because it has similar structures and mechanisms of action to typical antimicrobial peptides, we expect to transform Aβ42 into an antimicrobial peptide with antimicrobial activity. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a highly effective and safe Aβ42 variant antimicrobial peptide and its application.

[0005] Studies have shown that the natural amyloid peptide Aβ42 derived from the human brain has certain antibacterial activity against some bacteria, but the antibacterial effect against some bacteria is poor (MIC>50μM). Therefore, the present invention is based on the Aβ42 amyloid peptide, and obtains a variant with higher antibacterial performance by modifying it, as a powerful alternative for the new generation of antibacterial drugs.

[0006] The Aβ42 variant antimicrobial peptide of the present invention is based on the amyloid aggregation segment sequence (the 16th to 22nd amino acids of Aβ42) of the natural amyloid peptide Aβ42 (as shown in the sequence SEQ ID NO:1), repeats this aggregation segment, adds 3 arginines at both ends (having a stronger inhibitory effect on aggregation than other amino acids), and inserts a four-amino acid sequence YNGK (having a strong tendency to form β-turn and inhibit amyloid aggregation) between the two repeated aggregation segments, thereby obtaining the variant antimicrobial peptide Aβ-6R-YNGK, whose amino acid sequence is shown in the sequence SEQ ID NO:2.

[0007] The Aβ42 variant antimicrobial peptide of the present invention repeats the amyloid aggregation segment sequence (the 16th to 22nd amino acids of Aβ42) of Aβ42 (as shown in the sequence SEQ ID NO:1), adds 5 arginines at both ends, and inserts the four-amino acid sequence YNGK between the two repeated aggregation segments to obtain the variant antimicrobial peptide Aβ-10R-YNGK, whose amino acid sequence is shown in the sequence SEQ ID NO:3.

[0008] The Aβ42 variant antimicrobial peptide of the present invention reversely repeats the amyloid aggregation segment sequence (the 16th to 22nd amino acids of Aβ42) of Aβ42 (as shown in the sequence SEQ ID NO:1), adds 3 arginines at both ends, and inserts the four-amino acid sequence YNGK between the two reverse repeated aggregation segments to obtain the variant antimicrobial peptide Aβ-6R-YNGK-F, whose amino acid sequence is shown in the sequence SEQ ID NO:4.

[0009] The Aβ42 variant antimicrobial peptide of the present invention reversely repeats the amyloid aggregation segment sequence (the 16th to 22nd amino acids of Aβ42) of Aβ42 (as shown in the sequence SEQ ID NO:1), adds 5 arginines at both ends, and inserts the four-amino acid sequence YNGK between the two reverse repeated aggregation segments to obtain the variant antimicrobial peptide Aβ-10R-YNGK-F, whose amino acid sequence is shown in the sequence SEQ ID NO:5.

[0010] Furthermore, the C-terminus of the Aβ42 variant antimicrobial peptide is modified by amidation, and the N-terminus is modified by acetylation.

[0011] Furthermore, the molecular weight of the modified antimicrobial peptides Aβ-6R-YNGK and Aβ-6R-YNGK-F is 3087.67Da; the molecular weight of Aβ-10R-YNGK and Aβ-10R-YNGK-F is 3712.42Da.

[0012] Application of the Aβ42 variant antimicrobial peptide of the present invention in the preparation of antimicrobial preparations and related preparations such as anticancer preparations.

[0013] The antibacterial preparation has an inhibitory and killing effect on Gram-negative bacteria and / or Gram-positive bacteria, including Staphylococcus epidermidis, Escherichia coli, Escherichia fergusonii, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria innocua, Pseudomonas aeruginosa, etc.

[0014] The physicochemical properties of wild-type and modified Aβ42 antimicrobial peptides were evaluated and analyzed, including minimum inhibitory concentration (MIC) value, aggregation kinetics, secondary structure analysis, membrane interaction analysis, hemolytic activity analysis, and anticancer activity analysis. The MIC value is the minimum concentration value for inhibiting Gram-positive bacteria Bacillus subtilis, Bacillus cereus, Staphylococcus epidermidis, Listeria innocua and Gram-negative bacteria Escherichia coli, Escherichia fergusonii, and Pseudomonas aeruginosa; aggregation kinetics is to incubate the antimicrobial peptide with thioflavin T (ThT), and the β-pleated sheet formed by the aggregation of the antimicrobial peptide can specifically bind to thioflavin T (ThT), thereby changing the fluorescence intensity, and the change in the number of aggregates formed is indicated by the change in the fluorescence intensity of thioflavin T binding; secondary structure analysis is to detect the far-ultraviolet circular dichroism spectrum of the antimicrobial peptide in PBS buffer and liposomes simulating membrane environment; membrane interaction analysis is to detect the changes in bacterial cell membrane after incubation of antimicrobial peptide with bacteria through scanning electron microscopy; hemolytic activity analysis is to evaluate the killing effect of antimicrobial peptide on normal mammalian cells through the activity of antimicrobial peptide in destroying red blood cell membrane to release hemoglobin; anticancer activity analysis is to evaluate the killing effect of antimicrobial peptide on cancer cells through the activity of antimicrobial peptide in inhibiting the growth of cancer cells.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention is based on the existing natural amyloid peptide sequence, inserts a sequence with specific structure and effect (YNGK with a strong tendency to form β-turn and inhibit amyloid aggregation) and adds a sequence with specific effect at both ends (3 / 5 consecutive Args that can inhibit amyloid aggregation) for modification, obtains short peptides through artificial synthesis, and measures the antibacterial activity and other related physicochemical properties of the obtained series of short peptides to evaluate whether they are AMPs and the activity intensity; the present invention is based on the existing amyloid peptide sequence and antibacterial activity information, rationally designs and transforms it, and verifies it through experiments, which can efficiently and quickly screen antimicrobial peptides, and solve the current problems of difficulty in obtaining antimicrobial peptides and poor antibacterial effects.

[0016] The modified antimicrobial peptides provided by the present invention have the following advantages: the series of antibacterial peptides have inhibitory and killing effects on Gram-negative bacteria and Gram-positive bacteria, specifically including Staphylococcus epidermidis, Escherichia coli, Escherichia fergusonii, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria innocua, and Pseudomonas aeruginosa, and have good application prospects. The modified antimicrobial peptides of the present invention can be used to prepare antibacterial drugs (antibacterial inhibitors, such as inhibitors against Gram-negative bacteria or inhibitors against Gram-positive bacteria). Because bacterial cells and cancer cells have many similarities, many antimicrobial peptides also show anticancer activity, so the anticancer application of the modified antimicrobial peptides of the present invention is also within the scope of protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The aggregation kinetics of the natural amyloid peptide Aβ42 and its modified peptides.

[0018] Figure 2 Far-UV circular dichroism spectra of natural amyloid peptide Aβ42 and its modified peptides.

[0019] Figure 3 This is a scanning electron micrograph of the interaction between the modified peptide of natural amyloid peptide Aβ42 and bacteria.

[0020] Figure 4 This is a comparison chart of the hemolytic activity of natural amyloid peptide Aβ42 and its modified peptide.

[0021] Figure 5 It is the hemolysis rate of natural amyloid peptide Aβ42 and its modified peptide.

[0022] Figure 6 Cell survival rate for the anticancer activity of native amyloid peptide Aβ42 and its modified peptides. DETAILED DESCRIPTION

[0023] The present invention is not limited to the following specific implementations, and any design structure and concept of the present invention, with simple changes or modifications, falls within the protection scope of the present invention. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0024] The present invention is further described in detail below with reference to specific examples.

[0025] The experimental drugs used in the present invention can all be purchased through commercial channels. The models and specifications of some experimental instruments used in the present invention are described below.

[0026] Antimicrobial peptide: The antimicrobial peptide used in the design of the present invention is prepared and synthesized by Shanghai Jier Biochemical Company using Fmoc solid phase synthesis, with a purity of more than 98%.

[0027] The strains and source models used: Escherichia coli (E.coli) and Bacillus subtilis (B.subtilis) were provided by the laboratory; Staphylococcus epidermidis (S.epidermidis), Pseudomonas aeruginosa (P.aeruginosa), Listeria innocua (L.innocua), Salmonella typhimurium (S.typhimurium), and Bacillus cereus (B.cereus) were purchased from Beijing Biobo Biotechnology Co., Ltd.

[0028] Reagents used: PBS buffer, pure water, acetonitrile, ampicillin (100 mg / mL), and thioflavin.

[0029] Culture medium: LB liquid culture medium (sterilized at 121°C for 20 min).

[0030] Experimental instruments: SpectraMax M5 fully automatic microplate reader (MeiGu Molecular Instruments (Shanghai) Co., Ltd.), shaking incubator (Shanghai Minquan Instrument Co., Ltd.), circular dichroism spectrometer.

[0031] The original amino acid sequence of Aβ42 is shown in sequence SEQ ID NO: 1; the amino acid sequence of variant antimicrobial peptide Aβ-6R-YNGK is shown in sequence SEQ ID NO: 2; the amino acid sequence of variant antimicrobial peptide Aβ-10R-YNGK is shown in sequence SEQ ID NO: 3; the amino acid sequence of variant antimicrobial peptide Aβ-6R-YNGK-F is shown in sequence SEQ ID NO: 4; the amino acid sequence of variant antimicrobial peptide Aβ-10R-YNGK-F is shown in sequence SEQ ID NO: 5. Example 1: Design of antibacterial peptides

[0032] Table 1 shows the sequences of the antimicrobial peptides after design and modification.

[0033]

[0034] When natural amyloid peptide Aβ42 and its variants are synthesized, their C-terminus is amidated and their N-terminus is acetylated. N-terminal acetylation and C-terminal amidation can reduce the overall charge of the peptide, so its overall solubility may be reduced, and it is closer to the parent protein, enhancing its ability to enter cells. And because terminal acetylation and amidation produce a mimic that is closer to the natural protein, the stability of the peptide can also be improved, thereby improving its resistance to exopeptidases such as proteases, endoplasmic reticulase and synthetase. Therefore, these modifications can improve the biological activity of the peptide. Example 2: Determination of minimum inhibitory concentration (MIC) of antibacterial peptides

[0035] The determination of the minimum inhibitory concentration (MIC) was carried out according to the standard method of CLSI. The single colony of the strain was picked into the LB liquid culture medium with an inoculation stick, placed in a constant temperature shaking incubator at 37°C and 220rpm for overnight culture, and then prepared into a 104CFU / mL bacterial solution. 100μL of bacterial solution was added to a 96-well plate, and the antimicrobial peptide was diluted by a 2-fold dilution method. 100μL of antimicrobial peptide was added to each well to make the final concentrations of 50, 20, 10, 5, and 1μM, respectively. The negative control group replaced 100μL of the antimicrobial peptide solution with an equal amount of PBS buffer, and the positive control group replaced 100μL of the antimicrobial peptide solution with an equal amount of ampicillin. There were three parallel samples for each treatment. The 96-well plate was placed in a constant temperature shaking incubator at 37°C and 220rpm for 12-18h until a turbid liquid visible to the naked eye appeared in the negative control well. The concentration of antimicrobial peptide that can completely inhibit bacterial growth (wells are clear) is the MIC value of the antimicrobial peptide against the bacteria.

[0036] Table 2 shows the MIC values ​​(μM) of the natural amyloid peptide Aβ42 and its modified peptides against various bacteria.

[0037]

[0038] The results of antibacterial activity test showed that compared with the natural amyloid peptide Aβ42, the antibacterial activity of the variants Aβ-6R-YNGK, Aβ-6R-YNGK-F, Aβ-10R-YNGK and Aβ-10R-YNGK-F designed by us was significantly enhanced. Example 3: Aggregation kinetics of antibacterial polypeptides

[0039] The β-pleated sheet aggregate structure formed by proteins or polypeptides can specifically bind to thioflavin T (ThT), thereby changing the fluorescence intensity. The change in fluorescence intensity of thioflavin T binding can indicate the change in the number of aggregates formed. The aggregation of Aβ42, Aβ-6R-YNGK, Aβ-6R-YNGK-F, Aβ-10R-YNGK and Aβ-10R-YNGK-F at different concentrations (25μM, 50μM, 100μM) was detected. The ThT fluorescence kinetic samples were placed in a 96-well black ELISA plate, and three parallel experiments were set up for each sample. The ThT fluorescence intensity was measured at 25°C on a Spectra Max M5 multi-detection reader (Molecular Devices Limited), with an excitation wavelength of 440nm, an emission wavelength of 485nm, and a slit wavelength of 2nm. Before each measurement, the sample was shaken for 3 seconds to mix, and the fluorescence was read every two minutes.

[0040] Figure 1The results of monitoring the aggregation kinetics of the natural amyloid peptide Aβ42 and its mutants are shown in Figure 2. The aggregation kinetics results show that Aβ42 aggregates, while the designed mutants do not aggregate. Example 4: Determination of the secondary structure of antimicrobial peptides

[0041] Far-ultraviolet circular dichroism spectra were recorded for the peptides in PBS solution and in liposomes with simulated membranes, with a wavelength range of 200-250 nm, a step length of 1 nm, and an optical path length of 1 cm.

[0042] Figure 2 Far-ultraviolet circular dichroism spectra of natural amyloid peptide Aβ42 and its variants. The results show that Aβ42 forms a small amount of helical structure in the simulated membrane environment, indicating that it can interact with the membrane, but the intensity is not strong; while the designed antimicrobial peptides are induced to form more abundant secondary structures in the simulated membrane environment, indicating that they interact more strongly with the membrane. Therefore, it is inferred that the designed antimicrobial peptides can interact more strongly with the bacterial cell membrane, fold into a more regular secondary structure and insert into the bacterial membrane, thereby causing more serious membrane damage and cell death. Example 5: Analysis of the interaction between antimicrobial peptides and bacterial cell membranes - SEM characterization

[0043] The bacteria were cultured in LB at 37°C until the exponential phase, centrifuged at 1000 rpm for 10 min, washed twice with 10 mM PBS, and resuspended to an OD of 600 is 0.2. The cell suspension was incubated with different peptides at 1×MICs for 1 h at 37°C. The control group was run without peptides. After incubation, the cells were collected by centrifugation at 4°C and 5000 rpm for 5 min and then washed three times with PBS. Then, the bacterial cells were fixed with 2.5% (v / v) glutaraldehyde at 4°C for 2 h, and the fixed samples were washed twice with PBS and then dehydrated in graded ethanol solutions (50%, 70%, 90% and 100%) for 10 min. They were then transferred to a mixture of anhydrous ethanol and tert-butanol (1:1, v / v) for 20 min, and then transferred to pure tert-butanol for 30 min. After freeze-drying and gold plating, they were observed using a scanning electron microscope.

[0044] Figure 3 This is a scanning electron microscope image of the interaction between the natural amyloid peptide Aβ42 mutant and bacteria. The SEM results show that after the modified antimicrobial peptide came into contact with the bacteria, the bacterial cell membranes were ruptured and the contents flowed out. This further proves that the antimicrobial peptide designed and modified in the present invention exerts its antibacterial effect by interacting with the bacterial cell membrane. Example 6: Determination of hemolytic activity of antimicrobial peptides

[0045] The killing effect of antimicrobial agents on normal mammalian cells is generally evaluated by the hemolytic activity of red blood cells. Take 10mL of 4% mouse red blood cells into a centrifuge tube, centrifuge at 4℃ and 3000rpm for 5min, discard the upper serum, and leave the red blood cell pellet. Centrifuge and wash the red blood cells three times with an equal amount of normal saline to remove the residual serum. Dilute the red blood cells after centrifugation and washing with normal saline to 5% (v / v). Take 300μL of red blood cell solution into a centrifuge tube, and then add 300μL of a series of 2-fold dilution gradient antimicrobial peptide solutions. Use 100μL of normal saline as the negative control of the experiment, and use 100μL of 0.1% Triton X-100 solution as the positive control of the experiment. Place the centrifuge tube in a constant temperature shaker at 37℃ and 220rpm for incubation for 1h. After the reaction is completed, centrifuge at 4℃ and 3000rpm for 5min to precipitate the red blood cells. The upper clear liquid in the centrifuge tube was aspirated into a 96-well plate, and the absorbance at 540 nm was detected by an ELISA instrument. The hemolysis rate was calculated according to the following formula: Hemolysis rate (%) = (Abs peptide-Abs negative) / (Abs positive-Abs negative) × 100%.

[0046] Figure 4 A comparison of the hemolytic activity of the natural amyloid peptide Aβ and its variants.

[0047] Figure 5 is the hemolysis rate of natural amyloid peptide Aβ and its variants.

[0048] like Figure 4 , Figure 5 As shown, the hemolysis rates of antimicrobial peptides Aβ-10R-YNGK and Aβ-10R-YNGK-F were 8.71% and 8.25% at a concentration of 5μM, respectively (when the hemolysis rate was greater than 5%, it was considered hemolysis); Aβ-10R-YNGK and Aβ-10R-YNGK-F could inhibit bacteria only at concentrations above 5μM, and hemolysis had already occurred at this concentration, indicating that the antimicrobial peptide did not have good safety; the hemolysis rate of antimicrobial peptide Aβ-6R-YNGK-F was 3.86% at a concentration of 10μM, while the hemolytic activity of antimicrobial peptide Aβ-6R-YNGK was still below 5% at a high concentration of 50μM. These results show that the antimicrobial peptide Aβ-6R-YNGK after design and modification has high antimicrobial activity while ensuring high safety. Example 7: Determination of anticancer activity of antimicrobial peptides

[0049] The anticancer activity of antimicrobial peptides was evaluated by CCK-8 method. U937 (human lymphoma cell line) cells were cultured in 1640 medium (supplemented with 9% fetal bovine serum and 1% penicillin-streptomycin solution) in a CO2 incubator at 37°C. When the cells grew to 80%-90% full, the cells were collected by centrifugation, the single cell suspension was mixed, the cells were counted using a blood cell counting plate, the cell concentration of the single cell suspension was determined, and the cells were plated in a 96-well plate at a density of 10,000 cells / well, and 90 μL of culture medium and 10 μL of antimicrobial peptide solutions of different concentrations were added (the final concentration of antimicrobial peptides in the 96-well plate was 50 μM, 20 μM, 10 μM, 5 μM, and 1 μM). Six replicate wells were set for each concentration, and 100 μL of PBS was added to the outermost well to prevent the evaporation of water in the well plate from affecting the drug concentration. After the antimicrobial peptides were co-cultured with the cells for 24 hours, 20 μL of CCK-8 solution was added and cultured in a CO2 incubator at 37°C for 1-4 hours. The plate was removed and shaken for 10 minutes. The absorbance was measured at 450 nm using a microplate reader from Meigu Molecular Instruments (Shanghai) Co., Ltd. The survival rate was calculated according to the following formula: Survival rate (%) = (OD of drug-dosing well 450 -Zero hole OD 450 ) / (blank hole OD 450 -Zero hole OD 450 )×100% The drug-added wells were for adding antimicrobial peptides, the blank wells were for pure cells without adding antimicrobial peptides, and the zero-adjusted wells were for pure culture medium without adding antimicrobial peptides and cells.

[0050] Figure 6 Cell survival for the anticancer activity of the native amyloid peptide Aβ and its mutants.

[0051] like Figure 6 As shown in the results, the modified antimicrobial peptides all reduced the survival rate of cancer cells in a dose-dependent manner. At a concentration of 50 μM, the survival rate of cancer cells of all antimicrobial peptides was less than 20%. It is worth noting that compared with other peptides, the antimicrobial peptides Aβ-10R-YNGK and Aβ-10R-YNGK-F, which are more hemolytic, have significantly higher anticancer activity, especially at low concentrations, which may be due to the similarities between blood cells and cancer cells in certain aspects of the membrane.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An efficient and safe Aβ42 variant antimicrobial peptide, characterized by: The Aβ42 variant antimicrobial peptide is based on the amyloid aggregation segment sequence of the natural amyloid peptide Aβ42, repeating the aggregation segment, adding three arginines at both ends, and inserting a four-amino acid sequence YNGK between the two repeated aggregation segments to obtain the variant antimicrobial peptide Aβ-6R-YNGK, whose amino acid sequence is shown in SEQ ID NO: 2; Alternatively, the Aβ42 variant antimicrobial peptide repeats the amyloid aggregation segment sequence of Aβ42, adds 5 arginine residues at both ends, and inserts a four-amino acid sequence YNGK between the two repeated aggregation segments to obtain a variant antimicrobial peptide Aβ-10R-YNGK, whose amino acid sequence is shown in SEQ ID NO: 3; Alternatively, the Aβ42 variant antimicrobial peptide inverts the amyloid aggregation segment sequence of Aβ42, adds three arginine residues at both ends, and inserts a four-amino acid sequence YNGK between the two aggregation segments inverted, to obtain a variant antimicrobial peptide Aβ-6R-YNGK-F, the amino acid sequence of which is shown in SEQ ID NO: 4; Alternatively, the Aβ42 variant antimicrobial peptide inverts the amyloid aggregation segment sequence of Aβ42, adds 5 arginines at both ends, and inserts the four-amino acid sequence YNGK between the two inverted repeated aggregation segments to obtain the variant antimicrobial peptide Aβ-10R-YNGK-F, whose amino acid sequence is shown in SEQ ID NO:

5.

2. Use of the Aβ42 variant antimicrobial peptide according to claim 1 in the preparation of antimicrobial preparations.

3. The use according to claim 2, characterized in that: The antibacterial preparation has an inhibitory and killing effect on Gram-negative bacteria and / or Gram-positive bacteria.

4. The use according to claim 3, characterized in that: The Gram-negative bacteria and / or Gram-positive bacteria include one or more of Staphylococcus epidermidis, Escherichia coli, Escherichia fergusonii, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Listeria innocua, and Pseudomonas aeruginosa.

5. Use of the Aβ42 variant antimicrobial peptide according to claim 1 in the preparation of anticancer preparations.

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