Preparation And Application Of Short-chain Antimicrobial Peptides Based On One-bead-one-substance Method Combined With Cell Membrane Chromatograph

Antibiotic resistance is an important issue affecting global health,which have significant influence on social and economic,and the development of new antimicrobial agents is imminent.Antimicrobial peptides(AMPs)appear to be a new option to solve this problem.The mechanism of action of AMP involves intracellular targets and membrane disruption.Antimicrobial peptides have broad-spectrum antimicrobial activity and can rapidly treat and kill a variety of targets,including Gram-negative bacteria,Gram-positive bacteria,fungi,and tumor cells.Therefore,AMP can exert effective effects on antibioticresistant bacteria,protozoa,yeast and fungi.Importantly,because they do not bind to specific receptors,AMPs are less prone to drug resistance.Combining bacterial membrane chromatography and one-bead-one-substance method,this subject developed a membrane chromatography packing and successfully used it for the screening of antimicrobial peptides.The screened antimicrobial peptides have excellent antibacterial properties.The main work is as follows:1.We have successfully prepared a cell membrane chromatography packing.Using a modified St?ber method,silica microspheres with an average particle size of about 4 μm were obtained.Then,a water-soluble photosensitive polymer diazo resin(DR)was synthesized,and the DR was used to modify the bacterial cell membrane onto the surface of silica microspheres to achieve functional modification of the silica spheres.2.Short peptides with antibacterial properties were successfully screened out using the membrane chromatography packing material.The screened antimicrobial peptide is Alanine-Valine-Glycine-Alanine-Valine(AVGAV).The antimicrobial properties and minimum inhibitory concentrations(MICs)of antimicrobial peptides were studied.The antimicrobial peptide was found to have antibacterial activity against a variety of bacteria,including Escherichia coli,Staphylococcus aureus,Candida albicans,Pseudomonas aeruginosa,Salmonella paratyphi B,and Staphylococcus epidermidis,and the minimum inhibitory concentrations were 150 μg/m L,250 μg/m L,200 μg/m L,and 700 μg/m L,respectively.μg/m L,500 μg/m L,800 μg/m L.And under different p H,boiling heating,gastric juice environment and oxidative conditions,the antimicrobial peptide has better stability.3.Antimicrobial peptides have good biocompatibility.When the antimicrobial peptide concentration completely inhibited the growth and reproduction of Escherichia coli,it did not show significant cytotoxicity to mouse fibroblasts(L929).The guinea pig skin irritation test proved that the antimicrobial peptide had neither skin irritation nor skin allergy.In the acute oral toxicity test,the rats remained healthy for two weeks.In a mouse wound bacterial infection model,it exhibited excellent antibacterial and wound healing effects.4.The antimicrobial peptide can inhibit bacteria from developing drug resistance.Under the sub-lethal concentration,the experiment of bacterial subculture was carried out,and the antimicrobial peptide did not change the minimum inhibitory concentration of bacteria within 14 generations of bacterial passage.However,in the 7th generation,the corresponding antibiotics began to show resistance5.On the basis of the method reported in the literature,the silica gel powder was modified by 3-(Trimethoxysilyl)propyl methacrylate(MPS),and the column chromatography silica gel powder was successfully prepared.Compared with commercial silica gel powder,the self-made modified silica gel powder has a better separation effect in the separation of thiophene substances,and is expected to be applied in the separation of antimicrobial peptides and other compounds.