Inhibitory Effect Of Antimicrobial Peptides On Propionibacerium Acnes

Acne is a common skin disease in people,usually with acne,cyst as the main performance,accompanied by scar.Not only that,the existence of acne has become a great burden on people’s life and psychology.At present,there are some limitations in the practical application of the commonly used treatment methods for acne.Therefore,it is of great practical significance to seek new treatment methods for acne.Propionibacterium acnes is one of the important causes of acne.Antimicrobial peptides are a class of basic peptides with broad-spectrum antibacterial activity.Antimicrobial peptides often have special spatial structure,which can specifically combine with the target to quickly detect and kill the target.According to the antibacterial peptide ZXR-2 patented by our laboratory in 2015,we designed a series of peptides for preliminary screening.The antibacterial peptide has broad-spectrum antibacterial properties,high activity and is not easy to inactivate.In this study,peptide modification was carried out according to the specific needs to improve the selectivity,bactericidal activity and anti-biofilm activity of peptides.The modified peptides were divided into four series: IL,ILV,ILN and L.According to these four series of 24 peptides,the corresponding antibacterial effect screening was carried out,in order to screen out peptide sequences with obvious inhibitory effect on Propionibacterium acnes,and provide new ideas and methods for the follow-up treatment of acne.Firstly,a large number of peptides were screened to determine whether they have antibacterial effect.The MIC of peptides with certain antibacterial effect at the concentration of 25 μg/ m L was further determined.The results showed that in addition to the original ZXR series,many peptides in IL and ILV series also showed good antibacterial activity.In order to determine the anti-biofilm activity of these peptides,the bacterial survival rate and biofilm residue in the biofilm were determined by MTT method and crystal violet staining method.The results showed that ILV-1,ILV-2,ILV-5 and IL-4 showed better killing effect on bacteria in biofilm,while IL-5 showed stronger ability to remove bacteria in biofilm.Comparative analysis found that the shorter the peptide,the smaller the hydrophobic moment,and the larger the side chain group of the amino acid residue,the smaller the antibacterial activity of the peptide.In addition,the stronger the tendency of the C-terminus or the N-terminus of the peptide to form an α-helix,the better the antibacterial activity of the peptide.These conclusions can provide some reference for subsequent experiments.These peptide molecules will provide effective precursor molecules for the research and development of anti-acne drugs,and also provide a certain research basis for the development of related products.