Study On The Interaction Between ?-helical Peptides And Surfactants

In daily life,skin diseases such as dandruff and body acne are mostly caused by bacteria,mold,and fungi.In order to solve the problems caused by these pathogenic microorganisms,antibacterial agents such as methylisothiazolinone(MIT)are often added to shampoos or skin care products,but these drugs can cause neurotoxins and skin allergies,even lead to cancer.The IIKK-type alpha-helical peptides is a high cell selective antibacterial agent and are able to kill bacteria and tumor cells while not producing toxicity to normal cells.In order to reduce the toxicity in daily chemical products,In this study,we use IIKK-type helical peptides to replace the traditional type of preservative,and studied the interaction between IIKK-type helical peptides and surfactants in detail.In this thesis,we studied threesurfactants,including anionic surfactants,nonionic surfactants,and zwitterionic surfactants.Surface activity,secondary structure and antibacterial activity were investigated by L-B membrane instrument,Circular Dichroism spectroscopy and,antibacterial experiment.The experimental results showed that when the molar ratio of the helical peptide and the anionic surfactant is 3:11,a good antibacterial activity can be achieved;the interaction between the nonionic surfactant and the helical peptide is weak and does not affect the antibacterial activity;When react with The interaction between peptide and zwitterionic surfactantswere effected by pH.At pH 6.4,the interaction between the surfactant and the helix peptide is weak.and showed good anti-bacterial ability when adding 5 ?M helix peptide at this pH.At pH 10.4,the helical peptide and the surfactant have synergistic effect and increase the antibacterial activity(minimum inhibitory concentration is 1.5 ?M).The research results are useful for studying the application of alpha-helicals antibacterial peptides in daily chemical products.