Differential Expression Of Bioactive Peptides In The Skin Of Rana Dybowskii Under Bacterial Challenges

Amphibian skin antimicrobial peptides have activity of broad-spectrum antibacterial,anti-tumor, poorly-immunogenic and unique antibacterial mechanism.Therefore,amphibian skin antimicrobial active peptides have become an international research hot topic in the fields of biology as new sources of candidate molecules for antibiotic agents.This study drew methanol extract from Rana dybowskii skin stimulated by E.coli and S.aureus antigen though injecting to lymphatic sac of forest frog back,and then got skin active peptides by through SephadexG-50 and RP-HPLC purification.This research included comparison on expression differences associated with skin active peptides of Rana dybowskii stimulated by E.coli and S.aureus antigen and observation on antibacterial effects of skin active peptides components on E.coli and S.aureus and analysis on different expression rules of skin active peptides of Rana dybowskii through antibacterial test in vitro to provide new ideas for screening skin active peptides and studying on effect and principles of active peptide as important effective factors of inborn immunity system in process of biological evolution.The results showed that antibacterial activity of components of Rana dybowskii skin active peptides increased;there were expression differences under different bacteria stimulation condition in HPLC fingerprinting;the 2^ndpeak,3^rdpeak,4^thpeak,8^thpeak,11^th peak and 13^thpeak were relevant with resistant to Gram-negative Bacilli,whereas the 3^rdpeak, 4^thpeak,5^thpeak,6^thpeak and 9^thpeak were relevant with resistant to Gram-positive Bacilli; during certain time,major peaks showed upregulated expression and enhanced antibacterial activity as stress time increased by bacteria.These results suggested that Rana dybowskii skin selective expressed antibacterial peptide components under different antigen stress condition; organism enhanced antibacterial activity though combined peptide and increased expression quantity under certain microorganism stress condition.