Basic Research On The Specific Neutralizing Peptides Of The Skin Secretions Of Bombina Maxima Under The Stress Of Endotoxin

Infection is one of the leading causes of human death.At the moment,most infectious diseases are caused by endotoxins released by gram-negative bacteria.Sepsis caused by endotoxin and septic shock are the most common and intractable critical diseases in clinical practice,the fatality rate is so high,but there is no effective treatment.Antimicrobial peptides are also known as host defense peptides,they are small peptides with broad-spectrum antimicrobial activity,rapid onset,broad antimicrobial spectrum,low resistance and wide antibacterial spectrum are their advantages.Furthermore,they are still effective against drug-resistant bacteria,better effective than conventional antibiotics in fungicidal effectiveness.So antimicrobial peptides are thought to be potential clinical substitutes for antibiotics to cure bacterial infections.Bombina maxima is endemic to Yunnan,Guizhou and other places in China,its skin secretions contain a large number of bioactive substances.Unlike Mammalia,Bombina maxima can produce some specific bioactive peptides(antimicrobial peptides)in response to environmental stress,currently isolated peptides such as maximin,maximin H and maximin S have significant biological activity.However,it remains to be studied whether there are endotoxin neutralizing peptides in the skin secretions of Bombina maxima.In this study,Bombina maxima as the main research object we used the escherichia coli endotoxin solution to stress them,measured transcriptome of skin tissues at different time points after stimulation and collected the skin secretions.Through molecular sieve and reversed-phase high performance liquid chromatography to conduct the isolation and purification of secretions.Detected the neutralization activity of bioactive peptides towards the LPS-EB biotin with SSA biosensor.Carried out the molecular weight detection and sequence determination of the best bioactive peptides towards LPS.Ultimately found two peptides which primary structures are composed of 11 amino acid residues and 10 amino acid residues.