Cathelicidin-DM is an Antimicrobial Peptide from <i>Duttaphrynus melanostictus</i> and Has Wound-Healing Therapeutic Potential

Abstract

Antimicrobial peptides (AMPs) are a class of templates with application potential for drug development. Amphibians are important sources of AMPs. <i>Duttaphrynus melanostictus</i> is the main source of traditional Chinese medicine "Chansu", which has anti-infection effect while without a clear mechanism. This study aimed to find the cathelicidin peptide in <i>D. melanostictus</i> and then investigate the activity <i>in vivo</i> and <i>in vitro</i>, and an AMP-encoding gene (cathelicidin-DM, GenBank: KJ820824.1) was obtained from the constructed cDNA library of <i>D. melanostictus</i>. The MIC test and SYTOX Green uptake were used for the evaluation of the bactericidal capacity and mechanisms. The serum stability tests were used for the evaluation of the application potential. The skin wound infection model and <i>in vivo</i> imaging were used for <i>in vitro</i> application of possibility evaluation. The results showed that cathelicidin-DM was a 37 amino acid AMP with good bactericidal ability, which was similar to melittin: both can kill bacteria within 15 min. Moreover, cathelicidin-DM exhibits good therapeutic potential in the mouse wound infection model, and it can be enriched to the site of infection for treatment. Thus, cathelicidin-DM could be a new template for antimicrobial drug development given its good antibacterial activity <i>in vivo</i> and <i>in vitro</i>.