Molecular modeling of four Dermaseptin-related peptides of the gliding tree frog Agalychnis spurrelli

Abstract

In this research, we present a preliminary computational study of four Dermaseptin-related peptides from the skin exudate of thegliding tree frogAgalychnis spurrelli. Experimentally, the amino acid sequence of these peptides was elucidated throughmolecular cloning and tandem mass spectrometry and synthetic peptides were assayed againstE. coli,S. aureus,andC. albicansto determine their antimicrobial properties. With the sequences on hand, a computational study of the structureswas carried out, obtaining their physicochemical properties, secondary structure, and their similarity to other known peptides. Amolecular docking study of these peptides was also performed against cell membrane and several enzymes are known to be vitalfor the organisms. Results showed that Dermaseptin-related peptides areα-helical cationic peptides with an isoelectric pointabove 9.70 and a positive charge of physiological pH. Introducing theses peptides in a database, it was determined that theiridentity compared with known peptides range from 36 to 82% meaning these four Dermaseptins are novel peptides. Thispreliminary study of molecular docking suggests the mechanism of action of this peptide is not given by the inhibition ofessential enzymatic pathways, but by cell lysis.