Ocurrencia de actividad antimicrobiana en la secreción de la piel de Callimedusa ecuatoriana y caracterización estructural del péptido Ikiam 2599

Abstract

Defensive peptides from amphibian skin secretions have generated great interest in the world for their antibacterial, antifungal, antiprotozoal, wound healing, antioxidant, and even anticancer capabilities. Between them, antimicrobial peptides (AMPs) are considered as a potential therapeutic alternative against infections caused by microorganisms resistant to conventional antibiotics. In Phyllomedusidae family, new AMPs have been described, with strong antimicrobial activity with low or no hemolytic activity, considering them potential for clinical development. In Ecuador, there are species belonging to this family, with biomedical potential that are in danger of extinction and unexplored as a source of new MPAs, such as Callimedusa ecuatoriana. This study reports for the first time analysis of the antimicrobial potential of C. ecuatoriana cutaneous secretion through fractionation by high performance liquid chromatography (HPLC), antimicrobial assays and matrix assisted mass spectrometry (MALDI-TOF MS). In addition, the primary structure of the first peptide (Ikiam2599) from C. ecuatoriana skin obtained by molecular cloning is reported. From the analysis of its precursor sequence against described peptides, it was identified that Ikiam2599 peptide belongs to the recently described Picturin family. The synthetic peptide Ikiam2599 lacks hemolytic and antibacterial activity against Escherichia coli and Staphylococus aureus: additionally, it lack antifungal activity. This study demonstrates the biomedical potential of the C. ecuatoriana cutaneous secretion, also showing the potential of unexplored biological and molecular diversity in endemic species of Ecuador