AurH1: a new heptapeptide derived from Aurein1.2 antimicrobial peptide with specific and exclusive fungicidal activity

Abstract

Due to the increasing incidence of fungal opportunistic infections and emergence of antibiotic-resistant fungal strains, antimicrobial peptides (AMPs) are considered as ideal candidates for antifungal compounds. In silico methods can reduce the limitations of natural AMPs such as toxicity and instability and improve their antimicrobial properties and selectivity. In this study, we designed AurH1, a new truncated peptide, based on the six-amino acid sequence of Aurein1.2. Further, the antimicrobial activities and toxicity effects of AurH1 on human skin fibroblast cells and red blood cells were investigated. Finally, field emission scanning electron microscopy (FE-SEM) and flow cytometry were performed in order to study the mechanism of action of AurH1. The results indicated that AurH1 had only antifungal activity (at a minimal inhibitory concentration (MIC) of 7.3-125 μg/mL) without any antibacterial effects on the selected bacteria, while Aurein1.2 had both antifungal and antibacterial activities as positive control. Furthermore, AurH1 did not show any toxicity on Hu02 cells and human red blood cells at its MIC range. In conclusion, it became clear that AurH1 is a selective peptide against fungi with no toxic effects on the selected bacteria and human cells.