Isolation, Characterization and Mode of Action of a Plant-Derived Antifungal Peptide, Cc-AFP1 Against Aspergillus Fumigatus

Abstract

\n Among novel molecules with therapeutic efficacy, antifungal peptides (AFPs) have recently been attracted due to their unique ability to evade fungal pathogens. In this study, a novel AFP, Cc-AFP1 (MW ~ 3.759 kDa) isolated from Carum carvi L. was purified by precipitation and chromatography techniques. Sequence analysis by Edman degradation revealed a fragment of 36 amino acid residues as RVCFRPVATYLGVCGVSGACRDHCVKLGSCVYKGPG. The tertiary structure prediction using the I-TASSER showed α-helix and random coil structure. Cc-AFP1 had a net charge of +4 and hydrophobicity ratio of 44%. The antifungal activity of Cc-AFP1 was confirmed against Aspergillus species with MIC values in the range of 8-16 µg/mL. Cc-AFP1 had less than 5% hemolytic activity at 8-16 µg/mL on human red blood cells, while it was nontoxic for HEK293 cell lines. Stability analysis showed that Cc-AFP1 activity was maintained at different temperatures (20 to 80ºC) and pH (8 to 10). The results of a propidium iodide uptake and transmission electron microscopy showed that the antifungal activity of Cc-AFP1 could be attributed to altering the fungal cell membrane permeability. Taken together, these results indicate that Cc-AFP1 may be an attractive molecule to develop as a novel antifungal agent combating fungal infections cause by Aspergillus species.