Identification of an antifungal peptide from Trapa natans fruits with inhibitory effects on Candida tropicalis biofilm formation

Due to recent emergence of fungal pathogens resistant to current antifungal therapies, several studies have been focused on screening of plant peptides to find novel compounds having antifungal activities. Here, a novel antifungal plant peptide, with molecular mass of 1230 Da was purified from fruits of Trapa natans by reverse phase high performance liquid chromatography using 300SB-C18 column and named as Tn-AFP1. Determination of complete amino acid sequences of this peptide by tandem mass spectrometry showed to contain following eleven amino acid residues: LMCITIPLDCSN. Purified Tn-AFP1 showed the inhibition of Candida tropicalis growth in vitro and disrupted the biofilm formation in a concentration dependent manner. It also showed downregulation of MDR1 and ERG11 gene expression in real time-PCR analysis. In silico molecular modeling predicted the structure of Tn-AFP1 as a single coil attached by a unique disulfide bond. Characterization of Tn-AFP1 could contribute in designing novel derivative(s) of this peptide for the development of more effective antimycotic compounds. (C) 2011 Elsevier Inc. All rights reserved.