Interaction of a novel antimicrobial peptide isolated from the venom of solitary bee Colletes daviesanus with phospholipid vesicles and Escherichia coli cells

0436961 - ÚOCHB 2015 RIV GB eng J - Journal Article
Čujová, Sabína - Bednárová, Lucie - Slaninová, Jiřina - Straka, J. - Čeřovský, Václav
Interaction of a novel antimicrobial peptide isolated from the venom of solitary bee Colletes daviesanus with phospholipid vesicles and Escherichia coli cells.
Journal of Peptide Science. Roč. 20, č. 11 (2014), s. 885-895. ISSN 1075-2617. E-ISSN 1099-1387
Institutional support: RVO:61388963
Keywords : antimicrobial peptides * wild-bee venom * CD spectroscopy * large unilamellar vesicles * membrane permeabilization * electron microscopy
Subject RIV: CE - Biochemistry
Impact factor: 1.546, year: 2014

The peptide named codesane (COD), consisting of 18 amino acid residues and isolated from the venom of wild bee Colletes daviesanus (Hymenoptera:Colletidae), falls into the category of cationic -helical amphipathic antimicrobial peptides. In our investigations, synthetic COD exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and Candida albicans but also noticeable hemolytic activity. COD and its analogs (collectively referred to as CODs) were studied for the mechanism of their action. The interaction of CODs with liposomes led to significant leakage of calcein entrapped in bacterial membrane-mimicking large unilamellar vesicles made preferentially from anionic phospholipids while no calcein leakage was observed from zwitterionic liposomes mimicking membranes of erythrocytes. The preference of CODs for anionic phospholipids was also established by the blue shift in the tryptophan emission spectra maxima when the interactions of tryptophan-containing COD analogs with liposomes were examined. Those results were in agreement with the antimicrobial and hemolytic activities of CODs. Moreover, we found that the studied peptides permeated both the outer and inner cytoplasmic membranes of Escherichia coli. This was determined by measuring changes in the fluorescence of probe N-phenyl-1-naphthylamine and detecting cytoplasmic -galactosidase released during the interaction of peptides with E.coli cells. Transmission electron microscopy revealed that treatment of E.coli with one of the COD analogs caused leakage of bacterial content mainly from the septal areas of the cells.
Permanent Link: http://hdl.handle.net/11104/0240879