A 28-mer Fragment Derived from Enterocin CRL35 Displays an Unexpected Bactericidal Effect on Listeria Cells

MASIAS, EMILSE; DA SILVA SANCHES, PAULO RICARDO; DUPUY, FERNANDO; ACUÑA, LEONARDO; BELLOMIO, AUGUSTO; CILLI, EDUARDO; SAAVEDRA, LUCILA; MINAHK, CARLOS

PROTEIN AND PEPTIDE LETTERS

BENTHAM SCIENCE PUBL LTD

Lugar: Oak Park; Año: 2015

0929-8665

Two shorter peptides derived from enterocin CRL35, a 43-mer bacteriocin, were synthesized i.e. the N-terminal fragment spanning from residues 1 to 15, and a 28-mer fragment that represents the C-terminal of enterocin CRL35, residues 16 to 43. The individual peptides showed no activity when combined. While the 28-mer peptide displayed an unpredicted antimicrobial activity, 15-mer peptide had no consistent anti-Listeria effect. The dissociation constants calculated from experimental data indicated that all peptides could bind at similar extent to sensitive cells. However, transmembrane electrical potential was not dissipated to the same level by the different peptides; whereas the full-length and the C-terminal 28-mer fragment induced almost full dissipation, the 15-mer fragment produced only a slow and incomplete effect. Furthermore, a different interaction of each peptide with membranes was demonstrated based on studies carried out with liposomes, leading us to conclude that activity was related to structure rather than to net positive charges. These results open up the possibility of designing new peptides based on the 28-mer fragment with enhanced activity, which would represent a promising approach for combating Listeria and other pathogens.