28-mer peptide from enterocin CRL35 displays bacericidal activity

MASIAS, E; DA SILVA SANCHES, PR; SAAVEDRA,L; BELLOMIO, A; CILLI, E; MINAHK, C

Villa Carlos Paz, Cordoba

Congreso; XLII Reunión Anual Sociedad Argentina de Biofisica; 2013

Enterocin CRL35 is a pediocin-like bacteriocin produced by Enterococcus mundtii CRL35. This antimicrobial peptide is active against food-borne pathogen Listeria monocytogenes. In this work we used the following synthetic peptides: the full-length bacteriocin (43- mer) and short derived peptides from the C-terminus and N-terminus of enterocin CRL35 (28-mer and 15-mer respectively). Peptide binding to target cells was analyzed by fluorescence polarization. The Ka values calculated from experimental data indicated that the 3 peptides could bind similarly to the sensitive cells. Dissipation of membrane potential assays showed that although all 3 peptides were able to dissipate the transmembrane electrical potential, the 15-mer peptide produced a slower and incomplete dissipation. 43-mer has a MIC of 100 nM while 28-mer and 15-mer have a much higher values of 10 and 20 μM, respectively. However, only 43-mer and 28-mer peptides displayed bactericidal effect against target cells. 15-mer peptide showed a bacteriostatic effect since no cells were killed by this peptide in HEPES buffer. 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.