Susceptibility of bacterial, eukaryotic and artificial membranes to the disruptive action of the cationic peptides Pep 5 and nisin

Abstract

The cationic bactericidal peptides Pep 5 and nisin render membranes permeable to low‐Mr compounds. All Gram‐positive bacteria treated with these peptides showed an immediate efflux of entrapped radioactive markers. The uptake of α‐[14C]methylglucoside by the phosphoenolpyruvate‐dependent phosphotransferase system was stimulated by Pep 5, supporting previous results that pep 5 abolishes the membrane potential. Oxygen consumption was inhibited, presumably due to lack of ADP. Escherichia coli became sensitive to Pep 5 and nisin when the outer membrane was bypassed by osmotic shock or by formation of cytoplasmic membrane vesicles. In contrast, Mycoplasma cells and erythrocytes were unaffected by Pep 5 and nisin in concentrations up to 1 mM. Human lung fibroblasts released only small amounts of ATP when treated with Pep 5 and nisin in μM concentrations. Eukaryotic and Mycoplasma cells were disrupted more effectively by the bee venom peptide melittin, which displays overall structural similarities to Pep 5 and nisin. Various artificial membranes were not affected by Pep 5, nisin, or melittin.

Synergistic Antimicrobial Effect of Nisin and ρ-Cymene onSalmonella entericaSerovar Typhiin Vitroand on Ready-to-Eat Food

“…16) Cell inactivation is a result of cellular damage which can range from the disruption of proton motive force to loss of membrane integrity. 17,18) However, nisin is not active against gram-negative bacteria. Their outer membrane, consisting of substantial amounts of protein, phospholipid, and lipopolysaccharide, acts as a barrier to the action of nisin on the cytoplasmic membrane.…”

“…23) Cells of Escherichia coli exhibited nisin sensitivity when their outer membrane was subjected to osmotic shock. 17,24) Treatment with trisodium phosphate increased the nisin sensitivity of E. coli, Campylobacter jejuni, Pseudomonas fluorescens, and Salmonella enteritidis. As observed with the nisin treatment, -cymene used alone did not inhibit S. Typhi.…”

Analysis of the gene expression profile of Staphylococcus aureus treated with nisin

“…It was demonstrated that in vitro, nisin inhibited bacterial cell-wall biosynthesis (Reisinger, Seidel, Tschesche, & Hammes, 1980). Subsequently, it was shown that nisin kills bacterial cells by interfering with basic energy transduction at the cytoplasmic membrane (Kordel & Sahl, 1986;Ruhr & Sahl, 1985). It was found that pores formed in the membrane by the nisin molecules allowed the diffusion of small compounds, as no transport system for ATP has been reported (Abee, Rombouts, Hugenholtz, Guihard, & Letellier, 1994).…”

Mutational analysis and chemical modification of Cys24 of lactococcin B, a bacteriocin produced by Lactococcus lactis

“…Lactococcins A and B specifically inhibit the growth of lactococci, and their modes of action have been studied. Both are small cationic, hydrophobic peptides that structurally resemble several peptide antibiotics which permeabilize membranes (Kordel & Sahl, 1986;Kordel e t al., 1988; Schaller e t a]., Galvez et al, 1991 ;Gao e t al., 1991). At lactococcin concentrations that do not affect immune cells, both bacteriocins rapidly dissipate the membrane potential of glucose-energized sensitive cells of L. lactis and cause efflux of preaccumulated amino acids (Van Belkum e t al., 1991b;Venema e t al., 1993).…”