PLNC8 beta peptide

Bacteriocins are antimicrobial peptides that are produced by most microorganisms that contribute their defence mechanisms. PLNC8 α and PLNC8 β are class II bacteriocins. Both L- and D-PLNC8 αβ caused rapid disruption of lipid membrane integrity and were effective against both susceptible and antibiotic resistant strains. The D-enantiomer was stable against proteolytic degradation by trypsin compared to the L-enantiomer. Of the truncated peptides, β1–22, β7–34 and β1–20 retained an inhibitory activity. The peptides diffused rapidly (2 min) through the bacterial cell wall and permeabilized the cell membrane, causing swelling with a disorganized peptidoglycan layer. Interestingly, sub-MIC concentrations of PLNC8 αβ substantially enhanced the effects of different antibiotics in an additive or synergistic manner. PLNC8 αβ is active against Staphylococcus spp. and may be developed as adjuvant in combination therapy to potentiate the effects of antibiotics and reduce their overall use. PLNC8 α and β are short peptides, composed of 29 and 34 amino acids, respectively, and show structural stability against heat and pH. Both PLNC8 α and β are membrane active on their own, but whereas more than 5 μM of PLNC8 α was required to induce substantial perturbation of lipid bilayer integrity in a liposomal model system, less than 0.1 μM PLNC8 β caused the same effects.