Synergy between Histone-Derived Antimicrobial Peptides and Conventional Antibiotics

Abstract

Circular dichroism and dye leakage assays revealed that the amidated Cterminus maintains better peptide structural stability and ability to disrupt membranes than the carboxylic form. Similarly, 31 P and 2 H solid-state NMR displayed that the C-terminal amidated peptide had a stronger interaction with the phospholipid headgroups and a slight effect on the lipid acyl chains. Cell viability and antibacterial assays showed that the amidated C-terminus induced greater antibacterial and cytotoxic effect while the carboxylic C-terminus promoted mild cytotoxic effect and reduced antibacterial efficacy. Overall, the results showed that the C-terminus of maculatin is critical in modulating the peptide mode of action.