Short arginine-rich lipopeptides: From self-assembly to antimicrobial activity.

In this paper, we examine antimicrobial and cytotoxic activities, self-assembly and interactions with anionic and zwitterionic membranes of short arginine-rich lipopeptides: C16-RRRR-NH2, C14-RRRR-NH2, C12-RRRR-NH2, and C16-PRRR-NH2. They show a tendency to self-assembly into micelles, but it is not required for antimicrobial activity. The membrane binding of the lipopeptides can be accompanied by other factors such as: peptide aggregation, pore formation or micellization of phospholipid bilayer. The shortening of the acyl chain results in compounds with a lower haemolytic activity and a slightly improved antimicrobial activity against Gram-positive bacteria, what indicates enhanced cell specificity. Results of coarse-grained molecular dynamics simulations indicate different organization of membrane lipids upon binding of arginine-based lipopeptides and the previously studied lysine-based ones.