Reducing Self-Assembly by Increasing Net Charge: Effect on Biological Activity of Mastoparan C

Abstract

The ability of amphipathic peptides to arrange themselves in aqueous solutions, known as self-assembly, has been found to reduce the effectiveness of these peptides in interacting with cell membranes. Therefore, minimizing their tendency to self-assemble could be a potential strategy for enhancing the pharmacological properties of antimicrobial peptides (AMPs). To explore this idea, this study prepared a series of natural peptides mastoparan C (MPC) with increased net charge and hydrophilicity via alanine-to-lysine substitution and investigated the impact on the biological activity. The preliminary data suggested the influence of both the overall positive charge and the position of a lysine residue on the selfassembly of MPC and its derivatives. Besides, the analogue MPC-A5K,A8K displayed higher anticancer activity and comparable antimicrobial activity with significantly lower hemolysis than MPC. Hence, reducing self-assembly by expanding the cationic area could be a promising approach for developing potent and selective AMPs.