Optimizing Amphipathic Antimicrobial Peptides via Helical Wheel Rotation.

Antimicrobial peptides (AMPs) have emerged as promising candidates for combating drug-resistant pathogens and certain cancer types. However, their therapeutic applications are often limited by undesired hemolytic activity, while many AMPs exhibit only moderate potency. Herein, the "helical wheel rotation" strategy as a simple, cost-effective, and modular approach to optimize the pharmacological properties of amphipathic α-helical AMPs without altering their amino acid composition is explored. Using BP52 as a model peptide, six rotational variants (BP52-A1 to BP52-A6) and two sequence-modified derivatives (BP52-B1 and BP52-B2) are developed to assess their antimicrobial, anticancer, and hemolytic properties. Several derivatives, especially BP52-A6, exhibit enhanced antimicrobial activity and reduced hemolysis while maintaining or improving potency toward cancer cells. Importantly, all derivatives show substantially reduced hemolytic activity compared to BP52. These findings highlight the potential of helical wheel rotation as a valuable peptide engineering strategy to fine-tune selectivity and multifunctionality of AMPs for therapeutic applications.