Rational antimicrobial peptide engineering through amino acid scanning and targeted point mutations

With the increasing use of antimicrobial peptides (AMPs) as alternatives to conventional antibiotics, understanding the structural and physicochemical determinants underlying their activity has become essential for the development of effective therapeutic agents. This review provides a state-of-the-art overview of how residue-specific modifications, particularly through amino acid scanning approaches, contribute to the elucidation of structure-activity relationships in AMPs. Different scanning strategies are discussed, highlighting how systematic substitutions reveal the role of individual residues in modulating antimicrobial activity, membrane interaction, and structural stability. Particular emphasis is given to how variations in charge, hydrophobicity, and conformational flexibility influence peptide behavior, including the identification of residues critical for membrane binding, insertion, and disruption. In addition, the impact of specific amino acids on peptide function is analyzed in the context of targeted modifications that enhance activity while maintaining selectivity. Finally, the integration of data derived from these approaches with computational tools and peptide databases is discussed to support rational design strategies. Together, these advances provide a framework for the strategic optimization of antimicrobial peptides, contributing to the development of more effective and selective antimicrobial agents.