Study on antimicrobial activity of sturgeon skin mucus polypeptides (Rational Design, Self-Assembly and Application).

Despite the favorable biocompatibility of natural antimicrobial peptides (AMPs), their scarcity limits their practical application. Through rational design, the activity of AMPs can be enhanced to expand their application. In this study, we selected a natural sturgeon epidermal mucus peptide, AP-16 (APATPAAPALLPLWLL), as the model molecule and studied its conformational regulation and antimicrobial activity through amino acid substitutions and -terminal lipidation. The structural and morphological transitions of the peptide self-assemblies were investigated using circular dichroism and transmission electron microscopy. Following amino acid substitution, the conformation of AL-16 (AKATKAAKALLKLWLL) did not change. Following -terminal alkylation, the C-AL-16 and C-AL-16 conformations changed from random coil to β-sheet or α-helix, and the self-assembly changed from nanofibers to nanospheres. AL-16, C-AL-16, and C-AL-16 presented significant antimicrobial activity against and at low concentrations. -terminal alkylation effectively extended the shelf life of . These results support the application of natural AMPs.