LAUSR

ε-Poly-L-lysine (ε-PL) is a natural antimicrobial cationic peptide. Antimicrobial activity of ε-PL is closely related to its molecular weight (Mw). However, the antimicrobial mechanisms of ε-PL with different Mws are still vague. In this study, Saccharomyces cerevisiae was used as the model system to analyze the mechanism from these three aspects: cell wall, cell membrane, and metabolism. The results showed that high-Mw ε-PL (1-3 kDa and >3 kDa) and commercial ε-PL product caused cell wall lesions, and significantly improved cell membrane permeability compared to low-Mw ε-PL (<1 kDa), resulting in leaking of the protoplasm through the pores and cell death. Furthermore, metabolomics analysis showed that high-Mw ε-PL (1-3 kDa and >3 kDa) and product displayed higher inhibition effect on the glycolysis pathway and tricarboxylic cycle than that of low-Mw ε-PL (<1 kDa).