Multispectral bioactivity studies of N-terminal fatty acid modified antimicrobial peptide Andricin B.

A series of Andricin B derivatives were designed and synthesized using fatty acid modification at N-terminus of the antimicrobial peptides. The hydrophobicity of Andricin B was altered through fatty acid modification, and the bioactivity was investigated. The interaction between Andricin B and its derivatives with DNA was measured using multi-spectroscopy. Spectroscopic analysis revealed that Andricin B and its derivatives can interact with ct-DNA and G-quadruplexes DNA, and the interaction related with the length of fatty acid chain. Antimicrobial activity tests showed a significant increase using peptides with 8-10 carbons fatty acid chain. C10-Andricin B exhibited the highest antimicrobial activity, with up to a 16-fold enhancement compared to the original peptide Andricin B. Meanwhile, the protease hydrolysis stability test showed that fatty acid modification improved the stability of Andricin B against protease. Scanning electron microscopy results distinctly showed that C8-Andricin B could rupture the cell wall of bacteria. All results indicated that fatty acid modification peptides are an effective strategy for enhancing activity and stability of antimicrobial peptides. This research provides valuable insights for further research on antimicrobial peptides.