Truncated Equinin B Variants Reveal the Sequence Determinants of Antimicrobial Selectivity

科学分野:

• Marine natural products; Antimicrobial peptides; Biochemistry

背景:

• Equinin B, a marine peptide from Actinia equina, shows broad-spectrum antibacterial activity.; Investigating smaller active regions and tunable properties of Equinin B is crucial for developing novel antimicrobials.

研究 の 目的:

• To identify a smaller active region within Equinin B with tunable properties.; To explore modifications of peptide fragments for enhanced selectivity and reduced cytotoxicity.

主な方法:

• Synthesis and characterization of three peptide fragments (EB1, EB2, EB3).; Antibacterial activity assays against Gram-positive and Gram-negative bacteria.; Hemolytic activity assays and membrane depolarization studies.; In silico modeling of peptide-membrane interactions.

主要な成果:

• The 11-residue C-terminal fragment (EB3) selectively targeted Gram-positive bacteria.; Modifications of EB3 reduced hemolytic activity and increased bacterial specificity.; EB3 disrupts bacterial membranes via pore formation or carpet-like mechanisms, with phenylalanine contributing to membrane interaction.

結論:

• The 11-residue C-terminal fragment of Equinin B is a tunable, membrane-targeting motif.; This fragment offers a blueprint for developing safer, selective antimicrobial peptides with reduced cytotoxicity.; Mechanistic novelty in membrane disruption was observed.