The Antimicrobial Peptide Polyphemusin Localizes to the Cytoplasm of <i>Escherichia coli</i> following Treatment

Abstract

The horseshoe crab peptide polyphemusin I possesses high antimicrobial activity, but its mechanism of action is as yet not well defined. Using a biotin-labeled polyphemusin I analogue and confocal fluorescence microscopy, we showed that the peptide accumulates in the cytoplasm of wild-type Escherichia coli within 30 min after addition without causing substantial membrane damage.