Deletion of all cysteines in tachyplesin I abolishes hemolytic activity and retains antimicrobial activity and lipopolysaccharide selective binding.

ABSTRACT: Tachyplesin I is a cyclic beta-sheet antimicrobial peptide isolated from the hemocytes of Tachypleus tridentatus. The four cysteine residues in tachyplesin I play a structural role in imparting amphipathicity to the peptide which has been shown to be essential for its activity. We investigated the role of amphipathicity using an analogue of tachyplesin I (TP-I), CDT (KWFRVYRGIYRRR-NH(2)), in which all four cysteines were deleted. Like TP-I, CDT shows antimicrobial activity and disrupts Escherichia coli outer membrane and model membranes mimicking bacterial inner membranes at micromolar concentrations. The CDT peptide does not cause hemolysis up to 200 microg/mL while TP-I showed about 10% hemolysis at 100 microg/mL and about 25% hemolysis at 150 microg/mL. Peptide-into-lipid titrations und

SUBMITTER: Ramamoorthy A 

PROVIDER: S-EPMC2515376 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature