Antibacterial activities of synthetic peptides corresponding to the carboxy-terminal region of human beta-defensins 1-3.
The antibacterial activities of synthetic human beta-defensin analogs, constrained by a single disulfide bridge and in the reduced form, have been investigated. The peptides span the carboxy-terminal region of human beta-defensins (HBD-1-3), which have a majority of cationic residues present in the native defensins. The disulfide constrained peptides exhibited activity against Escherichia coli and Staphylococcus aureus whereas the reduced forms were active only against E. coli. The antibacterial activities were attenuated in the presence of increasing concentrations of NaCl and divalent cations such as Ca(2+) and Mg(2+). The site of action was the bacterial membrane. Peptides spanning the carboxy-terminal region of human beta-defensins could be of help in understanding facets of antimicrobial activity of beta-defensins such as salt sensitivity and mechanisms of bacterial membrane damage.
Krishnakumari
Viswanatha
V
Center for Cellular and Molecular Biology, Uppal Road, Hyderabad 500007, India.
Singh
Shashi
S
Nagaraj
Ramakrishnan
R
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D004926:Escherichia coli / Q000187:drug effects* / Q000648:ultrastructure; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D023083:beta-Defensins / Q000138:chemical synthesis / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; C406407:DEFB1 protein, human; C422950:DEFB103A protein, human; C106641:DEFB4A protein, human; D010446:Peptide Fragments; D023083:beta-Defensins