title: Effect of D-amino acid substitution on the stability, the secondary structure, and the activity of membrane-active peptide.
abstract: Several diastereomers and an enantiomer of KKVVFKVKFKK, an antimicrobial peptide that acts on the lipid membrane of pathogens were synthesized to investigate the effect of D-amino acid substitution on stability, secondary structure, and activity. The stability of the peptide in serum was improved greatly by the D-amino acid substitutions. D-Amino acid substitutions at the N- and/or C-terminal of the peptide, which had little effect on the alpha-helical structure, and all D-amino acid substitutions that formed a left-handed alpha-helix maintained antimicrobial activity, whereas D-amino acid substitutions in the middle of the amino acid sequence disrupted the alpha-helical structure, resulting in the complete loss of activity. This result confirmed that the peptide did not interact with chiral receptors, enzymes, or any chiral component of the membrane. D-Amino acid substitutions at the termini reduced the inhibition of the activity by heat-inactivated serum, which indicated that local change of chirality or change of secondary structure induced by D-amino acid substitutions might affect the interactions between the peptide and certain components in the serum. The present study suggests that partial D-amino acid substitution is a useful technique to improve the in vivo activity of antimicrobial peptides.
authors.affiliation: Protein Chemistry Laboratory, Mogam Biotechnology Research Institute, Youngin City, Kyunggi-Do, Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Hong
authors.forename: J E
authors.initials: JE
authors.lastname: Oh
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000935:Antifungal Agents / Q000737:chemistry* / Q000494:pharmacology; D002175:Candida / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D002942:Circular Dichroism; D004355:Drug Stability; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D017433:Protein Structure, Secondary; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D000935:Antifungal Agents; D010455:Peptides