title: Structure-antibacterial, antitumor and hemolytic activity relationships of cecropin A-magainin 2 and cecropin A-melittin hybrid peptides.
abstract: In order to elucidate the structure-antibiotic activity relationship of cecropin A-magainin 2 and cecropin A-melittin hybrid peptides, several truncated peptides and the analogues with amino acid substitutions were synthesized and their antibacterial, antitumor and hemolytic activities of were examined. Cecropin A-magainin 2 hybrid analog, L16-CA(1-8)-MA(1-12) (termed as L-CA-MA in this study: KWKLFKKIGIGKFLHLAKKF-NH2), is known to have potent antibacterial and antitumor activity with less hemolytic activity. We found that the C-terminal region of L-CA-MA is more involved in the alpha-helical structure on cell membrane-like environment than N-terminal one by circular dichroism analysis. Deletion of the Gly-Ile-Gly sequence, the central hinge region of L-CA-MA, produced a considerable reduction in antitumor and hemolytic activity rather than an antibacterial one. The insertion of Pro, Gly-Ile or Gly-Pro in this hinge region of L-CA-MA caused retention of both antibacterial and antitumor activity while causing a significant decrease in hemolytic activity. However, the substitution with Gly-Pro-Gly instead of the Gly-Ile-Gly in CA(1-8)-MA(1-12), CA(1-8)-ME(1-12), CA(1-13)-MA(1-13) and CA(1-13)-ME(1-13) hybrids resulted in a drastic decrease in antibacterial, antitumor and hemolytic activity. The increase of hydrophobicity at position 16 in CA(1-8)-MA(1-12) by substituting Trp or Phe induced a significant increase in hemolytic activity without a considerable change in either antibacterial or antitumor activity. Therefore, these results suggested that the appropriate flexibility in the hinge region of CA-MA and CA-ME hybrid peptides and the appropriate hydrophobicity at position 16 in the hydrophobic region of CA (1-8)-MA(1-12) are important in potent antibacterial and antitumor activity with no hemolytic effect.
authors: Engineering Research Unit, Korea Research Institute of Bioscience and Biotechnology, KIST, Yusong, Taejon, Korea.
authors: S Y
authors: SY
authors: Shin
authors: J H
authors: JH
authors: Kang
authors: K S
authors: KS
authors: Hahm
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002942:Circular Dichroism; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D054806:Magainins; D008555:Melitten / Q000737:chemistry* / Q000494:pharmacology; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship; D029867:Xenopus Proteins
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents; D054806:Magainins; D009842:Oligopeptides; D010446:Peptide Fragments; D010455:Peptides; D011993:Recombinant Fusion Proteins; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus; D008555:Melitten; C031161:cecropin A