Biological activities of synthetic analogs of halocidin, an antimicrobial peptide from the tunicate Halocynthia aurantium.
Halocidin is a heterodimer antimicrobial peptide previously isolated from the tunicate Halocynthia aurantium. Based on the larger monomer (18Hc) of halocidin, nine halocidin congeners, including a series of 6 peptides truncated successively from the carboxyl-terminal end of 18Hc and 3 analogs (18HcKK, K19Hc, and K19HcKK), which have lysine residues in place of two internal histidines or have a lysine added to the amino terminus of the 18Hc molecule, were prepared. Each peptide was also converted into a homodimeric version. The antimicrobial activities of halocidin congeners truncated from the C terminus were dramatically decreased, suggesting that the full length of 18Hc is required for maintaining its maximum antimicrobial activity. Dimer forms of halocidin congeners exhibited stronger antimicrobial activities than the monomer of the corresponding peptide. Four dimer peptides (di-18Hc, di-18HcKK, di-K19Hc, and di-K19HcKK) were analyzed for antimicrobial activities against 10 clinically isolated antibiotic-resistant bacteria in elevated concentrations of NaCl or MgCl(2). Of the peptides studied here, di-K19Hc retained invariably strong activity against all bacteria in diverse conditions and also showed much reduced hemolytic activity against human erythrocytes.
Jang
Woong Sik
WS
Department of Life Science, Hoseo University, Asan City, Choongnam-Do 336-795, South Korea.
Kim
Chong Han
CH
Kim
Kyu Nam
KN
Park
Shin Yong
SY
Lee
Joon Ha
JH
Son
Seok Min
SM
Lee
In Hee
IH
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D024881:Drug Resistance, Bacterial; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D008555:Melitten / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D014561:Urochordata / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; C447608:P18 antimicrobial peptide; D010455:Peptides; C553095:di-K19Hc peptide; C460842:halocidin; D008555:Melitten