title: Characterization and structure identification of an antimicrobial peptide, hominicin, produced by Staphylococcus hominis MBBL 2-9.
abstract: Hominicin, antimicrobial peptide displaying potent activity against Staphylococcus aureus ATCC 25923, methicillin-resistant S. aureus (MRSA) ATCC 11435 and vancomycin-intermediate S. aureus (VISA) CCARM 3501, was purified by chloroform extraction, ion-exchange column chromatography and reverse-phase HPLC from culture supernatant of Staphylococcushominis MBBL 2-9. Hominicin exhibited heat stability up to 121 degrees C for 15min and activity under both acidic and basic conditions (from pH 2.0 to 10.0). Hominicin was cleaved into two fragments after treatment with proteinase K, resulting in the loss of its antibacterial activity, while it was resistant to trypsin, alpha-chymotrypsin, pepsin and lipase. The molecular mass of hominicin determined by mass spectrometry was 2038.4Da. LC-mass spectrometry and NMR spectroscopy analyses of the two fragments revealed the sequence of hominicin as DmIle-Dhb-Pro-Ala-Dhb-Pro-Phe-Dhb-Pro-Ala-Ile-Thr-Glu-Ile-Dhb-Ala-Ala-Val-Ile-Ala-Dmp, which had no similarity with other antimicrobial peptides previously reported. The present study is the first report of this novel antimicrobial peptide, which has uncommon amino acid residues like the ones in Class I group and shows potent activity against clinically relevant S. aureus, MRSA and VISA.
authors.affiliation: School of Chemical and Biological Engineering, Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-744, Republic of Korea.
authors.forename: Pyoung Il
authors.initials: PI
authors.lastname: Kim
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
authors.forename: Changmin
authors.initials: C
authors.lastname: Sung
authors.forename: Hwang-Soo
authors.initials: HS
authors.lastname: Joo
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Kim
authors.forename: Tokutaro
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Daejoong
authors.initials: D
authors.lastname: Park
authors.forename: Byung-Gee
authors.initials: BG
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D006094:Gram-Positive Bacteria / Q000187:drug effects; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D041181:Staphylococcus hominis / Q000235:genetics / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; C552119:hominicin peptide, Staphylococcus hominis