title: Purification, characterization, and sequencing of novel antimicrobial peptides, Tu-AMP 1 and Tu-AMP 2, from bulbs of tulip (Tulipa gesneriana L.).
abstract: Novel antimicrobial peptides (AMP), designated Tu-AMP 1 and Tu-AMP 2, were purified from the bulbs of tulip (Tulipa gesneriana L.) by chitin affinity chromatography and reverse-phase high-performance liquid chromatography (HPLC). They bind to chitin in a reversible way. They were basic peptides having isoelectric points of over 12. Tu-AMP 1 and Tu-AMP 2 had molecular masses of 4,988 Da and 5,006 Da on MALDI-TOF MS analysis, and their extinction coefficients of 1% aqueous solutions at 280 nm were 3.3 and 3.4, respectively. Half of all amino acid residues of Tu-AMP 1 and Tu-AMP 2 were occupied by cysteine, arginine, lysine, and proline. The concentrations of peptides required for 50% inhibition (IC(50)) of the growth of plant pathogenic bacteria and fungi were 2 to 20 microg/ml. The structural characteristics of Tu-AMP 1 and Tu-AMP 2 indicated that they were novel thionin-like antimicrobial peptides, though Tu-AMP 2 was a heterodimer composes of two short peptides joined with disulfide bonds.
authors.affiliation: Department of Biochemical Science and Technology, Faculty of Agriculture, Kagoshima University, Korimoto, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Fujimura
authors.forename: Mineo
authors.initials: M
authors.lastname: Ideguchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Minami
authors.forename: Keiichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Tadera
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D015169:Colony Count, Microbial; D023082:Defensins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D005670:Fusarium / Q000187:drug effects; D005848:Geotrichum / Q000187:drug effects; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D016415:Sequence Alignment; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D031447:Tulipa / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D023082:Defensins; D010940:Plant Proteins