title: Isolation, purification and de novo sequencing of TBD-1, the first beta-defensin from leukocytes of reptiles.
abstract: A novel peptide with antimicrobial activity was isolated from leukocytes of the European pond turtle Emys orbicularis and purified to homogeneity by preparative gel electrophoresis followed by reversed phase chromatography. It was highly active in vitro against Escherichia coli, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus, and Candida albicans. The isolated peptide was sequenced de novo by tandem mass spectrometry using both collision-induced and electron-transfer dissociation in combination with different chemical derivatization techniques. The 40-residue peptide, called TBD-1 (turtle beta-defensin 1), represents the first defensin isolated from reptilian leukocytes. It contains three disulfide bonds and shows high structural similarities to beta-defensins isolated from birds and mammals.
authors.affiliation: Institute of Bioanalytical Chemistry, Center for Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Leipzig, Germany.
authors.forename: Christin
authors.initials: C
authors.lastname: Stegemann
authors.forename: Alexander
authors.initials: A
authors.lastname: Kolobov
authors.forename: Yulia F
authors.initials: YF
authors.lastname: Leonova
authors.forename: Daniel
authors.initials: D
authors.lastname: Knappe
authors.forename: Olga
authors.initials: O
authors.lastname: Shamova
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Ovchinnikova
authors.forename: Vladimir N
authors.initials: VN
authors.lastname: Kokryakov
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds; D005260:Female; D006461:Hemolysis / Q000187:drug effects; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D008322:Mammals; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D030162:Reptilian Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*; D016415:Sequence Alignment; D014426:Turtles; D023083:beta-Defensins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification*
chemical_list: D030162:Reptilian Proteins; D023083:beta-Defensins