title: The disulphide bond pattern of bitistatin, a disintegrin isolated from the venom of the viper Bitis arietans.
abstract: The disulphide bond pattern of the long disintegrin bitistatin (83 amino acids, 14 cysteines) was established using structural information gathered by amino acid analysis, N-terminal sequencing, and molecular mass determination of fragments isolated by reversed-phase HPLC after polypeptide degradation with trypsin and oxalic acid. A computer program was used to calculate all possible combinations of disulphide-bonded peptides matching the mass spectrometric data, and the output was filtered using compositional and sequence data. Disulphide bonds between cysteines 16-34, 18-29, 28-51, 42-48, 47-72, and 60-79 are conserved in medium-long disintegrins flavoridin and kistrin (70 amino acids, 12 cysteines), and the two cysteine residues at positions 5 and 24 found in bitistatin but not in other disintegrin molecules are disulphide-bridged. This linkage creates an extra, large loop, which, depending on whether the NMR structure of flavoridin or kistrin is used for modelling the structure of bitistatin, lies opposite or nearly parallel, respectively, to the biologically active RGD-containing loop.
authors.affiliation: Institut für Reproduktionsmedizin, Tierärztliche Hochschule, Hannover-Kirchrode, Germany. jcalvete@repro.tiho-hannover.de
authors.forename: J J
authors.initials: JJ
authors.lastname: Calvete
authors.forename: M
authors.initials: M
authors.lastname: Schrader
authors.forename: M
authors.initials: M
authors.lastname: Raida
authors.forename: M A
authors.initials: MA
authors.lastname: McLane
authors.forename: A
authors.initials: A
authors.lastname: Romero
authors.forename: S
authors.initials: S
authors.lastname: Niewiarowski
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D003435:Crotalid Venoms; D019483:Disintegrins / Q000737:chemistry*; D004220:Disulfides; D036341:Intercellular Signaling Peptides and Proteins; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D011487:Protein Conformation; D016415:Sequence Alignment; D012910:Snake Venoms; D012984:Software; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin; D014757:Viper Venoms; D017819:Viperidae
chemical_list: D003435:Crotalid Venoms; D019483:Disintegrins; D004220:Disulfides; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments; D010455:Peptides; D012910:Snake Venoms; D014757:Viper Venoms; C062186:bitistatin; C069044:flavoridin protein, Trimeresurus; C067623:kistrin; D014357:Trypsin