title: 1H-NMR studies and secondary structure of the RGD-containing snake toxin, albolabrin.
abstract: Albolabrin is a naturally occurring peptide from snake venom containing the sequence Arg-Gly-Asp (RGD). It inhibits platelet aggregation by blocking the binding of fibrinogen to the glycoprotein Gp IIb-IIIa, on the surface of activated platelets. Albolabrin consists of 73 residues with six intramolecular disulphide bonds. The 1H-NMR spectrum of albolabrin has been assigned using homonuclear two-dimensional techniques and its secondary structure determined. Like kistrin and echistatin, two related peptides from snake venom, albolabrin appears to have little regular secondary structure in solution. Several bends and two short distorted beta sheets are observed. The RGD sequence, important for binding to the receptor, lies in a mobile loop joining two strands of one of these beta sheets. This loop undergoes a pH-dependent conformational change.
authors.affiliation: School of Biochemistry, University of Birmingham, England.
authors.forename: M
authors.initials: M
authors.lastname: Jaseja
authors.forename: K J
authors.initials: KJ
authors.lastname: Smith
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: J A
authors.initials: JA
authors.lastname: Williams
authors.forename: H
authors.initials: H
authors.lastname: Trayer
authors.forename: I P
authors.initials: IP
authors.lastname: Trayer
authors.forename: E I
authors.initials: EI
authors.lastname: Hyde
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003435:Crotalid Venoms / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D036341:Intercellular Signaling Peptides and Proteins; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry*; D017433:Protein Structure, Secondary; D017386:Sequence Homology, Amino Acid; D012910:Snake Venoms; D014461:Ultracentrifugation; D014757:Viper Venoms / Q000737:chemistry
chemical_list: D003435:Crotalid Venoms; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D012910:Snake Venoms; D014757:Viper Venoms; C057986:echistatin; C064595:albolabrin; C067623:kistrin