title: Biochemical characterization of a new disintegrin, flavostatin, isolated from Trimeresurus flavoviridis venom.
abstract: We biochemically characterized a new disintegrin, flavostatin, isolated from Trimeresurus flavoviridis venom. Flavostatin inhibited ADP-, collagen-, and thrombin receptor agonist peptide-induced platelet aggregation in human platelet-rich plasma (IC50 range: 59 to 111 nM) and blocked the binding of biotinylated human fibrinogen to purified GPIIb/IIIa with an inhibitory potency 31,000-fold higher than that of Arg-Gly-Asp-Ser (RGDS). Flavostatin strongly inhibited high-shear-stress-induced platelet aggregation in platelet-rich plasma (PRP) with an IC50 value of 188 nM. Fluorescein isothiocyanate (FITC)-conjugated flavostatin saturably bound to unstimulated and ADP-stimulated washed platelets with high affinity (Kd values: 38 and 21 nM, respectively); the corresponding number of binding sites was 86460 and 79192 per platelet. In competition experiments with several glycoprotein IIb/IIIa antagonists, the binding of FITC-conjugated flavostatin to platelets was completely inhibited by ReoPro, triflavin, TP9201, MK383 and GR144053, but not by YM207, YM337 and B6A3.
authors.affiliation: Institute for Drug Discovery Research, Yamanouchi Pharmaceutical Co Ltd, Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Sakai
authors.forename: Y
authors.initials: Y
authors.lastname: Taniuchi
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Maruyama
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: S
authors.initials: S
authors.lastname: Kaku
authors.forename: S
authors.initials: S
authors.lastname: Yano
authors.forename: O
authors.initials: O
authors.lastname: Inagaki
authors.forename: K
authors.initials: K
authors.lastname: Tomioka
authors.forename: I
authors.initials: I
authors.lastname: Yanagisawa
authors.forename: T
authors.initials: T
authors.lastname: Takenaka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D003435:Crotalid Venoms / Q000737:chemistry*; D019483:Disintegrins / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
chemical_list: D003435:Crotalid Venoms; D019483:Disintegrins; D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C102800:flavostatin; C046617:arginyl-glycyl-aspartyl-serine