Biochemical characterization of a new disintegrin, flavostatin, isolated from Trimeresurus flavoviridis venom.
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.
Kawasaki
T
T
Institute for Drug Discovery Research, Yamanouchi Pharmaceutical Co Ltd, Ibaraki, Japan.
Sakai
Y
Y
Taniuchi
Y
Y
Sato
K
K
Maruyama
K
K
Shimizu
M
M
Kaku
S
S
Yano
S
S
Inagaki
O
O
Tomioka
K
K
Yanagisawa
I
I
Takenaka
T
T
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
D003435:Crotalid Venoms; D019483:Disintegrins; D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; C102800:flavostatin; C046617:arginyl-glycyl-aspartyl-serine