title: Tetrafibricin: a nonpeptidic fibrinogen receptor inhibitor from Streptomyces neyagawaensis. (II). Its antiplatelet activities.
abstract: Tetrafibricin; a nonpeptidic fibrinogen inhibitor from microbial origin, showed potent antiaggregation activities on human platelet aggregation induced by either ADP, thrombin or collagen (IC50s = 5.6, 7.6 and 11 microM, respectively) in platelet rich plasma. The ability to inhibit aggregation in platelets treated with chymotrypsin confirmed the GPIIb/IIIa blockage of tetrafibricin. Tetrafibricin blocked the release of serotonin induced by ADP but it did not block the release reaction induced by thrombin. When added to platelets formerly aggregated with ADP, tetrafibricin caused rapid and complete deaggregation. As for the selectivity among other Arg-Gly-Asp -dependent integrins, tetrafibricin seems to be more specific for glycoprotein (GP) IIb/IIIa than RGDS is. This is because it had no effect on adhesion of bovine aortic endothelial cells to RGD-containing proteins. Tetrafibricin is the first nonpeptidic fibrinogen receptor inhibitor that may be valuable for the study on platelet aggregation inhibitors.
authors.affiliation: Nippon Roche Research Center, Kanagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Satoh
authors.forename: Y
authors.initials: Y
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Kamiyama
authors.forename: M
authors.initials: M
authors.lastname: Arisawa
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology; D002417:Cattle; D015550:Cell Degranulation / Q000187:drug effects; D002918:Chymotrypsin / Q000494:pharmacology; D005340:Fibrinogen / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D018942:Macrolides; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism; D013302:Streptomyces / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D009842:Oligopeptides; D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; C027539:fibrinopeptides gamma; C082780:tetrafibricin; D012701:Serotonin; D000244:Adenosine Diphosphate; D005340:Fibrinogen; C046617:arginyl-glycyl-aspartyl-serine; D002918:Chymotrypsin