RGD肽类血小板聚集抑制剂的研究Ⅱ.N─乙酰─精氨酰─甘氨酰─天冬氨酰─苯乙酰胺体外抗血小板聚集活性

IN VITRO EFFECT OF A PEPTIDE MIMETTIC (AC-RGD_(pe)) OF RGD AS AN ANTIPLATELET

精氨酰─甘氨酰─天冬氨酸（RGD）是纤维蛋白原（Fg）等粘附蛋白与血小板糖蛋白（GP）Ⅱb／Ⅲa／识别和结合的氨基酸序列，我们合成的含RGD肽段的Ac─Arg─Gly─Asp─NHCH2CH2Ph在体外能预防ADP（终浓度为5．0μM）诱导的血小板聚集，并表现出较强的浓度依赖性。血浆中3小时后仍有较高的生物学活性。IC50＝76．42±55．42μM。

Platelet aggregation requires binding of fibrinogen (Fg) to activated platelets glycoprotein (GP).Ⅱb/Ⅲa receptor and inhibition of this binding blocks platelet aggregation. Ac-RGDpe is a mimetic of the RGD-containing peptide sequence that is recognized by the platelet GPⅡb/Ⅲa receptor. It prevented platelet aggregation in response to ADP (final-concentration 5 μM) in platelet rich plasma, Ic50=76. 42±55. 42 .The data demonstrate that Ac-RGDpe,a peptide mimetic of the natural Fg binding sequence, is capable of blocking platelet aggregation in vitro.