抗血小板单克隆抗体片段的抗栓效应研究

目的 :研究抗血小板膜糖蛋白IIIa(GPIIIa)单克隆抗体 (mAb)SZ 2 1F(ab′) 2 片段的抗血栓效应。方法 :用木瓜蛋白酶在偏酸条件下 ( pH5 .5 )消化 2 0h ,经DEAE 5 2NaCl梯度洗脱消化产物 ,以得到F(ab′) 2 片段。收集产物经SDS PAGE鉴定 ,并通过ELISA和血小板聚集抑制试验 ,观察所获F(ab′) 2 片段免疫原活性和抗栓活性。结果 :该法制备F(ab′) 2 片段的得率为 6 0 .32 % ;酶免法测定其效价为 0 .8× 10 -9mol/L ;体外血小板聚集抑制半数有效剂量 (ED5 0 )为 3.395mg/L。F(ab′) 2 片段与血小板的结合性及对血小板聚集功能的抑制效果均高于完整的IgG。 结论 :利用木瓜蛋白酶制备的抗血小板mAbSZ 2 1的F(ab′) 2 片段 ,产率高且其抗栓活性与免疫原活性均优于完整的mAbIgG ,为mAbSZ 2 1用于临床抗血栓治疗展现了良好的前景

Studies on the antithrombotic effects of anti-platelet mAb SZ-21 F(ab′)2 fragment

AIM:To research the biological effect of the F(ab')(2) of anti-platelet GPIIIa mAb SZ-21. METHODS: The F(ab')(2) fragment was obtained with papain digestion for 20 hours at 4 degrees Celsius, under acid condition(pH 5.5). The products were purified through DEAE-52 ion exchange column and the first eluted peak components were verified as F(ab')(2) by SDS-PAGE. The immunoactivity and its antithrombotic effects of fragment were detected by ELISA and platelet aggregation inhibition test, respectively. RESULTS: The recovery rate of the fragment was 60.32%, its immunoactivity was 0.8 x10(-9) mol/L by ELISA. The 50% effective dose (ED(50)) in the platelet aggregate inhibition test was 3.395 mg/L. CONCLUSION: The F(ab')(2) fragment was superior to intact IgG in binding to platelets and inhibiting platelet aggregation. Thus the F(ab')(2) fragment of mAb SZ-21 opens up broad prospects for its application to the clinical antithrombotic therapy.