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 AIM: To investigate the antithrombotic effect of anti-platelet glycoprotein IIIa (GPIIIa) monoclonal antibody (mAb) SZ 2 1F (ab ’) 2 fragment. Methods: Digested with papain in acidic condition (pH5.5) for 20 h. The digested product was eluted with DEAE 5 2 NaCl gradient to obtain F (ab ’) 2 fragment. The collected products were identified by SDS PAGE and the immunogenicity and antithrombin activity of F (ab ’) 2 fragments were observed by ELISA and platelet aggregation inhibition test. Results: The yield of F (ab ’) 2 fragment prepared by the method was 60.32%. The potency of the method was 0.8 × 10 -9 mol / L by enzyme-linked immunosorbent assay. The half effective dose of platelet aggregation inhibitor (ED50 ) Was 3.395 mg / L. The binding of F (ab ’) 2 fragments to platelets and the inhibitory effect on platelet aggregation were higher than those of intact IgG. Conclusion: F (ab ’) 2 fragment of anti-platelet mAbSZ 2 1 prepared by papain has high yield and better antithrombotic and immunogenic activity than intact mAb IgG for mAbSZ 2 1 for clinical antithrombotic therapy Shows a good future