纤维蛋白原Bβ318～320 KGD基序与血小板功能的关系  

Relationship Between Fibrinogen Bβ Chain KGD Structure and Platelet Function

作　　者：程津新[1] 毛用敏[1] 张燕杰[1] 平立芳 崔让庄[1] 

机构地区：[1]天津市心血管病研究所,300051

出　　处：《天津医药》2004年第6期347-349,共3页Tianjin Medical Journal

摘　　要：目的 :探讨纤维蛋白原 (Fbg)Bβ链318～320KGD结构是否为血小板膜糖蛋白GPⅡb/Ⅲa的配基及此结构在血小板止血和血栓形成功能中的作用。方法:采用Site directedmutagenesis方法制备FbgBβEGS重组克隆,转染中国仓鼠卵细胞 (CHO),体外表达变异纤维蛋白原,并进行血小板聚集和纤维蛋白凝块收缩实验。结果:变异Fbg 和正常Fbg比较,血小板聚集率无明显差异 ,BβEGSFbg 使凝块收缩反应的启始时间明显延迟,凝块收缩速率高于正常Fbg,变异Fbg 与正常Fbg 凝块大小相似。结论:血小板聚集率不受EGS结构的影响,EGS结构使凝块收缩反应出现异常,FbgBβKGD结构可能是与血小板膜GPⅡb/Ⅲa受体结合的配基。Objective:To observe the effects of fibrinogen variant(BβEGS instead of KGD)on platelet agˉgregation and clot retraction,so as to confirm whether fibrinogen Bβchain318～320KGD is a ligand of fibˉrinogen receptor on platelet surface and to investigate its effect on platelet function.Method:Recombinant mutant clone of Fbg BβEGS was constructed by site_directed mutagenesis and transfected into CHO cell line to express variant protein.Experiments of platelet aggregation and clot retraction were performed with mutant and normal fibrinogen.Results:There was no significant difference between mutant and normal fibrinogen in platelet aggregation assays.The rate of aggregation for both Fbg was nearly the same.The lag time of variant Fbg was significant delayed in clot retraction and its retraction rate was higher than that in normal.Conclusion:Platelet aggregation was not affected by BβEGS structure,BβKGD sequence was not the key site for this reaction.BβEGS causes an abnormal clot retraction.BβKGD may be a ligand of receptor on platelet surface and involved in the fibrin clot retraction.

关 键 词：纤维蛋白原 Bβ318~320KGD基序 血小板 血栓形成 止血 出血性疾病 血栓性疾病 

分 类 号：R554[医药卫生—血液循环系统疾病]