O-linked carbohydrate of recombinant von Willebrand factor influences ristocetin-induced binding to platelet glycoprotein 1b.
O-linked carbohydrate of recombinant von Willebrand factor influences ristocetin-induced binding to platelet glycoprotein 1b.
复制标题
重组冯维勒布兰德因子的 O 连接碳水化合物影响瑞斯托菌素诱导的血小板糖蛋白 1b 结合。
DOI：
10.1172/jci116112
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Lynch,DC
中科院分区：
文献类型：
--
作者：
Carew,JA;Quinn,SM;Stoddart,JH;Lynch,DC
通过将人血管性血友病因子(VWF)的全长cDNA导入糖代谢缺陷的中国仓鼠卵巢细胞系，我们制备了特异性缺失O-连接碳水化合物的重组VWF。我们已经在几个结构和结合特性方面比较了这种糖基化程度较低的重组VWF和完全糖基化的重组VWF。合成了缺乏O-连接糖链的VWF，组装成多聚体，并以明显正常的方式分泌，在细胞外环境中不易降解。在与肝素或I型胶原结合的能力上，它与完全糖基化的VWF没有区别，但与福尔马林固定的血小板上的糖蛋白1b相互作用较差。这种相互作用的减弱表现在与血小板的整体结合减弱，以及在瑞斯托菌素存在的情况下促进血小板凝集的能力减弱。相比之下，在有肉豆根素存在的情况下，没有发现血小板结合方面的差异。这些数据表明，O-连接的碳水化合物可能在Ristoctin促进的VWF-糖蛋白1b相互作用中发挥作用，并表明碳水化合物修饰的异常可能导致VWF和血小板之间依赖于Ristoctin的反应性改变，这些反应被描述为一些不同形式的von Willebrand病。
By transfecting the full-length cDNA for human von Willebrand factor (vWf) into a line of Chinese hamster ovary cells with a defect in carbohydrate metabolism, we have prepared recombinant vWf specifically lacking O-linked carbohydrates. We have compared this under-glycosylated protein to fully glycosylated recombinant vWf with respect to several structural and binding properties. vWf deficient in O-linked glycans was synthesized, assembled into multimers, and secreted in an apparently normal manner and was not prone to degradation in the extracellular milieu. It did not differ from fully glycosylated vWf in ability to bind to heparin or to collagen type I but did interact less well with glycoprotein 1b on formalin-fixed platelets. This decreased interaction was evidenced in both a lessened overall binding to platelets and in diminished capacity to promote platelet agglutination, in the presence of ristocetin. In contrast, no difference was seen in platelet binding in the presence of botrocetin. These data indicate a possible role for O-linked carbohydrates in the vWf-glycoprotein 1b interaction promoted by ristocetin and suggest that abnormalities in carbohydrate modification might contribute to the altered ristocetin-dependent reactivity between vWf and platelets described for some variant forms of von Willebrand disease.Images