Structure, composition and heparin binding properties of a human cytomegalovirus glycoprotein complex designated gC-II.
Structure, composition and heparin binding properties of a human cytomegalovirus glycoprotein complex designated gC-II.
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称为 gC-II 的人巨细胞病毒糖蛋白复合物的结构、组成和肝素结合特性。
DOI：
10.1099/0022-1317-74-2-255
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Gehrz,R
中科院分区：
文献类型：
--
作者：
Kari,B;Gehrz,R
分析了一个家族的人巨细胞病毒（HCMV）二硫键连接的糖蛋白复合物命名为GC-II的结构和肝素结合特性。gC-II复合物含有两组糖蛋白，命名为组1和组2。这些糖蛋白通过将病毒体短时间暴露于还原剂而彼此分离。这表明这些糖蛋白之间的二硫键位于病毒粒子的外表面。尽管这些糖蛋白不再结合，但它们不从病毒体释放，表明它们是跨膜糖蛋白。约75 - 90%的gC-II复合物和18%的含有HCMV gB糖蛋白的复合物从病毒体包膜结合固定化肝素获得。当病毒体与[3 H]肝素一起孵育时，gC-II复合物比gB复合物结合更多的肝素，大约三倍。这些数据表明，gC-II复合物具有更大的肝素结合能力。用还原剂处理病毒体后，gC-II糖蛋白对肝素的亲和力大大降低，而gB糖蛋白的亲和力仅略有降低。因此，高阶结构是重要的肝素结合的gC-II复合物，但不是由那些gB。相对于gC-II第1组糖蛋白，更大部分的gC-II第2组糖蛋白在还原后仍与肝素结合，这表明第2组糖蛋白可能是gC-II复合物的重要肝素结合组分。用可溶性肝素或0·65 m-NaCl从固定化肝素洗脱gB和gC-II复合物，表明两者都与肝素形成离子键。硫酸软骨素不能有效地从固定化肝素洗脱HCMV包膜糖蛋白。因此，葡糖胺聚糖骨架的结构对于HCMV糖蛋白与肝素的结合是重要的。
The structure and heparin binding properties of a family of human cytomegalovirus (HCMV) disulphide-linked glycoprotein complexes designated gC-II were analysed. gC-II complexes contain two groups of glycoproteins designated Group 1 and Group 2. These glycoproteins were separated from each other by short exposure of virions to a reducing agent. This showed that the disulphide bonds between these glycoproteins were on the external surface of the virion. Although these glycoproteins were no longer associated they were not released from the virion, suggesting that they were transmembrane glycoproteins. Approximately 75 to 90% of the gC-II complexes and 18% of the complexes containing the HCMV gB glycoprotein obtained from the virion envelope bound immobilized heparin. When virions were incubated with [3H]heparin, gC-II complexes bound more heparin than gB complexes, by approximately threefold. These data showed that gC-II complexes had a greater heparin-binding capacity. After treatment of virions with a reducing agent the affinity of gC-II glycoproteins for heparin was greatly reduced whereas the affinity of gB glycoproteins was only slightly reduced. Thus, higher order structure was important for heparin binding by gC-II complexes but not by those of gB. Relative to gC-II Group 1 glycoproteins, a greater portion of gC-II Group 2 glycoproteins still bound to heparin after reduction, suggesting that Group 2 glycoproteins may be the important heparin binding component of the gC-II complexes. Both gB and gC-II complexes were eluted from immobilized heparin with soluble heparin or 0·65m-NaCl suggesting that both formed ionic bonds with heparin. Chondroitin sulphate was not effective at eluting HCMV envelope glycoproteins from immobilized heparin. Thus, the structure of the glucosaminoglycan backbone is important to the binding of HCMV glycoproteins to heparin.