Sanchez A, Yang Z Y, Xu L, Nabel G J, Crews T, Peters C J
Special Pathogens Branch, Division of Viral and Rickettsial Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA.
J Virol. 1998 Aug;72(8):6442-7. doi: 10.1128/JVI.72.8.6442-6447.1998.
The glycoproteins expressed by a Zaire species of Ebola virus were analyzed for cleavage, oligomerization, and other structural properties to better define their functions. The 50- to 70-kDa secreted and 150-kDa virion/structural glycoproteins (SGP and GP, respectively), which share the 295 N-terminal residues, are cleaved near the N terminus by signalase. A second cleavage event, occurring in GP at a multibasic site (RRTRR downward arrow) that is likely mediated by furin, results in two glycoproteins (GP1 and GP2) linked by disulfide bonding. This furin cleavage site is present in the same position in the GPs of all Ebola viruses (R[R/K]X[R/K]R downward arrow), and one is predicted for Marburg viruses (R[R/K]KR downward arrow), although in a different location. Based on the results of cross-linking studies, we were able to determine that Ebola virion peplomers are composed of trimers of GP1-GP2 heterodimers and that aspects of their structure are similar to those of retroviruses, paramyxoviruses, and influenza viruses. We also determined that SGP is secreted from infected cells almost exclusively in the form of a homodimer that is joined by disulfide bonding.
对一种扎伊尔埃博拉病毒株所表达的糖蛋白进行了分析，以确定其切割、寡聚化及其他结构特性，从而更好地明确其功能。50至70千道尔顿的分泌型糖蛋白和150千道尔顿的病毒体/结构糖蛋白（分别为SGP和GP），它们共有295个N端残基，在N端附近被信号肽酶切割。第二次切割事件发生在GP的一个多碱性位点（RRTRR↓），可能由弗林蛋白酶介导，产生两个通过二硫键相连的糖蛋白（GP1和GP2）。所有埃博拉病毒的GP中，该弗林蛋白酶切割位点都位于相同位置（R[R/K]X[R/K]R↓），马尔堡病毒预计也有一个切割位点（R[R/K]KR↓），不过位置不同。基于交联研究结果，我们能够确定埃博拉病毒体包膜突起由GP1 - GP2异二聚体的三聚体组成，其结构方面与逆转录病毒、副粘病毒和流感病毒相似。我们还确定SGP几乎完全以通过二硫键连接的同二聚体形式从受感染细胞中分泌出来。
