THE NS1 PROTEIN OF TICK-BORNE ENCEPHALITIS-VIRUS FORMS MULTIMERIC SPECIES UPON SECRETION FROM THE HOST-CELL
THE NS1 PROTEIN OF TICK-BORNE ENCEPHALITIS-VIRUS FORMS MULTIMERIC SPECIES UPON SECRETION FROM THE HOST-CELL
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DOI：
10.1099/0022-1317-75-12-3453
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发表时间：
1994-12-01
影响因子：
3.8
通讯作者：
STEPHENSON, JR
中科院分区：
文献类型：
--
作者：
CROOKS, AJ;LEE, JM;STEPHENSON, JR
黄病毒引起对两种病毒编码的膜相关糖蛋白的体液免疫反应。一种是主要的病毒粒子表面包膜蛋白(E)，被抗体识别，另一种是分泌的，严重糖基化的非结构蛋白（NS1）。接种任一蛋白均可引起保护性免疫应答，E和NS1单特异性单克隆抗体的被动转移也可引起保护性免疫应答。本文报道的实验表明，无论是感染了蜱传脑炎病毒（TBEV）的细胞，还是感染了含有NS1基因的缺陷重组腺病毒的细胞，NS1的分泌形式主要以五聚体或六聚体的形式出现，偶尔也以十聚体或十二聚体的形式出现。然而，这种蛋白质的细胞内形式仅以二聚体的形式出现。从细胞分泌的高M(r)形式对洗涤剂非常敏感，这表明它们是通过疏水键结合在一起的。细胞内和细胞外形式的二聚体都可以被热解离，但在不同的温度。与来自蚊媒病毒的类似蛋白不同，来自tbev感染细胞的NS1蛋白不能在环境温度下被极端ph解离。对该蛋白抗原结构的研究表明，它具有几个高度保守的表位，证实了早期氨基酸序列分析的类似结论。
Flaviviruses elicit a humoral immune response to two virus-encoded, membrane-associated glycoproteins. One is the major virion surface envelope protein (E), which is recognized by antibody, whereas the other is a secreted, heavily glycosylated non-structural protein (NS1). Inoculation with either protein can give rise to a protective immune response, as can the passive transfer of E and NS1 monospecific monoclonal antibodies. Experiments reported here demonstrate that the secreted form of NS1, whether from cells infected with tick-borne encephalitis virus (TBEV) or from cells infected with a defective recombinant adenovirus containing the NS1 gene, occurs chiefly as a pentamer or hexamer and occasionally as a decamer or dodecamer. Intracellular forms of this protein however occur only as dimers. The higher M(r) forms secreted from the cell are exquisitely sensitive to detergent, suggesting they are held together by hydrophobic bonds. Both intracellular and extracellular forms of the dimer can be dissociated by heat, but at different temperatures. Unlike similar proteins from mosquito-borne viruses, NS1 from TBEV-infected cells cannot be dissociated at ambient temperatures by extremes of pH. Studies on the antigenic structure of this protein show it to have several highly conserved epitopes, confirming similar earlier conclusions from amino acid sequence analyses.