Flavivirus capsid is a dimeric alpha-helical protein
Flavivirus capsid is a dimeric alpha-helical protein
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DOI：
10.1128/jvi.77.12.7143-7149.2003
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发表时间：
2003-06-01
影响因子：
5.4
通讯作者：
Kuhn, RJ
中科院分区：
文献类型：
--
作者：
Jones, CT;Ma, LX;Kuhn, RJ
将黄热病病毒和登革病毒的衣壳蛋白在大肠杆菌中进行了表达，纯化后的衣壳蛋白纯度较高，可用于核磁共振生化鉴定和结构鉴定。研究了衣壳蛋白在溶液中的低聚性质。在没有核酸的情况下，这两种蛋白质在溶液中主要是二聚体。用远紫外圆二色谱进一步分析这两种蛋白质，表明它们主要是α螺旋的。登革热病毒衣壳的二级结构元素是通过序列特异性主干共振指定的化学位移索引确定的。登革热病毒衣壳蛋白不含C末端信号序列，由4个α螺旋组成。最长的α螺旋，20个残基，位于C末端，具有两亲性。相反，N末端被发现是无结构的，可以在不破坏蛋白质结构完整性的情况下被移除。
The capsid proteins of two flaviviruses, yellow fever virus and dengue virus, were expressed in Escherichia coli and purified to near homogeneity suitable for biochemical characterization and structure determination by nuclear magnetic resonance. The oligomeric properties of the capsid protein in solution were investigated. In the absence of nucleic acid, both proteins were predominately dimeric in solution. Further analysis of both proteins with far-UV circular dichroism spectroscopy indicated that they were largely alpha-helical. The secondary structure elements of the dengue virus capsid were determined by chemical shift indexing of the sequence-specific backbone resonance assignments. The dengue virus capsid protein devoid of its C-terminal signal sequence was found to be composed of four alpha helices. The longest alpha helix, 20 residues, is located at the C terminus and has an amphipathic character. In contrast, the N terminus was found to be unstructured and could be removed without disrupting the structural integrity of the protein.