Cryo-electron microscopy studies of empty capsids of human parvovirus B19 complexed with its cellular receptor
Cryo-electron microscopy studies of empty capsids of human parvovirus B19 complexed with its cellular receptor
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DOI：
10.1073/pnas.93.15.7502
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发表时间：
1996-07-23
影响因子：
11.1
通讯作者：
Rossmann, MG
中科院分区：
文献类型：
--
作者：
Chipman, PR;AgbandjeMcKenna, M;Rossmann, MG
人类细小病毒b19vp2衣壳的三维结构，单独和与它的细胞受体复合物，糖苷，已被确定为26埃分辨率。通过玻璃化样品的低温电子显微照片重建了B19衣壳结构，在二十面体的2重轴和3重轴上有凹陷，在5重轴周围有峡谷状区域。类似的结果在之前从x射线衍射数据得出的8埃分辨率图中也有发现。其他细小病毒结构沿着五重二十面体轴有一个圆柱形通道，而B19的密度覆盖了五重轴。糖脂受体分子结合到B19：糖苷复合物的5重轴上的凹陷处。球状糖苷的四糖组分的模型，组织成三聚体纤维，很好地符合代表球状糖苷受体的差异密度。逃逸突变使中和抗体映射到衣壳表面紧邻全球糖苷附着位点的区域。抗原表位靠近受体位点表明，病毒传染性的中和是通过防止病毒附着到细胞上引起的。
The three-dimensional structures of human parvovirus B19 VP2 capsids, alone and complexed with its cellular receptor, globoside, have been determined to 26 Angstrom resolution. The B19 capsid structure, reconstructed from cryo-electron micrographs of vitrified specimens, has depressions on the icosahedral 2-fold and 3-fold axes, as well as a canyon-like region around the 5-fold axes. Similar results had previously been found in an 8 Angstrom resolution map derived from x-ray diffraction data. Other parvoviral structures have a cylindrical channel along the 5-fold icosahedral axes, whereas density covers the 5-fold axes in B19. The glycolipid receptor molecules bind into the depressions on the 5-fold axes of the B19:globoside complex. A model of the tetrasaccharide component of globoside, organized as a trimeric fiber, fits well into the difference density representing the globoside receptor. Escape mutations to neutralizing antibodies map onto the capsid surface at regions immediately surrounding the globoside attachment sites. The proximity of the antigenic epitopes to the receptor site suggests that neutralization of virus infectivity is caused by preventing attachment of viruses to cells.