Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, USA.
J Virol. 2012 May;86(10):5959-62. doi: 10.1128/JVI.05990-11. Epub 2012 Mar 7.
At 37°C, the structure of poliovirus is dynamic, and internal polypeptides VP4 and N terminus of VP1 (residues 1 to 53) externalize reversibly. An Fab fragment of a monospecific antibody, which binds to residues 39 to 55 of VP1, was utilized to locate the N termini of VP1 in native (160S) particles in this "breathing" state. Fab and virus were mixed and imaged via cryogenic electron microscopy. The resulting reconstruction showed the capsid expands similarly to the irreversibly altered cell entry intermediate (135S) particle, but the N terminus of VP1 is located near the 2-fold axes, instead of the "propeller tip" as in 135S particles.
在 37°C 下，脊髓灰质炎病毒的结构是动态的，内部多肽 VP4 和 VP1 的 N 端（残基 1 至 53）可逆地外化。利用针对 VP1 残基 39 至 55 的单特异性抗体的 Fab 片段，将该 Fab 片段用于定位在这种“呼吸”状态下的天然（160S）颗粒中的 VP1 的 N 端。通过低温电子显微镜混合 Fab 和病毒并对其进行成像。重建结果显示衣壳的扩张类似于不可逆改变的细胞进入中间产物（135S）颗粒，但 VP1 的 N 端位于 2 倍轴附近，而不是像 135S 颗粒那样位于“螺旋桨尖端”。
