摘要
目的:通过测定汉逊酵母重组表达的EV71类病毒颗粒的三维结构,对重组EV71 VLP进行结构确认;通过EV71成熟病毒颗粒、天然空心颗粒及重组类病毒颗粒三者的三维结构比对,分析重组EV71 VLP与天然EV71病毒颗粒的结构异同,为重组EV71类病毒颗粒疫苗的抗原性、免疫原性及保护机制提供结构学分析依据。结果:通过单颗粒三维重构计算获得了分辨率达到近原子分辨率的EV71 VLP三维重构密度图,并根据密度图搭建了重组EV71VLP的原子模型。重组EV71类病毒颗粒是具有二十面体对称性的球状颗粒,直径33nm,在二次轴部位具有一条狭长的孔洞,连通颗粒内外,这一结构特征与EV71天然空心颗粒是一致的,而与表面完全闭合的EV71成熟病毒颗粒不同。将EV71类病毒颗粒的结构单元(protomer,由VP0、VP1与VP3三个蛋白组成)分别与EV71两种天然颗粒形式(实心、空心)各自的结构单元进行结构比对可以发现,EV71类病毒颗粒与天然空心颗粒结构单元的三维结构高度近似,而与实心颗粒(成熟病毒颗粒)存在差异,差异主要体现在VP0与VP1相对于VP3的逆时针扭转。结论:重组EV71VLP的颗粒整体特征及结构单元三维结构虽然与EV71成熟病毒颗粒存在一定的差异,但它与EV71天然空心颗粒在三维结构上高度近似,因此重组EV71 VLP在分子水平上很好的模拟了天然病毒的一种颗粒形式。
引文
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