Anthony I D, Bullivant S, Dayal S, Bellamy A R, Berriman J A
Department of Cellular and Molecular Biology, University of Auckland, New Zealand.
J Virol. 1991 Aug;65(8):4334-40. doi: 10.1128/JVI.65.8.4334-4340.1991.
Negatively stained preparations of rotavirus imaged with a low dose of electrons provide sufficient contrast to reveal surface projections or spikes. The number of spikes found projecting from different particles indicates that not all 60 peripentonal sites are occupied. Treatment at pH 11.2 with 250 mM ammonium hydroxide specifically removes the spikes, yielding smooth double-shelled particles of the same diameter as that of the native virus. Protein analysis confirms that the released spikes are composed of polypeptide VP4 (or its two cleavage products VP5* and VP8*) and that the smooth particle retains the other major outer shell protein VP7. Spikeless particles can be decorated by a monoclonal antibody specific for the major immunodominant neutralizing domain of VP7, implying that removal of the spikes does not denature the VP7 that is retained on the surface of the smooth particle.
用低剂量电子成像的轮状病毒负染制剂提供了足够的对比度，以揭示表面突起或刺突。从不同颗粒上突出的刺突数量表明，并非所有60个五邻体周边位点都被占据。在pH 11.2条件下用250 mM氢氧化铵处理可特异性去除刺突，产生与天然病毒直径相同的光滑双层颗粒。蛋白质分析证实，释放的刺突由多肽VP4（或其两个裂解产物VP5和VP8）组成，并且光滑颗粒保留了另一种主要的外壳蛋白VP7。无刺突颗粒可以被针对VP7主要免疫显性中和结构域的单克隆抗体修饰，这意味着去除刺突不会使保留在光滑颗粒表面的VP7变性。
