Zhang Hong, Yu Xue-Kui, Lu Xing-Ying, Zhang Jing-Qiang, Zhou Z Hong
Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, 77030, USA.
Virology. 2002 Jun 20;298(1):45-52. doi: 10.1006/viro.2002.1473.
Cytoplasmic polyhedrosis virus (CPV, genus Cypovirus) is a unique member of the family Reoviridae which lacks the outer protective shells that exist in all other members, yet exhibits unusual stability. We have analyzed the effects of different acidic, basic, detergent, and urea treatments on CPV capsids. The integrity of the CPV capsids was unaffected under high-pH conditions that disrupted the orthoreovirus inner core, consistent with its ability to maintain structural integrity in extremely alkaline environments during infection. However, it was sensitive to low pH, detergents, and urea, similarly to other viruses in this family. The three-dimensional structure comparisons by electron cryomicroscopy of the intact empty CPV capsid with the "spikeless" capsid whose turrets were removed by chemical treatments revealed the interaction footprint of the turret on the capsid shell. The observed structural changes associated with the removal of the turret suggest critical structural roles of the turret in maintaining capsid integrity in addition to its enzymatic activities.
细胞质多角体病毒（CPV，呼肠孤病毒属）是呼肠孤病毒科的一个独特成员，它没有其他所有成员都有的外部保护壳，但却表现出不同寻常的稳定性。我们分析了不同的酸性、碱性、去污剂和尿素处理对CPV衣壳的影响。在破坏正呼肠孤病毒内核的高pH条件下，CPV衣壳的完整性未受影响，这与其在感染期间在极端碱性环境中维持结构完整性的能力一致。然而，与该科的其他病毒一样，它对低pH、去污剂和尿素敏感。通过电子冷冻显微镜对完整的空CPV衣壳与通过化学处理去除了炮塔的“无刺”衣壳进行三维结构比较，揭示了炮塔在衣壳壳上的相互作用足迹。观察到的与炮塔去除相关的结构变化表明，炮塔除了具有酶活性外，在维持衣壳完整性方面还起着关键的结构作用。
