Zhirnov O P, Grigoriev V B
D. I. Ivanovsky Virology Institute, Moscow, Russia.
Virology. 1994 Apr;200(1):284-91. doi: 10.1006/viro.1994.1188.
Influenza C (Flu C) viruses comprise an internal ribonucleoprotein (RNP) and an outer lipoprotein envelope with surface spike glycoproteins and the M1 protein matrix. The lipoprotein envelope and spike glycoproteins are solubilized by nonionic detergent in a pH-independent manner. In contrast, disassembly of the M1 protein matrix appears to depend on pH. Treatment of Flu C viruses with nonionic detergent in neutral or alkaline medium (pH 9.0-7.4) results in disintegration of the virion M1 matrix and leads to a significant release of RNP free of the M1 protein. In acidic medium (pH 6.0-5.0), the M1 matrix is not removed and the viral core-like complex of RNP along with the M1 matrix cover is released. Since Flu A and B viruses were characterized by acid-dependent disassembly of the virion M1 matrix, Flu C viruses seem to resemble the paramyxoviruses, which also show a neutral-alkaline pH dependence on matrix disintegration. These observations suggest that uncoating mechanisms of influenza C viruses and paramyxoviruses in target cells may be similar.
丙型流感病毒（Flu C）由内部核糖核蛋白（RNP）和带有表面刺突糖蛋白及M1蛋白基质的外部脂蛋白包膜组成。脂蛋白包膜和刺突糖蛋白可通过非离子去污剂以不依赖pH的方式溶解。相比之下，M1蛋白基质的解离似乎依赖于pH。在中性或碱性介质（pH 9.0 - 7.4）中用非离子去污剂处理丙型流感病毒会导致病毒粒子M1基质解体，并导致大量不含M1蛋白的RNP释放。在酸性介质（pH 6.0 - 5.0）中，M1基质不会被去除，RNP与M1基质覆盖物形成的病毒核心样复合物会被释放。由于甲型和乙型流感病毒的特征是病毒粒子M1基质的酸依赖性解离，丙型流感病毒似乎类似于副粘病毒，副粘病毒在基质解离方面也表现出对中性 - 碱性pH的依赖性。这些观察结果表明，丙型流感病毒和副粘病毒在靶细胞中的脱壳机制可能相似。
