番茄病毒的热稳定性和脱壳机制：差示量热法研究

The thermal stability and decapsidation mechanism of tymoviruses: a differential calorimetric study.

作者信息

Mutombo K, Michels B, Ott H, Cerf R, Witz J

机构信息

Laboratoire d'Ultrasons et de Dynamique des Fluides Complexes, Unité de Recherche Associée au CNRS no 851, Université Louis Pasteur, Strasbourg, France.

出版信息

Biochimie. 1993;75(8):667-74. doi: 10.1016/0300-9084(93)90097-c.

DOI:10.1016/0300-9084(93)90097-c

PMID:8286439

Abstract

The thermal stability of virions present in purified suspensions of three tymoviruses, turnip yellow mosaic virus (TYMV), belladonna mottle virus (BelMV) and eggplant mosaic virus (EMV) was investigated by microcalorimetry. Virions are less stable than natural empty shells at 4.5 < or = pH < or = 8.5. Polyvalent cations present in TYMV stabilize the virions at pH < or = 5.0 only. Virions decapsidate in three steps: i) the release of the viral RNA, probably through a hole in the capsid; ii) the dissociation of the artificial empty shells thus formed; and iii) the denaturation of the dissociated components. An exothermic process accompanies the first step. Structural implications are discussed.

摘要

通过微量量热法研究了三种芜菁黄花叶病毒（TYMV）、颠茄斑驳病毒（BelMV）和茄子花叶病毒（EMV）纯化悬浮液中病毒粒子的热稳定性。在4.5≤pH≤8.5范围内，病毒粒子比天然空壳更不稳定。TYMV中存在的多价阳离子仅在pH≤5.0时稳定病毒粒子。病毒粒子的脱壳分三步进行：i）病毒RNA的释放，可能是通过衣壳上的一个孔；ii）由此形成的人工空壳的解离；iii）解离成分的变性。第一步伴随着一个放热过程。讨论了其结构意义。