The thermal stability and decapsidation mechanism of tymoviruses: a differential calorimetric study.
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.
Mutombo
K
K
Laboratoire d'Ultrasons et de Dynamique des Fluides Complexes, Unité de Recherche Associée au CNRS no 851, Université Louis Pasteur, Strasbourg, France.
Michels
B
B
Ott
H
H
Cerf
R
R
Witz
J
J
D002152:Calorimetry, Differential Scanning; D002213:Capsid / Q000737:chemistry / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008854:Microscopy, Electron; D010944:Plants; D012367:RNA, Viral / Q000737:chemistry; D017806:Tymovirus / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D014771:Virion / Q000737:chemistry
D012367:RNA, Viral