Open AccessPartially Disordered Structure in Intravirus Coat Protein of Potyvirus Potato Virus A
Author(s) -
Alexander L. Ksenofontov,
Viiu Paalme,
Alexander M. Arutyunyan,
Pavel I. Semenyuk,
Н. В. Федорова,
Reet Rumvolt,
Ludmila A. Baratova,
Lilian Järvekülg,
Е. Н. Добров
Publication year - 2013
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0067830
Subject(s) - potyvirus , circular dichroism , differential scanning calorimetry , crystallography , chemistry , protein secondary structure , potato virus y , biophysics , virus , plant virus , biochemistry , virology , biology , physics , thermodynamics
Potyviruses represent the most biologically successful group of plant viruses, but to our knowledge, this work is the first detailed study of physicochemical characteristics of potyvirus virions. We measured the UV absorption, far and near UV circular dichroism spectra, intrinsic fluorescence spectra, and differential scanning calorimetry (DSC) melting curves of intact particles of a potato virus A (PVA). PVA virions proved to have a peculiar combination of physicochemical properties. The intravirus coat protein (CP) subunits were shown to contain an unusually high fraction of disordered structures, whereas PVA virions had an almost normal thermal stability. Upon heating from 20°C to 55°C, the fraction of disordered structures in the intravirus CP further increased, while PVA virions remained intact at up to 55°C, after which their disruption (and DSC melting) started. We suggest that the structure of PVA virions below 55°C is stabilized by interactions between the remaining structured segments of intravirus CP. It is not improbable that the biological efficiency of PVA relies on the disordered structure of intravirus CP.