Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/194203
Type: Artigo de periódico
Title: Tobacco Mosaic Virus Disassembly By High Hydrostatic Pressure In Combination With Urea And Low Temperature.
Author: Bonafe, C F
Vital, C M
Telles, R C
Gonçalves, M C
Matsuura, M S
Pessine, F B
Freitas, D R
Vega, J
Abstract: We investigated the effect of low temperature and urea combined with high pressure on tobacco mosaic virus (TMV). The evaluation of its aggregation state and denaturation process was studied using gel filtration, transmission electron microscopy, and spectroscopic methods. The incubation at 2.5 kbar induced 18% dissociation, and decreasing of temperature to -19 degreesC promoted additional dissociation to 72%, with stabilization of the dissociation products. Under such conditions, extensive denaturation did not occur. The apparent enthalpy and entropy of dissociation (Delta and TDelta) were -9.04 kcal/mol subunit and -15.1 kcal/mol subunit, respectively, indicating that the TMV association is an entropicly driven process. The apparent free energy of stabilization given by the presence of RNA is at least -1.7 kcal/mol subunit. Urea-induced dissociation of TMV samples and incubation at high-pressure promoted a higher degree of dissociation. The volume change of dissociation decreased in magnitude from -16.3 to -3.1 mL/mol of dissociated subunit, respectively, in the absence and presence of 2.5 M urea, suggesting exposure of the protein-protein interface to the solvent. High-pressure induced remarkable TMV denaturation in the presence of 2.5 M urea, with a volume change of -101 mL/mol of denatured subunit. The apparent enthalpy and entropy of denaturation (Delta and TDelta) by 1.75 M urea at 2.5 kbar was -11.1 and -10.2 kcal/mol subunit, respectively, demonstrating that the TMV protein coat presents an apparent free energy of denaturation by urea close to zero. Although the processes could not be assumed to be pure equilibria, these thermodynamic parameters could be derived by assuming a steady-state condition.
Subject: Atmospheric Pressure
Cold Temperature
Hydrostatic Pressure
Kinetics
Light
Microscopy, Electron
Protein Denaturation
Scattering, Radiation
Spectrometry, Fluorescence
Tobacco Mosaic Virus
Urea
Viral Proteins
Virus Assembly
Rights: fechado
Identifier DOI: 10.1021/bi980349n
Address: http://www.ncbi.nlm.nih.gov/pubmed/9693006
Date Issue: 1998
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_9693006.pdf161 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.