Mass Determination of Rous Sarcoma Virus Virions by Scanning Transmission Electron Microscopy
AUTOR(ES)
Vogt, Volker M.
FONTE
American Society for Microbiology
RESUMO
The internal structural protein of retroviruses, Gag, comprises most of the mass of the virion, and Gag itself can give rise to virus-like particles when expressed in appropriate cells. Previously the stoichiometry of Gag in virions was inferred from indirect measurements carried out 2 decades ago. We now have directly determined the masses of individual particles of the prototypic avian retrovirus, Rous sarcoma virus (RSV), by using scanning transmission electron microscopy. In this technique, the number of scattered electrons in the dark-field image integrated over an individual freeze-dried virus particle on a grid is directly proportional to its mass. The RSV virions had a mean mass of 2.5 × 108 Da, corresponding to about 1,500 Gag molecules per virion. The population of virions was not homogeneous, with about one-third to two-thirds of the virions deviating from the mean by more than 10% of the mass in two respective preparations. The mean masses for virions carrying genomes of 7.4 or 9.3 kb were indistinguishable, suggesting that mass variability is not due to differences in RNA incorporation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=112795Documentos Relacionados
- Composition of native and reconstituted chromatin particles: direct mass determination by scanning transmission electron microscopy.
- Mass and molecular composition of vesicular stomatitis virus: a scanning transmission electron microscopy analysis.
- Molecular weight of RNA subunits of Rous sarcoma virus determined by electron microscopy.
- Determination of Bacterial Cell Dry Mass by Transmission Electron Microscopy and Densitometric Image Analysis
- Mass determination and estimation of subunit stoichiometry of the bacterial hook-basal body flagellar complex of Salmonella typhimurium by scanning transmission electron microscopy.
