Amsacta moorei entomopoxvirus expresses an active superoxide dismutase
| Autor: | David A. Ostrov, W. B. Greenleaf, R. W. Moyer, M. N. Becker |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Gene Expression Regulation
Viral Models Molecular Amsacta Genes Viral Immunology Blotting Western Molecular Sequence Data Replication Biology medicine.disease_cause Microbiology Cell Line Superoxide dismutase Viral Proteins Virology medicine Escherichia coli Animals Amino Acid Sequence RNA Messenger Cloning Molecular Peptide sequence Gene chemistry.chemical_classification Superoxide Dismutase biology.organism_classification Blotting Northern Molecular biology Recombinant Proteins Lepidoptera Molecular Weight Open reading frame Zinc Enzyme chemistry Cell culture Insect Science biology.protein Entomopoxvirinae RNA Viral Dimerization Sequence Alignment Copper Gene Deletion |
| Zdroj: | Journal of virology. 78(19) |
| ISSN: | 0022-538X |
| Popis: | The entomopoxvirus from Amsacta moorei serves as the prototype of the group B entomopoxviruses. One of the interesting genes found in Amsacta moorei entomopoxvirus (AmEPV) is a superoxide dismutase ( sod ) (open reading frame AMV255). Superoxide dismutases (SODs) catalyze the conversion of superoxide radicals to hydrogen peroxide and oxygen. Many vertebrate poxviruses contain a sod gene, but to date, none have been demonstrated to be active. There are three families of SODs, characterized by their metal ion-binding partners, Fe, Mn, or Cu and Zn. Poxvirus enzymes belong to the Cu-Zn SOD family. Unlike inactive vertebrate poxvirus SODs, AMVSOD contains all the amino acids necessary for function. We expressed and purified a 6X-His-tagged version of the AMVSOD in Escherichia coli . The recombinant AMVSOD demonstrates superoxide dismutase activity both in an in situ gel assay and by stopped flow spectrophotometry. The k cat / K m for AMVSOD is 4 × 10 7 M −1 s −1 . In infected cells, the AMVSOD protein behaves as a dimer and is catalytically active; however, disruption of the gene in AMEPV has little or no effect on growth of the virus in cell culture. An analysis of mRNA expression indicates that AMV sod is expressed late during infection of Lymantria dispar (Ld652) cells and produces a discrete nonpolydisperse transcript. Characterization of protein expression with a monoclonal antibody generated against AMVSOD confirms that the AMVSOD protein can be classified as a late, postreplicative gene. Therefore, AMVSOD is the first example of an active poxvirus SOD. |
| Databáze: | OpenAIRE |
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