| 1 | Author
| M. Aria, C. Alvarez-Ossorioa, FranciscoJ G M Uriana3, FranciscoF. De La Rosab, AngelM. Relimpioa | Requires cookie* | | Title
| Purification and Characterization of Nitrate Reductase from the Halophile Archaebacterium Haloferax mediterranei  | | | Abstract
| Nitrate reductase is induced in cells o f H aloferax mediterranei by the presence o f nitrate upon anaerobic conditions. This enzyme was purified more than 35-fold with a yield o f 49%. Densitograms o f polyacrylamide gel electrophoresis show the preparation to be 85% purity. The best enzyme preparation has a specific activity o f 13.6 U /m g protein. It is the first halo philic nitrate reductase that has been purified near to homogeneity. The purification consists o f five steps: an amm onium sulphate precipitation and four successive gel chromatographies with Sepharose C L -4B, calcium phosphate, D EAE-Sephacel and Sephacryl S-200. An average Mr o f 170,000 was estimated by gel chromatography and non-denaturing gel electrophoresis. Effectiveness o f electron donors, cofactors and inhibitors are reported. At low salt concentra tion the halophilic nitrate reductase was inactivated follow ing first-order kinetics. The K m for nitrate depends on salt concentration and shows values in the range from 2.5 to 6.7 m M . | | |
Reference
| Z. Naturforsch. 47c, 670—6 (1992); received April 7/June 15 1992 | | |
Published
| 1992 | | |
Keywords
| Halophilic Nitrate Reductase, Enzyme Purification, Enzyme Characterization, Haloferax mediterranei | | |
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| default:Reihe_C/47/ZNC-1992-47c-0670.pdf | | | Identifier
| ZNC-1992-47c-0670 | | | Volume
| 47 | |
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