Thiosulfate Reductase of Desulfovibrio vulgaris
AUTOR(ES)
Haschke, Richard H.
RESUMO
The thiosulfate reductase of Desulfovibrio vulgaris has been purified and some of its properties have been determined. Only one protein component was detected when the purified enzyme was subjected to polyacrylamide gel electrophoresis at pH values of 8.9, 8.0, and 7.6. In the presence of H2, the enzyme, when coupled to hydrogenase and with methyl viologen as an electron carrier, catalyzed the reduction of thiosulfate to hydogen sulfide. The use of specifically labeled 35S-thiosulfate revealed that the outer sulfur atom was reduced to sulfide and the inner sulfur atom was released as sulfite. Thus, the enzyme catalyzes the reductive dismutation of thiosulfate to sulfide and sulfite. The molecular weight of the enzyme was determined by sedimentation equilibrium (16,300) and amino acid analysis (15,500). The enzyme sedimented as a single, symmetrical component with a calculated sedimentation coefficient of 2.21S. Amino acid analysis revealed the presence of two half-cystine residues per mole of enzyme and a total of 128 amino acid residues. Carbohydrate and organic phosphorus analyses revealed the presence of 9.2 moles of carbohydrate and 4.8 moles of phosphate per mole of enzyme. The substrate specificity of the enzyme was studied.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=285136Documentos Relacionados
- Formation of Thiosulfate from Sulfite by Desulfovibrio vulgaris
- Characterization of a novel thiosulfate-forming enzyme isolated from Desulfovibrio vulgaris.
- Role of Thiosulfate in Bisulfite Reduction as Catalyzed by Desulfovibrio vulgaris
- Characterization of a trithionate reductase system from Desulfovibrio vulgaris.
- Bisulfite reductase of Desulfovibrio vulgaris: explanation for product formation.
