title: Alkaline low spin form of sulfite reductase hemeprotein subunit.
abstract: The reversible reduction and reoxidation of Escherichia coli sulfite reductase hemeprotein subunit at pH 9.9 produces high and low spin ferric species, the latter with properties distinct from any alkaline low spin yet reported. With virtually no effect on the 298 degrees K optical spectrum, chloride drastically reduces the low spin EPR intensity and produces a high spin conformer pattern like that seen at pH 11. The distribution of g = 5 and g = 2.29 species in the doubly-reduced enzyme is also pH-sensitive.
authors.affiliation: Department of Biochemistry, Duke University, Durham, NC.
authors.forename: L J
authors.initials: LJ
authors.lastname: Young
authors.forename: L M
authors.initials: LM
authors.lastname: Siegel
mesh_terms: D002712:Chlorides; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000201:enzymology*; D005990:Glycerol; D006420:Hemeproteins / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000032:analysis*; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000032:analysis*; D010710:Phosphates
chemical_list: D002712:Chlorides; D006420:Hemeproteins; D046911:Macromolecular Substances; D010710:Phosphates; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors; D005990:Glycerol