title: Resolution of the hemes of hydroxylamine oxidoreductase by redox potentiometry and optical spectroscopy.
abstract: Optical spectroscopy combined with redox potentiometry has resolved the hemes of hydroxylamine oxidoreductase into 6 thermodynamically distinct classes. There are apparently 4 classes of heme c553, with Em7-values of 295 mV, 10 mV, -190 mV and -390 mV, present in a stoichiometry of 1:1:2:1; two equivalents of heme c559, Em7 O mV, and one of heme P-460, an unusual chromophore, with Em7 -260 mV.
mesh_terms: D006418:Heme / Q000032:analysis*; D007700:Kinetics; D009606:Nitrosomonas / Q000201:enzymology*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D011199:Potentiometry; D013379:Substrate Specificity
chemical_list: D006418:Heme; D010088:Oxidoreductases; C021401:hydroxylamine dehydrogenase