Visualization of hepatic sulfite oxidase in crude tissue preparations by electron paramagnetic resonance spectroscopy


Journal Article

Sulfite oxidase (sulfite:O2 oxidoreductase, EC has been purified to homogeneity from rat liver and has been found to be similar to those previously isolated from other sources. The purified enzyme is a molybdohemoprotein and on addition of sulfite displays the g = 1.97 electron paramagnetic resonance signal of pentavalent molybdenum. The shape of the signal undergoes uniquely characteristic changes with alteration of pH and of anionic composition. Rat liver homogenates display a well-defined EPR signal at g = 1.97. The effects of pH and of anions on the "native" signal in liver homogenates are identical to those produced on the EPR signal of purified enzyme. This is in contrast to the insensitivity of the molybdenum EPR signal of purified rat liver xanthine oxidase to these conditions. The subcellular distribution of the native signal corresponds to the distribution of sulfite oxidase activity. In addition, the amplitudes of native EPR signals at g = 1.97 in various tissues of the rat and in livers from several other species paralleled the sulfite oxidase activity. © 1974.

Full Text

Duke Authors

Cited Authors

  • Kessler, DL; Johnson, JL; Cohen, HJ; Rajagopalan, KV

Published Date

  • January 17, 1974

Published In

  • Bba Enzymology

Volume / Issue

  • 334 / 1

Start / End Page

  • 86 - 96

International Standard Serial Number (ISSN)

  • 0005-2744

Digital Object Identifier (DOI)

  • 10.1016/0005-2744(74)90152-1

Citation Source

  • Scopus