title: Radiation inactivation of hepatic sulfite oxidase.
abstract: Sulfite oxidase (EC 1.8.3.1), purified from chicken liver, is comprised of two identical subunits of 55 kDa, each of which contains a molybdenum and heme prosthetic group. The functional size of sulfite oxidase was determined by radiation inactivation analysis using both full, sulfite:cytochrome c reductase, and partial, sulfite:ferricyanide reductase, catalytic activities. Inactivation of full enzyme activity indicated a target size of 42 kDa while the partial activity indicated a target size of 25 kDa. These results confirm the earlier findings of two equivalent subunits and suggest the presence of a functional domain within the subunit structure that contains the molybdenum center and exhibits a smaller molecular mass than that of the enzyme subunit.
authors.forename: M J
authors.initials: MJ
authors.lastname: Barber
authors.forename: L P
authors.initials: LP
authors.lastname: Solomonson
authors.forename: M J
authors.initials: MJ
authors.lastname: McCreery
mesh_terms: D000818:Animals; D002645:Chickens; D003720:Densitometry; D007158:Immunologic Techniques; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight; D008982:Molybdenum / Q000032:analysis; D010088:Oxidoreductases / Q000528:radiation effects*; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000302:isolation & purification / Q000528:radiation effects*
chemical_list: D008982:Molybdenum; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors