title: A novel membrane associated carbonyl reducing enzyme is present in smooth endoplasmic reticulum of mouse liver.
abstract: Evidence supporting the existence of two distinct carbonyl (metyrapone) reducing enzymes which differ in subcellular localization and immunological homology has been provided. A soluble enzyme, designated as carbonyl reductase (EC 1.1.1.184) is located in the cytosol. The distribution of the second, membrane associated, MPON-reductase shows an excellent linear correlation to NADPH-cytochrome c reductase and, on the other hand, is reciprocal to the RNA/protein ratio of submicrosomal preparations. This indicates that the membrane associated MPON-reductase is exclusively located in the smooth endoplasmic reticulum. Using antibodies against the purified membrane associated enzyme the extent of immunological crossreaction corresponds well to the specific activities of MPON-reductase in the granular fractions, thus further confirming the localization of this enzyme within this organelle. The absence of antigenic crossreaction to cytosolic MPON-reductase indicates differences also in terms of the immunological relationship between the two enzymes.
authors: Department of Pharmacology and Toxicology, Philipps-University of Marburg, Germany.
authors: T
authors: T
authors: Ahlers
authors: H P
authors: HP
authors: Bode
authors: K J
authors: KJ
authors: Netter
authors: E
authors: E
authors: Maser
mesh_terms: D000429:Alcohol Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D000449:Aldehyde Reductase; D000074408:Aldo-Keto Reductases; D000818:Animals; D002458:Cell Fractionation; D004591:Electrophoresis, Polyacrylamide Gel; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D005260:Female; D008099:Liver / Q000201:enzymology*; D008797:Metyrapone / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D000429:Alcohol Oxidoreductases; D000074408:Aldo-Keto Reductases; C073803:metyrapone reductase; D000449:Aldehyde Reductase; C000614209:AKR7A5 protein, mouse; D008797:Metyrapone