Comparison of the properties of semipurified mitochondrial and cytosolic monoamine oxidases from rat brain.
Mitochondrial and cytosolic monoamine oxidases were purified 220- and 129-fold, respectively, from rat brain. The purification procedure involved extraction (without the use of detergents for mitochondrial monoamine oxidase), ammonium sulfate precipitation, and chromatography on Sephadex G-25 and a DEAE-cellulose column. The properties of both enzymes with kynuramine as substrate, including Km values and pH optima at different kynuramine concentrations; the Rf values on polyacrylamide gel electrophoresis; and the thermal inactivation patterns were different. 2-Mercaptoethanol, together with heat treatment, released the flavin and decreased the enzyme activity differentially for the two enzymes. The absorption spectrum showed a "Red shift" in the absorption maxima when the spectra of the non-Triton-treated purified preparations were compared with those of the Triton-treated ones, thus possibly revealing that the mitochondrial and the cytosolic monoamine oxidases may be two different enzyme entities.
D000818:Animals; D001921:Brain / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008623:Mercaptoethanol / Q000494:pharmacology; D008928:Mitochondria / Q000201:enzymology*; D008995:Monoamine Oxidase / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013053:Spectrophotometry
D005182:Flavin-Adenine Dinucleotide; D008623:Mercaptoethanol; D008995:Monoamine Oxidase