title: Separation of mitochondrial membranes of Neurospora crassa. II. Submitochondrial localization of the isoleucine-valine biosynthetic pathway.
abstract: Separation of Neurospora mitochondrial outer membranes from the inner membrane/matrix fraction was effected by digitonin treatment and discontinuous density gradient centrifugation. The solubilization of four isoleucine-valine biosynthetic enzymes was studied as a function of digitonin concentration and time of incubation in the detergent. The kinetics of the appearance of valine biosynthetic function in fractions outside of the inner membrane/matrix fraction, coupled with enzyme solubilization patterns similar to that for the matrix marker, mitochondrial malate dehydrogenase, indicate that the four isoleucine-valine pathway enzymes are localized in the mitochondrial matrix.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D003580:Cytochromes; D004071:Digitalis Glycosides; D006836:Hydro-Lyases / Q000378:metabolism; D007532:Isoleucine / Q000096:biosynthesis*; D007737:Kynurenine; D008190:Lyases / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism; D008566:Membranes; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000166:cytology / Q000201:enzymology; D010088:Oxidoreductases / Q000378:metabolism; D012503:Saponins; D013150:Spirostans; D013386:Succinates; D000637:Transaminases / Q000378:metabolism; D014633:Valine / Q000096:biosynthesis*
chemical_list: D003580:Cytochromes; D004071:Digitalis Glycosides; D012503:Saponins; D013150:Spirostans; D013386:Succinates; D007532:Isoleucine; D007737:Kynurenine; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; D008291:Malate Dehydrogenase; D000637:Transaminases; D008190:Lyases; D006836:Hydro-Lyases; D014633:Valine