title: Reconstitution of Micrococcus lysodeikticus reduced nicotinamide adenine dinucleotide and L-malate dehydrogenases with dehydrogenase-depleted membrane residues: a basis for restoration of oxidase activities.
abstract: Deoxycholate disruption of Micrococcus lysodeikticus protoplast membranes resulted in solubilization of both l-malate and reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase enzymes (substrate: 2,6-dichlorophenolindophenol oxidoreductases). Insoluble residues contained cytochromes of the b, c, and a type. Solubilized dehydrogenases were reconstituted with insoluble residues by treatment of disrupted membranes with magnesium ions. Most of the solubilized l-malate and NADH dehydrogenase activities were precipitated by magnesium ions independent of enzyme reconstitution with insoluble residues. Reconstituted dehydrogenases explained the mechanism for restoration of disrupted l-malate and NADH oxidase activities (4). Black light irradiation inhibited oxidase activities of both native and reconstituted membranes. These irradiated membrane oxidases were partially restored by exogenous napthoquinones [K(2(20)) and K(2(50))] but not by CoQ((6)). Reconstitution experiments showed that native membrane napthoquinone was retained in the insoluble residues of deoxycholate-disrupted membranes.
mesh_terms: D001647:Bile Acids and Salts / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D003580:Cytochromes / Q000378:metabolism*; D004579:Electron Transport; D008274:Magnesium / Q000494:pharmacology; D008291:Malate Dehydrogenase / Q000378:metabolism* / Q000528:radiation effects; D008837:Micrococcus / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D008956:Models, Chemical; D009243:NAD; D009285:Naphthoquinones / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism* / Q000528:radiation effects; D011485:Protein Binding; D011523:Protoplasts / Q000187:drug effects; D011830:Radiation Effects; D012997:Solvents; D013053:Spectrophotometry; D014461:Ultracentrifugation; D014466:Ultraviolet Rays
chemical_list: D001647:Bile Acids and Salts; D003580:Cytochromes; D009285:Naphthoquinones; D012997:Solvents; D009243:NAD; D010088:Oxidoreductases; D008291:Malate Dehydrogenase; D008274:Magnesium