title: Characterization and regulation of NADP+-isocitrate dehydrogenase from Saccharopolyspora erythraea.
abstract: NADP+-Isocitrate dehydrogenase (ICDH) activity was detected in cell-free extracts of Saccharopolyspora erythraea CA340, an erythromycin producer. Apparent Km values for DL-isocitrate and NADP+ were 0.14 microM and 0.026 microM, respectively. ATP, ADP, GTP, citric acid, oxaloacetate, alpha-ketoglutarate, glyoxalate and glyoxalate plus oxaloacetate, each at 1 mM concentration, caused 50, 20 10, 50, 25, 60, 20 and 50% inhibition of ICDH activity, respectively. Phosphoenolpyruvate, fructose 1,6-diphosphate and pyruvate had no effect. ICDH specific activity profile was growth-associated and activity with dextrose or fructose as sole carbon source, was twice of that obtained with lactose.
authors.affiliation: Department of Molecular Biology and Biotechnology, Institute for Biomedical Research, National University of Mexico, Mexico, D.F., Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Alvarado
authors.forename: Maria Elena
authors.initials: ME
authors.lastname: Flores
mesh_terms: D003470:Culture Media; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004917:Erythromycin / Q000096:biosynthesis; D005285:Fermentation; D005632:Fructose / Q000378:metabolism / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007521:Isocitrate Dehydrogenase / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D007523:Isocitrates / Q000378:metabolism; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D025282:Mycelium / Q000201:enzymology / Q000302:isolation & purification; D009249:NADP / Q000378:metabolism; D062907:Oxaloacetic Acid / Q000494:pharmacology; D019289:Pyruvic Acid / Q000378:metabolism; D016930:Saccharopolyspora / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D013696:Temperature
chemical_list: D003470:Culture Media; D007523:Isocitrates; D007656:Ketoglutaric Acids; D062907:Oxaloacetic Acid; D005632:Fructose; D009249:NADP; D004917:Erythromycin; D019289:Pyruvic Acid; C034219:isocitric acid; D007521:Isocitrate Dehydrogenase; C039355:isocitrate dehydrogenase (NADP+); D005947:Glucose