RESUMO

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.

Assuntos

Isocitrato Desidrogenase/metabolismo , Saccharopolyspora/enzimologia , Meios de Cultura , Dimerização , Eletroforese em Gel de Poliacrilamida , Eritromicina/biossíntese , Fermentação , Frutose/metabolismo , Frutose/farmacologia , Glucose/metabolismo , Glucose/farmacologia , Concentração de Íons de Hidrogênio , Isocitrato Desidrogenase/biossíntese , Isocitrato Desidrogenase/química , Isocitratos/metabolismo , Ácidos Cetoglutáricos/metabolismo , Cinética , Micélio/enzimologia , Micélio/isolamento & purificação , NADP/metabolismo , Ácido Oxaloacético/farmacologia , Ácido Pirúvico/metabolismo , Saccharopolyspora/crescimento & desenvolvimento , Saccharopolyspora/metabolismo , Temperatura