Alvarado Alejandra, Flores Maria Elena
Department of Molecular Biology and Biotechnology, Institute for Biomedical Research, National University of Mexico, Mexico, D.F., Mexico.
Biotechnol Lett. 2003 Jul;25(14):1175-8. doi: 10.1023/a:1024542426956.
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.
在红霉素产生菌糖多孢红霉菌CA340的无细胞提取物中检测到了NADP⁺-异柠檬酸脱氢酶(ICDH)活性。DL-异柠檬酸和NADP⁺的表观Km值分别为0.14微摩尔和0.026微摩尔。ATP、ADP、GTP、柠檬酸、草酰乙酸、α-酮戊二酸、乙醛酸以及乙醛酸加草酰乙酸,浓度均为1毫摩尔时,分别对ICDH活性产生50%、20%、10%、50%、25%、60%、20%和50%的抑制作用。磷酸烯醇式丙酮酸、果糖1,6-二磷酸和丙酮酸没有影响。ICDH比活性谱与生长相关,以葡萄糖或果糖作为唯一碳源时的活性是乳糖作为唯一碳源时的两倍。