Kinetic properties of glucose-6-phosphate dehydrogenase from lamb kidney cortex


Ulusu N., Tandogan B., Tezcan F.

BIOCHIMIE, vol.87, no.2, pp.187-190, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 87 Issue: 2
  • Publication Date: 2005
  • Doi Number: 10.1016/j.biochi.2004.11.002
  • Title of Journal : BIOCHIMIE
  • Page Numbers: pp.187-190

Abstract

Glucose-6-phosphate dehydrogenase is the key regulatory enzyme of the pentose phosphate pathway and one of the products of this enzyme; NADPH has a critical role in the defence system against the free radicals. In this study, glucose-6-phosphate dehydrogenase from lamb kidney cortex kinetic properties is examined. The purification procedure is composed of two steps after ultracentrifugation for rapid and easy purification: 2'. 5'-ADP Sepharose 4B affinity and DEAE Sepharose Fast Flow anion exchange chromatography. Previously, we used this procedure for the purification of glucose-6-phosphate dehydrogenase from bovine lens. The double reciprocal plots and product inhibition studies showed that the enzyme obeys 'Ordered Bi Bi' mechanisin: K-m (NADP+) K-m (G-6-P) and Ki (G-6-P) (dissociation constant of the enzyme-G-6-P complex) were found to be 0.018 +/- 0.002, 0.039 +/- 0.006 and 0.029 +/- 0.005 mM, respectively, by using nonlinear regression analysis. The enzyme was stable at 4 degrees C for a week. (c) 2004 Elsevier SAS. All rights reserved.