Glycerol-3-phosphate dehydrogenase is a cytosolic isatin-binding protein


1. Institute of Biomedical Chemistry, Russian Academy of Medical Sciences
2. Moscow State University, Moscow, Russia
Type: Short communication
PubMed Id: 16119092
Year: 2003 vol: 49  issue:6  pages: 627-631
Abstract: Isatin is an endogenous indole widely distributed in mammalian tissues and body fluids. The presence of isatin-binding proteins has been recognised in particulate and soluble fractions of various organs and tissues. However, identified targets of isatin action (monoamine oxidase, natriuretic peptide receptor type A and soluble NO-stimulated guanylate cyclase) cannot account for all biological activity of this compound. Highly purified glycerol-3-phosphate dehydrogenase (GPDH) from rabbit muscle effectively interacts with the isatin analogue immobilised on the cuvette of IAsys optical biosensor. This effect was specific because the other NAD-dependent cytosolic enzyme purified from rabbit muscle, lactate dehydrogenase failed to interact with the immobilised isatin analogue. Replacement of the cuvette medium for washing buffer did not cause total dissociation of GPDH-isatin complexes. This suggests involvement of several types of enzyme-isatin interaction including tight binding. Low (10 mM) and high (100 mM) concentrations of isatin caused different effects on GPDH activity: the former significantly increased apparent Km for NAD, whereas the latter decreased apparent Vmax and increased Кm.
Download PDF:
Reference: Buneeva O.A., Gnedenko O.V., Panova N.G., Medvedeva M.V., Ivanov Yu.D., Medvedev A.E., Glycerol-3-phosphate dehydrogenase is a cytosolic isatin-binding protein, Biomeditsinskaya khimiya, 2003, vol: 49(6), 627-631.