Evidence for a role of a vicinal dithiol in catalysis and proton pumping in mitochondrial nicotinamide nucleotide transhydrogenase
The effect of glutathione, glutathione disulfide and the dithiol reagent phenylarsine oxide on purified soluble as well as reconstituted mitochondrial nicotinamide nucleotide transhydrogenase from beef heart was investigated. Glutathione disulfide and phenylarsine oxide caused an inhibition of transhydrogenase, the extent of which was dependent on the presence of either of the transhydrogenase substrates. In the absence of NADPH glutathione protected partially against inactivation by glutathione disulfide and phenylarsine oxide. In the presence of NADPH glutathione also inhibited transhydrogenase. Reconstituted transhydrogenase vesicles behaved differently as compared to the soluble transhydrogenase and was partially uncoupled by GSSG. It is concluded that transhydrogenase contains a dithiol that is essential for catalysis as well as for proton translocation.
- Research Organization:
- Univ. of Stockholm, Sweden
- OSTI ID:
- 6934853
- Journal Information:
- Biochem. Biophys. Res. Commun.; (United States), Vol. 2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ARSENIC COMPOUNDS
BIOLOGICAL EFFECTS
GLUTATHIONE
HYDROGENASES
ENZYME ACTIVITY
DISULFIDES
MITOCHONDRIA
NAD
NADP
PROTONS
BARYONS
CELL CONSTITUENTS
COENZYMES
DRUGS
ELEMENTARY PARTICLES
ENZYMES
FERMIONS
HADRONS
NUCLEONS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOIDS
OXIDOREDUCTASES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOPROTECTIVE SUBSTANCES
560300* - Chemicals Metabolism & Toxicology