Showing papers in "Indian Journal of Biochemistry & Biophysics in 1984"

A modified spectrophotometric assay of superoxide dismutase.

Abstract: A simple and rapid method for the assay of superoxide dismutase in biological samples is described. Present method takes advantage of the inhibition of NADH-dependent-nitroblue tetrazolium reduction by the dismutase. Inhibition of the chromogen formation by superoxide dismutase was linear with increase in enzyme concentrations. The chromogen extract in butanol was stable even up to 48 hr. Superoxide dismutase activity, as assayed by the modified method, was in good agreement with that obtained using other methods.

Inhibition of mitochondrial electron transport and energy transduction by 2-methyl-4-dimethylaminoazobenzene in vitro

Abstract: 2-Methyl-4-dimethylaminoazobenzene (I) [54-88-6] inhibited electron transport and phosphorylation in tightly coupled rat liver mitochondria. It stimulated state 4 respiration, decreased ADP/O ratio, inhibited state 3 oxidation and abolished respiratory control. These effects reveal its action as an inhibitor uncoupler. Consistent with its preferential inhibition of the NADH-ubiquinone segment of the respiratory chain, ferricyanide reduction was far more sensitive to inhibition by I when NAD+-linked substrates were used as electron donors than when succinate was used. Like a true uncoupler, it stimulated the dormant ATPase [9000-83-3] activity in tightly coupled mitochondria in the presence and absence of Mg. However, in the absence of added Mg, dinitrophenol-stimulated activity was drastically inhibited indicating its action as a membrane destabilizing agent. In sonic submitochondrial particles, I inhibited energy-linked reverse electron transport and transhydrogenase reaction.

Effect of physical and chemical modifications on molecular and agglutinating properties of rice lectin.

Abstract: A purified rice lectin has been shown to contain two fragments, one of 85,000, the other of 15,000 mol. wt. The lectin has been subjected to various treatments which result in partial or total loss of activity. Acetylation or succinylation decreases activity, as does removal of metal. [on SciFinder(R)]