A new NAD -isomer was prepared, in which the D-ribose of the adenosine moiety was substituted by the enantiomeric L-ribose. As compared to nicotinamide-adenine-dinucleotide (NAD) and NADH the coenzyme isomer (D,L)-NAD and its dihydroform (D,L)-NADH are far less tightly bound to lactate dehydrogenase and alcohol dehydrogenase from horse liver. In the presence of the second substrate (D,L)-NAD an...

Aldehyde dehydrogenase 1A1 (ALDH1A1) is a member of the aldehyde dehydrogenase superfamily that oxidizes aldehydes to their corresponding acids, reactions that are coupled to the reduction of NAD+ to NADH. We report here that ALDH1A1 can also use glutathione (GSH) and dihydrolipoic acid (DHLA) as electron donors to reduce NAD+ to NADH. The GSH/DHLA-dependent NAD+-reduction activity of ALDH1A1 i...

1. The decrease in the protein fluorescence (F) of Neurospora crassa glutamate dehydrogenase is linearly related to the increase in the fraction of the coenzyme sites occupied by NADPH (alpha) at pH6.35. Under these conditions NADPH causes this enzyme to dissociate to monomers. 2. There is a non-linear relationship of F to alpha for NADH binding to give the alcohol dehydrogenase-NADH-isobutyram...

The alkaloids from Chelidonium majus L. which had a significant inhibitory effect in mitochondrial respiration were those which contain a positive charge due to a quaternary nitrogen atom, i.e., chelerythrine, sanguinarine, berberine and coptisine, both with malate+glutamate or with succinate as substrates. When malate+glutamate was used as substrate, chelerythrine and berberine, which contain ...

This study investigated the effect of the anthracycline anti biotics on oxygen radical metabolism by cardiac mitochondria! reduced nicotinamide adenine dinucleotide (NADH) dehydrogenase [NADH:(acceptor)oxidoreductase, EC 1.6.99.3], Superoxide formation by NADH dehydrogenase after anthracycline treatment appeared to follow saturation kinetics with an apparent Km of 167.3, 73.3, 64.0, or 47.6 (iM...

1. The concentrations of the oxidized and reduced substrates of the lactate-, beta-hydroxybutyrate- and glutamate-dehydrogenase systems were measured in rat livers freeze-clamped as soon as possible after death. The substrates of these dehydrogenases are likely to be in equilibrium with free NAD(+) and NADH, and the ratio of the free dinucleotides can be calculated from the measured concentrati...

Both NADH dehydrogenase (complex I) and aconitase are inactivated partially in vitro by superoxide (O2-.) and other oxidants that cause loss of iron from enzyme cubane (4Fe-4S) centers. We tested whether hypoxia-reoxygenation (H-R) by itself would decrease lung epithelial cell NADH dehydrogenase, aconitase, and succinate dehydrogenase (SDH) activities and whether transfection with adenoviral ve...

1. Lipoyl dehydrogenase (NADH: lipoamide oxidoreductase, ED 1.6.4.3) and two asparagusate dehydrogenases from asparagus mitochondria were purified by a series of steps, freezing and thawing, sodium dodecylsulfate extraction, and chromatography on Sephadex G-200 and DEAE-cellulose. 2. Lipoyl dehydrogenase was highly specific for alpha-lipoic acid, which could not be replaced at all by asparagus...

The expression of complex I and two homologues of bacterial and yeast NADH dehydrogenases, NDA and NDB, have been studied in potato leaf mitochondria. The mRNA level of NDA is completely light dependent and shows a diurnal rhythm with a sharp maximum just after dawn. NDA protein quantity and internal rotenone-insensitive NADH dehydrogenase activity are also light dependent. These findings sugge...

Studies of respiration on glucose in procyclic Trypanosoma congolense in the presence of rotenone, antimycin, cyanide, salicylhydroxamic acid and malonate have indicated the presence of NADH dehydrogenase, cytochrome b-c1, cytochrome aa3, trypanosome alternate oxidase and NADH fumarate reductase/succinate dehydrogenase pathway that contributes electrons to coenzyme Q of the respiratory chain. T...