Oxidation−Reduction Properties of the Regulatory Disulfides of Sorghum Chloroplast Nicotinamide Adenine Dinucleotide Phosphate−Malate Dehydrogenase†

Biochemistry ◽  
2000 ◽  
Vol 39 (12) ◽  
pp. 3344-3350 ◽  
Author(s):  
Masakazu Hirasawa ◽  
Eric Ruelland ◽  
Isabelle Schepens ◽  
Emmanuelle Issakidis-Bourguet ◽  
Myroslawa Miginiac-Maslow ◽  
...  
Keyword(s):  
Malate Dehydrogenase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Oxidation Reduction

scholarly journals The role of nicotinamide–adenine dinucleotide phosphate-dependent malate dehydrogenase and isocitrate dehydrogenase in the supply of reduced nicotinamide–adenine dinucleotide phosphate for steroidogenesis in the superovulated rat ovary

1970 ◽  
Vol 117 (1) ◽  
pp. 73-83 ◽  
Author(s):  
A. P. F. Flint ◽  
R. M. Denton
Keyword(s):  
Malate Dehydrogenase ◽  
Isocitrate Dehydrogenase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Tissue Homogenate ◽  
Kinetic Properties ◽  
Rat Ovary ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Effect Of Glucose

1. Superovulated rat ovary was found to contain high activities of NADP–malate dehydrogenase and NADP–isocitrate dehydrogenase. The activity of each enzyme was approximately four times that of glucose 6-phosphate dehydrogenase and equalled or exceeded the activities reported to be present in other mammalian tissues. Fractionation of a whole tissue homogenate of superovulated rat ovary indicated that both enzymes were exclusively cytoplasmic. The tissue was also found to contain pyruvate carboxylase (exclusively mitochondrial), NAD–malate dehydrogenase and aspartate aminotransferase (both mitochondrial and cytoplasmic) and ATP–citrate lyase (exclusively cytoplasmic). 2. The kinetic properties of glucose 6-phosphate dehydrogenase, NADP–malate dehydrogenase and NADP–isocitrate dehydrogenase were determined and compared with the whole-tissue concentrations of their substrates and NADPH; NADPH is a competitive inhibitor of all three enzymes. The concentrations of glucose 6-phosphate, malate and isocitrate in incubated tissue slices were raised at least tenfold by the addition of glucose to the incubation medium, from the values below to values above the respective Km values of the dehydrogenases. Glucose doubled the tissue concentration of NADPH. 3. Steroidogenesis from acetate is stimulated by glucose in slices of superovulated rat ovary incubated in vitro. It was found that this stimulatory effect of glucose can be mimicked by malate, isocitrate, lactate and pyruvate. 4. It is concluded that NADP–malate dehydrogenase or NADP–isocitrate dehydrogenase or both may play an important role in the formation of NADPH in the superovulated rat ovary. It is suggested that the stimulatory effect of glucose on steroidogenesis from acetate results from an increased rate of NADPH formation through one or both dehydrogenases, brought about by the increases in the concentrations of malate, isocitrate or both. Possible pathways involving the two enzymes are discussed.

scholarly journals RESPIRATION AND PROTEIN SYNTHESIS IN ESCHERICHIA COLI MEMBRANE-ENVELOPE FRAGMENTS

1969 ◽  
Vol 42 (3) ◽  
pp. 715-732 ◽  
Author(s):  
Richard W. Hendler ◽  
Amelia H. Burgess ◽  
Raymond Scharff
Keyword(s):  
Escherichia Coli ◽  
Malate Dehydrogenase ◽  
Nicotinamide Adenine Dinucleotide ◽  
Krebs Cycle ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Reduced Form ◽  
E Coli ◽  
Membrane Envelope ◽  
Krebs Cycle Intermediates

This paper describes experiments conducted with membranous and soluble fractions obtained from Escherichia coli that had been grown on succinate, malate, or enriched glucose media. Oxidase and dehydrogenase activities were studied with the following substrates: nicotinamide adenine dinucleotide, reduced form (NADH), nicotinamide adenine dinucleotide phosphate, reduced form (NADPH), succinate, malate, isocitrate, glutamate, pyruvate, and α-ketoglutarate. Respiration was virtually insensitive to poisons that are commonly used to inhibit mitochondrial systems, namely, rotenone, antimycin, and azide. Succinate dehydrogenase and NADH, NADPH, and succinate oxidases were primarily membrane-bound whereas malate, isocitrate, and NADH dehydrogenases were predominantly soluble. It was observed that E. coli malate dehydrogenase could be assayed with the dye 2,6-dichlorophenol indophenol, but that porcine malate dehydrogenase activity could not be assayed, even in the presence of E. coli extracts. The characteristics of E. coli NADH dehydrogenase were shown to be markedly different from those of a mammalian enzyme. The enzyme activities for oxidation of Krebs cycle intermediates (malate, succinate, isocitrate) did not appear to be under coordinate genetic control.

scholarly journals Applications of Oxidoreductases

2020 ◽  
Author(s):  
Sandhya Rani Gogoi
Keyword(s):  
Electron Acceptor ◽  
Nicotinamide Adenine Dinucleotide ◽  
Diagnostic Tests ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Organic Substrates ◽  
Acceptor Molecule ◽  
Practical Applications ◽  
Oxidation Reduction ◽  
Potential Applications

Oxidoreductases comprise of a large group of enzymes catalyzing the transfer of electrons from an electron donor to an electron acceptor molecule, commonly taking nicotinamide adenine dinucleotide phosphate (NADP) or nicotinamide adenine dinucleotide (NAD) as cofactors. Research on the potential applications of oxidoreductases on the growth of oxidoreductase-based diagnostic tests and better biosensors, in the design of inventive systems for crucial coenzymes regeneration, and in the creation of oxidoreductase-based approaches for synthesis of polymers and oxyfunctionalized organic substrates have made great progress. This chapter focuses on biocatalytic applications of oxidoreductases, since many chemical and biochemical transformations involve oxidation/reduction processes, developing practical applications of oxidoreductases has long been a significant target in biotechnology. Oxidoreductases are appropriate catalysts owing to their biodegradability, specificity and efficiency and may be employed as improved biocatalysts to substitute the toxic/expensive chemicals, save on energy/resources consumption, generate novel functionalities, or reduce complicated impacts on environment.

Effect of Niacin on Mitochondria of Allium Cepa Root Cells

1967 ◽  
Vol 25 ◽  
pp. 78-79
Author(s):  
M. Arif Hayat
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Hydrogen Transfer ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Nicotinamide Adenine ◽  
Root Tips ◽  
Root Cells ◽  
Transfer Processes ◽  
Standard Procedures ◽  
A Cell ◽  
Critical Interest

Although it is recognized that niacin (pyridine-3-carboxylic acid), incorporated as the amide in nicotinamide adenine dinucleotide (NAD) or in nicotinamide adenine dinucleotide phosphate (NADP), is a cofactor in hydrogen transfer in numerous enzyme reactions in all organisms studied, virtually no information is available on the effect of this vitamin on a cell at the submicroscopic level. Since mitochondria act as sites for many hydrogen transfer processes, the possible response of mitochondria to niacin treatment is, therefore, of critical interest.Onion bulbs were placed on vials filled with double distilled water in the dark at 25°C. After two days the bulbs and newly developed root system were transferred to vials containing 0.1% niacin. Root tips were collected at ¼, ½, 1, 2, 4, and 8 hr. intervals after treatment. The tissues were fixed in glutaraldehyde-OsO4 as well as in 2% KMnO4 according to standard procedures. In both cases, the tissues were dehydrated in an acetone series and embedded in Reynolds' lead citrate for 3-10 minutes.

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