Changes in Levels of Nicotinamide Adenine Nucleotides and Krebs Cycle Intermediates in Mung Bean Leaves after Illumination

Changes in levels of nicotinamide adenine nucleotides were measured during a short (30 min) period of illumination following a dark period. Two phases in the time course were found. In the first phase, during the first minute of illumination, a rapid decline in oxidized nicotinamide adenine dinucleotide occurred which represented a net loss of nicotinamide adenine nucleotide. In the subsequent, second phase during illumination, a slower decline in oxidized nicotinamide adenine dinucleotide was found which was coincident with increases in nicotinamide adenine dinucleotide phosphate(s). The changes in the reduced nicotinamide adenine nucleo� tides were relatively small during illumination.

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RESPIRATION AND PROTEIN SYNTHESIS IN ESCHERICHIA COLI MEMBRANE-ENVELOPE FRAGMENTS

The Journal of Cell Biology ◽

10.1083/jcb.42.3.715 ◽

1969 ◽

Vol 42 (3) ◽

pp. 715-732 ◽

Cited By ~ 11

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.

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Control of the Krebs Cycle**Abbreviations F1-ATPase; the mitochondrial ATP-synthesizing complex; NAD, nicotinamide adenine dinucleotide (oxidized form-NAD+; reduced form-NADH); NADP, nicotinamide adenine dinucleotide phosphate.

Metabolism and Respiration ◽

10.1016/b978-0-12-675402-5.50012-x ◽

1980 ◽

pp. 243-278 ◽

Cited By ~ 3

Author(s):

J.T. WISKICH

Keyword(s):

Nicotinamide Adenine Dinucleotide ◽

Krebs Cycle ◽

Nicotinamide Adenine Dinucleotide Phosphate ◽

Nicotinamide Adenine ◽

Reduced Form ◽

F1 Atpase

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Effect of Niacin on Mitochondria of Allium Cepa Root Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060404 ◽

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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