NADH oxidase system of Agrobacterium tumefaciens

Intact pigeon heart mitochondria showed 10-30% ubiquinone reduction in the absence of substrates. This reduction could not be ascribed to endogenous substrates, as judged by lack of effect of inhibitors and uncouplers and by the very low endogenous respiratory rate. Addition of NADH in the presence of antimycin caused further reduction of about 10% ubiquinone, apparently coupled to the rotenone- and antimycin-sensitive exo-NADH oxidase system [Rasmussen (1969) FEBS Lett. 2, 157-162]. Citric acid cycle substrates reduced most of the remaining ubiquinone in the presence of antimycin; 15-20% of the total ubiquinone content was still in the oxidized form under the most reducing conditions. Three pools of ubiquinone therefore appeared to be present in heart mitochondria: a metabolically inactive pool consisting of reduced as well as oxidized ubiquinone, a pool coupled to oxidation of added (cytoplasmic) NADH, and the well-known pool coupled to citric acid cycle oxidations. Ferricyanide selectively oxidized the ubiquinol reduced by added NADH, indicating that this pool is situated on the outer surface of the mitochondrial inner membrane. Ubiquinone reduction levels were determined with a new method, which is described in detail.

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Bubble Column Enables Higher Reaction Rate for Deracemization of ( R,S )‐1‐Phenylethanol with Coupled Alcohol Dehydrogenase/NADH Oxidase System

Advanced Synthesis & Catalysis ◽

10.1002/adsc.201900213 ◽

2019 ◽

Cited By ~ 5

Author(s):

Mafalda Dias Gomes ◽

Bettina R. Bommarius ◽

Shelby R. Anderson ◽

Brent D. Feske ◽

John M. Woodley ◽

...

Keyword(s):

Alcohol Dehydrogenase ◽

Reaction Rate ◽

Nadh Oxidase ◽

Bubble Column ◽

Oxidase System

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Enzyme Activity of the Cytochrome System of the Egg and Larva of the Cattle Tick (Boophilus Microplus)

Australian Journal of Biological Sciences ◽

10.1071/bi9730453 ◽

1973 ◽

Vol 26 (2) ◽

pp. 453 ◽

Cited By ~ 2

Author(s):

AG Shanahan ◽

JE O'hagan

Keyword(s):

Enzyme Activity ◽

Cytochrome C ◽

Cytochrome C Oxidase ◽

Nadh Oxidase ◽

Boophilus Microplus ◽

Cattle Tick ◽

Oxidase System ◽

Cytochrome C Reductase ◽

Nadh Cytochrome ◽

Eggs And Larvae

The enzymatic activities of the succinate-<;ytochrome c reductase system, the NADH--cytochrome c reductase system, the NADH oxidase system, and cytochrome c oxidase were determined spectrophotometrically in particulate preparations of eggs and larvae of B. micro plus.

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The intracellular Na+ and K+ composition of the moderately halophilic bacterium, Paracoccus halodenitrificans

Canadian Journal of Microbiology ◽

10.1139/m80-083 ◽

1980 ◽

Vol 26 (4) ◽

pp. 496-502 ◽

Cited By ~ 20

Author(s):

M. Sadler ◽

M. McAninch ◽

R. Alico ◽

L. I. Hochstein

Keyword(s):

Stationary Phase ◽

Growth Medium ◽

Nadh Oxidase ◽

Halophilic Bacterium ◽

Oxidase System ◽

Final Value ◽

Moderately Halophilic Bacterium ◽

Nacl Concentration ◽

Atp Pool ◽

Membrane Bound

The intracellular concentrations of Na+ and K+ in exponentially growing Paracoccus halodenitrificans were independent of the NaCl concentration of the growth medium. The observed values were approximately 100 and 300 mM for Na+ and K+, respectively. In stationary phase cells, the ultimate values for Na+ depended on the NaCl concentration of the growth medium. With cells grown in the presence of 1 M NaCl, the value was about 500 mM; for cells grown in the presence of 3 M NaCl, the value was about 1.1 M. The K+ concentration in stationary phase cells was unaffected by the NaCl concentration in the growth medium. The final value was about 100 mM. Associated with these changes were changes in the ATP pool and decreases in the activities of the NADH oxidase system and the membrane-bound ATPase. It is proposed that the decrease in the activities of these enzymes may account for the ion flows observed in stationary phase cells.

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Enzymatic Properties of the Membrane-bound NADH Oxidase System in the Aerobic Respiratory Chain of Bacillus cereus

BMB Reports ◽

10.5483/bmbrep.2004.37.6.753 ◽

2004 ◽

Vol 37 (6) ◽

pp. 753-756 ◽

Cited By ~ 9

Author(s):

Man-Suk Kim ◽

Young-Jae Kim

Keyword(s):

Bacillus Cereus ◽

Respiratory Chain ◽

Nadh Oxidase ◽

Enzymatic Properties ◽

Oxidase System ◽

Membrane Bound

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The NADH oxidase system (external) of muscle mitochondria and its role in the oxidation of cytoplasmic NADH

Biochemical Journal ◽

10.1042/bj2290631 ◽

1985 ◽

Vol 229 (3) ◽

pp. 631-641 ◽

Cited By ~ 24

Author(s):

U F Rasmussen ◽

H N Rasmussen

Keyword(s):

Oxidase Activity ◽

Nadh Oxidase ◽

Specific Activity ◽

Reductase Activity ◽

Heart Mitochondria ◽

Freezing And Thawing ◽

Oxidase System ◽

Muscle Mitochondria ◽

Nadh Oxidase Activity

An exo-NADH oxidase system [NADH oxidase system (external)], effecting intact-mitochondrial oxidation of added NADH, was studied in pigeon heart mitochondria. Breast muscle mitochondria showed an equal specific activity of the system. The exo-NADH oxidase activity (200 micron mol of NADH/min per g of protein) equalled two-thirds of the State-3 respiratory activity with malate + pyruvate or one-seventh of the total NADH oxidase activity of heart mitochondria. The activity was not caused by use of proteinase in the preparation procedure and all measured parameters were very reproducible from preparation to preparation. The activity is therefore most likely not due to preparation artefacts. The exo-NADH oxidase system is present in all mitochondria in the preparation and is not confined to a subpopulation. The system reduced all cytochrome anaerobically and direct interaction with all cytochrome oxidase was demonstrated by interdependent cyanide inhibition. The exo-NADH oxidase system seems to be located at the outer surface of the mitochondrial inner membrane because, for instance, only this system was rapidly inhibited by rotenone, and ferricyanide could act as acceptor in the rotenone-inhibited system (reductase activity = 20 times oxidase activity). In the presence of antimycin, added NADH reduced only a part of the b-cytochromes. Freezing and thawing the mitochondria, one of the methods used for making them permeable to NADH, destroyed this functional compartmentation. The characteristics of the exo-NADH oxidase system and the malate-aspartate shuttle are compared and the evidence for the shuttle's function in heart in vivo is re-evaluated. It is proposed that oxidation of cytoplasmic NADH in red muscles primarily is effected by the exo-NADH oxidase system.

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