scholarly journals Nitric Oxide Reductase Activity in Heme–Nonheme Binuclear Engineered Myoglobins through a One-Electron Reduction Cycle

2018 ◽  
Vol 140 (50) ◽  
pp. 17389-17393 ◽  
Author(s):  
Sinan Sabuncu ◽  
Julian H. Reed ◽  
Yi Lu ◽  
Pierre Moënne-Loccoz
Keyword(s):  
Nitric Oxide ◽  
Reductase Activity ◽  
Nitric Oxide Reductase ◽  
Reduction Cycle ◽  
Electron Reduction

Detergent inhibition of nitric-oxide reductase activity

1987 ◽  
Vol 911 (3) ◽  
pp. 334-340 ◽  
Author(s):  
J.P. Shapleigh ◽  
K.J.P. Davies ◽  
W.J. Payne
Keyword(s):  
Nitric Oxide ◽  
Reductase Activity ◽  
Nitric Oxide Reductase

Proton transfer in bacterial nitric oxide reductase

2006 ◽  
Vol 34 (1) ◽  
pp. 188-190 ◽  
Author(s):  
U. Flock ◽  
J. Reimann ◽  
P. Ädelroth
Keyword(s):  
Nitric Oxide ◽  
Proton Transfer ◽  
Structural Model ◽  
No Reduction ◽  
Paracoccus Denitrificans ◽  
Proton Donor ◽  
Nitric Oxide Reductase ◽  
Reduction Of No ◽  
Proton Coupled Electron Transfer ◽  
Electron Reduction

The NOR (nitric oxide reductase) from Paracoccus denitrificans catalyses the two-electron reduction of NO to N2O (2NO+2H++2e−→N2O+H2O). The NOR is a divergent member of the superfamily of haem-copper oxidases, oxygen-reducing enzymes which couple the reduction of oxygen with translocation of protons across the membrane. In contrast, reduction of NO catalysed by NOR is non-electrogenic which, since electrons are supplied from the periplasmic side of the membrane, implies that the protons needed for NO reduction are also taken from the periplasm. Thus NOR must contain a proton-transfer pathway leading from the periplasmic side of the membrane into the catalytic site. The proton pathway has not been identified, and the mechanism and timing of proton transfer during NO reduction is unknown. To address these questions, we have studied the reaction between NOR and the chemically less reactive oxidant O2 [Flock, Watmough and Ädelroth (2005) Biochemistry 44, 10711–10719]. When fully reduced NOR reacts with O2, proton-coupled electron transfer occurs in a reaction that is rate-limited by internal proton transfer from a group with a pKa of 6.6. This group is presumably an amino acid residue close to the active site that acts as a proton donor also during NO reduction. The results are discussed in the framework of a structural model that identifies possible candidates for the proton donor as well as for the proton-transfer pathway.

scholarly journals Introducing a 2-His-1-Glu Nonheme Iron Center into Myoglobin Confers Nitric Oxide Reductase Activity

2010 ◽  
Vol 132 (29) ◽  
pp. 9970-9972 ◽  
Author(s):  
Ying-Wu Lin ◽  
Natasha Yeung ◽  
Yi-Gui Gao ◽  
Kyle D. Miner ◽  
Lanyu Lei ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reductase Activity ◽  
Nonheme Iron ◽  
Nitric Oxide Reductase ◽  
Iron Center

scholarly journals Identification, Functional Studies, and Genomic Comparisons of New Members of the NnrR Regulon in Rhodobacter sphaeroides

2009 ◽  
Vol 192 (4) ◽  
pp. 903-911 ◽  
Author(s):  
Angela Hartsock ◽  
James P. Shapleigh
Keyword(s):  
Nitric Oxide ◽  
Rhodobacter Sphaeroides ◽  
Nitrite Reductase ◽  
Reductase Activity ◽  
Nitrite Reduction ◽  
No Production ◽  
Nitric Oxide Reductase ◽  
New Members ◽  
Functional Studies ◽  
The Status

ABSTRACT Analysis of the Rhodobacter sphaeroides 2.4.3 genome revealed four previously unidentified sequences similar to the binding site of the transcriptional regulator NnrR. Expression studies demonstrated that three of these sequences are within the promoters of genes, designated paz, norEF, and cdgA, in the NnrR regulon, while the status of the fourth sequence, within the tat operon promoter, remains uncertain. nnrV, under control of a previously identified NnrR site, was also identified. paz encodes a pseudoazurin that is a donor of electrons to nitrite reductase. paz inactivation did not decrease nitrite reductase activity, but loss of pseudoazurin and cytochrome c2 together reduced nitrite reduction. Inactivation of norEF reduced nitrite and nitric oxide reductase activity and increased the sensitivity to nitrite in a taxis assay. This suggests that loss of norEF increases NO production as a result of decreased nitric oxide reductase activity. 2.4.3 is the only strain of R. sphaeroides with norEF, even though all four of the strains whose genomes have been sequenced have the norCBQD operon and nnrR. norEF was shown to provide resistance to nitrite when it was mobilized into R. sphaeroides strain 2.4.1 containing nirK. Inactivation of the other identified genes did not reveal any detectable denitrification-related phenotype. The distribution of members of the NnrR regulon in R. sphaeroides revealed patterns of coselection of structural genes with the ancillary genes identified here. The strong coselection of these genes indicates their functional importance under real-world conditions, even though inactivation of the majority of them does not impact denitrification under laboratory conditions.

scholarly journals Characterization of the norB Gene, Encoding Nitric Oxide Reductase, in the Nondenitrifying Cyanobacterium Synechocystis sp. Strain PCC6803

2002 ◽  
Vol 68 (2) ◽  
pp. 668-672 ◽  
Author(s):  
Andrea B�sch ◽  
B�rbel Friedrich ◽  
Rainer Cramm
Keyword(s):  
Nitric Oxide ◽  
Reductase Activity ◽  
Nitric Oxide Reductase ◽  
Wild Type ◽  
Gene Encoding ◽  
Single Subunit ◽  
Transcriptional Fusions ◽  
Synechocystis Sp ◽  
Negative Mutant

ABSTRACT A norB gene encoding a putative nitric oxide reductase is present in the genome of the nondenitrifying cyanobacterium Synechocystis sp. strain PCC6803. The gene product belongs to the quinol-oxidizing single-subunit class of nitric oxide reductases, discovered recently in the denitrifier Ralstonia eutropha. Heterologous complementation of a nitric oxide reductase-negative mutant of R. eutropha with norB from Synechocystis restored nitric oxide reductase activity. With reduced menadione as the electron donor, an enzymatic activity of 101 nmol of NO per min per mg of protein was obtained with membrane fractions of Synechocystis wild-type cells. Virtually no nitric oxide reductase activity was present in a norB-negative mutant of Synechocystis. Growing cells of this mutant are more sensitive toward NO than wild-type cells, indicating that the presence of a nitric oxide reductase is beneficial for Synechocystis when the cells are exposed to NO. Transcriptional fusions with the chloramphenicol acetyltransferase reporter gene were constructed to monitor norB expression in Synechocystis. Transcription of norB was not enhanced by the addition of the NO-generating agent sodium nitroprusside.

Separation of soluble denitrifying enzymes and cytochromes from Pseudomonas perfectomarinus

1973 ◽  
Vol 19 (7) ◽  
pp. 861-872 ◽  
Author(s):  
C. D. Cox Jr. ◽  
W. J. Payne
Keyword(s):  
Nitric Oxide ◽  
Electron Donor ◽  
Nitrite Reductase ◽  
Reductase Activity ◽  
Electron Flow ◽  
Deae Cellulose ◽  
The Other ◽  
Nitric Oxide Reductase ◽  
Effective Electron ◽  
Nitrite Reductase Activity

Nitrite and nitric oxide reductases were found soluble in extracts of Pseudomonas perfectomarinus cultured anaerobically at the expense of nitrate and ruptured with the French pressure cell. Malic enzyme, transhydrogenase, and flavin reductase that provided electron flow for these reductases were soluble as well. Nitrous oxide reductase remained particle-bound. Exogenous NADH was a poor electron donor for crude extracts, but a combination of malate, NADP, and NAD served well in the reduction of nitrite and nitric oxide. Nitrite reductase activity lost on dialysis of crude extract was restored by addition of this combination. Addition of free flavins was required for reduction of nitrite and nitric oxide. A nitrite reductase complex was separated from the nitric oxide reductase by gel filtration and DEAE-cellulose chromatography. NADH was an effective electron donor for this system with flavins provided as well. A c-type cytochrome with a split-α peak (perhaps associated with a d type) and two additional c-type cytochromes were separated from the nitrite reductase fraction. One of the latter (RI) emerged oxidized, the other (RII) reduced. Only nitric oxide oxidized RII. When these cytochromes were added to reaction mixtures containing nitrite reductase, activity was increased most by the split-α fraction. After reduction with dithionite, the absorption spectrum of the split-α cytochrome was returned to the oxidized spectrum by addition of nitrite but not the other oxides. A significant amount of a c-type cytochrome remained bound to the nitric oxide reductase fraction. A combination of malic acid, NAD, and NADP was more effective than NADH as electron donor for this system with free flavins provided as well. Addition of RI increased the rate of nitric oxide reduction by this fraction.

A Flavodiiron Protein and High Molecular Weight Rubredoxin fromMoorella thermoaceticawith Nitric Oxide Reductase Activity†

Biochemistry ◽  
2003 ◽  
Vol 42 (10) ◽  
pp. 2806-2815 ◽  
Author(s):  
Radu Silaghi-Dumitrescu ◽  
Eric D. Coulter ◽  
Amaresh Das ◽  
Lars G. Ljungdahl ◽  
Guy N. L. Jameson ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Reductase Activity ◽  
Nitric Oxide Reductase

scholarly journals A theoretical study on nitric oxide reductase activity in a ba3-type heme-copper oxidase

2006 ◽  
Vol 1757 (1) ◽  
pp. 31-46 ◽  
Author(s):  
L. Mattias Blomberg ◽  
Margareta R.A. Blomberg ◽  
Per E.M. Siegbahn
Keyword(s):  
Nitric Oxide ◽  
Theoretical Study ◽  
Reductase Activity ◽  
Nitric Oxide Reductase ◽  
Copper Oxidase

scholarly journals The Nitric Oxide Reductase Activity of CytochromecNitrite Reductase fromEscherichia coli

2008 ◽  
Vol 283 (15) ◽  
pp. 9587-9594 ◽  
Author(s):  
Jessica H. van Wonderen ◽  
Bénédicte Burlat ◽  
David J. Richardson ◽  
Myles R. Cheesman ◽  
Julea N. Butt
Keyword(s):  
Nitric Oxide ◽  
Reductase Activity ◽  
Nitric Oxide Reductase ◽  
Fromescherichia Coli
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