Reduction of aryl-nitroso compounds by pyridine and flavin coenzymes

Leskovac, Vladimir; Svirčević, Jasmina; Trivić, Svetlana; Popović, M.; Radulović, Mirjana

doi:10.1016/0020-711x(89)90279-6

Cited by 19 publications

(14 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The only metabolite which accumulated could be reduced to 4-aminobenzoate by treatment with zinc in HCl solution, which suggested that the metabolite was 4-hydroxylaminobenzoate (not available as authentic compound). The accumulation of 4-nitrosobenzoate could be excluded, since it would have been spontaneously reduced to 4-hydroxylaminobenzoate by NADPH (4,30).…”

Section: Resultsmentioning

confidence: 99%

3-Hydroxylaminophenol Mutase from Ralstonia eutropha JMP134 Catalyzes a Bamberger Rearrangement

et al. 1999

View full text Add to dashboard Cite

3-Hydroxylaminophenol mutase from Ralstonia eutrophaJMP134 is involved in the degradative pathway of 3-nitrophenol, in which it catalyzes the conversion of 3-hydroxylaminophenol to aminohydroquinone. To show that the reaction was really catalyzed by a single enzyme without the release of intermediates, the corresponding protein was purified to apparent homogeneity from an extract of cells grown on 3-nitrophenol as the nitrogen source and succinate as the carbon and energy source. 3-Hydroxylaminophenol mutase appears to be a relatively hydrophobic but soluble and colorless protein consisting of a single 62-kDa polypeptide. The pI was determined to be at pH 4.5. In a database search, the NH2-terminal amino acid sequence of the undigested protein and of two internal sequences of 3-hydroxylaminophenol mutase were found to be most similar to those of glutamine synthetases from different species. Hydroxylaminobenzene, 4-hydroxylaminotoluene, and 2-chloro-5-hydroxylaminophenol, but not 4-hydroxylaminobenzoate, can also serve as substrates for the enzyme. The enzyme requires no oxygen or added cofactors for its reaction, which suggests an enzymatic mechanism analogous to the acid-catalyzed Bamberger rearrangement.

show abstract

Section: Resultsmentioning

confidence: 99%

3-Hydroxylaminophenol Mutase from Ralstonia eutropha JMP134 Catalyzes a Bamberger Rearrangement

et al. 1999

View full text Add to dashboard Cite

show abstract

“…It is unlikely that oxygen-insensitive nitroreductases release the nitroso intermediates during the reduction of nitroaromatic compounds. The reduction of a nitroso group yielding a hydroxylamino group does not require much activation energy, and therefore most nitrosoaromatic compounds spontaneously react with reduced pyridine and flavin nucleotide cofactors (4,28). Nitrosobenzene also served as a substrate for 3NP nitroreductase from R. eutropha JMP134 and was converted faster than nitrobenzene, indicating that the initial two-electron transfer forming the nitroso intermediate is the rate-limiting step of the complete reductive sequence.…”

Section: Discussionmentioning

confidence: 99%

Chemoselective Nitro Group Reduction and Reductive Dechlorination Initiate Degradation of 2-Chloro-5-Nitrophenol by Ralstonia eutropha JMP134

Schenzle

Lenke

Spain

et al. 1999

Appl Environ Microbiol

View full text Add to dashboard Cite

Ralstonia eutropha JMP134 utilizes 2-chloro-5-nitrophenol as a sole source of nitrogen, carbon, and energy. The initial steps for degradation of 2-chloro-5-nitrophenol are analogous to those of 3-nitrophenol degradation in R. eutropha JMP134. 2-Chloro-5-nitrophenol is initially reduced to 2-chloro-5-hydroxylaminophenol, which is subject to an enzymatic Bamberger rearrangement yielding 2-amino-5-chlorohydroquinone. The chlorine of 2-amino-5-chlorohydroquinone is removed by a reductive mechanism, and aminohydroquinone is formed. 2-Chloro-5-nitrophenol and 3-nitrophenol induce the expression of 3-nitrophenol nitroreductase, of 3-hydroxylaminophenol mutase, and of the dechlorinating activity. 3-Nitrophenol nitroreductase catalyzes chemoselective reduction of aromatic nitro groups to hydroxylamino groups in the presence of NADPH. 3-Nitrophenol nitroreductase is active with a variety of mono-, di-, and trinitroaromatic compounds, demonstrating a relaxed substrate specificity of the enzyme. Nitrosobenzene serves as a substrate for the enzyme and is converted faster than nitrobenzene.

show abstract

“…Earlier studies indicated that such stabilization is higher in FAD-dependent dehydrogenases than in FADdependent oxidases. The oxidases are therefore less efficient generators of superoxide anion radicals, compared to the dehydrogenases (111,131). The different mechanisms of the FAD-dependent reactions with molecular oxygen roughly correlate with the enzyme reactivities to sulfite (130).…”

Section: Oxygen-dependent Reactions Of the Dihydrolipoamide Dehydrmentioning

confidence: 99%

Redox-Driven Signaling: 2-Oxo Acid Dehydrogenase Complexes as Sensors and Transmitters of Metabolic Imbalance

Bunik

2019

Antioxidants & Redox Signaling

View full text Add to dashboard Cite

Interaction of 2-oxo acid dehydrogenase complexes with thioredoxins, peroxiredoxins and glutaredoxins mediates scavenging of the thiyl radicals and ROS generated by the complexes, underlying signaling of disproportional availability of 2-oxo acids, CoA and NAD+ in key metabolic branch points through thiol-disulfide exchange and medically important HIF, mTOR, PARP and sirtuins. High reactivity of the co-produced ROS and thiyl radicals to iron-sulfur clusters and nitric oxide, peroxynitrite reductase activity of peroxyredoxins and transnitrosylating function of thioredoxin, implicate the side reactions of 2-oxo acid dehydrogenase complexes in nitric-oxide-dependent signaling and damage.

show abstract

Reduction of aryl-nitroso compounds by pyridine and flavin coenzymes

Cited by 19 publications

References 28 publications

3-Hydroxylaminophenol Mutase from Ralstonia eutropha JMP134 Catalyzes a Bamberger Rearrangement

3-Hydroxylaminophenol Mutase from Ralstonia eutropha JMP134 Catalyzes a Bamberger Rearrangement

Chemoselective Nitro Group Reduction and Reductive Dechlorination Initiate Degradation of 2-Chloro-5-Nitrophenol by Ralstonia eutropha JMP134

Redox-Driven Signaling: 2-Oxo Acid Dehydrogenase Complexes as Sensors and Transmitters of Metabolic Imbalance

Contact Info

Product

Resources

About