Back حمض النتريك دي-أكسجيناز Arabic Ossido nitrico diossigenasi Italian 一酸化窒素ジオキシゲナーゼ Japanese Azot-monoksid dioksigenaza Serbo-Croatian Azot-monoksid dioksigenaza Serbian
| nitric oxide dioxygenase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
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| Identifiers | |||||||||
| EC no. | 1.14.12.17 | ||||||||
| CAS no. | 214466-78-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
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Nitric oxide dioxygenase (EC 1.14.12.17) is an enzyme that catalyzes the conversion of nitric oxide (NO) to nitrate (NO−
3)
.[2] The net reaction for the reaction catalyzed by nitric oxide dioxygenase is shown below:
- 2NO + 2O2 + NAD(P)H → 2NO3− + NAD(P)+ + H+
Nitric oxide is a ubiquitous small molecule that is integrated in a wide variety of physiological processes including smooth muscle vasodilation, platelet disaggregation, neurotransmission, and immune response to bacterial infection.[3][4] Overproduction of this signaling molecule can be lethal to cells by poisoning cellular energy production. The most sensitive targets of NO are aconitase, an enzyme that catalyzes the isomerization of citrate to isocitrate in the citric acid cycle, and cytochrome oxidase, the last enzyme in the respiratory electron transport chain of mitochondria.[5] Additionally NO, with its lone radical on the nitrogen atom, is implicated in a number of secondary mechanisms of toxicity, including catalase inhibition (resulting in hydrogen peroxide toxicity), Fe-S center iron liberation, and the formation of dinitosyl-iron complexes.
Due to the potential lethality of NO, cells benefitted greatly from the evolution of an enzyme capable of catalyzing the conversion of toxic NO to nitrate. A 'nitric oxide dioxygenase' is an enzyme that is capable of carrying out this reaction. NO dioxygenase belongs to the family of oxidoreductases, more specifically those acting on paired donors, with O2 as oxidant and with incorporation of two atoms of oxygen into the other donor.
- ^ PDB: 1gvh; Ilari A, Bonamore A, Farina A, Johnson KA, Boffi A (June 2002). "The X-ray structure of ferric Escherichia coli flavohemoglobin reveals an unexpected geometry of the distal heme pocket". J. Biol. Chem. 277 (26): 23725–32. doi:10.1074/jbc.M202228200. PMID 11964402.
- ^ Forrester MT, Foster MW (May 2012). "Protection from nitrosative stress: a central role for microbial flavohemoglobin". Free Radic. Biol. Med. 52 (9 =): 1620–33. doi:10.1016/j.freeradbiomed.2012.01.028. PMID 22343413.
- ^ Moncada S, Palmer RM, Higgs EA (June 1991). "Nitric oxide: physiology, pathophysiology, and pharmacology". Pharmacol. Rev. 43 (2): 109–42. PMID 1852778.
- ^ Fang FC (October 2004). "Antimicrobial reactive oxygen and nitrogen species: concepts and controversies". Nat. Rev. Microbiol. 2 (10): 820–32. doi:10.1038/nrmicro1004. PMID 15378046. S2CID 11063073.
- ^ Gardner PR, Costantino G, Szabó C, Salzman AL (October 1997). "Nitric oxide sensitivity of the aconitases". J. Biol. Chem. 272 (40): 25071–6. doi:10.1074/jbc.272.40.25071. PMID 9312115.