Enzymes
| UniProtKB help_outline | 1,508 proteins |
Reaction participants Show >> << Hide
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Namehelp_outline
Fe(II)-heme b-[protein]
Identifier
RHEA-COMP:18975
Reactive part
help_outline
- Name help_outline heme b Identifier CHEBI:60344 Charge -2 Formula C34H30FeN4O4 InChIKeyhelp_outline KABFMIBPWCXCRK-RGGAHWMASA-J SMILEShelp_outline CC1=C(CCC([O-])=O)C2=[N+]3C1=Cc1c(C)c(C=C)c4C=C5C(C)=C(C=C)C6=[N+]5[Fe--]3(n14)n1c(=C6)c(C)c(CCC([O-])=O)c1=C2 2D coordinates Mol file for the small molecule Search links Involved in 22 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline nitric oxide Identifier CHEBI:16480 (CAS: 10102-43-9) help_outline Charge 0 Formula NO InChIKeyhelp_outline MWUXSHHQAYIFBG-UHFFFAOYSA-N SMILEShelp_outline [N]=O 2D coordinates Mol file for the small molecule Search links Involved in 23 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,727 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
Fe(III)-heme b-[protein]
Identifier
RHEA-COMP:18976
Reactive part
help_outline
- Name help_outline Fe(III)-heme b Identifier CHEBI:55376 Charge -1 Formula C34H30FeN4O4 InChIKeyhelp_outline GGIDWJQWCUJYRY-RGGAHWMASA-J SMILEShelp_outline CC1=C(CCC([O-])=O)C2=[N+]3C1=Cc1c(C)c(C=C)c4C=C5C(C)=C(C=C)C6=[N+]5[Fe-]3(n14)n1c(=C6)c(C)c(CCC([O-])=O)c1=C2 2D coordinates Mol file for the small molecule Search links Involved in 5 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline nitrate Identifier CHEBI:17632 (Beilstein: 3587575; CAS: 14797-55-8) help_outline Charge -1 Formula NO3 InChIKeyhelp_outline NHNBFGGVMKEFGY-UHFFFAOYSA-N SMILEShelp_outline [O-][N+]([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 26 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:78091 | RHEA:78092 | RHEA:78093 | RHEA:78094 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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| Gene Ontology help_outline |
Publications
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Nitric-oxide dioxygenase function of human cytoglobin with cellular reductants and in rat hepatocytes.
Gardner A.M., Cook M.R., Gardner P.R.
Cytoglobin (Cygb) was investigated for its capacity to function as a NO dioxygenase (NOD) in vitro and in hepatocytes. Ascorbate and cytochrome b(5) were found to support a high NOD activity. Cygb-NOD activity shows respective K(m) values for ascorbate, cytochrome b(5), NO, and O(2) of 0.25 mm, 0. ... >> More
Cytoglobin (Cygb) was investigated for its capacity to function as a NO dioxygenase (NOD) in vitro and in hepatocytes. Ascorbate and cytochrome b(5) were found to support a high NOD activity. Cygb-NOD activity shows respective K(m) values for ascorbate, cytochrome b(5), NO, and O(2) of 0.25 mm, 0.3 microm, 40 nm, and approximately 20 microm and achieves a k(cat) of 0.5 s(-1). Ascorbate and cytochrome b(5) reduce the oxidized Cygb-NOD intermediate with apparent second order rate constants of 1000 m(-1) s(-1) and 3 x 10(6) m(-1) s(-1), respectively. In rat hepatocytes engineered to express human Cygb, Cygb-NOD activity shows a similar k(cat) of 1.2 s(-1), a K(m)(NO) of 40 nm, and a k(cat)/K(m)(NO) (k'(NOD)) value of 3 x 10(7) m(-1) s(-1), demonstrating the efficiency of catalysis. NO inhibits the activity at [NO]/[O(2)] ratios >1:500 and limits catalytic turnover. The activity is competitively inhibited by CO, is slowly inactivated by cyanide, and is distinct from the microsomal NOD activity. Cygb-NOD provides protection to the NO-sensitive aconitase. The results define the NOD function of Cygb and demonstrate roles for ascorbate and cytochrome b(5) as reductants. << Less