Enzymes
UniProtKB help_outline | 2 proteins |
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- Name help_outline ubiquinone-10 Identifier CHEBI:46245 (Beilstein: 1900141; CAS: 303-98-0) help_outline Charge 0 Formula C59H90O4 InChIKeyhelp_outline ACTIUHUUMQJHFO-UPTCCGCDSA-N SMILEShelp_outline COC1=C(OC)C(=O)C(C\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CCC=C(C)C)=C(C)C1=O 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 hydrogen sulfide Identifier CHEBI:29919 (CAS: 15035-72-0) help_outline Charge -1 Formula HS InChIKeyhelp_outline RWSOTUBLDIXVET-UHFFFAOYSA-M SMILEShelp_outline [S-][H] 2D coordinates Mol file for the small molecule Search links Involved in 56 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline glutathione Identifier CHEBI:57925 Charge -1 Formula C10H16N3O6S InChIKeyhelp_outline RWSXRVCMGQZWBV-WDSKDSINSA-M SMILEShelp_outline [NH3+][C@@H](CCC(=O)N[C@@H](CS)C(=O)NCC(=O)[O-])C(=O)[O-] 2D coordinates Mol file for the small molecule Search links Involved in 104 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,717 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline S-sulfanylglutathione Identifier CHEBI:58905 Charge -1 Formula C10H16N3O6S2 InChIKeyhelp_outline QBOLVLBSUGJHGB-WDSKDSINSA-M SMILEShelp_outline [NH3+][C@@H](CCC(=O)N[C@@H](CSS)C(=O)NCC([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 6 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline ubiquinol-10 Identifier CHEBI:64183 Charge 0 Formula C59H92O4 InChIKeyhelp_outline QNTNKSLOFHEFPK-UPTCCGCDSA-N SMILEShelp_outline COc1c(O)c(C)c(C\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CC\C=C(/C)CCC=C(C)C)c(O)c1OC 2D coordinates Mol file for the small molecule Search links Involved in 6 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:62608 | RHEA:62609 | RHEA:62610 | RHEA:62611 | |
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Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
UniProtKB help_outline |
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Related reactions help_outline
More general form(s) of this reaction
Publications
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Modulation of catalytic promiscuity during hydrogen sulfide oxidation.
Landry A.P., Ballou D.P., Banerjee R.
The mitochondrial sulfide oxidation pathway prevents the toxic accumulation of hydrogen sulfide (H<sub>2</sub>S), a signaling molecule that is maintained at low steady-state concentrations. Sulfide quinone oxidoreductase (SQR), an inner mitochondrial membrane-anchored protein, catalyzes the first ... >> More
The mitochondrial sulfide oxidation pathway prevents the toxic accumulation of hydrogen sulfide (H<sub>2</sub>S), a signaling molecule that is maintained at low steady-state concentrations. Sulfide quinone oxidoreductase (SQR), an inner mitochondrial membrane-anchored protein, catalyzes the first and committing step in this pathway, oxidizing H<sub>2</sub>S to persulfide. The catalytic cycle comprises sulfide addition to the active site cysteine disulfide in SQR followed by sulfur transfer to a small molecule acceptor, while a pair of electrons moves from sulfide, to FAD, to coenzyme Q. While its ability to oxidize H<sub>2</sub>S is well characterized, SQR exhibits a remarkable degree of substrate promiscuity in vitro that could undermine its canonical enzyme activity. To assess how its promiscuity might be contained in vivo, we have used spectroscopic and kinetic analyses to characterize the reactivity of alternate substrates with SQR embedded in nanodiscs ( ndSQR) versus detergent-solubilized enzyme ( sSQR). We find that the membrane environment of ndSQR suppresses the unwanted addition of GSH but enhances sulfite addition, which might become significant under pathological conditions characterized by elevated sulfite levels. We demonstrate that methanethiol, a toxic sulfur compound produced in significant quantities by colonic and oral microbiota, can add to the SQR cysteine disulfide and also serve as a sulfur acceptor, potentially interfering with sulfide oxidation when its concentrations are elevated. These studies demonstrate that the membrane environment and substrate availability combine to minimize promiscuous reactions that would otherwise disrupt sulfide homeostasis. << Less