Reaction participants Show >> << Hide
- Name help_outline L-homocysteine Identifier CHEBI:58199 Charge 0 Formula C4H9NO2S InChIKeyhelp_outline FFFHZYDWPBMWHY-VKHMYHEASA-N SMILEShelp_outline [NH3+][C@@H](CCS)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 20 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 9,176 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 54 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline L-homolanthionine Identifier CHEBI:178194 Charge 0 Formula C8H16N2O4S InChIKeyhelp_outline MBEPFGPQVBIIES-WDSKDSINSA-N SMILEShelp_outline [NH3+][C@@H](CCSCC[C@H]([NH3+])C([O-])=O)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:68652 | RHEA:68653 | RHEA:68654 | RHEA:68655 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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H2S biogenesis by human cystathionine gamma-lyase leads to the novel sulfur metabolites lanthionine and homolanthionine and is responsive to the grade of hyperhomocysteinemia.
Chiku T., Padovani D., Zhu W., Singh S., Vitvitsky V., Banerjee R.
Although there is a growing recognition of the significance of hydrogen sulfide (H(2)S) as a biological signaling molecule involved in vascular and nervous system functions, its biogenesis and regulation are poorly understood. It is widely assumed that desulfhydration of cysteine is the major sour ... >> More
Although there is a growing recognition of the significance of hydrogen sulfide (H(2)S) as a biological signaling molecule involved in vascular and nervous system functions, its biogenesis and regulation are poorly understood. It is widely assumed that desulfhydration of cysteine is the major source of H(2)S in mammals and is catalyzed by the transsulfuration pathway enzymes, cystathionine beta-synthase and cystathionine gamma-lyase (CSE). In this study, we demonstrate that the profligacy of human CSE results in a variety of reactions that generate H(2)S from cysteine and homocysteine. The gamma-replacement reaction, which condenses two molecules of homocysteine, yields H(2)S and a novel biomarker, homolanthionine, which has been reported in urine of homocystinuric patients, whereas a beta-replacement reaction, which condenses two molecules of cysteine, generates lanthionine. Kinetic simulations at physiologically relevant concentrations of cysteine and homocysteine, reveal that the alpha,beta-elimination of cysteine accounts for approximately 70% of H(2)S generation. However, the relative importance of homocysteine-derived H(2)S increases progressively with the grade of hyperhomocysteinemia, and under conditions of severely elevated homocysteine (200 microm), the alpha,gamma-elimination and gamma-replacement reactions of homocysteine together are predicted to account for approximately 90% of H(2)S generation by CSE. Excessive H(2)S production in hyperhomocysteinemia may contribute to the associated cardiovascular pathology. << Less
J. Biol. Chem. 284:11601-11612(2009) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.