Organization of the human mitochondrial hydrogen sulfide oxidation pathway.
J Biol Chem
; 289(45): 30901-10, 2014 Nov 07.
Article
in En
| MEDLINE
| ID: mdl-25225291
ABSTRACT
Sulfide oxidation is expected to play an important role in cellular switching between low steady-state intracellular hydrogen sulfide levels and the higher concentrations where the physiological effects are elicited. Yet despite its significance, fundamental questions regarding how the sulfide oxidation pathway is wired remain unanswered, and competing proposals exist that diverge at the very first step catalyzed by sulfide quinone oxidoreductase (SQR). We demonstrate that, in addition to sulfite, glutathione functions as a persulfide acceptor for human SQR and that rhodanese preferentially synthesizes rather than utilizes thiosulfate. The kinetic behavior of these enzymes provides compelling evidence for the flow of sulfide via SQR to glutathione persulfide, which is then partitioned to thiosulfate or sulfite. Kinetic simulations at physiologically relevant metabolite concentrations provide additional support for the organizational logic of the sulfide oxidation pathway in which glutathione persulfide is the first intermediate formed.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Quinone Reductases
/
Hydrogen Sulfide
/
Mitochondria
Limits:
Humans
Language:
En
Journal:
J Biol Chem
Year:
2014
Document type:
Article