Three enzymatic activities catalyze the oxidation... : FEBS Journal, The (original) (raw)

Three enzymatic activities catalyze the oxidation of sulfide to thiosulfate in mammalian and invertebrate mitochondria

Tatjana M. Hildebrandt
Manfred K. Grieshaber

FEBS Journal, The

275

(

)

3352

3361

July 2008

Hydrogen sulfide is a potent toxin of aerobic respiration, but also has physiological functions as a signalling molecule and as a substrate for ATP production. A mitochondrial pathway catalyzing sulfide oxidation to thiosulfate in three consecutive reactions has been identified in rat liver as well as in the body-wall tissue of the lugworm, Arenicola marina. A membrane-bound sulfide: quinone oxidoreductase converts sulfide to persulfides and transfers the electrons to the ubiquinone pool. Subsequently, a putative sulfur dioxygenase in the mitochondrial matrix oxidizes one persulfide molecule to sulfite, consuming molecular oxygen. The final reaction is catalyzed by a sulfur transferase, which adds a second persulfide from the sulfide: quinone oxidoreductase to sulfite, resulting in the final product thiosulfate. This role in sulfide oxidation is an additional physiological function of the mitochondrial sulfur transferase, rhodanese.