Hydrogen sulfide and mitochondria

Abstract

There are different opinions about the role of hydrogen sulfide (H2S) in catalytic and energy processes, but the biochemistry of all possible effects of H2S is not well studied yet. The enzymatic synthesis of H2S is catalyzed by cystathionine-γ-lyase, cystathionine-β-synthase, cysteine aminotransferase and in mitochondria by 3-mercaptopyruvate sulfurtransferase only. H2S may function as an energy substrate to sustain the ATP synthesis under stress conditions, but in high concentration H2S inhibits respiratory complex IV, blocking electron transport and proton pumping. The interaction between glucose in high concentrtaion, H2S, and the KATP channels may constitute a novel mechanism for the control of insulin secretion. The positive effect of H2S on the bioenergetic function of mitochondria may be used in therapy of many diseases.