Impact of Hydrogen Sulfide on Mitochondrial and Bacterial Bioenergetics
This review focuses on the effects of hydrogen sulfide (H<sub>2</sub>S) on the unique bioenergetic molecular machines in mitochondria and bacteria—the protein complexes of electron transport chains and associated enzymes. H<sub>2</sub>S, along with nitric oxide and carbon mon...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/22/23/12688 |
| Summary: | This review focuses on the effects of hydrogen sulfide (H<sub>2</sub>S) on the unique bioenergetic molecular machines in mitochondria and bacteria—the protein complexes of electron transport chains and associated enzymes. H<sub>2</sub>S, along with nitric oxide and carbon monoxide, belongs to the class of endogenous gaseous signaling molecules. This compound plays critical roles in physiology and pathophysiology. Enzymes implicated in H<sub>2</sub>S metabolism and physiological actions are promising targets for novel pharmaceutical agents. The biological effects of H<sub>2</sub>S are biphasic, changing from cytoprotection to cytotoxicity through increasing the compound concentration. In mammals, H<sub>2</sub>S enhances the activity of F<sub>o</sub>F<sub>1</sub>-ATP (adenosine triphosphate) synthase and lactate dehydrogenase via their <i>S</i>-sulfhydration, thereby stimulating mitochondrial electron transport. H<sub>2</sub>S serves as an electron donor for the mitochondrial respiratory chain via sulfide quinone oxidoreductase and cytochrome <i>c</i> oxidase at low H<sub>2</sub>S levels. The latter enzyme is inhibited by high H<sub>2</sub>S concentrations, resulting in the reversible inhibition of electron transport and ATP production in mitochondria. In the branched respiratory chain of <i>Escherichia coli</i>, H<sub>2</sub>S inhibits the <i>bo</i><sub>3</sub> terminal oxidase but does not affect the alternative <i>bd</i>-type oxidases. Thus, in <i>E. coli</i> and presumably other bacteria, cytochrome <i>bd</i> permits respiration and cell growth in H<sub>2</sub>S-rich environments. A complete picture of the impact of H<sub>2</sub>S on bioenergetics is lacking, but this field is fast-moving, and active ongoing research on this topic will likely shed light on additional, yet unknown biological effects. |
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| ISSN: | 1661-6596 1422-0067 |