SOD1 is an essential H2S detoxifying enzyme

Paradoxically, the primary route of H2S detoxification is thought to occur inside the mitochondrial matrix via a series of relatively slow enzymatic reactions that are unlikely to compete with its rapid inhibition of cytochrome c oxidase.

Therefore, alternative or complementary cellular mechanisms of H2S detoxification are predicted to exist.

Here, superoxide dismutase [Cu-Zn] (SOD1) is shown to be an efficient H2S oxidase that has an essential role in limiting cytotoxicity from endogenous and exogenous sulfide.

Decreased SOD1 expression resulted in increased sensitivity to H2S toxicity in yeast and human cells, while increased SOD1 expression enhanced tolerance to H2S."

About SOD1

The protein (both wild-type and ALS1 variants) has a tendency to form fibrillar aggregates in the absence of the intramolecular disulfide bond or of bound zinc ions. These aggregates may have cytotoxic effects. Zinc binding promotes dimerization and stabilizes the native form. (R2)