Figure 3
From: Emergent role of gasotransmitters in ischemia-reperfusion injury
Enzymatic Synthesis of Hydrogen Sulfide. There are three enzymatic pathways involved in the synthesis of hydrogen sulfide (H2S) in mammalian systems. Cystathionine β-synthase (CBS) produces H2S through a reaction involving the generation of cystathionine from homocysteine and L-cysteine from cystathione. Cystathionine γ-lyase (CGL or CSE) produces H2S through a reaction involving the generation of L-cysteine from cystathionine. 3-mercaptopyruvate sulfur transferase (3MST) produces H2S through a reaction involving the generation of 3-mercaptopyruvate (3MP) from α-ketoglutarate (α-KG) by cysteine aminotransferase (CAT).