Table 1.

Enzymes responsible for H₂S production in mammalian cells

Nomenclature (EC number)	Common Abbreviation	Endogenous substrates	Cofactors	Inhibitors
Cystathionine β‐synthase (4.2.1.22)	CBS	L‐cysteine l‐homocysteine	Pyridoxal phosphate	AOAA
Cystathionine γ‐lyase (4.4.1.1)	CSE	L‐cysteine	Pyridoxal phosphate	Aminoethoxyvinylglycine
				AOAA
				β‐cyano‐l‐alanine
				Propargylglycine
L‐cysteine : 2 oxoglutarate aminotransferase (4.4.1.13)	CAT	L‐cysteine	Pyridoxal Phosphate	Compound 3a
3‐mercaptopyruvate sulfurtransferase (2.8.1.2)	3‐MPST	3‐mercaptopyruvic acid	Zn2+	–

CAT and 3‐MPST function in combination to generate H₂S.

Adapted from (Alexander et al., 2015a).

CAT, Cysteine:2‐oxoglutarate aminotransferase.

^aToutle et al. 2013.