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Hydrogen sulphide synthesis C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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Hydrogen sulfide is a gasotransmitter, with similarities to nitric oxide and carbon monoxide. Although the enzymes indicated below have multiple enzymatic activities, the focus here is the generation of hydrogen sulphide (H2S) and the enzymatic characteristics are described accordingly. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are pyridoxal phosphate (PLP)-dependent enzymes. 3-mercaptopyruvate sulfurtransferase (3-MPST) functions to generate H2S; only CAT is PLP-dependent, while 3-MPST is not. Thus, this third pathway is sometimes referred to as PLP-independent. CBS and CSE are predominantly cytosolic enzymes, while 3-MPST is found both in the cytosol and the mitochondria. For an authoritative review on the pharmacological modulation of H2S levels, see Szabo and Papapetropoulos, 2017 [7].


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CBS (Cystathionine β-synthase) C Show summary »

CSE (Cystathionine γ-lyase) C Show summary »

CAT (L-Cysteine:2-oxoglutarate aminotransferase) C Show summary »

MPST (3-Mercaptopyruvate sulfurtransferase) C Show summary »

Target Id 1446
Nomenclature 3-Mercaptopyruvate sulfurtransferase
Common abbreviation MPST
Previous and unofficial names human liver rhodanese | MST | TST2
Genes MPST (Hs), Mpst (Mm), Mpst (Rn)
Ensembl ID ENSG00000128309 (Hs), ENSMUSG00000071711 (Mm), ENSRNOG00000000185 (Rn)
UniProtKB AC P25325 (Hs), Q99J99 (Mm), P97532 (Rn)
EC number
Endogenous substrates
3-mercaptopyruvic acid pKm 2.9 [6]
pyruvic acid
I3MT-3 pIC50 5.6 [5]
Comment Pioglitazone and rosiglitazone inhibit bacterial 3-MST [3], but have not been shown to inhibit the mammalian orthologue.

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NC-IUPHAR subcommittee and family contributors

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How to cite this family page

Database page citation (select format):

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Fabbro D, Kelly E, Mathie AA, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Davies JA et al. (2023) The Concise Guide to PHARMACOLOGY 2023/24: Enzymes. Br J Pharmacol. 180 Suppl 2:S289-373.