MPST transfers sulfur atom from 3MPYR to form CysS248-MPST

Stable Identifier
Reaction [transition]
Homo sapiens
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Hydrogen polysulfides (H2Sn, where n>=2) are also endogenously produced by 3-mercaptopyruvate sulfurtransferase (MPST aka 3MST) directly from 3-mercaptopyruvate (3MPYR) generated by cysteine (aspartate) aminotransferase (GOT2) (Kimura et al. 2013, Kimura et al. 2015, Koike et al. 2017). Where n=2, the H2S2 species is called hydrogen persulfide (aka disulfane). MPST can release either H2S or H2Sn depending on the interaction with thioredoxin. When there is strong interaction with thioredoxin, H2S is released. 3MST receives sulfur from 3MPYR to persulfurate (oxidise) cysteine-248 residue of its reaction centre.

H2S2 is the dominant form produced with H2S3 detected at lower concentrations in cells or tissues. Up to H2S35 may exist (Steudel 2003), but under physiological conditions, when n reaches 8, it forms a crown shape and precipitates. H2Sn activate transient receptor potential ankyrin 1 (TRPA1) channels (Kimura et al. 2013), facilitate translocation of nuclear factor like-2 (NRF2) to the nucleus by modifying its binding partner kelch-like ECH-associated protein 1 (KEAP1) (Koike et al. 2013), regulates the activity of the tumor suppressor phosphatase and tensin homolog (PTEN) (Greiner et al. 2013), and reduces blood pressure by activating protein kinase G1a (Stubbert et al. 2014). Another persulfurated molecule, cysteine persulfide, which may be involved in the regulation of cellular redox homeostasis, is also produced by MPST (Kimura et al. 2017).

Literature References
PubMed ID Title Journal Year
26437775 Identification of H2S3 and H2S produced by 3-mercaptopyruvate sulfurtransferase in the brain

Toyofuku, Y, Koike, S, Kimura, Y, Ogasawara, Y, Shibuya, N, Kimura, H, Nagahara, N, Lefer, D

Sci Rep 2015
23413359 Polysulfides are possible H2S-derived signaling molecules in rat brain

Tsugane, M, Kimura, Y, Oka, J, Mikami, Y, Kimura, H, Osumi, K

FASEB J. 2013
27484215 Hydrogen polysulfide (H2S n ) signaling along with hydrogen sulfide (H2S) and nitric oxide (NO)

Kimura, H

J Neural Transm (Vienna) 2016
29055825 Analysis of endogenous H2S and H2Sn in mouse brain by high-performance liquid chromatography with fluorescence and tandem mass spectrometric detection

Kimura, Y, Kawamura, K, Koike, S, Ogasawara, Y, Shibuya, N, Kimura, H

Free Radic. Biol. Med. 2017
Catalyst Activity

3-mercaptopyruvate sulfurtransferase activity of MPST [mitochondrial matrix]

Orthologous Events
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