The mercaptopyruvate pathway in cysteine catabolism: a physiologic role and related disease of the multifunctional 3-mercaptopyruvate sulfurtransferase.

The conversion of cysteine to 3-sulfino-alanine is a major pathway in cysteine catabolism. Cysteine dioxygenase catalyzes the reaction and dietary intake of the essential amino acid methionine and the semi-essential amino acid cysteine increases the level of this enzyme by suppressing enzyme degradation via polyubiquitination. The production of cellular antioxidants such as glutathione, thioredoxin, and their families is important in cysteine metabolism, and these cellular antioxidants have critical roles in the maintenance of the cellular redox status.

The activation mechanism of human porphobilinogen synthase by 2-mercaptoethanol: intrasubunit transfer of a reserve zinc ion and coordination with three cysteines in the active center.

Human porphobilinogen synthase [EC.4.2.

Affinity labeling of a catalytic site, cysteine(247), in rat mercaptopyruvate sulfurtransferase by chloropyruvate as an analog of a substrate.

A bisubstrate enzyme, rat mercaptopyruvate sulfurtransferase (EC 2.8.1.

Do antidotes for acute cyanide poisoning act on mercaptopyruvate sulfurtransferase to facilitate detoxification?

A well-known combined therapy for acute cyanide poisoning is intravenous administration of sodium nitrite, sodium thiosulfate and cobalt EDTA. Sodium nitrite oxidizes oxy-hemoglobin, resulting in methemoglobin, which has a high affinity for cyanide. Sodium thiosulfate is a substrate of thiosulfate: cyanide sulfurtransferase (rhodanese, EC.