What is "sulfiredoxin"

n. (context biochemistry English) An oxidoreductase enzyme involved in antioxidant metabolism.

In enzymology, a sulfiredoxin is an enzyme that catalyzes the chemical reaction

peroxiredoxin-(S-hydroxy-S-oxocysteine) + ATP + 2 R-SH $\rightleftharpoons$ peroxiredoxin-(S-hydroxycysteine) + ADP + phosphate + R-S-S-R

The 3 substrates of this enzyme are peroxiredoxin-(S-hydroxy-S-oxocysteine), ATP, and a thiol, whereas its 4 products are peroxiredoxin-(S-hydroxycysteine), ADP, phosphate, and a disulfide.

This enzyme is involved in antioxidant metabolism by re-activating peroxiredoxins, which are a group of peroxidases, when these enzymes are inhibited by over-oxidation.

This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with other, known, acceptors. The systematic name of this enzyme class is peroxiredoxin-(S-hydroxy-S-oxocysteine):thiol oxidoreductase [ATP-hydrolysing; peroxiredoxin-(S-hydroxycysteine)-forming]. Other names in common use include Srx1, sulphiredoxin, and peroxiredoxin-(S-hydroxy-S-oxocysteine) reductase.