InterPro domain: IPR039798

This entry contains sulfhydryl oxidases that are flavin-dependent [ 1 ]. Sulfhydryl oxidase 1 (QSOX1 or quiescin Q6) oxidizes sulfhydryl groups in peptide and protein thiols to disulfides with the reduction of oxygen to hydrogen peroxide, permitting disulfide bond formation. QSOX1 is predominantly found in the Golgi [ 2 ]. Sulfhydryl oxidase 2 (QSOX2) is predominantly located in the plasma and in the nuclear membrane and regulates the sensitization of neuroblastoma cells for interferon-gamma-induced apoptosis [ 3 ].

1. Homology between egg white sulfhydryl oxidase and quiescin Q6 defines a new class of flavin-linked sulfhydryl oxidases. J. Biol. Chem. 274, 31759-62
2. Intracellular catalysis of disulfide bond formation by the human sulfhydryl oxidase, QSOX1. Biochem. J. 404, 403-11
3. Neuroblastoma-derived sulfhydryl oxidase, a new member of the sulfhydryl oxidase/Quiescin6 family, regulates sensitization to interferon gamma-induced cell death in human neuroblastoma cells. Cancer Res. 63, 7742-52