Tryptophan 2,3-dioxygenase (EC 1.13.11.11; UniProt P48775; also known as TDO, TO, TRPO, Tryptamin 2,3-dioxygenase, Tryptophan oxygenase, Tryptophan pyrrolase, Tryptophanase) is encoded by the TDO2 (also known as TDO) gene (Gene ID 6999) in human. TDO2 is a cytosolic heme-containing enzyme that exists as a homotetramer, where the N terminal residues of each monomer form part of the substrate binding site in an adjacent monomer. Tryptophan 2,3-dioxygenase (TDO2) catalyzes the first step of the kynurenine pathway, namely the conversion of tryptophan to kynurenine (Kyn), which can also be catalyzed by indoleamine 2,3-dioxygenase 1 (IDO1) or IDO2. IDO1 is expressed in tissues throughout the body, while TDO2 is predominantly expressed in the liver. Altered tryptophan metabolism and increased secretion of tryptophan metabolites are found in solid tumors, including in breast cancer. TDO2-mediated Kyn production in triple-negative breast cancer (TNBC) cells is reported to activate aryl hydrocarbon receptor (AhR), an endogenous kynurenine receptor. Inhibiting TDO2 or AhR via pharmacologic or genetic means is reported to result in increased sensitivity to anoikis, as well as decreased proliferation, migration, and invasion of TNBC cells.
Synonyms: Tryptophan 2, 3-dioxygenase, TDO, TO, TRPO, Tryptamin 2, 3-dioxygenase, Tryptophan oxygenase, Tryptophan pyrrolase, Tryptophanase
Application: Immunohistochemistry Analysis: A 1:50 dilution from a representative lot detected TDO2 in human kidney, liver, and small intestine tissue sections.
Other Notes: Concentration: Please refer to lot specific datasheet.