Tryptophan 2'-dioxygenase

In enzymology, a tryptophan 2'-dioxygenase (EC 1.13.99.3) is an enzyme that catalyzes the chemical reaction

L-tryptophan + O
₂ + H⁺
${\displaystyle \rightleftharpoons }$ (indol-3-yl)glycolaldehyde + CO
₂ + NH⁺
₄

Thus, the 3 substrates of this enzyme are L-tryptophan, O
₂ and <span class="chemf nowrap">H<span style="display:inline-block;margin-bottom:-0.3em;vertical-align:0.8em;line-height:1em;font-size:80%;text-align:left"><sup style="font-size:inherit;line-height:inherit;vertical-align:baseline">+</sup><br/><sub style="font-size:inherit;line-height:inherit;vertical-align:baseline"></sub></span></span>, whereas its 3 products are (indol-3-yl)glycolaldehyde, CO
₂, and NH⁺
₄.

Classification

This enzyme belongs to the family of oxidoreductases, specifically those acting on single donors with O₂ as oxidant and incorporation of two atoms of oxygen into the substrate (oxygenases). The oxygen incorporated need not be derived from O miscellaneous.

Nomenclature

The systematic name of this enzyme class is L-tryptophan:oxygen 2'-oxidoreductase (side-chain-cleaving). Other names in common use include indole-3-alkane alpha-hydroxylase, tryptophan side-chain alpha,beta-oxidase, tryptophan side chain oxidase II, tryptophan side-chain oxidase, TSO, indolyl-3-alkan alpha-hydroxylase, tryptophan side chain oxidase type I, TSO I, TSO II, and tryptophan side chain oxidase.

Biological role

This enzyme participates in tryptophan metabolism. It employs one cofactor, heme.

References

• Roberts J, Rosenfeld HJ (1977). "Isolation, crystallization, and properties of indolyl-3-alkane alpha-hydroxylase. A novel tryptophan-metabolizing enzyme". J. Biol. Chem. 252 (8): 2640–7. PMID 15994.
• Takai K, Ushiro H, Noda Y, Narumiya S, Tokuyama T (1977). "Crystalline hemoprotein from Pseudomonas that catalyzes oxidation of side chain of tryptophan and other indole derivatives". J. Biol. Chem. 252 (8): 2648–56. PMID 15995.

This page was last edited on 26 August 2023, at 16:09