:O-aminophenol oxidase

{{DISPLAYTITLE:o-aminophenol oxidase}}

{{Infobox enzyme

| Name = o-Aminophenol oxidase

| EC_number = 1.10.3.4

| CAS_number = 9013-85-8

| GO_code =

| image =

| width =

| caption =

}}

o-Aminophenol oxidase ({{EC number|1.10.3.4}}, isophenoxazine synthase, o-aminophenol:O₂ oxidoreductase, 2-aminophenol:O₂ oxidoreductase, GriF) is an enzyme with systematic name 2-aminophenol:oxygen oxidoreductase.{{cite journal | vauthors = Nair PM, Vaidyanathan CS | title = Isophenoxazine synthase | journal = Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects | volume = 81 | pages = 507–16 | date = March 1964 | issue = 3 | pmid = 14170322 | doi = 10.1016/0926-6569(64)90135-x }}{{cite journal | vauthors = Nair PM, Vining LC | title = Isophenoxazine synthase apoenzyme from Pycnoporus coccineus | journal = Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation | volume = 96 | pages = 318–27 | date = February 1965 | issue = 2 | pmid = 14298835 | doi = 10.1016/0926-6593(65)90015-9 }}{{cite journal | vauthors = Subba Rao PV, Vaidyanathan CS | title = Studies on the metabolism of o-aminophenol. Purification and properties of isophenoxazine synthase from Bauhenia monandra | journal = Archives of Biochemistry and Biophysics | volume = 118 | issue = 2 | pages = 388–94 | date = February 1967 | pmid = 4166439 | doi = 10.1016/0003-9861(67)90365-7 }}{{cite journal | vauthors = Suzuki H, Furusho Y, Higashi T, Ohnishi Y, Horinouchi S | title = A novel o-aminophenol oxidase responsible for formation of the phenoxazinone chromophore of grixazone | journal = The Journal of Biological Chemistry | volume = 281 | issue = 2 | pages = 824–33 | date = January 2006 | pmid = 16282322 | doi = 10.1074/jbc.M505806200 | doi-access = free }} This enzyme catalyses the following chemical reaction

: 2 o-aminophenol + O₂ + acceptor {{eqm}} 2-aminophenoxazin-3-one + reduced acceptor + 2 H₂O (overall reaction)

: (1a) 2 2-aminophenol + O₂ {{eqm}} 2 6-iminocyclohexa-2,4-dienone + 2 H₂O

: (1b) 2 6-iminocyclohexa-2,4-dienone + acceptor {{eqm}} 2-aminophenoxazin-3-one + reduced acceptor (spontaneous)

o-Aminophenol oxidase is a flavoprotein.