EC Explorer

1.14.14.45

aromatic aldoxime N-monooxygenase

(1) (E)-indol-3-ylacetaldehyde oxime + [reduced NADPH—hemoprotein reductase] + glutathione + O₂ = S-[(E)-N-hydroxy(indol-3-yl)acetimidoyl]-L-glutathione + [oxidized NADPH—hemoprotein reductase] + 2 H₂O (overall reaction);;(1a) (E)-indol-3-ylacetaldehyde oxime + [reduced NADPH—hemoprotein reductase] + O₂ = 1-(1H-indol-3-yl)-2-aci-nitroethane + [oxidized NADPH—hemoprotein reductase] + H₂O;;(1b) 1-(1H-indol-3-yl)-2-aci-nitroethane + glutathione = S-[(E)-N-hydroxy(indol-3-yl)acetimidoyl]-L-glutathione + H₂O (spontaneous);;(2) (E)-phenylacetaldehyde oxime + [reduced NADPH—hemoprotein reductase] + glutathione + O₂ = S-[(Z)-N-hydroxy(phenyl)acetimidoyl]-L-glutathione + [oxidized NADPH—hemoprotein reductase] + 2 H₂O (overall reaction);;(2a) (E)-phenylacetaldehyde oxime + [reduced NADPH—hemoprotein reductase] + O₂ = 1-aci-nitro-2-phenylethane + [oxidized NADPH—hemoprotein reductase] + H₂O;;(2b) 1-aci-nitro-2-phenylethane + glutathione = S-[(Z)-N-hydroxy(phenyl)acetimidoyl]-L-glutathione + H₂O (spontaneous);;

CYP83B1 (gene name)

(E)-indol-3-ylacetaldoxime,[reduced NADPH—hemoprotein reductase],glutathione:oxygen oxidoreductase (oxime-hydroxylating)

This cytochrome P-450 (heme thiolate) enzyme is involved in the biosynthesis of glucosinolates in plants. The enzyme catalyses the N-hydroxylation of aromatic aldoximes derived from L-tryptophan, L-phenylalanine, and L-tyrosine, forming an aci-nitro intermediate that reacts non-enzymically with glutathione to produce an N-alkyl-thiohydroximate adduct, the committed precursor of glucosinolates. In the absence of glutathione, the enzyme is suicidal, probably due to interaction of the reactive aci-nitro compound with catalytic residues in the active site.

created 2017