Cofactor, topaquinone (2,4,5-trihydroxyphenylalanine), is a modified residue, generated from active site tyrosine residue (Tyr466) by self-catalysis (see [6]). Although this enzyme binds a copper ion and two calcium ions as cofactors per subunit, the calcium ions are not involved in catalysis. The following compounds can be inculded as substrate and product, respectively: Phenethylamine;C05332 Phenylacetaldehyde;C00601 According to the literature [13], this enzyme catalyzes two half-reactions: (I) reductive half-reaction, and (II) oxidative half-reaction. These half-reactions can be subdivided into several basic reactions in terms of RLCP classification. (I) Reductive half-reaction: (A) Exchange of double-bonded atoms; Schiff-base formation; Substrate amine forms a Schiff-base with topaquinone, generating iminoquinone=substrate and H2O (dehydration): (B) Isomerization from iminoquinone=substrate complex to aminoquinol=product complex: (C) Exchange of double-bonded atoms; Schiff-base deformation; H2O reacts with the intermediate, generating aminoquinol and product aldehyde (hydration): (II) Oxidative half-reaction: (D) Reduction of dioxygen (O2) by aminoquinol, to produce hydrogen peroxide (H2O2) and iminoquinone (Hydride transfer): (E) Exchange of double-bonded atoms; Schiff-base deformation; H2O reacts with the intermediate, generating topaquinone and product ammonia (hydration):
amine oxidase (pyridoxal containing) (incorrect)
semicarbazide-sensitive amine oxidase (ambiguous)
Glycine, serine and threonine metabolism
Substrate Schiff-base (Iminoquinone=substrate)
Product Schiff-base (Aminoquinol=product)
TYT 466(iminoquinone-substrate analogue)
PAQ 466(2-oxy-4-hydroxy-5-(2-hydrazinopyridine)phenylalanine)
Models and molecular orbital semiempirical calculations in the study of the spectroscopic properties of bovine serum amine oxidase quinone cofactor.
Crystallization and preliminary X-ray analysis of copper amine oxidase from Escherichia coli K-12.
Identification of topaquinone, as illustrated for pig kidney diamine oxidase and Escherichia coli amine oxidase.
Characterization of the topa quinone cofactor in amine oxidase from Escherichia coli by resonance Raman spectroscopy.
Catalytic aerobic deamination of activated primary amines by a model for the quinone cofactor of mammalian copper amine oxidases.
Copper amine oxidase: a novel use for a tyrosine.
Crystal structure of a quinoenzyme: copper amine oxidase of Escherichia coli at 2 A resolution.
The copper-topaquinone-phenylhydrazine-adduct geometry in Escherichia coli amine oxidase derivatized with phenylhydrazines substituted with 19F-NMR relaxation measurements.
Intermediates in the catalytic cycle of copper-quinoprotein amine oxidase from Escherichia coli.
Catalytic mechanism of the quinoenzyme amine oxidase from Escherichia coli: exploring the reductive half-reaction.
The active site base controls cofactor reactivity in Escherichia coli amine oxidase: x-ray crystallographic studies with mutational variants.
Visualization of dioxygen bound to copper during enzyme catalysis.
Trihydroxyphenylalanine quinone (TPQ) from copper amine oxidases and lysyl tyrosylquinone (LTQ) from lysyl oxidase.
Conserved tyrosine-369 in the active site of Escherichia coli copper amine oxidase is not essential.
Copper amine oxidase: cunning cofactor and controversial copper.
Irreversible inhibition of pig kidney copper-containing amine oxidase by sodium and lithium ions.
Probing the catalytic mechanism of Escherichia coli amine oxidase using mutational variants and a reversible inhibitor as a substrate analogue.
Rates of oxygen and hydrogen exchange as indicators of TPQ cofactor orientation in amine oxidases.
Towards the development of selective amine oxidase inhibitors. Mechanism-based inhibition of six copper containing amine oxidases.
Defining redox state of X-ray crystal structures by single-crystal ultraviolet-visible microspectrophotometry.
Oxygen activation in a copper-containing amine oxidase.
Copper-containing amine oxidases. Biogenesis and catalysis; a structural perspective.
Medical implications from the crystal structure of a copper-containing amine oxidase complexed with the antidepressant drug tranylcypromine.
Exploring the binding mode of semicarbazide-sensitive amine oxidase/VAP-1: identification of novel substrates with insulin-like activity.