The multi-functional topa-quinone copper amine oxidases.
The mature copper amine oxidases (CAOs) contain a tyrosine-derived 2,4,5-trihydroxyphenylalanyl quinone (topa quinone or TPQ) and a cupric ion in close proximity. Through a combination of structural, spectroscopic and kinetic analyses, a chemical mechanism for the self-processing of an active site tyrosine to TPQ has been proposed. Once formed, TPQ acts as a switch between the heterolytic transformation of amine substrates to aldehydes, via a pyridoxal phosphate-like Schiff base complex, and one electron chemistry involving reduction of molecular oxygen. The relationship between the biogenetic and catalytic processes is discussed.
Klinman
Judith P
JP
Department of Chemistry, University of California, Berkeley, CA 94720, USA. klinman@socrates.berkeley.edu
D006631:Amine Oxidase (Copper-Containing) / Q000502:physiology*; D002384:Catalysis; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives* / Q000378:metabolism*
D004295:Dihydroxyphenylalanine; C067626:6-hydroxydopa quinone; D006631:Amine Oxidase (Copper-Containing)