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Structural Snapshots from the Oxidative Half-reaction of a Copper Amine Oxidase: Implications for O2 Activation

Overview
Journal J Biol Chem
Specialty Biochemistry
Date 2013 Aug 14
PMID 23940035
Citations 9
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Abstract

The mechanism of molecular oxygen activation is the subject of controversy in the copper amine oxidase family. At their active sites, copper amine oxidases contain both a mononuclear copper ion and a protein-derived quinone cofactor. Proposals have been made for the activation of molecular oxygen via both a Cu(II)-aminoquinol catalytic intermediate and a Cu(I)-semiquinone intermediate. Using protein crystallographic freeze-trapping methods under low oxygen conditions combined with single-crystal microspectrophotometry, we have determined structures corresponding to the iminoquinone and semiquinone forms of the enzyme. Methylamine reduction at acidic or neutral pH has revealed protonated and deprotonated forms of the iminoquinone that are accompanied by a bound oxygen species that is likely hydrogen peroxide. However, methylamine reduction at pH 8.5 has revealed a copper-ligated cofactor proposed to be the semiquinone form. A copper-ligated orientation, be it the sole identity of the semiquinone or not, blocks the oxygen-binding site, suggesting that accessibility of Cu(I) may be the basis of partitioning O2 activation between the aminoquinol and Cu(I).

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References
1.
Drummond J, Matthews R . Nitrous oxide degradation by cobalamin-dependent methionine synthase: characterization of the reactants and products in the inactivation reaction. Biochemistry. 1994; 33(12):3732-41. DOI: 10.1021/bi00178a033. View

2.
Turowski P, McGuirl M, Dooley D . Intramolecular electron transfer rate between active-site copper and topa quinone in pea seedling amine oxidase. J Biol Chem. 1993; 268(24):17680-2. View

3.
Emsley P, Cowtan K . Coot: model-building tools for molecular graphics. Acta Crystallogr D Biol Crystallogr. 2004; 60(Pt 12 Pt 1):2126-32. DOI: 10.1107/S0907444904019158. View

4.
Kishishita S, Okajima T, Kim M, Yamaguchi H, Hirota S, Suzuki S . Role of copper ion in bacterial copper amine oxidase: spectroscopic and crystallographic studies of metal-substituted enzymes. J Am Chem Soc. 2003; 125(4):1041-55. DOI: 10.1021/ja017899k. View

5.
Medda R, Padiglia A, Bellelli A, Pedersen J, Agro A, Floris G . CuI-semiquinone radical species in plant copper-amine oxidases. FEBS Lett. 1999; 453(1-2):1-5. DOI: 10.1016/s0014-5793(99)00675-4. View