CAO enzymes

Copper amine oxidase (CAO) enzymes carry out the aerobic oxidation of primary amines to aldehydes (Scheme 14.8a). While copper is present in the active site, substrate oxidation proceeds by an organocatalytic pathway involving an o-quinone cofactor via a transamination mechanism (Scheme 14.8b). 

For some recent reviews, see Pfenosil, J.E., Kut, O.M., Dunn, I.J. and Heinzle, E., Immobilized biocatalysts. In Ullman s Biotechnology and Biochemical Engineering, vol. 2. Wiley-VCH, Weinheim, 2007, pp. 683-734 Sheldon, R. A., Enzyme immobilization the quest for optimum performance. Adv. Synth. Catal., 2007, 349, 1289-1307 End, N. and Schoning, K.-U., Immobilized biocatalysts in industrial research and production. Topics Curr. Chem., 2004, 242, 273-317 Bornscheuer, U.T., Immobilizing enz3mies how to create more suitable biocatalysts. Angew. Chem. Int. Ed., 2003,42, 3336-3337 Cao, L. Immobilised enzymes science or art Curr. Opin. Chem. Biol., 2005, 9, 217-226. 

Cao, F. (2005) Carrier-Bound Immobilized Enzymes, Principles, Applications and Design, Wiley-VCH, Weinheim. 

A specific enzyme acts as catalyst in the fermentation of reactant A. At a given enzyme concentration in the aqueous feed stream (25 liter/min) find the volume of plug flow reactor needed for 95% conversion of reactant A (Cao = 2 mol/liter). The kinetics of the fermentation at this enzyme concentration is given by... 

We wish to treat 0.1 mVmin of this waste water having Cao = 10 mmol/m to 90% conversion with this enzyme at concentration Cg. 

Cao L (2005) Immobihsed enzymes Science or art Curr Opin Chem Biol 9(2) 217-226... 

Cao, L., van Rantwijk, F. and Sheldon, R.A. (2000) Cross-linked enzyme aggregates a simple and effective method for the immobilization of penicillin acylase. Org. Lett., 2, 1361. 

Dooley et al. first proposed an inner-sphere electron transfer mechanism where O2 binds directly to copper(I) 55 this was based upon precedence that suggested very rapid reactions between O2 and synthetic copper(I) compounds used as spectroscopic models for enzyme active sites. A three-coordinate copper(I) geometry in the CAOs had been demonstrated upon reduction with dithionite under anaerobic conditions.56 The reduction of the enzyme anaerobically with primary amine substrates actually produces two states, a copper(I)/semiquinone and a copper (II)/aminoquinol (Figure 9.11). In plant-derived and bacterial CAOs, these states have been demonstrated to exist in rapid equilibrium, due to intraprotein electron... 

Cao L, van Langen L, Sheldon RA (2003) Immobilised enzymes carrier-bound or carrier-free Curr Opin Biotechnol 14 387-394... 

Zhang XY, Tan YL, Cao LY, Wu GY, Xu Q, et al. 2006. Antioxidant enzymes and lipid peroxidation in different forms of schizophrenia treated with typical and atypical antipsychotics. Schizophr Res 81 291-300. 

Cao, H and Preiss, J. 1996. Evidence for essential arginine residues at tre active site of maize branching enzymes. J. Protein Chem. 15, 291-304. 

Li HA, Cao ZJ, Zhang YH, Lau CW, Lu JZ (2010) Combination of quantum dot fluorescence with enzyme chemiluminescence for multiplexed detection of lung cancer biomarkers. Anal Meth 2 1236-1242... 

Cao, L., Van Langen, L., and Sheldon, R. 2003. Immobilised enzymes Carrier bound or carrier-free Current Opinion in Biotechnology, 14 387-94. 

Yan, Y., U.T. Bornscheuer, L. Cao, and R.D. Schmid, Lipase-Catalyzed Solid-Phase Synthesis of Sugar Fatty Acid Esters. Removal of By-Products by Azeotropic Distillation, Enzyme Microb. Technol. 25 725-728 (1999). 

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