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Gewählte Doctoral Thesis:

Dagmar Brugger (2015): Engineering pyranose 2-oxidase for applications in biosensors and bio-fuelcells through modified oxygen reactivity.
Doctoral Thesis - Institut für Lebensmitteltechnologie, BOKU-Universität für Bodenkultur, pp XIV / 154 S.. UB BOKU obvsg

Data Source: ZID Abstracts
The flavoprotein pyranose 2-oxidase (POx) attracts interest as potential component in biosensors/biofuel cells. The homotetrameric protein is involved in the ligninolytic system. POx catalyzes the regioselective oxidation of aldopyranoses, preferentially D-glucose, at C-2 using molecular oxygen, benzoquinone, radicals or chelated metal ions as electron acceptors. Reduced oxygen reactivity is a desirable property for applications in biosensors/biofuel cells because of more effective electron transfer and reduced H2O2 production resulting in reduced oxidative damage to the biocomponent and the surrounding environment. In this study we aimed to identify amino acid residues of POx involved in oxygen reactivity. A semi-rational protein engineering approach was applied: eleven amino acids around the active site were chosen as target positions for site-saturation mutagenesis. Using a screening assay in 96-well plates five variants with decreased oxidase activity and maintained dehydrogenase activity were identified. To investigate the applicability to biosensors/biofuel cells POx variants were immobilized onto screen-printed carbon electrodes modified with gold nanoparticles and apparent kinetic constants were determined electrochemically employing 1,4-benzoquinone as electron mediator.

Betreuer: Haltrich Dietmar
1. Berater: Oostenbrink Chris
2. Berater: Peterbauer Clemens Karl

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