Glucose oxidase

The glucose oxidase enzyme (GOx) (EC 1.1.3.4) binds to beta-D-glucose (an isomer of the six carbon sugar, glucose) and aids in breaking the sugar down into its metabolites. GOx is a dimeric protein which catalyzes the oxidation of beta-D-glucose into D-glucono-1,5-lactone which then hydrolyzes to gluconic acid.

In order to work as a catalyst, GOx requires a cofactor, flavin adenine dinucleotide (FAD). FAD is a common component in biological oxidation-reduction (redox reactions). Redox reactions involve a gain or loss of electrons from a molecule. In the GOx catalyzed redox reaction, FAD works as the initial electron acceptor and is reduced to FADH2. Then FADH2 is oxidized by the final electron acceptor, molecular oxygen (O2) which can do so because it has a higher reduction potential. O2 (oxygen gas) is then reduced to hydrogen peroxide (H2O2).

The glucose oxidase enzyme is commonly used in biosensors to detect levels of glucose by keeping track of the number of electrons passed through the enzyme by connecting it to an electrode and measuring the resulting charge. This has a possible application in the world of nanotechnology when used in conjuntion with tiny electrodes as glucose sensors for diabetics.

External links

• To learn more about the glucose oxidase enzyme, click here.
• To learn more about biosensors, click here.