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1.1.3.10: pyranose oxidase

This is an abbreviated version!
For detailed information about pyranose oxidase, go to the full flat file.

Word Map on EC 1.1.3.10

Reaction

D-glucose
+
O2
=
2-dehydro-D-glucose
+
H2O2

Synonyms

C-2 specific pyranose-2-oxidase, carbohydrate oxidase, glucose 2-oxidase, glucose-2-oxidase, P2O, P2Ox, POX, PROD, PyOx, pyranose 2-Oxidase, pyranose oxidase, pyranose-2-oxidase, pyranose/oxygen 2-oxidoreductase, pyranose: oxygen 2-oxidoreductase, pyranose:oxygen 2-oxidoreductase, pyranose:oxygen-2-oxidoreductase, TmP2Ox

ECTree

     1 Oxidoreductases
         1.1 Acting on the CH-OH group of donors
             1.1.3 With oxygen as acceptor
                1.1.3.10 pyranose oxidase

pH Range

pH Range on EC 1.1.3.10 - pyranose oxidase

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pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
5 - 10
-
activity range
5 - 9
5.5 - 11
-
pH 5.5: about 40% of maximal activity, pH 11: about 40% of maximal activity
5.5 - 8.5
-
substrate D-glucose, measuring oxygen consumption (computer-interfaced Oxy-32 oxygen-monitoring system), 30°C, varying concentrations of both D-glucose and oxygen. Ping-pong kinetic mechanism at pH values below 7.0 and an ordered mechanism at pH above 7.0
6.5 - 8
-
at pH 8.0, the enzyme still retains 45% of its maximal activity observed at pH 6.5
8 - 11
optimal buffer combination for the pyranose 2-oxidase systems determined
additional information
-
flavin oxidation occurs via different pathways depending on the pH of the environment. At pH values lower than 8.0, the reduced enzyme reacts with O2 to form a C4a-hydroperoxyflavin intermediate, leading to elimination of H2O2. At pH 8.0 and higher, the majority of the reduced enzyme reacts with O2 via a pathway that does not allow detection of the C4a-hydroperoxyflavin, and flavin oxidation occurs with decreased rate constants upon the rise in pH. The switching between the two modes of enzyme oxidation is controlled by protonation of a group which has a pKa of 7.6, stopped-flow spectrophotometry, overview. The protonation of the group which controls the mode of flavin oxidation cannot be rapidly equilibrated with outside solvent. Using a double-mixing stopped-flow experiment, a rate constant for proton dissociation from the reaction site is determined to be 21.0 s-1