EC Number   |
pH Minimum |
pH Maximum |
Reference |
|---|
   1.1.3.10 | -999 |
- |
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 |
724369 |
| 1.1.3.10 | 5 |
9 |
- |
389646 |
| 1.1.3.10 | 5 |
9 |
at pH 5.0 in citrate buffer and pH 9.0 in glycine-NaOH buffer, the enzyme displays about 60% of its maximum activity. The activity begins to decline dramatically below pH 5.0 and above pH 9.0 |
741354 |
| 1.1.3.10 | 5 |
10 |
activity range |
724369 |
| 1.1.3.10 | 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 |
695870 |
| 1.1.3.10 | 5.5 |
11 |
pH 5.5: about 40% of maximal activity, pH 11: about 40% of maximal activity |
655049 |
| 1.1.3.10 | 6 |
8.5 |
- |
389638 |
| 1.1.3.10 | 6.5 |
8 |
at pH 8.0, the enzyme still retains 45% of its maximal activity observed at pH 6.5 |
741475 |
| 1.1.3.10 | 8 |
11 |
optimal buffer combination for the pyranose 2-oxidase systems determined |
686372 |
