The effect of oxygen upon the kinetics of glucose oxidase inactivation

The effect of oxygen upon the inactivation rate of glucose oxidase was studied. Tests on enzyme stability during catalytic turnover were conducted under a range of oxygen partial pressures. A standard activity assay was used to monitor changes in glucose oxidase activity. Studies revealed that oxygen influenced the inactivation of glucose oxidase. Inactivation rates during catalytic turnover ranged between 0.01143 +/‐ 0.0016 h ‐1 under 10 kPa oxygen to 0.04879 +/‐ 0.0023 h ‐1 under 101 kPa oxygen. Statistically different inactivation rates were obtained at oxygen partial pressures of 10,15, 21, 51, and 76 kPa. The enzymatic turnover number decreased from 11.0 X 10 4 to 5.7 X 10 4 when the oxygen partial pressure increased from 10 to 101 kPa, suggesting that enzyme utilization was most efficient at low oxygen partial pressures (<15 kPa).