The effect of oxygen upon the kinetics of glucose oxidase inactivation

Authors

  • Ramakrishnan Venugopal,

    1. Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S lA4
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  • Bradley A. Saviue

    Corresponding author
    1. Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S lA4
    • Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada M5S lA4
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Abstract

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-1under 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 104 to 5.7 X 104when the oxygen partial pressure increased from 10 to 101 kPa, suggesting that enzyme utilization was most efficient at low oxygen partial pressures (<15 kPa).

Abstract

On a étudié l'effet de l'oxygène sur la vitesse d'inactivation de l'oxydase de glucose. Des essais ont été menés sur la stabilité des enzymes durant le cycle catalytique pour une game de pressions partielles de l'oxygène. Au moyen d'un essai d'activité standard, on a surveillé les changements survenant dans l'activité de l'oxydase glucose.

L'étude révèle que l'oxygène influence l'inactivation de l'oxydase glucose. Les vitesses d'inactivation durant le cycle catalytique varient entre 0,01143 +/- 0,0016 h-1 à une pression d'oxygtne de 10 kPa et 0,04879 +/- 0,0023 h-1 à une pression d'oxygèe de 101 kPa. Des vitesses d'inactivation statistiquement différentes ont été obtenues à des pressions d'oxygéne partielles de 10, 15, 21, 51 et 76 kPa. Le nombre de cycles enzymatiques diminue de 11,0 X 104 à 5,7 x 104 lorsque la pression d'oxygéne partielle augmente de 10 à 101 kPa, ce qui laisse croire que l'utilisation des enzymes a été plus efficace à de faibles pressions d'oxygène partielles (<15 kPa).

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