Effects of high hydrostatic pressure or hydrophobic modification on thermal stability of xanthine oxidase
| Autor: | Ali Halalipour, Michael R. Duff, Elizabeth E. Howell, José I. Reyes-De-Corcuera |
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| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Xanthine Oxidase Hydrostatic pressure Kinetics Inorganic chemistry Bioengineering Activation energy Biosensing Techniques 01 natural sciences Applied Microbiology and Biotechnology Biochemistry Benzoates 03 medical and health sciences chemistry.chemical_compound Aniline Reaction rate constant 010608 biotechnology Enzyme Stability Hydrostatic Pressure Animals Thermal stability Chromatography Aniline Compounds Atmospheric pressure Temperature 030104 developmental biology Monomer Milk chemistry Cattle Hydrophobic and Hydrophilic Interactions Food Analysis Biotechnology |
| Zdroj: | Enzyme and microbial technology. 103 |
| ISSN: | 1879-0909 |
| Popis: | The effect of high hydrostatic pressure (HHP) on the kinetics of thermal inactivation of xanthine oxidase (XOx) from bovine milk was studied. Inactivation of XOx followed pseudo-first-order kinetics at 0.1-300MPa and 55.0-70.0°C. High pressure up to at least 300MPa stabilized XOx at all the studied temperatures. The highest stabilization effect of HHP on XOx was at 200-300MPa at 55.0 and 58.6°C, and at 250-300MPa at 62.3-70.0°C. The stability of XOx increased 9.5 times at 300MPa and 70.0°C compared to atmospheric pressure at the same temperature. The activation energy of inactivation of XOx decreased with pressure and was 1.9 times less at 300MPa (97.0±8.2kJmol-1) than at 0.1MPa (181.7±12.1kJmol-1). High pressure decreased the dependence of the rate constant of inactivation to temperature effects compared to atmospheric pressure. The stabilizing effect of HHP on XOx was highest at 70.0°C where the activation volume of inactivation of XOx was 28.9±2.9cm3mol-1. A second approach to try to increase XOx stability involved hydrophobic modification using aniline or benzoate. However, the thermal stability of XOx remained unaffected after 8-14 modifications of carboxyl side groups per XOx monomer with aniline, or 12-17 modifications of amino side groups per XOx monomer with benzoate. |
| Databáze: | OpenAIRE |
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