Eurythermalism and the temperature dependence of enzyme activity
| Autor: | Robert Eisenthal, S. Craig Cary, David J. Saul, Michael J. Danson, Charis Shepherd, Roy M. Daniel, Michelle E. Peterson, Charles Kai-Wu Lee |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Acclimatization
Enthalpy Thermodynamics Models Biological Biochemistry Evolution Molecular 03 medical and health sciences Enzyme activator Protein stability Genetics Statistical analysis Thermus Molecular Biology 030304 developmental biology chemistry.chemical_classification 0303 health sciences Bacteria biology Thermophile 030302 biochemistry & molecular biology Temperature Psychrobacter Enzyme assay Enzymes Enzyme Activation Quantitative measure Enzyme chemistry biology.protein Biotechnology |
| Zdroj: | The FASEB Journal. 21:1934-1941 |
| ISSN: | 1530-6860 0892-6638 |
| Popis: | The "Equilibrium Model" has provided new tools for describing and investigating enzyme thermal adaptation. It has been shown that the effect of temperature on enzyme activity is not only governed by deltaG(double dagger)(cat) and deltaG(double dagger)(inact) but also by two new intrinsic parameters, deltaH(eq) and T(eq), which describe the enthalpy and midpoint, respectively, of a reversible equilibrium between active and inactive (but not denatured) forms of enzyme. Twenty-one enzymes from organisms with a wide range of growth temperatures were characterized using the Equilibrium Model. Statistical analysis indicates that T(eq) is a better predictor of growth temperature than enzyme stability (deltaG(double dagger)(inact)). As expected from the Equilibrium Model, deltaH(eq) correlates with catalytic temperature tolerance of enzymes and thus can be declared the first intrinsic and quantitative measure of enzyme eurythermalism. Other findings shed light on the evolution of psychrophilic and thermophilic enzymes. The findings suggest that the description of the Equilibrium Model of the effect of temperature on enzyme activity applies to all enzymes regardless of their temperature origins and that its associated parameters, deltaH(eq) and T(eq), are intrinsic and necessary parameters for characterizing the thermal properties of enzymes and their temperature adaptation and evolution. |
| Databáze: | OpenAIRE |
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