Biotechnology and Bioengineering · 2003 · 17 citations · 14 references
Life SciencesBiochemistryMolecular BiologyEnzyme MechanismEnzymologyProtein FoldingEnzyme KineticsFolding KineticsProtein DynamicsProtein Folding DynamicsProtein Folding PathwaysProtein StructureAggregationConcentrationEnzyme Deactivation MechanismsFirst-order ReactionKinetic Folding PathwaysOverall Reaction OrderProtein Aggregation KineticsProtein Folding Of Enzymes
Cutinase in aqueous solution at pH 4.5 deactivates following a parallel pathway. At 53 degrees C, 88% of the cutinase molecules are in the unfolded conformation, which can aggregate with a reaction order of 3 if the protein concentration is high (>/=12 microM). The aggregates show a sixfold increase in size as determined by dynamic light scattering. This aggregation process is the first phase observed during a deactivation experiment; however, after significant cutinase depletion and maturation of the aggregates, a first-order step starts to dominate and a second phase independent of the protein concentration is observed. Kinetic partitioning between aggregation and first-order irreversible changes of the unfolded conformation can occur during enzyme deactivation when the equilibrium between the native and the unfolded conformation is shifted and kept toward the unfolded conformation.
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The Mechanism of Irreversible Enzyme Inactivation at 100°C
Tim J. Ahern, Alexander M. Klibanov · Science · 1985 · 446 citations