Related Experiment Video
Updated: Aug 2, 2026

Steady-state, Pre-steady-state, and Single-turnover Kinetic Measurement for DNA Glycosylase Activity
Published on: August 19, 2013
Analysis of progress curves for enzyme-catalyzed reactions: application to unstable enzymes, coupled reactions and
1Department of Biochemistry, University of Queensland, Brisbane, Australia.
Abstract:
There are several advantages to the use of progress curves to analyze the the kinetic properties of enzymes but most studies still rely on rate measurements. One of the reasons for this may be that progress curve analysis relies on the enzyme and the reactants being completely stable under assay conditions. Here a method is described that relaxes this requirement and allows progress curve analysis to be applied to unstable enzymes. The procedure is based on a combination of numerical integration and non-linear regression to fit rate equations to the progress curve data. The analysis is verified using simulated data and illustrated by application to the reaction catalyzed by alkaline phosphatase, measured in the presence of 10 mM EGTA where it has a half-life of 3 1/2 min. The method may also be applied to other experimental systems where the development over time reveals important properties but where an analytical solution of the underlying model is not known. This extension is illustrated by two systems: the coupled reactions catalyzed by pyruvate kinase and lactate dehydrogenase under conditions where both enzymes have similar activity; and the transient-state kinetics of the reaction catalyzed by glutamate dehydrogenase.
Related Concept Videos
Enzyme Kinetics
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Introduction to Enzyme Kinetics
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
Catalytically Perfect Enzymes
Introduction to Mechanisms of Enzyme Catalysis
Introduction to Mechanisms of Enzyme Catalysis
Fast Reactions

