Related Experiment Video
Updated: May 20, 2026

Steady-state, Pre-steady-state, and Single-turnover Kinetic Measurement for DNA Glycosylase Activity
Published on: August 19, 2013
Transient step-like kinetics of enzyme reaction on fragmented-condensed substrates
Elena Del Favero1, Antonio Raudino, Martina Pannuzzo
1Department of Medical Chemistry, Biochemistry and Biotechnologies, University of Milan, L.I.T.A., Via F.lli Cervi 93, 20090 Segrate, Italy.
Abstract:
We followed the process of enzymatic digestion of ganglioside GD1a, operated by sialidase on aggregated micelles. The product is the ganglioside GM1, lacking the external sialic acid. The structural aspects and the kinetics connected to the process occurring on a fragmented-condensed substrate, the ganglioside micelles, are investigated by small angle X-ray scattering (SAXS). Observed at short times, the kinetics of the reaction shows a transient step-like decay, while it tends to a smooth Michaelis-Menten kinetics in the late stages. We propose a model, based on the fragmented-condensed nature of the substrate, that well reproduces the experimental observation without invoking any feedback mechanism in the reaction, usually required for an oscillatory behavior. The model predicts an initial regime dominated by the strict enzyme-substrate interaction, with a step-like appearance.
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...
Fast Reactions
Induced-fit Model
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical characteristics of...
Enzymes
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Transition State Theory

