Related Experiment Video
Updated: Sep 9, 2026

Determination of Protein-ligand Interactions Using Differential Scanning Fluorimetry
Published on: September 13, 2014
Effect of a contaminating competitive ligand on ligand-binding curves. Inverse protein concentration dependence
1Fysisk Institut, Odense Universitet, Denmark.
Abstract:
A theoretical binding model is considered which provides an explanation for the inverse protein concentration dependence observed for a variety of ligands. The model describes the inhibition of binding caused by a highly bound contaminant. The complete binding equation is derived and examined in terms of form, limits, and protein dependence. Furthermore, several approximate relations are derived which are useful for obtaining initial estimates of the model parameters and for a qualitative test of the applicability of the model. It is found that the binding curve may show a characteristic plateau at a saturation equal to the uncontaminated fraction of the protein and that the free ligand concentration at half saturation depends linearly on protein concentration. The practical implications of the present findings are discussed based on an analysis of simulated as well as experimental data.
Related Concept Videos
Ligand Binding Sites
Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
The Equilibrium Binding Constant and Binding Strength
Ligand Binding and Linkage
Cooperative Allosteric Transitions
Quantitative Aspects of Drug-Receptor Interaction
Protein-Drug Binding: Determination Methods
Indirect methods involve isolating the bound drug from its free form in biological samples such as blood, serum, or plasma. These techniques aim to measure the percentage of drugs bound to proteins. Equilibrium dialysis is a commonly used method where the free drug concentration at equilibrium is measured by separating the bound...

