In biochemistry, a binding site is a region on a protein, DNA, or RNA to which specific other molecules and ions—in this context collectively called ligands—form a chemical bond.
Binding sites also exist on antibodies as specifically coded regions that bind antigens based upon their structure.
The term saturation refers to the fraction of total binding sites that are occupied at any given time. When more than one type of ligand can bind to a binding site, competition ensues.
An equilibrium exists between unbound ligands and bound ligands.
Binding sites also exhibit chemical specificity, a measure of the types of ligands that will bond, and affinity, which is a measure of the strength of the chemical bond.
Binding sites are often an important component of the functional characterization of biomolecules. For example, the characterization the binding site of a substrate to an enzyme is essential to model the reaction mechanism responsible for the chemical change from substrate to product.
A more specific type of binding site is the transcription factor binding site, present on DNA.
Famous quotes containing the words binding and/or site:
“Hate traps us by binding us too tightly to our adversary.”
—Milan Kundera (b. 1929)
“It’s given new meaning to me of the scientific term black hole.”
—Don Logan, U.S. businessman, president and chief executive of Time Inc. His response when asked how much his company had spent in the last year to develop Pathfinder, Time Inc.’S site on the World Wide Web. Quoted in New York Times, p. D7 (November 13, 1995)