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:
“[Government’s] true strength consists in leaving individuals and states as much as possible to themselves—in making itself felt, not in its power, but in its beneficence, not in its control, but in its protection, not in binding the states more closely to the center, but leaving each to move unobstructed in its proper orbit.”
—Andrew Jackson (1767–1845)
“It is not menstrual blood per se which disturbs the imagination—unstanchable as that red flood may be—but rather the albumen in the blood, the uterine shreds, placental jellyfish of the female sea. This is the chthonian matrix from which we rose. We have an evolutionary revulsion from slime, our site of biologic origins. Every month, it is woman’s fate to face the abyss of time and being, the abyss which is herself.”
—Camille Paglia (b. 1947)