Title: binding site
Long Title: IUPAC Gold Book - binding site
DOI: 10.1351/goldbook.B00649
Status: current

Definition
A specific region (or atom) in a molecular entity that is capable of entering into a stabilizing interaction with another molecular entity. An example of such an interaction is that of an active site in an enzyme with its substrate. Typical forms of interaction are by hydrogen bonding, coordination and ion pair formation. Two binding sites in different molecular entities are said to be complementary if their interaction is stabilizing.

Related Terms
- coordination: https://goldbook.iupac.org/terms/view/C01329
- hydrogen bonding: https://goldbook.iupac.org/terms/view/H02899
- ion pair: https://goldbook.iupac.org/terms/view/I03231
- molecular entity: https://goldbook.iupac.org/terms/view/M03986
- substrate: https://goldbook.iupac.org/terms/view/S06083

Source
- PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1089 (https://doi.org/10.1351/pac199466051077)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/B00649/html
- json: https://goldbook.iupac.org/terms/view/B00649/json
- xml: https://goldbook.iupac.org/terms/view/B00649/xml

Citation: Citation: 'binding site' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.B00649
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Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-05-10T04:18:01+00:00