Term: quaternary structure https://doi.org/10.1351/goldbook.Q05004 Definition: The defined organization of two or more macromolecules with tertiary structure such as a protein that are held together by hydrogen bonds and van der Waals and coulombic forces. Related Terms: 1) primary structure (http://doi.org/10.1351/goldbook.P04843). 2) secondary structure (http://doi.org/10.1351/goldbook.S05530). 3) tertiary structure (http://doi.org/10.1351/goldbook.T06282). Source: PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2216 (https://doi.org/10.1351/pac199668122193) Citation: 'quaternary structure' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.Q05004 License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. 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.