pro·​line ˈprō-ˌlēn How to pronounce proline (audio)
: an amino acid C5H9NO2 that can be synthesized by animals from glutamate

Examples of proline in a Sentence

Recent Examples on the Web Collagen is a protein made by the body from the essential amino acids proline and glycine with an assist from copper, zinc and vitamin C. One-third of the body’s protein is collagen. Sheah Rarback, Miami Herald, 24 Feb. 2024 The foods richest in collagen come from animals, but several fruits and vegetables are rich in vitamin C, amino acids proline and glycine, and minerals such as zinc and copper, all of which promote the synthesis of this essential protein. Alessandra Signorelli, Glamour, 24 Oct. 2023 The anti-inflammatory properties of collagen are due to its content of proline and glycine. Amber Smith, Discover Magazine, 23 Mar. 2022 Combining powerful amino acids such as glycine and proline, this product works to strengthen tendons, ligaments, bones, hair, skin, and nails. Amber Smith, Discover Magazine, 9 Jan. 2023 Repeats with a lot of proline, threonine and serine transform a typical protein to a mucin because of the polypeptide structure that is formed. Coren Walters-Stewart, Discover Magazine, 18 Oct. 2022 Bone broth is rich in amino acids like glycine and proline, which are needed for the production of collagen. Amber Smith, Discover Magazine, 21 Dec. 2022 These proteins rich in proline, however, do not have the key repetitive protein structures that help mucins bind to sugar molecules. Omer Gokcumen, The Conversation, 26 Aug. 2022 The most prevalent mutation in this T cell epitope is an amino acid substitution of proline for leucine, denoted as YLQLRTFLL or P272L mutation. William A. Haseltine, Forbes, 17 Aug. 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'proline.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


German Prolin, contraction of Pyrrolidin pyrrolidine (C4H9N), from International Scientific Vocabulary pyrrole + -idine

First Known Use

1904, in the meaning defined above

Time Traveler
The first known use of proline was in 1904

Dictionary Entries Near proline

Cite this Entry

“Proline.” Dictionary, Merriam-Webster, Accessed 14 Apr. 2024.

Medical Definition


pro·​line ˈprō-ˌlēn How to pronounce proline (audio)
: an amino acid C5H9NO2 that can be synthesized by animals from glutamate
abbreviation Pro

More from Merriam-Webster on proline

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!