leu·​cine | \ ˈlü-ˌsēn How to pronounce leucine (audio) \

Definition of leucine

: a white crystalline essential amino acid C6H13NO2 that is obtained by the hydrolysis of dietary protein (as of eggs, soy, or fish) and plays an important role in various physiological functions (as the regulation of insulin secretion and stimulation of protein synthesis in skeletal muscle)

Examples of leucine in a Sentence

Recent Examples on the Web To conduct these trials, the team used the gene editing tool CRISPR and also found that maternal embryonic leucine zipper kinase (MELK) does not have influence on cancer growth. Alex Zhavoronkov, Phd, Forbes, 2 June 2021 The first of these is a leucine to argentine substitution at amino acid 452 (L452R). William A. Haseltine, Forbes, 12 Apr. 2021 Pineapples contain valine and leucine, two amino acids that are essential to human health. Katy Severson, chicagotribune.com, 26 Feb. 2021 There’s also new research suggesting that getting enough high-quality leucine may reduce cognitive impairment—sometimes called brain fog—that many people cite as a menopausal symptom. Lindsay Warner, Outside Online, 8 Dec. 2020 This appears to be especially true of leucine, which research indicates has a unique role in your body’s ability to repair and build muscles. Amy Schellenbaum, Popular Science, 8 Sep. 2020 Studies done on supplements like leucine, which some early research suggested could kickstart the muscle-building process inside cells, haven’t panned out. Sara Chodosh, Popular Science, 3 Jan. 2019 Animal proteins are also higher than plant proteins in one particular amino acid, leucine, which is thought to be key to muscle protein synthesis. Carolyn L. Todd, SELF, 28 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'leucine.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of leucine

1826, in the meaning defined above

History and Etymology for leucine

French, from leuc- leuk-

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The first known use of leucine was in 1826

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Cite this Entry

“Leucine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/leucine. Accessed 21 Sep. 2021.

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More Definitions for leucine


leu·​cine | \ ˈlü-ˌsēn How to pronounce leucine (audio) \

Medical Definition of leucine

: a white crystalline essential amino acid C6H13NO2 obtained by the hydrolysis of most dietary proteins abbreviation Leu

More from Merriam-Webster on leucine

Britannica.com: Encyclopedia article about leucine


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