methionine

noun
me·​thi·​o·​nine | \ mə-ˈthī-ə-ˌnēn How to pronounce methionine (audio) \

Definition of methionine

: a crystalline sulfur-containing essential amino acid C5H11NO2S that occurs in the levorotatory form as a constituent of many proteins

Examples of methionine in a Sentence

Recent Examples on the Web These essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenyalinine, threonine, tryptophan and valine. Alyssa Jung, Good Housekeeping, 5 Oct. 2021 Limiting the essential amino acid methionine appears to amplify the effects of radiation and chemotherapy in mice with colon cancer and sarcomas. Jocelyn Kaiser, Science | AAAS, 1 Apr. 2021 Made from split peas, pea protein ($15, Amazon) contains all of the essential amino acids, but is low in one—methionine. Brierley Horton, Ms, Better Homes & Gardens, 26 Feb. 2021 The culprit is methionine, an amino acid that contains sulfur. Esther Mobley, SFChronicle.com, 7 May 2020 In the search for another path to the fountain of youth, researchers have been exploring the role of methionine and cysteine, two of the body's nine essential amino acids which contain sulfur. Sandee Lamotte, CNN, 3 Feb. 2020 In one early study of rats, limiting methionine by 80% increased the rats' lifespans by an average of 43%. Sandee Lamotte, CNN, 3 Feb. 2020 For example, grains are low in lysine, while beans and nuts are low in methionine, the FDA says. Carolyn L. Todd, SELF, 28 Aug. 2019 For instance, grains are low in an amino acid called lysine, while beans and nuts are low in methionine. Carolyn L. Todd, SELF, 20 June 2019

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

See More

First Known Use of methionine

1928, in the meaning defined above

History and Etymology for methionine

International Scientific Vocabulary, from methyl + thion- + -ine entry 2

Buying Guide

Our team at The Usage has selected the best protein powders.

Learn More About methionine

Time Traveler for methionine

Time Traveler

The first known use of methionine was in 1928

See more words from the same year

Dictionary Entries Near methionine

methionic acid

methionine

methobromide

See More Nearby Entries 

Statistics for methionine

Cite this Entry

“Methionine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/methionine. Accessed 25 Jan. 2022.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

More Definitions for methionine

methionine

noun
me·​thi·​o·​nine | \ mə-ˈthī-ə-ˌnēn How to pronounce methionine (audio) \

Medical Definition of methionine

: a crystalline sulfur-containing essential amino acid C5H11NO2S that occurs in the L-form as a constituent of many proteins (as casein and egg albumin), that is important especially as a source of sulfur for the biosynthesis of cysteine and as a source of methyl groups for transmethylation reactions (as in the biosynthesis of choline, creatine, and adrenaline), and that is used as a dietary supplement for human beings and their domestic mammals and poultry and in the treatment of fatty infiltration of the liver abbreviation Met

More from Merriam-Webster on methionine

Britannica.com: Encyclopedia article about methionine

WORD OF THE DAY

Test Your Vocabulary

Farm Idioms Quiz

  • cow coming home
  • What does 'poke' refer to in the expression 'pig in a poke'?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
Universal Daily Crossword

A daily challenge for crossword fanatics.

TAKE THE QUIZ
Love words? Need even more definitions?

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