Meaning of methionine in English:


Pronunciation /mɪˈθʌɪəniːn/


mass nounBiochemistry
  • A sulphur-containing amino acid which is a constituent of most proteins and is essential to the diet of vertebrates.

    Chemical formula: CH₃S(CH₂)₂CH(NH₂)COOH

    ‘They fix nitrogen and so contain high quality protein, including the essential amino acids methionine and cystine.’
    • ‘The oxidation sites of alpha-crystallin are considered to be methionine, cysteine and tryptophan amino acid residues.’
    • ‘For example, eggs are high in alanine and methionine; whey protein is high in tryptophan and threonine.’
    • ‘Contents of glutamine, asparagine, methionine, and tryptophan in the tissues were not determined by this method.’
    • ‘Homocysteine is an intermediary metabolite of essential dietary amino acid methionine.’


1920s from methyl + Greek theion ‘sulphur’.