Methionine is an alpha amino acid also known as Met or M. It is classified as a non-polar and hydrophobic amino acid. It has a molecular weight of 149.21 g/mol and its molecular formula is C5H11NO2S. Methionine is an 'essential amino acid' as it is not produced naturally in humans, and therefore must be ingested within the diet. However, diets low in methionine, such as a vegan diet, may, in fact, contribute to lower rates of certain cancers due to the amino acid's role in DNA methylation. The triplet code for methionine is AUG, which is always the first codon to be translated in an open reading frame - thus, methionine is always the first amino acid in a polypeptide chain. However, methionine may be removed if the protein is edited in the Golgi Apparatus.
- ↑ Cavuotoa P, Fenech MF. A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension. Cancer Treatment Reviews 2012; 38 issue 6: 7726-736
- ↑ Berg, J. M., Tymoczko, J. L., and Stryer, L. (2002). Biochemistry (5th ed.). New York: W.H. Freeman.