Selenomethionine

Selenomethionine is an amino acid containing selenium. The L-isomer of selenomethionine, known as Se-met and Sem, is a common natural food source of selenium. In vivo, selenomethionine is randomly incorporated instead of methionine and is readily oxidized. It’s antioxidant activity arises from its ability to deplete reactive species. Selenium and sulfur are chalcogen elements that share many chemical properties and the substitution of methionine to selenomethionine has no effect on proteins structure and function.

Incorporation of selenomethionine into proteins in place of Methionine aids the structure elucidation of proteins by X-ray crystallography using multi-wavelength anomalous diffraction (MAD). The incorporation of heavy atoms such as Selenium helps solving the phase problem in X-ray crystallography.


 * Chemical formula: C5H11NO2Se


 * IUPAC name: 2-amino-4-methylselanyl-butanoic acid


 * CAS number: 3211-76-5


 * Common three-letter abbreviation: MSE