Some chemical and biochemical properties of selenomethionine

Some chemical properties important to the biochemistry of the amino acid analogue selenomethionine were studied. It was found to be less soluble in demineralized distilled water, much less stable to acid hydrolysis, and of a different infrared spectrum than methionine itself. Selenomethionine reacted much more rapidly with cyanogen bromide to form homoserine than did methionine. A method of diagonal chromatography using cyanogen bromide vapors was introduced as a possible means of locating selenomethionine molecules in proteins. The results are discussed with regard to the possible effect of selenomethionine on protein structure and function, and to the chemical means of locating selenomethionine in selenoproteins.