Synthesis of L-selenodjenkolate and its degradation with methionine gamma-lyase.

A convenient method for the synthesis of a new selenium-containing amino acid, L-selenodjenkolate (3,3'-methylenediselenobis(2-aminopropionic acid)), is described. The starting material, selenocystine, was found to be prepared easily from commercially available beta-chloro-L-alanine, elemental selenium, and sodium borohydride. These synthetic procedures are useful for the preparation of the isotope-labeled compounds. The physiochemical properties of selenodjenkolate thus prepared are reported. This amino acid undergoes alpha, beta-elimination to produce pyruvate, formaldehyde, ammonia, and selenium by bacterial methionine gamma-lyase under aerobic conditions: the Vmax and Km values were determined to be 0.5 mumol/min/mg and 2.3 mM, respectively.