S-(1,2-dicarboxyethyl)glutathione in yeast: Partial purification of its synthesizing enzyme

S-(1,2-Dicarboxyethyl)glutathione (DCE-GS) was found in Saccharomyces cerev isiae, but not in bacterial species nor in a unicellular alga (Acetabularia acetabulm). The enzyme that catalyzes condensation of L-malate and glutath ione (GSH) to form DCE-GS was partially purified from baker's yeast. It had a molecular mass of 49 kDa and was monomeric and the K-m, values were 2.2 and 1.4 mM for L-malate and GSH, respectively The enzyme had a pH optimum o f 7.5. DCE-GS levels in yeast cells were significantly higher in aerobic cu ltures than in anaerobic ones, DCE-GS was synthesized in cells cultured bet ween 20 and 35 ?C.