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

Abstract

S-(1,2-Dicarboxyethyl)glutathione (I)CE-GS) was found in Saccharomyces cerevisiae, but not in bacterial species nor in a unicellular alga (Acetabularia acetabulm). The enzyme that catalyzes condensation of L-malate and glutathione (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 of 7.5. DCE-GS levels in yeast cells were significantly higher in aerobic cultures than in anaerobic ones. DCE-GS was synthesized in cells cultured between 20 and 35°C.