Thiolesterase that catalyzes the hydrolysis of S-D-lactoyl-glutathione to form glutathione and D-lactic acid. an S-(2-hydroxyacyl)glutathione + H2O = a 2-hydroxy carboxylate + glutathione + H(+) (R)-S-lactoylglutathione + H2O = (R)-lactate + glutathione + H(+) Binds 2 Zn(2+) ions per subunit. Secondary metabolite metabolism; methylglyoxal degradation; (R)-lactate from methylglyoxal: step 2/2. Monomer. Testis. A mitochondrial longer isoform in the N-terminus has been proven to exist in orthologs. Belongs to the metallo-beta-lactamase superfamily. Glyoxalase II family. Only one single gene encoding glyoxalase II has been identified in vertebrates. In yeast and higher plants, separate genes encode the cytosolic and mitochondrial forms of glyoxalase II. Truncated N-terminus. Cloning artifact.