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. Produced by alternative splicing. Also produced by alternative initiation at Met-49 of isoform 1. Alternative initiation has been proven in human. 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.