Glyoxalase I (GLO1)

Glyoxalase I (EC 4.4.1.5) is a glutathione-binding protein involved in the detoxification of methylglyoxal, a byproduct of glycolysis. GLO1 and glyoxalase II (GLO2) catalyze successive steps in the pathway. GLO1 catalyzes condensation of methylglyoxal and reduced glutathione to form S-lactoyl-glutathione; GLO2 (hydroxyacyl glutathione hydrolase) converts the latter substance to D-lactic acid and reduced glutathione .The human enzyme showed 42% amino acid homology with bacterial Glo1. Northern blot analysis identified a 2.2-kb mRNA transcript in colon tissue. There was a 12-fold increase of the GLO1 transcript in colon carcinoma tissue compared to normal colon tissue from the same patient, and the authors concluded that GLO1 gene expression was induced in colon carcinoma.