Assay of glyoxalase I in blood.
Glyoxalase I (S-lactoyl-glutathione methylglyoxal-lyase (isomerizing), EC 4.4.1.5) was assayed using alcoholic, acidic 2,4-dinitrophenylhydrazine to follow the disappearance of methylglyoxal over time, with the absorbance of formed methylglyoxal bis-hydrazone measured at 432 nm. Erythrocyte glyoxalase I activities were found to be 64, 41, and 18 mumole of S-lactoyl glutathione formed min-1 X ml-1 of red blood cells in rat, human, and rabbit blood and 174 mumole X min-1 X mg-1 of protein for yeast. The Km values found in millimolar hemimercaptal were about 0.5. Glyoxalase I activity can be determined in crude tissue preparations without interference from biological materials.
D000818:Animals; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D007700:Kinetics; D007791:Lactoylglutathione Lyase / Q000097:blood*; D008190:Lyases / Q000097:blood*; D008433:Mathematics; D011817:Rabbits; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013045:Species Specificity
D008190:Lyases; D007791:Lactoylglutathione Lyase