Analysis of glyoxalase-I from normal and tumor tissue from human colon.
Glyoxalase-I (Gly-I) is part of the glyoxalase system which converts methylglyoxal to D-lactic acid via an S-D-lactoylglutathione intermediate. This glutathione (GSH)-binding protein was purified from human colon tumors and corresponding normal tissue. The GSH-affinity purified fraction from normal human colon tissue showed enzyme activity of 30.6 +/- 11.5 mumol/min per mg protein, with methylglyoxal as substrate. Corresponding fractions from carcinomas showed significantly elevated Gly-I activity of 54.5 +/- 15 mumol/min per mg protein. Polyclonal antibodies made against human Gly-I cross-reacted weakly with mouse liver Gly-I but not with yeast Gly-I. Isoelectric points of Gly-I from human, mouse and yeast were determined to be 4.6, 4.9 and 7.0, respectively, by horizontal IEF. Immunohistochemical analysis confirmed the increase of Gly-I in human colon carcinoma in 16 out of 21 samples when compared to corresponding normal tissue. The elevated levels of Gly-I in colon tumors may be an indicator of the enhanced proliferative status of the neoplastic condition.
Department of Pharmacology, Fox Chase Cancer Center, Philadelphia, PA 19111.
S
S
Ranganathan
K D
KD
Tew
D000818:Animals; D000906:Antibodies / Q000276:immunology; D014408:Biomarkers, Tumor / Q000032:analysis; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007525:Isoelectric Focusing; D007791:Lactoylglutathione Lyase / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D051379:Mice; D012441:Saccharomyces cerevisiae
D000906:Antibodies; D014408:Biomarkers, Tumor; D007791:Lactoylglutathione Lyase