GLUTATHIONE S-TRANSFERASES - 2-DIMENSIONAL ELECTROPHORETIC PROTEIN MARKERS OF LEAD-EXPOSURE

Glutathione S-transferases (GST) are a family of detoxification isoenz ymes that catalyze the conjugation of xenobiotics and their metabolite s with reduced glutathione. Lead exposure in rats is known to induce G ST isoenzymes in the liver and kidney. These changes in expression hav e potential use as biomarkers of lead exposure. Because two-dimensiona l electrophoresis (2-DE) enables one to analyze both protein abundance changes and chemical changes in protein structure, 2-DE was used to d etermine the effect of in vivo lead exposure on GST isoform expression in rat kidney cytosols. Male Sprague-Dawley rats were exposed to inor ganic lead, and proteins were separated by conventional ISO-DALT and N EPHGE-DALT techniques and blotted for immunological identification. Le ad exposure caused detectable inductions in both GSTP1 and GSTM1 and q uantifiable charge modification in GSTP1. These preliminary data confi rm the utility of 2-D electrophoretic GST analysis as indicative of le ad exposure and toxicity and support its use for further elaboration o f lead's effects on renal protein expression.