RAPID ASSAY FOR THE ANALYSIS OF CLASS-III METALLOTHIONEINS BY CAPILLARY ZONE ELECTROPHORESIS IN CRUDE EXTRACTS OF MICROALGAL CELLS EXPOSED TO CADMIUM

An optimization strategy for the separation and analysis of class III metallothioneins from a complex matrix by capillary zone electrophores is (CZE) is presented and illustrated. Metallothioneins are a group of polypeptides used for many organisms to alleviate stresses imposed by exposure to heavy-metal excess. The analysis requires several steps: chromatography on exclusion or anion-exchange columns, ultrafiltration and HPLC with derivatization. In the present paper, a rapid and simpl e separation technique by CZE with an uncoated polyimide-clad fused-si lica capillary is described. This technique permits the analysis of th ese molecules without prior steps of purification and derivatization. The running conditions were voltage -12 kV, room temperature and 150 m M sodium phosphate buffer (pH 3.5). Based on this preliminary study, C ZE with an uncoated fused-silica capillary using sodium phosphate buff er appears to be a useful technique for the separation of class III me tallothioneins. (C) 1997 Elsevier Science B.V.