STRATEGIES FOR THE QUALITATIVE AND QUANTITATIVE-ANALYSIS OF METALLOTHIONEIN ISOFORMS BY CAPILLARY ELECTROPHORESIS

Metallothioneins (MT) are a heterogeneous family of proteins coded fro m multiple linked genes whose individual expression can be readily det ermined at the transcriptional level by assay of mRNA using specific D NA probes targeted against the untranslated regions. Analysis of trans lated protein products is more challenging since sequence variation, b etween MT isoforms can be as little as one in 61 amino acids. Separati on of these isoforms therefore requires a high resolution technique wh ich can exploit minor differences in charge or hydrophobicity. The use of capillary electrophoresis (CE) for MT isoform separation is review ed, including practical information on capillaries and electrolyte con ditions which are most suitable for qualitative evaluation of purified MT and also for quantification of isoforms from biological tissues. M ethods of sample preparation are discussed, as are methods of characte rising the separated components and enhancing sensitivity of their det ection. (C) 1998 Elsevier Science B.V. All rights reserved.