Comparison of CZE and MECC separations of MT isoforms

Abstract

In order to characterize the biological functions of individual isoforms and especially sub-isoforms of metallothioneins (MT), analytical methods that provide a high degree of resolution are needed. Capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MECC) have been successfully adapted to the separation of MT isoforms by several scientists. Earlier MECC using borate buffer with sodium dodecylsulphate (SDS) micelles at pH 8.4 was adapted to MT isoform separation [1–2]. Even though the results obtained were good there was still a lack of separation of individual sub-isoforms. Method development for metallothionein isoform analysis by capillary electrophoresis can be divided into two groups. Firstly, methods which give quantitative and qualitative information for each isoform and secondly methods which produce results for each individual sub-isoform. This work studies the applicability of tris-tricine buffer for isoform separation. It also looks at the effects of additions of another anionic surfactant, sodium cholate (SC) and organic solvent (MeOH), to the tristricine running buffer in order to gain separation of the sub-isoforms.