The Influence of Experimental Conditions and of Organic Solvents as modifiers on the Separation of Metallothionein Isoforms by Capillary Zone Electrophoresis in an Uncoated Capillary Column.

Putative metallothionein (MT) isoforms are readily separated by capillary zone electrophoresis (CZE) with tris(hydroxymethyl)aminomethane (Tris) - borate buffer using an uncoated polymide cladded fused-silica capillary column. The influence of buffer concentration and composition, pH, running voltage and temperature on the electrosmotic mobility and electrophoretic mobilities of the model samples (rabbit liver MT and horse kidney MT) are investigated. Also the use of organic solvents as buffer modifiers an their effect on separation of putative metallothionein isoforms is described. It is shown that organic solvent modification do significantly enhance the resolution. i.e. with organic solvents as modifiers it is possible to obtain a good separation of putative isoforms of rabbit liver MT in one run which needed two separate runs with either different pHs or different temperatures when performed with Tris-borate buffer without organic solvent modification. The effects of the organic solvents as modifiers were found to be solvent specific although the trends were in the same direction (i.e. decreasing electroosmotic mobility with increasing percentage of organic solvent). Differences in effect on individual putative MT isoforms were observed, which indicates differences in chemical and physical characteristics. A difference in polymorphism of horse kidney MT and rabbit liver MT is clearly noticed.

VIRTANEN Vesa;  BORDIN Guy;  RODRIGUEZ-FERNANDEZ Adela; 

1998-10-28

JRC17077