Theory and practical understanding of the migration behavior of proteins and peptides in CE and related techniques

Separation of Peptides by Capillary Electrophoresis

Peptides are an important class of analytes in chemistry, biochemistry, food chemistry, as well as medical and pharmaceutical sciences including biomarker analysis in peptidomics and proteomics. As a high-resolution technique, capillary electrophoresis (CE) is well suited for the analysis of polar compounds such as peptides. In addition, CE is orthogonal to high-performance liquid chromatography (HPLC) as both techniques are based on different physicochemical separation principles. For the successful development of peptide separations by CE, operational parameters including puffer pH, buffer concentration and buffer type, applied voltage, capillary dimensions, as well as background electrolyte additives such as detergents, ion-pairing reagents, cyclodextrins, (poly)amines, and soluble polymers have to be considered and optimized.

Electrophoretic and electrochromatographic separation of proteins in capillaries: an update covering 2007-2009

This review article covers 3-year period from 2007 to 2009 and is a continuation of the review article by V. Dolnik, [Electrophoresis 2008, 29, 143-156]. This article with 125 references describes recent developments in CE and CEC of proteins in capillary format and does not cover the developments of CE and CEC in microchip format, since Tran et al. review the microchip subject in this special issue. The present review article has four major topics including (i) the separation media, (ii) multidimensional separations, (iii) detection, and (iv) applications.

Retention of proteins and metalloproteins in open tubular capillary electrochromatography with etched chemically modified columns

Etched chemically modified capillaries with two different bonded groups (pentyl and octadecyl) are compared for their migration behavior of several common proteins and metalloproteins as well as metalloproteinases. Migration times, efficiency and peak shape are evaluated over the pH range of 2.1-8.1 to determine any effects of the bonded group on the electrochromatographic behavior of these compounds. One goal was to determine if the relative hydrophobicity of the stationary phase has a significant effect on proteins in the open tubular format of capillary electrochromatography as it does in HPLC. Reproducibility of the migration times is also investigated.