Albumins as a model system for investigating separations of closely related proteins on DNA stationary phases in capillary electrochromatography

G-quartet DNA stationary phases prepared by covalent attachment of the oligonucleotides to capillary surfaces were investigated for separations of albumins of different species in open tubular capillary electrochromatography (OTCEC). Albumins were chosen as a model system of proteins that do not exhibit strong, specific binding to G-quartet DNA, in order to determine if weak interactions with the stationary phases would be useful for separation of proteins that are highly similar in structure, function, and sequence. Results were compared with results obtained using capillary zone electrophoresis with a bare capillary and OTCEC results obtained using a scrambled sequence oligonucleotide that does not form a G-quartet structure. The comparison indicates advantages associated with the G-quartet phases for protein separations. (C) 2004 Elsevier B.V. All rights reserved.