Capillary electrochromatographic separation of bovine milk proteins using a G-quartet DNA stationary phase.
DNA oligonucleotides that form G-quartet structures were used as stationary phase reagents for separation of bovine milk proteins, including alpha-casein, beta-casein, kappa-casein, alpha-lactalbumin and beta-lactoglobulin. Both artificial protein mixtures and a skim milk sample were analyzed. The separations were performed using open-tubular capillary electrochromatography, in which the oligonucleotides were covalently attached to the inner surface of a fused-silica capillary. Better resolution was achieved using the G-quartet-coated capillaries than was achieved using either a bare capillary or a capillary coated with an oligonucleotide that does not form a G-quartet structure. A 4-plane G-quartet-forming stationary phase was able to resolve three peaks for alpha-casein and to detect thermal denaturation of the proteins in the milk sample. The results suggest that G-quartet stationary phases could be used to separate very similar protein structures, such as those arising from genetic variations or post-translational modifications.
Rehder-Silinski
Melanie A
MA
Department of Chemistry, P.M. Gross Chemical Laboratory, Duke University, Durham, NC 27705, USA.
McGown
Linda B
LB
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D006358:Hot Temperature; D008894:Milk Proteins / Q000737:chemistry / Q000302:isolation & purification*; D011489:Protein Denaturation
D008894:Milk Proteins; D004247:DNA