Rehder-Silinski Melanie A, McGown Linda B
Department of Chemistry, P.M. Gross Chemical Laboratory, Duke University, Durham, NC 27705, USA.
J Chromatogr A. 2003 Aug 8;1008(2):233-45. doi: 10.1016/s0021-9673(03)00973-7.
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.
形成G-四联体结构的DNA寡核苷酸被用作固定相试剂，用于分离牛乳蛋白质，包括α-酪蛋白、β-酪蛋白、κ-酪蛋白、α-乳白蛋白和β-乳球蛋白。对人工蛋白质混合物和脱脂乳样品都进行了分析。分离采用开管毛细管电色谱法进行，其中寡核苷酸共价连接到熔融石英毛细管的内表面。使用涂有G-四联体的毛细管比使用裸毛细管或涂有不形成G-四联体结构的寡核苷酸的毛细管具有更好的分离效果。一种形成4平面G-四联体的固定相能够分辨出α-酪蛋白的三个峰，并检测出乳样品中蛋白质的热变性。结果表明，G-四联体固定相可用于分离非常相似的蛋白质结构，例如由基因变异或翻译后修饰产生的结构。
