Li Daojin, Li Yang, Li Xinglin, Bie Zijun, Pan Xianghua, Zhang Qian, Liu Zhen
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China; Shanghai Tobacco Group Co., Ltd., Shanghai 200082, China.
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
J Chromatogr A. 2015 Mar 6;1384:88-96. doi: 10.1016/j.chroma.2015.01.050. Epub 2015 Jan 22.
Boronate affinity materials, as effective sample enrichment sorbents for glycoproteomic analysis, have attracted increasing attention in recent years. However, most of boronate affinity materials suffer from an apparent limitation, limited binding strength. As a result, extraction of glycoproteins of trace concentration is rather difficult or impossible. In this study, we present a high boronate avidity monolithic capillary. Branched polyethyleneimine (PEI) was used as a scaffold to amplify the number of boronic acid moieties. While 2,4-difluoro-3-formyl-phenylboronic acid (DFFPBA), which exhibited ultrahigh affinity toward cis-diol-containing compounds, was employed as an affinity ligand. Due to the PEI-assisted synergistic multivalent binding, the monolithic column exhibited high boronate avidity toward glycoproteins, with binding constants of 10(-6)-10(-7)M. Such binding strength was the highest among already reported boronic acid-functionalized materials that can be used for glycoproteomic analysis. Besides, the boronate avidity monolithic column exhibited one additional beneficial feature, lowered binding pH (≥6.5). These features greatly favored the selective enrichment of trace glycoproteins from real samples. The feasibility for practical applications was demonstrated with the selective enrichment of trace glycoproteins in human saliva. As compared with other boronate avidity/affinity materials, the boronate avidity monolithic capillary exhibited the best performance.
硼酸酯亲和材料作为糖蛋白质组分析中有效的样品富集吸附剂，近年来受到了越来越多的关注。然而，大多数硼酸酯亲和材料存在一个明显的局限性，即结合强度有限。因此，提取痕量浓度的糖蛋白相当困难甚至无法实现。在本研究中，我们展示了一种具有高硼酸亲和力的整体柱毛细管。支化聚乙烯亚胺（PEI）被用作支架以增加硼酸基团的数量。而对含顺式二醇化合物表现出超高亲和力的2,4-二氟-3-甲酰基苯硼酸（DFFPBA）被用作亲和配体。由于PEI辅助的协同多价结合，整体柱对糖蛋白表现出高硼酸亲和力，结合常数为10^(-6)-10^(-7)M。这种结合强度在已报道的可用于糖蛋白质组分析的硼酸功能化材料中是最高的。此外，硼酸亲和力整体柱还表现出另一个有益特性，即降低结合pH值（≥6.5）。这些特性极大地有利于从实际样品中选择性富集痕量糖蛋白。通过在人唾液中选择性富集痕量糖蛋白证明了其实际应用的可行性。与其他硼酸亲和力/亲和材料相比，硼酸亲和力整体柱毛细管表现出最佳性能。
