Abstract Human alpha (α1)-acid glycoprotein (AGP) is an acute phase protein whose plasma concentration increases several-folds in the presence of various diseases. The variability in AGP plasma concentration is expected to have a huge impact on the drug binding equilibrium. Therefore, a precise measurement of AGP-drug binding is of great demand for drug development. In the current study, an ionic liquid-based aqueous two-phase system combined with affinity capillary electrophoresis (ILATPS/ACE) was utilised in order to improve the accuracy of AGP-drug binding analysis through the measurements of electrophoretic mobilities. The utilisation of ILATPS has shown to have a positive impact on the stability of AGP activity solution during the storage for an extended period of time. In addition, the effect of various alkyl chains (C2-C10) of imidazolium-based ILs with concentrations ranging between 10.00 and 1000.0 μmol L−1 on the AGP binding with the anti-cancer drugs chlorambucil (CHL) and dacarbazine (DAC) was examined by the system developed (ILATPS/ACE). A 100.00 μmol L−1 1-ethyl-3-methylimidazolium chloride (EMImCl) prepared in the physiological buffer conditions containing AGP (5.00–100.00 µmol L−1) has provided an accurate apparent binding constant of 1.99 ± 0.11 and 6.95 ± 0.14 L mmol−1 with CHL and DAC respectively. Apart from the ACE analysis, EMImCl/phosphate buffer solution was found to be a distinguished system that could lengthen the stability of AGP activity for a period of time reaching 90 days during the solution storage at 4.00 °C. This effect is thought to be due to the easy conversion of one-phase EMImCl/phosphate buffer/AGP at the ambient lab temperature into the two-phase solution at refrigerator temperature, 4.00 °C, and vice versa. Therefore, the ILATP/ACE system could be used to enhance the accuracy for other AGP-drug bindings with a fast, easy to use, and cost-effective analysis.

中文翻译：

---

通过亲和毛细管电泳研究在咪唑基离子液体存在下人α-酸性糖蛋白与苯丁酸氮芥和达卡巴嗪的结合测量

摘要 人α(α1)-酸性糖蛋白(AGP)是一种急性时相蛋白，在各种疾病存在时血浆浓度升高数倍。预计 AGP 血浆浓度的变化会对药物结合平衡产生巨大影响。因此，对AGP-药物结合的精确测量是药物开发的巨大需求。在目前的研究中，基于离子液体的水性两相系统结合亲和毛细管电泳 (ILATPS/ACE)，通过测量电泳迁移率来提高 AGP 药物结合分析的准确性。ILATPS 的使用已表明在长时间储存​​期间对 AGP 活性溶液的稳定性有积极影响。此外，浓度范围为 10.00 至 1000.0 μmol L-1 的咪唑基 ILs 的各种烷基链 (C2-C10) 对 AGP 与抗癌药物苯丁酸氮芥 (CHL) 和达卡巴嗪 (DAC) 结合的影响通过系统开发（ILATPS/ACE）。在含有 AGP (5.00–100.00 µmol L-1) 的生理缓冲条件下制备的 100.00 μmol L-1 1-乙基-3-甲基咪唑氯化物 (EMImCl) 提供了 1.99 ± 0.11 和 6.95 ± 0.14 L 的准确表观结合常数mmol-1 分别与 CHL 和 DAC。除了 ACE 分析外，还发现 EMImCl/磷酸盐缓冲溶液是一个杰出的系统，它可以在 4.00 °C 的溶液储存期间延长 AGP 活性的稳定性达 90 天。这种效应被认为是由于环境实验室温度下的单相 EMImCl/磷酸盐缓冲液/AGP 容易转化为冰箱温度 4.00 °C 下的两相溶液，反之亦然。因此，ILATP/ACE 系统可用于通过快速、易于使用且具有成本效益的分析来提高其他 AGP 药物结合的准确性。