Temperature controlled ionic liquid aqueous two phase system (ILATPS) was used to improve the precision of pharmaceutical-AGP (human alpha (α1)-acid glycoprotein) binding measurements by affinity capillary electrophoresis (ACE). The effect of different types of short-chain alkyl imidazolium ILs within the concentration range of 10.0-1000.0 μmol L-1 on a propranolol (PRO)-AGP model was firstly investigated by ILATPS/ACE system. Use of 100.0 μmol L-1 1-butyl-3-methylimidazolium chloride (BMImCl) in 67.0 mmol L-1 potassium phosphate buffer (pH 7.4) containing low concentrations of AGP (5.0-100.0 µmol L-1) gave the highest precision value (2.98 ± 0.14 × 105 L/mol) which is in concord with the reported one (3.00 × 105) under similar experimental conditions. The proposed BMImCl/phosphate solution was a unique temperature controlled system to preserve AGP activity during the pre-analysis and within ACE measurements under lab conditions for about 30 days. This period could be prolonged by converting the one-phase solution into biphasic solution at 4 °C storage temperature and again it could get rapidly back into one-phase by raising the temperature with gentle shaking. This behavior could be attributed to the electrostatic interaction and π-π interaction between BMIm cations and negatively charged AGP ions (pI = 2.7). Moreover, the compatibility of ILATPS with ACE has been the critical factor to avoid precipitation of salts formed by anion exchange in the running buffer. The current ILATPS/ACE system was further used to rapidly and precisely estimate the binding constants of anticancer drugs methotrexate (MTX) and vinblastine (VBL) with human AGP. The obtained binding values have been in good agreements with their findings by high performance affinity chromatography (HPAC). This ILATP/ACE system could similarly be applied to improve the precision of other proteins binding measurements with consuming a small amount of protein and with shortening ACE analysis time.

中文翻译：

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温控离子液体水相两相系统结合亲和毛细管电泳进行快速精确的药物-蛋白质结合测量

温控离子液体水相两相系统 (ILATPS) 用于通过亲和毛细管电泳 (ACE) 提高药物-AGP（人α（α1）-酸性糖蛋白）结合测量的精度。ILATPS/ACE 系统首次研究了浓度范围为 10.0-1000.0 μmol L-1 的不同类型短链烷基咪唑鎓离子对普萘洛尔 (PRO)-AGP 模型的影响。在含有低浓度 AGP (5.0-100.0 µmol L-1) 的 67.0 mmol L-1 磷酸钾缓冲液 (pH 7.4) 中使用 100.0 μmol L-1 1-丁基-3-甲基咪唑氯化物 (BMImCl) 可获得最高的精度值(2.98 ± 0.14 × 105 L/mol) 这与在类似实验条件下报道的 (3.00 × 105) 一致。拟议的 BMImCl/磷酸盐溶液是一种独特的温度控制系统，可在实验室条件下在预分析和 ACE 测量期间保持 AGP 活性约 30 天。通过在 4°C 的储存温度下将单相溶液转化为双相溶液可以延长这一时间，通过轻轻摇动升高温度，它可以再次快速恢复为单相。这种行为可归因于 BMIm 阳离子和带负电荷的 AGP 离子之间的静电相互作用和 π-π 相互作用（pI = 2.7）。此外，ILATPS 与 ACE 的相容性是避免运行缓冲液中阴离子交换形成的盐沉淀的关键因素。当前的 ILATPS/ACE 系统进一步用于快速准确地估计抗癌药物甲氨蝶呤 (MTX) 和长春碱 (VBL) 与人 AGP 的结合常数。获得的结合值与他们通过高效亲和层析 (HPAC) 的发现非常吻合。这种 ILATP/ACE 系统可以类似地应用于提高其他蛋白质结合测量的精度，消耗少量蛋白质并缩短 ACE 分析时间。