應用親和性染料於離子液體中進行蛋白質液相╱液相萃取

Abstract

室溫離子液體（Room Temperature Ionic Liquids, RTILs）由於擁有低蒸氣壓、高熱穩定性及範圍□廣的極性、導電度等特殊的物理與化學性質，並且對實驗環境較為安全，在近年來引起了廣泛的研究熱潮。染料配體（affinity dye ligand）常應用於親和性管柱層析法中，對蛋白質進行純化處理。在本研究中發現，選擇在離子液體BMIM-PF6中具有良好溶解度的親和性染料Procion Blue MX-R，可成功將溶菌□（lysozyme）從水溶液中萃取進入離子液體；在pH 7的條件下，正向萃取率最高可達65 %。藉由1 M濃度氯化鈉的添加改變溶液離子強度，溶菌□被反萃出來回到水溶液中，其回收率約為40%。本實驗並嘗試以Procion Blue MX-R萃取不同種類蛋白質：細胞色素c，牛血紅素、卵白蛋白，發現皆無萃取效果，由此得知此萃取方法對蛋白質的親和力具有相當程度的擇擇性，或可為蛋白質液相/液相萃取技術提供了一個新的方式。

Owing to the special physical and chemical properties, such as low vapor pressure, high thermal stability, wide range of polarity and high conductivity, room temperature ionic liquids (RTILs) have attracted wide research interests. The affinity dyes have been employed in affinity chromatography for protein purification. In this study, we explored that lysozyme could be transferred from aqueous phase into an ionic liquid BMIM-PF6 with the aid of affinity dye procion blue MX-R in BMIM-PF6. The forward extraction efficiency (from the aqueous solution to the RTIL phase) reached ~65 % while the aqueous solution was at pH 7. The total lysozyme recovery reached ~40 % while a buffer solution with 1 M sodium chloride was used for the back extraction. The same dye-in-RTIL solution was found unable to extract cytochrome c, hemoglobin, and albumin. This technique may provide a new approach for protein liquid/liquid extractions.