离子液体1-丁基-3-三甲基硅咪唑六氟磷酸盐萃取细胞色素C  

Extraction of Cytochrome C by Ionic Liquid 1-Butyl-3-trimethyl Silylimidazolium Hexafluorophosphate

作　　者：程德红[1] 陈旭伟[1] 舒杨[1] 王建华[1] 

机构地区：[1]东北大学分析科学研究中心,沈阳110004

出　　处：《分析化学》2008年第9期1187-1190,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金重点项目(No.20635010);国家杰出青年科学基金(No.20725517)资助课题

摘　　要：建立了疏水性离子液体1-丁基-3-三甲基硅咪唑六氟磷酸盐(BtmsimPF6)萃取细胞色素C(Cyt-c)的新方法。在萃取条件为pH1.0,Cyt-c溶液体积3mL,BtmsimPF6体积400μL,萃取时间30min时,5mg/LCyt-c的萃取效率为85%。萃取机理研究表明:在酸性条件下,Cyt-c发生构型转变,肽链伸展,使疏水性基团外露,增加了Cyt-c在疏水性离子液体中的溶解性;同时,当pH<2.0时,血红素基团中的Fe与Met-80的配位断裂,空出第六个配位空间,离子液体咪唑阳离子进入到肽链孔穴与Fe发生配位,形成新的配位键,从而被萃取到离子液体中。A novel method was developed for the extraction of cytochrome c （Cyt-c） from aqueous solution into ionic liquid 1-butyl-3-trimethylsilylimidazolium hexafluorophosphate （Btmsim PF6 ）. An extraction efficiency of ca. 85% was achieved for 5.0 mg/L Cyt-c, by extracting 3 mL of Cyt-c aqueous solution with 400 μL of Btmsim PF6 for 30 min at pH 1.0. The extraction mechanisms were investigated by UV-Vis and circular dichroism spectra. It was demonstrated that conformation change of Cyt-c was encountered in an acidic medium （pH 〈 5 ） accompanied by the unfolding of peptide chain and the exposure of hydrophobic groups of berne, which results in the dissolution of Cyt-c in ionic liquid Btmsim PF6. Meanwhile, a cleavage of the 6th coordination bond of the iron atom occurred at pH 1.0 by releasing the Met-80 ligand and giving rise to a vacant coordination position. Thus, the covalent coordination between the cationic Btmsim ~ of ionic liquid and the iron atom of heme group facilitates the transfer of Cyt-c into ionic liquid Btmsim PF6.

关 键 词：细胞色素C 离子液体 萃取 机理 

分 类 号：O658.2[理学—分析化学]