Design of Phosphonium-Type Zwitterion as an Additive to Improve Saturated Water Content of Phase-Separated Ionic Liquid from Aqueous Phase toward Reversible Extraction of Proteins

International Journal of Molecular Sciences

Yoritsugu Ito¹  Yuki Kohno¹  Nobuhumi Nakamura¹ 

[1] Department of Biotechnology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei, Tokyo 184-8588, Japan; E-Mails:

关键词: ionic liquid/water biphasic system;    protein extraction;    zwitterion;    hydrophobicity;    recovering;   

DOI  :  10.3390/ijms140918350

来源: mdpi

【 摘 要 】

We designed phosphonium-type zwitterion (ZI) to control the saturated water content of separated ionic liquid (IL) phase in the hydrophobic IL/water biphasic systems. The saturated water content of separated IL phase, 1-butyl-3-methyimidazolium bis(trifluoromethanesulfonyl)imide, was considerably improved from 0.4 wt% to 62.8 wt% by adding N,N,N-tripentyl-4-sulfonyl-1-butanephosphonium-type ZI (P₅₅₅C4S). In addition, the maximum water content decreased from 62.8 wt% to 34.1 wt% by increasing KH₂PO₄/K₂HPO₄ salt content in upper aqueous phosphate buffer phase. Horse heart cytochrome c (cyt.c) was dissolved selectively in IL phase by improving the water content of IL phase, and spectroscopic analysis revealed that the dissolved cyt.c retained its higher ordered structure. Furthermore, cyt. c dissolved in IL phase was re-extracted again from IL phase to aqueous phase by increasing the concentration of inorganic salts of the buffer solution.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland