Department of Biological Engineering, Inha University, Incheon, 402-751, Republic of Korea.
Appl Biochem Biotechnol. 2013 Nov;171(5):1289-98. doi: 10.1007/s12010-013-0422-9. Epub 2013 Aug 23.
Ionic liquids (ILs) are molten salts which do not crystallize at room temperature. Tunable physicochemical properties of ILs including hydrophobicity and polarity facilitate their applications in many biological processes. In this study, a copper-based IL was employed in order to enhance the refolding efficiency of laccase from Trametes versicolor which requires copper as a cofactor. When 1-ethyl-3-methylimidazolium trichlorocuprate ([EMIM][CuCl₃]) was added to refolding buffer instead of urea, the laccase refolding yield was improved more than 2.7 times compared to the conventional refolding buffer which contains urea. When the refolding of laccase was carried out at different temperatures (4, 25, and 37 °C), the highest refolding yield was obtained at 25 °C. At low temperature, two conflicting effects, i.e., suppression of the aggregate formation and decrease of folding rate, influence the protein refolding. In contrast, a copper-based IL did not enhance the refolding of lysozyme, a non-copper-containing protein. From these results, we can conclude that this copper-based IL, [EMIM][CuCl₃], was exclusively effective on the refolding process of a copper-containing protein.
离子液体（ILs）是在室温下不结晶的熔融盐。ILs 的可调物理化学性质，包括疏水性和极性，使其在许多生物过程中得到应用。在这项研究中，使用了一种铜基 IL，以提高需要铜作为辅助因子的变色栓菌漆酶的复性效率。当 1-乙基-3-甲基咪唑三氯化铜([EMIM][CuCl₃])添加到复性缓冲液中而不是脲时，与含有脲的常规复性缓冲液相比，漆酶的复性产率提高了 2.7 倍以上。当在不同温度（4、25 和 37°C）下进行漆酶复性时，在 25°C 下获得了最高的复性产率。在低温下，两种相互矛盾的效应，即抑制聚集形成和降低折叠速率，影响蛋白质复性。相比之下，铜基 IL 并没有增强不含铜的蛋白质溶菌酶的复性。从这些结果可以得出结论，这种铜基 IL，[EMIM][CuCl₃]，专门对含铜蛋白质的复性过程有效。
