Institut für Biochemie und Biotechnologie, Martin-Luther-Universität Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany.
J Biotechnol. 2010 Oct 1;150(1):64-72. doi: 10.1016/j.jbiotec.2010.07.003. Epub 2010 Jul 12.
Several ionic liquids have been shown to act as suppressors of protein aggregation and to effectively promote the in vitro refolding of denatured proteins. In this work, the influence of the anion of these organic salts on their performance as refolding enhancers was tested, using a series of N-ethyl-N'-methyl imidazolium (EMIM) salts. Variation of the anion had a profound effect on the renaturation of the recombinant plasminogen activator rPA, which served as a model protein. The effect was roughly correlated with the stability of proteins in the tested aqueous ionic liquid solutions. Strongly destabilizing anions with higher alkyl substitutions like, e.g., hexyl sulfate were unable to promote protein refolding. However, the dimethyl and diethyl phosphate salts, which are known to be quite compatible with protein stability, also effectively suppressed renaturation, while alkylated sulfate anions with the same influence on protein stability did promote in vitro refolding. Only ionic liquid co-solvent systems with an intermediate capacity for solubilizing the proteinogenic amino acid tryptophan were found to permit effective renaturation of the model protein rPA. The most effective refolding enhancer among the tested ionic liquids was EMIM chloride.
已有研究表明，几种离子液体可以抑制蛋白质聚集，并有效地促进变性蛋白质的体外重折叠。在这项工作中，使用一系列 N-乙基-N'-甲基咪唑鎓（EMIM）盐测试了这些有机盐阴离子对其作为重折叠增强剂性能的影响。阴离子的变化对重组纤溶酶原激活剂 rPA 的复性有深远的影响，rPA 作为模型蛋白。这种影响与在测试的含水离子液体溶液中蛋白质的稳定性大致相关。具有更高烷基取代的强去稳定阴离子，如己基硫酸盐，不能促进蛋白质重折叠。然而，二甲基和二乙基磷酸盐盐，已知与蛋白质稳定性非常相容，也有效地抑制了复性，而对蛋白质稳定性有相同影响的烷基化硫酸盐阴离子则促进了体外重折叠。只有具有中等溶解蛋白色氨酸能力的离子液体共溶剂系统才被发现允许模型蛋白 rPA 的有效复性。在所测试的离子液体中，最有效的重折叠增强剂是 EMIM 氯化物。
