Thermal stability of lysozyme dissolved in aqueous solutions was examined in the presence of water-miscible aprotic ionic liquids consisting of 1-ethyl-3-methylimidazolium cation and several kinds of anions. Addition of ionic liquids to an aqueous solution containing lysozyme prevented unfolded proteins from aggregating irreversibly at high temperatures. The thermal denaturation curve of lysozyme with ionic liquids was entirely shifted to higher temperature, compared with that without ionic liquids. The remaining activity of lysozyme after the heat treatment was markedly dependent upon the kind and concentration of ionic liquids. The remaining activi-ties of lysozyme with 1.5 M 1-ethyl-3-methylimida-zolium tetrafluoroborate ([emim][BF4]) and 0.1 M 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][Tf]) exhibited 88 and 68% after the heat treatment at 90oC for 30 min, respectively, although that without ionic liquids was perfectly lost.
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机译：在由1-乙基-3-甲基咪唑鎓阳离子和几种阴离子组成的与水混溶的非质子离子液体的存在下，检查了溶解在水溶液中的溶菌酶的热稳定性。向含有溶菌酶的水溶液中加入离子液体可防止未折叠的蛋白质在高温下不可逆地聚集。与没有离子液体的溶菌酶相比，溶菌酶的热变性曲线完全移到了更高的温度。热处理后，溶菌酶的剩余活性明显取决于离子液体的种类和浓度。 1.5 M 1-乙基-3-甲基咪唑鎓四氟硼酸盐（[emim] [BF4]）和0.1 M 1-乙基-3-甲基咪唑鎓三氟甲烷磺酸（[emim] [Tf]）的溶菌酶的剩余活性显示为88和在90oC热处理30分钟后，分别有68％的样品消失了，尽管没有离子液体的样品也完全消失了。
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