天然低共熔溶剂对绿色荧光蛋白的保护作用

天然低共熔溶剂（natural deep eutectic solvent，NADES）是一种新型的绿色环保溶剂，可应用于天然活性物质的提取及生物催化。本研究以绿色荧光蛋白（green flurescent protein，GFP）为模式蛋白，探究了不同NADES对GFP在70 ℃下的稳定性的影响，发现氯化胆碱-山梨醇（Choline chloride sorbital，CS）对GFP在70 ℃的热处理下荧光保留率最好；并探究了不同含水量的CS天然低共熔溶剂对GFP稳定性的影响，发现在含水量为40%的CS天然低共熔溶剂中GFP的稳定性最佳；同时发现在含水量为40%的CS天然低共熔溶剂体系下的GFP可以提高对SDS的耐受性，但对H2O2的耐受性的提高不明显；CS天然低共熔溶剂也有利于提高脂肪酶AOL在45 ℃下的的热稳定性。综上CS天然低共熔溶剂对蛋白质有良好的保护作用，在食品加工及生物催化领域具有潜在的应用前景。
Natural deep eutectic solvent (NADES) is a new kind of “green” solvent, which can be applied to the extraction and biocatalysis of natural bioactive substances. In this study, green fluorescent protein (GFP) was used as a model protein for investigations on the protective effects of different NADESs on the stability of GFP at 70 ℃. It was found that the hightest fluorescence retention rate of GFP was in choline chloride sorbital (CS) under heat treatment at 70 ℃. The effect of the water content in CS NADES on the stability of GFP was examined, and CS NADES with a water content of 40% had the highest stability. CS NADES with 40% water content also enhanced the tolerance of GFP against SDS, but didn’t improve significantly the tolerance of GFP. CS NADES also contributed to the improvement of the thermal stability of lipase AOL at 45 ℃. In summary, CS NADESs provided a good protective effect on proteins and have application prospects in the fields of food processing and biocatalysis.