一种新型蛋白质沉淀体系——加压CO2-乙醇-水体系

将有机溶剂抗溶剂与高压气体等电沉淀技术结合起来，提出了一种新的蛋白质纯化方法.实验以加压CO₂为挥发性酸，乙醇为助沉淀剂，对BSA的等电沉淀进行了研究.由实验结果可知，本方法可使BSA处理浓度提高，CO₂操作压力降低，其中乙醇既具有促进沉淀的作用又具有降低BSA缓冲能力的作用.蛋白质稳定性测试结果表明，在实验操作条件下，BSA未发生不可逆的构象变化，能保持稳定.这些结果对该方法的进一步完善及其在蛋白质等生物活性成分分离纯化领域的应用具有借鉴作用.

A novel system for protein precipitation--carbon dioxide-water-ethanol system

A novel method for protein purification was presented, which was the integration of organic antisolvent and compressed gas isoelectric precipitation.In this work the study on isoelectric precipitation of BSA in the compressed carbon dioxide-aqueous system was carried out using ethanol as a precipitation assistant and CO 2 as a volatile acid.The precipitation was obvious and it proved that ethanol played two roles in the system.Firstly,ethanol facilitated BSA precipitation at the isoelectric point.Secondly,it reduced the buffer capacity of BSA.This resulted in a decrease of the pressure that was required to reach the isoelectric point so that precipitation could be attained with an increase of maximum BSA concentration that could be acidified to the isoelectric point.Furthermore,the BSA stability in the above processes was investigated, it was shown that there were no irreversible changes in the conformation of BSA, and BSA existed stably in all cases involved.All the experiments indicated that the improvement provided the novel system with an upper hand over the system reported before.The results would be helpful for the development of protein separation and purification techniques.