复合胶束辅助蛋白酶复性的研究

Protein Refolding Assisted by Thermosensitive Complex Micelles

提出了一种使用复合胶束模拟分子伴侣来辅助蛋白质折叠的方法.制备了3种由不同比例的嵌段共聚物聚乳酸-b-聚(N-异丙基丙烯酰胺)(PLA-b-PNIPAM)与聚乳酸-b-聚乙二醇(PLA-b-PEG)组成的温敏性的复合胶束(mixed-shell polymeric micelles,MSPMs),通过动态光散射考察了复合胶束在37℃以及在变性剂存在下的稳定性.以碳酸酐酶(CAB)和脂肪酶(Lipase)作为模型蛋白,研究了MSPM辅助蛋白质折叠的能力.结果表明,在高浓度变性剂存在下,PNIPAM仍具有温敏性,并且摩尔比为1∶1的PLA-b-PNIPAM和PLA-b-PEG制备的MSPM具有非常好的稳定性.不同比例的MSPM对于CAB和Lipase都具有辅助复性效果,远远高于没有MSPM时的自发复性.其中,摩尔比为1∶1的MSPM使CAB的复性率高达92.1%,Lipase的复性率也达到50%.

A new method for assisting protein folding by using thermosensitive mixed-shell polymeric micelles（MSPMs） as artificial chaperone was introduced.Three kinds of novel thermosensitive MSPMs with different ratios of PLA-b-PEG and PLA-b-PNIPAM were prepared.The stability of MSPMs at different concentrations of guanidine hydrochloride（Gu HCl） and urea or at 37 ℃ was characterizaed by dynamic light scattering（DLS）.Carbonic anhydrase B（CAB） and lipase were chosen as model proteins to illustrate the effect of protein refolding assisted by thermosensitive MSPMs.The results showed that the thermosensitive property of PNIPAM was maintained and the stability of MSPM with PLA-b-PNIPAM / PLA-b-PEG ratio of 1 ∶ 1 was very good even under conditions of high concentration of denaturant or 37 ℃.Furthermore,all the three kinds of MSPMs with ratio of 2∶ 1,1∶ 2 and 1∶ 1 can promote the refolding of denatured CAB and lipase,which are much higher than the yields of spontaneous refolding.The MSPM with molar ratio of 1 ∶ 1 can enhance the refolding yield of CAB to reach as high as 92.1% and that of lipase to reach 50%.