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 (GuHCl) 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%.