Molecular chaperone-like activity of hydrogel nanoparticles of hydrophobized pullulan: thermal stabilization with refolding of carbonic anhydrase B.
We have been studying the formation of hydrogel nanoparticles by the self-aggregation of hydrophobized polysaccharide and the effective complexation between these nanoparticles as a host and various globular soluble proteins as a guest. This paper describes a new finding that refolding of the heat-denatured enzyme effectively occurs with the nanoparticles and beta-cyclodextrin according to a mechanism similar to that of a molecular chaperone. In particular, the irreversible aggregation of carbonic anhydrase B (CAB) upon heating was completely prevented by complexation between the heat-denatured enzyme and hydrogel nanoparticles formed by the self-aggregation of cholesteryl group-bearing pullulan (CHP). The complexed CAB was released by dissociation of the self-aggregate upon the addition of beta-cyclodextrin. The released CAB refolded to the native form, and almost 100% recovery of the activity was achieved. The thermal stability of CAB was drastically improved by capture of the unfolded form which was then released to undergo refolding.
Akiyoshi
K
K
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida-Hommachi, Sakyo-ku, Kyoto 606-8501, Japan.
Sasaki
Y
Y
Sunamoto
J
J
D002256:Carbonic Anhydrases / Q000737:chemistry*; D018833:Chaperonins / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry*; D006001:Glycoconjugates / Q000737:chemistry*; D006358:Hot Temperature; D020100:Hydrogels / Q000737:chemistry*; D010316:Particle Size; D011489:Protein Denaturation; D017510:Protein Folding
D005936:Glucans; D006001:Glycoconjugates; D020100:Hydrogels; C009109:pullulan; D018833:Chaperonins; D002256:Carbonic Anhydrases