(619g) Cyclodextrin Conjugated Magnetic Nanoparticles as a Solid-Phase Artificial Chaperone for Protein Refolding

A solid-phase artificial chaperone (CD-APES-MNPs) was fabricated for protein refolding by grafting mono-tosyl-â-cyclodextrin (TsCD) onto (3-aminopropyl) triethoxysilane (APES) modified magnetic nanoparticles. For confirmation of the grafting of â-CD onto nano-sized magnetic particles, characterizations were carried out using Fourier Transform Infra-Red Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Vibrating Sample Magnetometer (VSM), X-ray Diffraction (XRD) and elemental analyses.

The use of CD-APES-MNPs as a solid-phase artificial chaperone to assist protein refolding in vitro was demonstrated using carbonic anhydrase from bovine (CA) and lysozyme as model proteins.Our refolding results indicate that the as-synthesized magnetic nanoparticles can greatly affect the refolding yields of thermally denatured CA and urea denatured lysozyme. Under the optimal refolding environment, the maximum refolding yield obtained was 89% for 0.029 mg/ml of CA and 70% for 0.05 mg/ml lysozyme proteins which were as the same level as that using liquid-phase artificial chaperone-assisted refolding. Additionally, the stripping agents can be easily separated from the refolded-active protein solution by magnetic decantation and can be re-used after recycling. Our results reveal that CD-APES-MNPs is a suitable and efficient host matrix for general use in solid-phase artificial chaperone-assisted refolding.