pH-sensitive polymer-assisted refolding of urea-denatured fibroblast growth factor

A pH-responsive polymer Eudragit S-100 has been found to assist in correct folding of FGF-2 (fibroblast growth factor-2) denatured with 8 mol/L urea and 10 mmol/L dithiothreitol at pH 7.2. The refolding of FGF-2 was performed by directly diluting denatured FGF-2 into a refolding buffer containing Eudragit S-100. The ability of Eudragit S-100 to enhance protein refolding level was investigated using MTT method, fluorescence emission spectroscopy and reverse phase HPLC. On the other hand, the result shows the ability of Eudragit S-100 to enhance the refolding level of protein is due to the interaction between Eudragit S-100 and positively charged FGF-2.