Refolding of denatured-reduced lysozyme facilitated by β-cyclodextrin

The oxidative refolding of denatured-reduced lysozyme in the presence of cetyl trimethyl ammonium bromide (CTAB) and/or β-cyclodextrin (β-CD) was investigated. The renaturation yield was improved in the presence of β-CD which inhibited the hydrophobic interaction between the unfolded protein molecules. However, β-CD concentration should be 3000-5000 times higher than the denatured enzyme to achieve a significant refolding effect. In contrast to β-CD, the refolding system with both CTAB and β-CD showed more favorable effect on the enzyme renaturation. With a properly enhanced guanidine hydrochloride concentration, the enzymatic activity of the denatured-reduced lysozyme could be completely regained. In addition, the optical pH (8.5) and temperature (37°C) was established for the CTAB+β-CD renaturation system.