(1) Preparation of denatured proteins
Denatured CA (0.25 mg/mL) was prepared by dissolving CA in 0.05 M Tris-HCl (pH 7.5) and 5 M GdnHCl at room temperature overnight and filtering with a 0.45 μm polysyringe philtre (product name) before use, to produce denatured CA solution.