Fig. 5.

CD spectra of the curcumin-converting enzyme and the ellipticity in different pH values. The CD spectra of CurA treated in 10-mM Britton-Robinson buffer pH 6.0 (A) and pH 2.1 (B); 0.1 mg/mL of the purified enzyme was treated at different pH values in 10-mM Britton-Robinson buffer and CD spectra were measured. The mollar ellipticity (θ) was then calculated for the different pHs. θ₂₂₂ was denoted by dotted line. (C) θ₂₂₂ at different pH values. The CD spectra of CurA after the pH was shifted from 6.0 to 6.0 (D) and from 2.1 to 6.0 (E); 0.1 mg/mL of the purified enzyme was treated at different pH values in 10-mM Britton-Robinson buffer and then shifted to the usual pH 6.0 using 40-mM Britton-Robinson buffer (pH 6.0), and then the CD spectrum was measured and θ₂₂₂ was denoted by a dotted line. (F), θ₂₂₂ after the pH had been shifted from various values to 6.0.