... A JASCO J 600 spectropolarimeter was used torecord the CD spectra. For far- and near-UV CD, cuvettesof 0. 1- and 10-cm pathlengths were used, respectively.Intrinsic tryptophan fluorescence (kex¼ ... carried out at room temperature(25 ± 2 C) in 20 mMTris/HCl, pH 8.0, containing 1 mMEDTA and 100 mMNaCl (buffer E).Circular dichroism and fluorescence experimentsFar-UV CD and fluorescence ... proteins. The effect of low concen-trations of GdnHCl on the secondary structure of CII wasexamined by measuring the CD at 220 nm as a function ofGdnHCl concentration. A significant increase (% 30%)...