Effects of buffer ionic composition on the native structure of PaBADH and SoBADH.

(A and B) SEC elution profiles of PaBADH (solid line) and SoBADH (dotted line) in 1 mM Pipes-TEAOH, pH 6.9, containing 1 mM EDTA and 0.5 mM DTT (non-salt buffer) (B), or in this buffer plus 250 mM KCl (K-buffer) (A). Arrows denote the positions of molecular-mass standards, from left to right: bovine tyroglobulin (670 kDa), bovine liver catalase (240 kDa), bovine gamma-globulin (158 kDa) and horse myoglobin (17 kDa). (C and D) DLS measurements. Hydrodynamic radius distribution plots of PaBADH (top of panels C and D) and SoBADH (bottom of panels C and D) in K-buffer (C) and non-salt buffer (D). Histograms are representative of volume-weighted size distributions of 0.25 mg/ml enzyme samples.