Figure 5.

Analysis of HvASR1 and TtASR1 by circular dichroism. (A) Far-UV CD spectra of HvASR1 and TtASR1 at 0.1 mg/mL in 10 mM sodium phosphate pH 7 at 20 °C. Data are representative of one out of three independent measurements. The inset shows the secondary structure content of the two proteins, as derived using CDSSTR. Grey or light red: unordered; white: turns; black or red: helix; hatched: strand. (B) Plot of the molar residue ellipticity (MRE) at 222 nm and at 200 nm of a set of well-characterized unfolded, random coil-like (RC-like) or premolten globule-like (PMG-like) proteins (from⁴⁰). The position in the plot of HvASR1 and TtASR1 is highlighted by a square and a triangle, respectively. (C) Molar residue ellipticity (MRE) at 230 nm of HvASR1 and TtASR1 as a function of the temperature. The experimental points in the 20–80 °C range were fitted to a sigmoidal curve. Protein and buffer concentrations were the same as described in (A). (D) Near-UV CD spectra of HvASR1 and TtASR1 at 1 mg/mL in 10 mM sodium phosphate pH 7 in the absence or presence of 2 mM ZnSO₄ at 20 °C. Data are representative of one out of two independent acquisitions.