Apo-1 PfRd is labile to chemical denaturation, while Apo-2 PfRd resists chemical denaturation.

<p><i>Panel a</i>. Far-UV CD spectra of Apo-1 PfRd at two different concentrations of Gdm.HCl. <i>Panel b</i>. Far-UV CD spectra of Apo-1 PfRd, Apo-2 PfRd and holo-PfRd (native) in 6M Gdm.HCl. <i>Panel c</i>. Fluorescence emission spectra of Apo-2 PfRd at two different concentrations of Gdm.HCl. <i>Panel d</i>. Fluorescence emission spectra of Apo-1 PfRd at two different concentrations of Gdm.HCl.