FIGURE 5.

Circular dichroism spectra of wild type and mutant ABCA4-ECD2 polypeptides. CD spectra were collected from highly purified homogeneous preparations of recombinant wild type (WT) and mutant ECD2 polypeptides. Far-UV (200–250 nm) CD spectra were acquired as described under “Experimental Procedures.” The concentrations of ECD2 polypeptides were 0.1 mg/ml in 10 mm NaPO₄ (pH 7.5), 25 mm NaCl.