A, Coomassie-stained gel containing aliquots of purified CD23 constructs. B, Gel filtration profile of the 4 CD23 constructs. Adsorptions at 210 and 280 nm (y-axes, milliabsorbance units [mAU]) recorded during elution (x-axes, elution volumes in milliliters and corresponding protein size ranges in kilodaltons) are shown. C, Circular dichroism analysis of the 4 CD23 constructs. An overlay of the 4 circular dichroism spectra of constructs CD23A to CD23D is shown. CD23A, red; CD23B, pink; CD23C, blue; CD23D, yellow. X-axis, wavelength [in nanometers]; y-axis, [θ]mr (mean-residue molar ellipticity).