Fig. 3.

Comparison of experimental structure factors $S_M\left(q\right)$ for α-crystallin solutions with polydisperse hard-sphere Percus–Yevick liquid-structure models, showing the basis for the parameter values $p=0.20$ and $d=15$ nm used in the present work. (Top) SAXS $S_M\left(q\right)$ for $c=290$ mg/mL, corresponding to a deduced $\varphi =0.49$. Percus–Yevick predictions are shown for three polydispersity parameters: $p=0$ (monodisperse, thin gray line), $p=0.1$ (dotted-dashed red line), and $p=0.20$ (thick black line). $p=0.20$ closely reproduces the measured $S_M\left(q\right)$, whereas the less polydisperse and monodisperse models do not match the data. (Bottom) Over the entire range of lower α-crystallin concentrations measured, the same polydisperse Percus–Yevick $S_M\left(q\right)$ with $p=0.20$ (solid lines) closely reproduces the experimental $S_M\left(q\right)$.