Fig. 5.

SAXS profiles of AT can be described as mixtures of AT₃ and AT₁₂. A, scattering curves for AT₃ and AT₁₂, computed from the dodecameric crystal structure (2bx9). B-D, left, experimental scattering intensities (black) for AT recorded over a range of pHs (6, 7, 7.5, 8) and concentrations (1.77, 0.89 and 0.44 mM), fit to a two-state model with varying fractions of AT₃ and AT₁₂. Profiles are offset in the y-axis from each other for visibility. Right, fitted volume fractions as a function of pH for each sampled concentration.