Fig. 4.

Sedimentation velocity experiments over a range of pH values can be fit with a three-state association model AT₃ ↔ (AT₃)₂ ↔ AT₁₂. Interference fringe shifts (gray dots) are globally fit across three AT concentrations (first three columns). Fits provided by the mechanistic model are in blue, green, and red lines. Only every tenth scan is shown. Residuals are below the data. Fourth column, sedimentation coefficient distributions with blue, red and green corresponding to the concentrations on the left, at pH 7.00 (A), pH 7.25 (B), pH 7.50 (C), pH 7.75 (D), and pH 8.00 (E).