Figure 5.
Global analysis of time-dependent changes in the HbCO SAXS/WAXS pattern following a T-jump. (A) Time-resolved scattering curves (same as Figure 4C sans offset). (B) Scattering vectors extracted from a two-state model that reproduces the time-resolved scattering curves in part A with high fidelity. This model assumes the hydration shell contribution (blue) to the scattering difference is constant over the time range explored, and assumes the amplitude of the protein contribution (red) evolves according to first-order kinetics. For comparison, the scattering difference for Hb is shown (green). (C) Least-squares fit amplitudes of the two scattering vectors. The red solid curve corresponds to [1 - exp(−t/30 μs)] and tracks time-dependent changes of the protein scattering pattern. The blue curve is constant over time and corresponds to the hydration shell contribution to the scattering difference.