Structural dynamics within the VWF C4 domain. (A) Experimental R₂/R₁ values derived from ¹⁵N relaxation NMR experiments at 600 MHz. Wt (black) and Y2561 variant (red) show similar profiles, indicating very similar dynamics. At high concentrations (hc, yellow), R₂/R₁ values increase globally. (B) MD simulation of spin relaxation parameters predicts a very similar profile except for the exchange contribution of V2547. Error bars indicate standard deviation produced from 4 trajectory subchunks. (C) Rotational correlation time (τ_c) of wt and Y2561 variant at 4 different field strengths. The Y2561 variant shows elevated τ_c values, which further increase upon elevated concentration. (D) R₂ values at 4 different fields for both wt and Y2561 variant are similar and show field dependence of R_ex for residue V2547. B₀, magnetic field strength.