Resolution dependence of the onset of protein dynamical transition. Neutron spectrometers with different resolutions (1, 13, 25.4 and 100 µeV) were applied. Elatic intensity S(q, Δt) of (a, b) dry H-LYS and H-LYS in D2O at h = 0.3, (c, d) dry H-MYO and H-MYO in D2O at h = 0.3, and (e-g) dry H-CYP and H-CYP in D2O at h = 0.4. All the experimental S(q, Δt) are normalized to data measured at ∼10 K and summed over values of q ranging from 0.45 to 1.75 Å−1. The dashed lines in each figure identify the onset temperatures of the transition, Ton, where the neutron data of the hydrated system deviate from the dry form. The same analyses are used in Figs. 2 to 4 and S2 to S5.

Hydration dependence of the onset of protein dynamical transition. S(q, Δt) of (a) dry H-CYP and H-CYP in D2O at h = 0.2 and 0.4 and (c) dry H-LYS and H-LYS in D2O at h = 0.18, 0.30 and 0.45, all measured using HFBS with the instrumental resolution of 1 μeV. All the Data in (c) were replotted from Ref. (26). (b) DSC curves obtained for dry H-CYP and H-CYP in water at h = 0.2 and 0.4. TDSC is defined as the midpoint between two heat flow baselines, where (35,36,49).

Resolution dependence of the anharmonic onset of hydration water. Neutron spectrometers with different resolutions (1, 25.4 and 100 µeV) were applied. S(q, Δt) of (a, b) dry D-GFP and D-GFP in H2O at h = 0.4, and (c-e) dry D-CYP and D-CYP in H2O at h = 0.4.

Hydration dependence of the anharmonic onset of hydration water. S(q, Δt), for dry D-CYP and D-CYP in H2O at h = 0.2 and 0.4, measured using HFBS neutron instrument with an energy resolution of 1 µeV.