Figure 2
THz-SAXS data for a BSA solution (c = 5.8 mg/mL) at a nominal power density of Φ = 6.5 mW/cm2 at 0.5 THz (THz source I). a) Single SAXS curves (exposure time: 0.2 s) out of a sequence of 250 frames without (‘THz off’), with (‘THz on’) and for alternating (‘THz alt. off/on’) THz irradiation. Dashed lines: Fits with an oligomeric mixture of BSA monomers and dimers (obtained with OLIGOMER). All curves were shifted along the logarithmic axis for clarity. (b) Radius of gyration Rg determined for a sequence of SAXS frames under different THz-irradiation. Dashed line: average Rg for ‘THz off’ measurements. (c) Normalized histograms of the Rg-distribution. Solid lines: Gaussian fits. (d) Difference of the average radius of gyration ΔRg between THz on- and off -states for several measurements. For alternating radiation, the respective adjacent on/off frames were used. For comparison: Size of the first hydration layer surrounding proteins in solution (dashed line).
