Extended Data Fig. 9: Determination of the photoactivation yield from steady state difference SAXS.
(a.) Smoothed difference SAXS curves (light–dark) on top of raw difference SAXS curves for 20 s illumination time. (b.) Zoom-in and overlay of the difference SAXS curves (light–dark) at all illumination times of AsLOV2. The difference signal saturated for illuminations of more than five seconds, indicating that the maximum photoactivation yield of 100% had been achieved. (c.) The XFEL scattering was then scaled to the SAXS scattering from Diamond to facilitate direct comparison between them. (d.) The photoactivation of the XFEL was subsequently determined by comparing the ratio between the scaled XFEL and the saturated SAXS difference scattering. From this analysis, we determined that the photoexcitation yield at the XFEL was approximately 15%. The scattering obtained from the SAXS experiment was smoothed using a Savitzky–Golay filter with a window length of 120 and 1st degree polynomial if nothing else is stated. The SAXS data was recorded at Diamond Light Source, beamline B21.
