KCS

Understanding the photocycle of Photoactive Yellow Protein (PYP) is critical for deciphering its biological functions, and may eventually provide valuable information for designing photo-sensing materials. For this reason, numerous attempts have been devoted to investigate its photocycle and signaling pathways. Unlike the classical X-ray crystallography using monochromatic X-rays without utilizing the pulsed structure of the synchrotron radiation, we conducted time-resolved Laue crystallography to search intermediates in the photocycle. After the photo-reaction is triggered by a picosecond laser pulse (pump), picosecond X-ray pulse (probe) from a synchrotron was used to investigate its structural dynamics. We succeeded in extracting early intermediate structures at 100 ps.