Light-induced dynamics changes of a LOV photoreceptor investigated using time-resolved quasi-elastic neutron scattering

Members of the LOV protein family are blue-light photoreceptors employing LOV domains as photosensory modules. LOV domains are structurally well-conserved that typically bind a flavin chromophore. Upon light absorption, they undergo a covalent bond formation between the C4a atom of the flavin ring and the sulfur of the neighboring cysteine residue. The photocycle is thermally reversible and in the dark, the FMN-cysteinyl adduct decays to the ground state on a timescale of seconds to days. In this proposal, we suggest investigating changes of molecular dynamics through the dark recovery process of the photoreceptor PpSB1-LOV by time-resolved (TR) QENS experiments on IRIS after illumination of the photoreceptor in situ in the neutron beam. TR-QENS experiments are suggested to be performed as function of temperature to provide deeper insights into the kinetic mechanism.