title: Conformational and Intermolecular Interaction Dynamics of Photolyase/Cryptochrome Proteins Monitored by the Time-Resolved Diffusion Technique.
abstract: Cryptochrome (CRY), a blue light sensor protein, possesses a similar domain structure to photolyase (PHR) that, upon absorption of light, repairs DNA damage. In this review, we compare the reaction dynamics of these systems by monitoring the reaction kinetics of conformational change and intermolecular interaction change based on time-dependent diffusion coefficient measurements obtained by using the pulsed laser-induced transient grating technique. Using this method, time-dependent biomolecular interactions, such as transient dissociation reactions in solution, have been successfully detected in real time. Conformational change in (6-4) PHR has not been detected after the photoexcitation by monitoring the diffusion coefficient. However, the repaired DNA dissociates from PHR with a time constant of 50 μs, which must relate to a minor conformational change. However, CRY exhibits a considerable diffusion change with a time constant of 400 ms, which indicates that the protein-solvent interaction is changed by the conformational change. The C-terminal domain of CRY is shown to be responsible for this change.
authors.affiliation: Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kondoh
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Terazima
mesh_terms: D056931:Cryptochromes / Q000737:chemistry*; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry*; D004058:Diffusion; D055668:Photochemical Processes; D011487:Protein Conformation; D012997:Solvents / Q000737:chemistry; D013997:Time Factors
chemical_list: D056931:Cryptochromes; D012997:Solvents; D004247:DNA; D004255:Deoxyribodipyrimidine Photo-Lyase