title: Transient protein softening during the working cycle of a molecular machine.
abstract: Proper functioning of proteins usually requires a certain internal flexibility provided by stochastic structural fluctuations on the picosecond time scale. In contrast with conventional steady-state experiments, we report on a novel type of (laser-neutron) pump-probe experiment combining in situ activation of protein function with a time-dependent test of protein dynamics using quasielastic neutron scattering. A "transient protein softening" is shown to occur during the photocycle of bacteriorhodopsin as a direct proof for the functional significance of protein flexibility.
authors.affiliation: Max-Volmer-Laboratories for Biophysical Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany. joerg.pieper@tu-berlin.de
authors.forename: Jörg
authors.initials: J
authors.lastname: Pieper
authors.forename: Alexandra
authors.initials: A
authors.lastname: Buchsteiner
authors.forename: Norbert A
authors.initials: NA
authors.lastname: Dencher
authors.forename: Ruep E
authors.initials: RE
authors.lastname: Lechner
authors.forename: Thomas
authors.initials: T
authors.lastname: Hauss
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D019617:Halobacterium salinarum / Q000737:chemistry; D007834:Lasers; D008956:Models, Chemical; D008958:Models, Molecular; D010777:Photochemistry; D017494:Proton Pumps / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013816:Thermodynamics
chemical_list: D017494:Proton Pumps; D001436:Bacteriorhodopsins