Pieper Jörg, Buchsteiner Alexandra, Dencher Norbert A, Lechner Ruep E, Hauss Thomas
Max-Volmer-Laboratories for Biophysical Chemistry, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
Phys Rev Lett. 2008 Jun 6;100(22):228103. doi: 10.1103/PhysRevLett.100.228103. Epub 2008 Jun 3.
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.
蛋白质的正常功能通常需要皮秒时间尺度上随机结构波动所提供的一定内部灵活性。与传统稳态实验不同，我们报道了一种新型的（激光 - 中子）泵浦 - 探测实验，该实验将蛋白质功能的原位激活与使用准弹性中子散射对蛋白质动力学的时间依赖性测试相结合。结果表明，在细菌视紫红质的光循环过程中会发生“瞬时蛋白质软化”，这直接证明了蛋白质灵活性的功能意义。
