Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States.
Department of Chemistry, Lomonosov Moscow State University, Moscow, 119992, Russia.
J Phys Chem B. 2021 Jan 28;125(3):757-770. doi: 10.1021/acs.jpcb.0c09221. Epub 2021 Jan 7.
We present the results of high-level electronic structure and dynamics simulations of the photoactive protein Dreiklang. With the goal of understanding the details of the Dreiklang photocycle, we carefully characterize the excited states of the ON- and OFF-forms of Dreiklang. The key finding of our study is the existence of a low-lying excited state of a charge-transfer character in the neutral ON form and that population of this state, which is nearly isoenergetic with the locally excited bright state, initiates a series of steps that ultimately lead to the formation of the hydrated dark chromophore (OFF state). These results allow us to refine the mechanistic picture of Dreiklang's photocycle and photoactivation.
我们呈现了光激活蛋白 Dreiklang 的高水平电子结构和动力学模拟的结果。为了深入理解 Dreiklang 光循环的细节，我们仔细描绘了 Dreiklang 的 ON 态和 OFF 态的激发态。我们研究的关键发现是中性 ON 态中存在一个具有电荷转移特征的低能激发态，而这个状态的填充，与局域激发的亮态几乎同能，引发了一系列步骤，最终导致形成水合的暗生色团（OFF 态）。这些结果使我们能够完善 Dreiklang 光循环和光激活的机制图像。
