Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HVAmsterdam, The Netherlands.
Institut für Biologie, Experimentelle Biophysik, Humboldt-Universität zu Berlin, Invalidenstrasse 42, 10115Berlin, Germany.
J Phys Chem Lett. 2023 Feb 16;14(6):1485-1493. doi: 10.1021/acs.jpclett.2c03110. Epub 2023 Feb 6.
Chrimson is a red-light absorbing channelrhodopsin useful for deep-tissue optogenetics applications. Here, we present the Chrimson reaction dynamics from femtoseconds to seconds, analyzed with target analysis methods to disentangle spectrally and temporally overlapping excited- and product-state dynamics. We found multiple phases ranging from ≈100 fs to ≈20 ps in the excited-state decay, where spectral features overlapping with stimulated emission components were assigned to early dynamics of K-like species on a 10 ps time scale. Selective excitation at the maximum or the blue edge of the absorption spectrum resulted in spectrally distinct but kinetically similar excited-state and product-state species, which gradually became indistinguishable on the μs to 100 μs time scales. Hence, by removing specific protein conformations within an inhomogeneously broadened ensemble, we resolved slow protein backbone and amino acid side-chain motions in the dark that underlie inhomogeneous broadening, demonstrating that the latter represents a dynamic interconversion between protein substates.
Chrimson 是一种红光吸收型通道视紫红质，可用于深层组织光遗传学应用。在这里，我们展示了 Chrimson 从飞秒到秒的反应动力学，通过目标分析方法进行分析，以解耦光谱和时间上重叠的激发态和产物态动力学。我们发现激发态衰减中有多个相位，范围从 ≈100 fs 到 ≈20 ps，其中与受激辐射成分重叠的光谱特征被分配到 K 样物质在 10 ps 时间尺度上的早期动力学。在吸收光谱的最大值或蓝色边缘处进行选择性激发，导致激发态和产物态物种具有明显但动力学相似的光谱特征，这些特征在 μs 到 100 μs 的时间尺度上逐渐变得难以区分。因此，通过在不均匀展宽的体系中去除特定的蛋白质构象，我们在黑暗中解析了导致不均匀展宽的慢蛋白骨架和氨基酸侧链运动，证明后者代表了蛋白质亚基之间的动态转换。
