Quantum dynamics of the femtosecond photoisomerization of retinal in bacteriorhodopsin.
Quantum dynamics of the femtosecond photoisomerization of retinal in bacteriorhodopsin.
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DOI：
10.1039/a801310a
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发表时间：
1998
影响因子：
3.4
通讯作者：
M. Ben-Nun;F. Molnár;Hui Lu;James C. Phillips;T. J. Martinez;K. Schulten
中科院分区：
文献类型：
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作者：
M. Ben-Nun;F. Molnár;Hui Lu;James C. Phillips;T. J. Martinez;K. Schulten
膜蛋白细菌视紫红质在由氨基酸侧基和水分子排列的结合位点中含有全反式视黄醇，所述氨基酸侧基和水分子引导视黄醇的光动力学。在吸收光时，视黄醛经历亚皮秒全反式->13-顺式光转化，涉及围绕双键的扭转。主要反应产物引发蛋白质中随后的事件，诱导质子通过细菌视紫红质泵送。量子化学计算表明，三个耦合的电子态，基态和两个紧密躺在激发态，参与运动沿着扭转反应坐标φ。这三个电子表面上的蛋白质视网膜系统的演变已经建模使用非绝热动力学的多产卵方法。我们发现，虽然大多数的人口转移发生在300 fs的时间尺度上，一些人口转移发生在一个更长的时间尺度上，偶尔延伸远远超过1 ps。
The membrane protein bacteriorhodopsin contains all-trans-retinal in a binding site lined by amino acid side groups and water molecules that guide the photodynamics of retinal. Upon absorption of light, retinal undergoes a subpicosecond all-trans-->13-cis phototransformation involving torsion around a double bond. The main reaction product triggers later events in the protein that induce pumping of a proton through bacteriorhodopsin. Quantum-chemical calculations suggest that three coupled electronic states, the ground state and two closely lying excited states, are involved in the motion along the torsional reaction coordinate phi. The evolution of the protein-retinal system on these three electronic surfaces has been modelled using the multiple spawning method for non-adiabatic dynamics. We find that, although most of the population transfer occurs on a timescale of 300 fs, some population transfer occurs on a longer timescale, occasionally extending well beyond 1 ps.