Coherent control of retinal isomerization in bacteriorhodopsin
Coherent control of retinal isomerization in bacteriorhodopsin
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DOI：
10.1126/science.1130747
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发表时间：
2006-09-01
期刊：
影响因子：
56.9
通讯作者：
Miller, R. J. Dwayne
中科院分区：
文献类型：
--
作者：
Prokhorenko, Valentyn I.;Nagy, Andrea M.;Miller, R. J. Dwayne
在细菌视紫红质中的视网膜分子从全反式到13-顺式状态的光异构化的主要步骤的光学控制在弱场条件下被证明（其中300个视网膜分子中只有1个在激发循环期间吸收光子），这与理解生物过程有关。通过调制光激发脉冲中光谱成分的相位和振幅，我们表明，激发时形成的13-顺式视黄醛的绝对量可以被增强或抑制+/-20%的产率，所述产率是使用具有相同光化能量的短变换限制脉冲观察到的。整形脉冲被证明是相位敏感的强度太低，访问不同的更高的电子状态，所以这些脉冲显然引导异构化通过建设性和破坏性的干涉效应，一个机制所观察到的振动相干性的签名支持。这些结果表明，在像蛋白质这样大而复杂的系统中，物质的波动特性可以被观察到，甚至可以被操纵。
Optical control of the primary step of photoisomerization of the retinal molecule in bacteriorhodopsin from the all-trans to the 13-cis state was demonstrated under weak field conditions (where only 1 of 300 retinal molecules absorbs a photon during the excitation cycle) that are relevant to understanding biological processes. By modulating the phases and amplitudes of the spectral components in the photoexcitation pulse, we showed that the absolute quantity of 13-cis retinal formed upon excitation can be enhanced or suppressed by +/-20% of the yield observed using a short transform-limited pulse having the same actinic energy. The shaped pulses were shown to be phase-sensitive at intensities too low to access different higher electronic states, and so these pulses apparently steer the isomerization through constructive and destructive interference effects, a mechanism supported by observed signatures of vibrational coherence. These results show that the wave properties of matter can be observed and even manipulated in a system as large and complex as a protein.