噬菌调理素中视网膜异构化作用的连贯控制
据《科学》杂志2006年9月1日封面文章报道，从全反式到13-顺式对噬菌调理素中视网膜分子光致异构化的第一个步骤的视力控制是在弱学科条件下被展示的，在这些条件下，300个视网膜分子中只有一个能在兴奋周期中吸收一个光子，这些条件与理解生物过程有密切联系。通过调节照片激感脉冲中光谱成分的状态和振幅，我们看到，激感上形成的13-顺式视网膜分子的绝对数量可以被增加或减少20%左右，这是通过使用一个有着同样光化学能量的限制变化短脉冲观察到的。变过形的脉冲在低强度下显得很敏感，这种强度很小，因此很难进入更高的电子状态。于是，很明显地，这些脉冲能给通过破坏性和建设性的干扰效应来操控异构化作用。观测到的振动一致信号更支持了这样一种机制。这些结果表明，物质的波属性能被一个和蛋白质一样大小及复杂的系统所观察甚至操控。
英文原文：
Coherent Control of Retinal Isomerization in Bacteriorhodopsin
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.
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