Kort R, Vonk H, Xu X, Hoff W D, Crielaard W, Hellingwerf K J
Department of Microbiology, University of Amsterdam, The Netherlands.
FEBS Lett. 1996 Mar 11;382(1-2):73-8. doi: 10.1016/0014-5793(96)00149-4.
Analysis of the chromophore p-coumaric acid, extracted from the ground state and the long-lived blue-shifted photocycle intermediate of photoactive yellow protein, shows that the chromophore is reversibly converted from the trans to the cis configuration, while progressing through the photocycle. The detection of the trans and cis isomers was carried out by high performance capillary zone electrophoresis and further substantiated by 1H NMR spectroscopy. The data presented here establish the photo-isomerization of the vinyl double bond in the chromophore as the photochemical basis for the photocycle of photoactive yellow protein, a eubacterial photosensory protein. A similar isomerization process occurs in the structurally very different sensory rhodopsins, offering an explanation for the strong spectroscopic similarities between photoactive yellow protein and the sensory rhodopsins. This is the first demonstration of light-induced isomerization of a chromophore double bond as the photochemical basis for photosensing in the domain of Bacteria.
对从光活性黄色蛋白的基态和长寿命蓝移光循环中间体中提取的发色团对香豆酸的分析表明，在光循环过程中，发色团从反式构型可逆地转变为顺式构型。通过高效毛细管区带电泳对反式和顺式异构体进行了检测，并通过1H NMR光谱进一步证实。本文提供的数据确立了发色团中乙烯基双键的光异构化作为光活性黄色蛋白（一种真细菌光感受蛋白）光循环的光化学基础。在结构上差异很大的感官视紫红质中也发生了类似的异构化过程，这为光活性黄色蛋白和感官视紫红质之间强烈的光谱相似性提供了解释。这是首次证明发色团双键的光诱导异构化作为细菌领域光传感的光化学基础。
