Ultrafast pump-probe spectroscopy of native etiolated oat phytochrome.
Ultrafast pump-probe spectroscopy of native etiolated oat phytochrome.
复制标题
天然黄化燕麦光敏色素的超快泵探针光谱。
DOI：
10.1021/bi00080a024
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Struve,WS
中科院分区：
文献类型：
--
作者：
Savikhin,S;Wells,T;Song,PS;Struve,WS
Pfr转化天然燕麦光敏色素。这些实验使用低强度激光脉冲在高重复率；快速的样品回收确保了基本上所有光敏色素都从Pr基态被激发。在波长> ~ 670 nm处，Pr*受激辐射衰减显示出寿命为~ 16和50 ~ 60 ps的主要成分。在受激辐射衰减之后，695 nm的渐近光r吸收光谱迅速形成。光激发一种或两种lumi-R中间体的光激发会立即重新产生荧光Pr*光敏色素，这在光谱和动力学上与直接照射基态Pr所产生的光敏色素没有区别。这与lumi-R作为一个物种的分配是一致的，在这个物种中，发色团从，，异构到，，构象。各向异性研究表明，在实验的500-ps时间窗内，各向异性衰减很小，因此Pr和lumi-R吸收跃迁矩的取向几乎是平行的。植物色素蛋白光敏色素光转化的激发态动力学和暗反应引起了相当大的兴趣（Linschitz etal., 1966； Cross等）。, 1968;Braslavsky等等。, 1980;Shimizaki et al., 1980；Cordonnier et al., 1981；Song et al., 1981,1986；Holzwarth et al., 1984；Ruzsicska et al., 1985；Brock et al., 1987)。绿色植物中的这种光感受器介导200多种生物反应的调节，包括叶绿素、类胡萝卜素、rubisco和类囊体膜的生物合成。黄化燕麦中未降解光敏色素
Pfr transformation innative oat phytochrome. These experiments were performed using low-intensity laser pulses at high repetition rate; fast sample recycling ensured that essentially all phytochrome species were excited from the Pr ground state. The Pr*-stimulated emission decay at wavelengths> 670 nm exhibits major components with lifetimes of~ 16 and 50-60 ps. Formation of the asymptotic 695-nm lumi-R absorption spectrum rapidly follows stimulated emission decay. Photoexcitation of one or both of the lumi-R intermediates instantaneously recreates fluorescing Pr* phytochrome, which is spectroscopically and kinetically indistinguishable from that generated by direct illumination of ground-state Pr. This is consistent with assignment of lumi-R as a species in which the chromophore has isomerized from the,, to the,, conformation. Anisotropy studies indicate that the orientations of the Pr and lumi-R absorption transition moments are nearly parallel, since little anisotropy decay occurs during the500-ps time window of these experiments.The excited-state kinetics and dark reactions associated with phototransformations of the plant chromoprotein phytochrome have attracted considerable interest (Linschitz et al., 1966; Cross etal., 1968; Braslavsky etal., 1980; Shimizaki et al., 1980; Cordonnier et al., 1981; Song et al., 1981, 1986; Holzwarth et al., 1984; Ruzsicska et al., 1985; Brock et al., 1987). This photoreceptor in green plants mediates the regulation of some 200 biological responses, including bio-synthesis of chlorophylls, carotenoids, rubisco, and thylakoid membranes. Undegraded phytochrome from etiolated oat