Institut de Physique de la Matière Condensée, Université de Lausanne, 1015 Lausanne, Switzerland.
Chemphyschem. 2001 May 18;2(5):310-5. doi: 10.1002/1439-7641(20010518)2:5<310::AID-CPHC310>3.0.CO;2-C.
Steady-state and picosecond (ps) fluorescence studies of wild-type bacteriorhodopsin (wt-bR) and of a nonisomerizing analog locked in the all-trans configuration have been performed. Extending earlier work done by femtosecond absorption spectroscopy, we observe a strong similarity between both proteins in both fluorescence spectra and Stokes shift thus confirming the previous result that the fluorescent state I460 of the native bR proteins is in the all-trans configuration. Comparison of the spectra of fluorescence and stimulated emission of the locked pigments indicates the presence of an excited-state absorption situated around 750 nm. Upon increase of the excitation energy, the time-integrated fluorescence shows an interesting weak blue shift, which is identical for both pigments. Finally, we discuss the primary structural processes in retinal and in the protein that lead to the sub-100 fs formation of I460 and in particular to the considerable Stokes shift.
已经对野生型细菌视紫红质（wt-bR）和锁定在全反式构型的非异构化类似物进行了稳态和皮秒（ps）荧光研究。扩展了先前通过飞秒吸收光谱完成的工作，我们在荧光光谱和斯托克斯位移方面观察到这两种蛋白质之间的强相似性，从而证实了先前的结果，即天然 bR 蛋白质的荧光态 I460 处于全反式构型。锁定色素的荧光和受激发射光谱的比较表明存在一个位于 750nm 左右的激发态吸收。随着激发能的增加，时间积分荧光显示出有趣的弱蓝移，这两种色素是相同的。最后，我们讨论了视黄醛和蛋白质中的主要结构过程，这些过程导致 I460 的形成时间短至 100fs，特别是导致相当大的斯托克斯位移。
