High-resolution carbon-13 NMR of retinal derivatives in the solid state
作者:G. S. Harbison、P. P. J. Mulder、H. Pardoen、J. Lugtenburg、J. Herzfeld、R. G. Griffin
DOI:10.1021/ja00303a001
日期:1985.8
tran~duction.~~~ However, in neither case are the spectroscopic properties of the intact protein similar to those of the free aldehydes, or of simple model compounds derived from it. Clearly, therefore, the conformational and electronic properties of the chromophores are strongly modulated by the approtein, and an understanding of the differences between bacteriorhodospin and rhodospin on the one hand, and retinal
Spontaneous Emission Study of the Femtosecond Isomerization Dynamics of Rhodopsin
作者:Gerd. G. Kochendoerfer、Richard A. Mathies
DOI:10.1021/jp960509+
日期:1996.1.1
The spontaneous emission spectra and yields of the visual pigment rhodopsin and its 9-cis retinal analog isorhodopsin have been measured following excitation at 472.7, 514.5, and 568.2 nm. The fluorescence quantum yields are (0.9 +/- 0.3) x 10(-5) for rhodopsin and (1.8 +/- 0.7) x 10(-5) for isorhodopsin. By use of a Strickler-Berg analysis, these quantum yields correspond to excited electronic state lifetimes of 50 and 100 fs for rhodopsin and isorhodopsin, respectively. The fluorescence spectra also undergo a blue-shift of similar to 1800 cm(-1) upon shifting the excitation wavelength from 568.2 to 472.7 nm. This is consistent with the idea that the emission arises from unrelaxed, nonstationary vibrational states. For rhodopsins, there is a correlation among these rapid initial nuclear dynamics out of the Franck-Condon region, the rapid photoisomerization rates, and the high isomerization quantum yields. These results support a new mechanism for the isomerization reaction dynamics in visual pigments where the reaction efficiency is mechanistically linked to the reaction rate through a dynamic Landau-Zener tunneling process.
Pitt et al., Biochemical Journal, 1955, vol. 59, p. 122,124