The study of terbium regenerated bacterirhodopsin  

作　　者：XU Bing ZHANG Yue HU Kunsheng 

机构地区：[1]Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China

出　　处：《Science China Chemistry》2005年第5期466-469,共4页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.30170235);a Grant for Key Program from Chinese Academy of Sciences(Grant No.KJCX1-SW-07).

摘　　要：The localization of Terbium (Tb3+) cations binding to deionized bacteriorhodopsin (bR) has been studied by using spectroscopic methods. It was found that adding Tb3+ cations to deionized bR affects the fluorescence lifetimes of tryptophan (Trp) in bR, the wavelength of fluo-rescence peak shifts “blue” and the peak value of fluorescence decreases. It was also found that adding one Tb3+ cation to deionized bR can restore the purple state from its blue state obviously. The measurements of absorbance, fluorescence and lifetime of fluorescence also show that when more than three Tb3+ cations are added, no further changes can be found. It is suggested that one Tb3+ specific binding site for the color-controlling is located on the exterior of the bR trimer structure to negatively charged lipids near Trp-10 and Trp-12. Three Tb3+ cations binding per bR is needed for the regenerated bR.The localization of Terbium (Tb3+) cations binding to deionized bacteriorhodopsin (bR) has been studied by using spectroscopic methods. It was found that adding Tb3+ cations to deionized bR affects the fluorescence lifetimes of tryptophan (Trp) in bR, the wavelength of fluo-rescence peak shifts “blue” and the peak value of fluorescence decreases. It was also found that adding one Tb3+ cation to deionized bR can restore the purple state from its blue state obviously. The measurements of absorbance, fluorescence and lifetime of fluorescence also show that when more than three Tb3+ cations are added, no further changes can be found. It is suggested that one Tb3+ specific binding site for the color-controlling is located on the exterior of the bR trimer structure to negatively charged lipids near Trp-10 and Trp-12. Three Tb3+ cations binding per bR is needed for the regenerated bR.

关 键 词：CATION binding  fluorescence  bacteriorhodopsin  terbium. 

分 类 号：N[自然科学总论]