Temperature-induced dissociation reaction and dynamics of light-harvesting complex II isolated from purple photosynthetic bacterium Rps.palustris  

作　　者：FENG Juan LI XueFeng LIU Yuan 

机构地区：[1]School of Life Science and Technology, University of Electronic Science & Technology of China, Chengdu 610054, China

出　　处：《Chinese Science Bulletin》2007年第8期1029-1035,共7页

基　　金：Supported by the National Natural Science Foundation of China(Grant No.20373079)

摘　　要：Steady-state absorption spectroscopy,circular dichroism,and resonance Raman spectroscopy have been used to investigate the thermal stability of LH2 complex isolated from purple photosynthetic bacterium Rps.palustris.The results show that:1)upon increasing the temperature,a transition from B800 and B850 to free bacteriochlorophyll(B780)happens;2)a gradual decrease and disappearance of CD signal in visible region occur;3)a shift of the frequency,belonging to C==C and C—C stretching vibration,to higher wavenumber takes place.It is suggested that LH2 complex can be dissociated in the presence of B800,B850 and carotenoids simultaneously.Single-exponential fitting on the dynamic decay curves gives the apparent time constants of hundreds of minutes for various pigments.Steady-state absorption spectroscopy, circular dichroism, and resonance Raman spectroscopy have been used to investigate the thermal stability of LH2 complex isolated from purple photosynthetic bacterium Rps. palustris. The results show that： 1） upon increasing the temperature, a transition from B800 and B850 to free bacteriochlorophyll （B780） happens; 2） a gradual decrease and disappearance of CD signal in visible region occur; 3） a shift of the frequency, belonging to C=C and C-C stretching vibration, to higher wavenumber takes place. It is suggested that LH2 complex can be dissociated in the presence of B800, B850 and carotenoids simultaneously. Single-exponential fitting on the dynamic decay curves gives the apparent time constants of hundreds of minutes for various pigments.

关 键 词：紫色光合细菌 沼泽红假单胞菌 温度诱导离解反应 反应动力学 捕光配合物Ⅱ 

分 类 号：Q939.112[生物学—微生物学] Q936