Investigations by picosecond polarized fluorescence spectrochronography of structural aspects of energy transfer in living cells of the green bacterium Chlorobium limicola

FEBS Letters

Freiberg, A.M.¹  Timpmann, K.E.¹  Fetisova, Z.G.¹ 

[1] A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Bldg. A, Moscow 119899 and Institute of Physics, Estonian SSR Academy of Sciences, Tartu 202 400, USSR

关键词: Antenna;    Fluorescence polarization;    Energy transfer;    Picosecond spectroscopy;    Bacterial photosynthesis;   

DOI  :  10.1016/0014-5793(87)80528-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The orientation of the long-wavelength (Q _y) transition moments of the antenna bacterioviridin (BVr) was examined in living cells of Chlorobium limicola. Previous linear dichroism studies [(1986) FEBS Lett. 199, 234–236] indicated that in each individual chromatophore of C. limicola the Q _y, transition moment vectors of the whole chlorosome BVr are essentially parallel to each other and are practically ideally oriented along the long axis of the chlorosome. We measured the picosecond polarized fluorescence decay kinetics for antenna bacteriochlorophyll (BChl) emissions upon selective excitation with polarized light of the Q _y, transition of BVr. The polarization (p) of the BVr fluorescence is measured to be constant during the BVr excited-state lifetime and to be equal to the limiting value of p achieved in monomeric BChl: P = + 0.42 ± 0.02. The results indicate convincingly that the excitation energy transfer within chlorosomes of C. limicola cells takes place between chromophores (or their coupled associates) with parallel transition moment vectors.

【 授权许可】

Unknown