Coherent Electron Transfer in Reaction Centers of YM210L and YM210L/HL168L Mutants of Rba. Sphaeroides
A role of tyrosine M210 in the charge separation and stabilization of separated charges was studied by analyzing of the femtosecond oscillations in the kinetics of decay of stimulated emission from P* and of a population of the primary charge separated state P+Ba- in the YM210L and YM210L/HL168L mutant reaction centers (RCs) of Rhodobacter (Rba.) sphaeroides in comparison with those in native RCs of Rba. Sphaeroides. Kinetics of P* decay at 940 nm of the both mutants show a significant slowing-down of the primary charge separation reaction in comparison with native RCs. Distinct damped oscillations in these kinetics with main frequency bands in the range of 90-150 cm-1 reflect mostly nuclear motions inside the dimer P. Formation of a very small absorption band of BA- at 1020 nm is registered in RCs of both mutants. The formation of the BA- band is accompanied by damped oscillations with main frequencies from 10 to 150 cm-1. Only a partial stabilization of the P+Ba- state is seen in the YM210L/HL168L mutant in the form of a small non-oscillating background of the 1020-nm kinetics. Similar charge stabilization is absent in the YM210L mutant. A model of oscillatory reorientation of the OH-group of TyrM210 in the electric fields of P+ and Ba- was proposed to explain a rapid stabilization of the P+Ba- state in native RCs. A conclusion was done that, probably, the absence of TyrM210 can not be compensated by lowering of the P+BA- free energy that is expected for the double YM210L/HL168L mutant.
Photosynthesis Charge separation Reaction center Wave packet Electron transfer
Andrei G Yakovlev Lyudmila G Vasilieva Tatyana I Khmelnitskaya Valentina A Shkuropatova Anatoli Ya Shkuropatov Vladimir A Shuvalov
A.N.Belozersky Institute of Chemical and Physical Biology, Moscow State University, Moscow 119991, R Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290
国际会议
15th International Conference on Photosynthesis(第15届国际光合作用大会)
北京
英文
91-94
2010-08-22（万方平台首次上网日期，不代表论文的发表时间）