PMID: 19916934Nov 18, 2009Paper

Primary processes of charge separation in reaction centers of YM210L/FM197Y and YM210L mutants of Rhodobacter sphaeroides

Biochemistry. Biokhimii︠a︡
A G YakovlevV A Shuvalov

Abstract

Difference femtosecond absorption spectroscopy with 20-fsec temporal resolution was applied to study a primary stage of charge separation and transfer processes in reaction centers of YM210L and YM210L/FM197Y site-directed mutants of the purple bacterium Rhodobacter sphaeroides at 90 K. Photoexcitation was tuned to the absorption band of the primary electron donor P at 880 nm. Coherent oscillations in the kinetics of stimulated emission of P* excited state at 940 nm and of anion absorption of monomeric bacteriochlorophyll B(A)(-) at 1020 nm were monitored. The absence of tyrosine YM210 in RCs of both mutants leads to strong slowing of the primary reaction P* --> P(+)B(A)(-) and to the absence of stabilization of separated charges in the state P(+)B(A)(-). Mutation FM197Y increases effective mass of an acetyl group of pyrrole ring I in the bacteriochlorophyll molecule P(B) of the double mutant YM210L/FM197Y by a hydrogen bond with OH-TyrM197 group that leads to a decrease in the frequency of coherent nuclear motions from 150 cm(-1) in the single mutant YM210L to ~100 cm(-1) in the double mutant. Oscillations with 100-150 cm(-1) frequencies in the dynamics of the P* stimulated emission and in the kinetics of the reversible format...Continue Reading

References

Oct 15, 1991·Proceedings of the National Academy of Sciences of the United States of America·M H VosJ L Martin
Aug 1, 1987·Proceedings of the National Academy of Sciences of the United States of America·J P AllenD C Rees
Oct 25, 1994·Proceedings of the National Academy of Sciences of the United States of America·X LinJ C Williams
Oct 15, 1998·Proceedings of the National Academy of Sciences of the United States of America·C RischelM H Vos

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