Primary electron transfer reactions in modified reaction centers from Rhodopseudomonas sphaeroides
- 1 March 1986
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences
- Vol. 83 (6) , 1690-1694
- https://doi.org/10.1073/pnas.83.6.1690
Abstract
Absorption spectra were measured by means of an optical multichannel analyzer in Rhodopseudomonas sphaeroides R-26 reaction centers (RCs) modified by treatment with NaBH4 at various times (.gtoreq. 1 ps) after the onset of a short excitation flash as 880 nm. Most of these RCs (75-95%) have only one "monomeric" bacteriochlorophyll-800 (B1) molecule and are as active as the original RCs. The duration of the excitation and measuring pulses was .apprxeq. 33 ps. If the center of the excitation pulse preceeded the center of the measuring pulse by 36-40 ps, the formation of a state PE (early state), which is converted to the state PF (P+ bacteriopheophytin-) in 4 .+-. 1 ps (1/e time), was observed. Also the kinetics and the spectrum of the stimulated emission (reflecting the kinetics and the emission spectrum of the excited state P*) were determined. The difference spectrum of the state PE approximately equals the sum of the spectra of the states that B1- is an intermediate in the electron transfer from P* to bacteriopheophytin, H1, tranferring this electron with a rate constant of (4 .times. 0.35 ps)-1 = 7 .times. 1011 s-1.This publication has 9 references indexed in Scilit:
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