Primary electron transfer kinetics in bacterial reaction centers with modified bacteriochlorophylls at the monomeric sites BA,B

The primary electron transfer has been investigated by femtosecond
time-resolved absorption spectroscopy in two chemically modified
reaction centers (RC) of Rhodobacter sphaeroides, in which the
monomeric bacteriochlorophylls BA and BB have both been exchanged
by 132- hydroxybacteriochlorophyll a or
[3-vinylJ-132-hydroxybacteriochlorophyll a. The kinetics of the
primary electron transfer are not influenced by the 132-hydroxy
modification. In RCs containing
[3-vinyl]-132-hydroxybacteriochlorophyll a the primary rate is
reduced by a factor of 10.