Weak temperature dependence of P (+) H A (-) recombination in mutant Rhodobacter sphaeroides reaction centers.

ABSTRACT: In contrast with findings on the wild-type Rhodobacter sphaeroides reaction center, biexponential P (+) H A (-)  → PH A charge recombination is shown to be weakly dependent on temperature between 78 and 298 K in three variants with single amino acids exchanged in the vicinity of primary electron acceptors. These mutated reaction centers have diverse overall kinetics of charge recombination, spanning an average lifetime from ~2 to ~20 ns. Despite these differences a protein relaxation model applied previously to wild-type reaction centers was successfully used to relate the observed kinetics to the temporal evolution of the free energy level of the state P (+) H A (-) relative to P (+) B A (-) . We conclude that the observed variety in the kinetics of charge recombination, together with the

SUBMITTER: Gibasiewicz K 

PROVIDER: S-EPMC4877430 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature