Electrogenic reduction of Rhodospirillum rubrum reaction centre bacteriochlorophyll P870+ by redox dyes Indication of intraprotein electron transfer

Abstract

AbstractReduction of laser flash-oxidized bacteriochlorophyll in Rhodospirillum rubrum reaction centre proteoliposomes or in cytochrome c2-deficient R. rubrum chromatophores by artificial redox dyes like N,N,N',N'-tetramethyl-p-phenylenediamine or phenazine methosulphate gives rise to an electrogenic phase in the millisecond range. This phase contributes as much as 20% to the total photoelectric response and is ascribed to vectorial electron transfer from the reaction centre protein surface to the protein-embedded Mg-porphyrin rings of P870+.Rhodospirillum rubrumMembrane potentialProteoliposomeReaction center bacteriochlorophyllIntramolecular electron transferRapid kinetic