Effect of cationic antiseptics on the vectorial electron and proton transfer in chromatophores of photosynthetic bacteria.

The effect of the cationic antiseptics octenidine and miramistin on electron transfer reactions in photosynthetic bacterial chromatophores of Cereibacter sphaeroides has been studied using direct electrometric and flash photolysis techniques. When the ubiquinone pool and cytochrome bc complex were oxidized, the addition of octеnidine at a concentration of 100 µM completely inhibited the generation of transmembrane electric potential difference (Δψ) caused by protonation of the doubly reduced secondary quinone acceptor Q in the reaction center and, accordingly, vectorial charge transfer within the bc complex in response to a second laser flash. The lack of an effect of octenidine and miramistin on the rapid rise of Δψ (τ < 0.