Electron transfer in gel-immobilized photosynthetic reaction centers

A bacterial photosynthetic reaction center was immobilized in polyacrylamide gel. The gel was incubated with electron transfer mediators and then dried. Intramolecular electron transfer in the reaction center embedded in the dried polyacrylamide gel was measured by xenon-flash photolysis. Electron transfer between redox centers such as bacteriochlorophyll dimers, hemes in the bound cytochrome and quinones were observed as reported with the reaction center in aqueous solution. The present findings clearly showed that the oxidized or reduced state of each redox center in the reaction center can be fixed in the dried gel using this method.