ISSN:
1432-1424
Keywords:
Key words: Bacterial photosynthesis — Electrogenic event — Charge transfer — Electron transfer — Monolayer
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract. Reaction centers from the photosynthetic bacterium Rhodobacter sphaeroides were oriented in phospholipid interfacial layers adsorbed to a Teflon film separating two electrolyte-filled compartments of a Teflon cell. Light-induced voltage changes were measured as a function of time across electrodes immersed in the cell compartments. The experimental system is characterized both experimentally and theoretically to relate the measured signals to the light-induced displacement currents in the reaction centers. Mathematical relations between the measured signals and the distances and geometries of the charge-transfer reactions are derived. At pH 8.0 the reaction centers were found to be oriented with ∼60% of the population oriented with the donor facing the aqueous phase. The density of the reaction centers in the layer was ∼1011 cm−2, which is close to that found in the native system. Reconstitution of the secondary quinone, Q B , in 90% of the RCs was achieved with an ∼100-fold excess of ubiquinone in the vesicle preparation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002329900435
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