Research is being conducted on the structure and function of photosynthetic reaction centers in the green sulfur bacteria. The specific objective is to study the donors and acceptors active in the electron transfer reactions that lead to charge stabilization in the primary quantum conversion process. Their identity and kinetic interactions are being analyzed by fast transient absorption spectroscopy and ESR. The work is facilitated by the use of bacteria grown in conditions that inhibit the synthesis of antenna pigment. Stable, purified reaction centers will be used to study the polypeptides and localization of the acceptors on the various sub-units. The possible involvement of a quinone as acceptor will be examined by organic solvent extraction and reconstitution. The primary reactions of light conversion to chemical energy during photosynthesis take place in pigment-protein complexes called reaction centers. The reaction centers of some bacteria have been thoroughly studied. The green bacteria occupy a key position for comparative and evolutionary study but their reaction centers have not been studied. This project focuses on the green bacteria reaction center because it appears to be very similar but a simplified version of the light capturing system of higher plants.
