Modelling Photosynthesis with Zn-II-Protoporphyrin All-DNA G-Quadruplex/Aptamer Scaffolds

摘要

All-DNA scaffolds act as templates for the organization of photosystem I model systems. A series of DNA templates composed of Zn-II-protoporphyrin IX ((ZnPPIX)-P-II)-functionalized G-quadruplex conjugated to the 3 '- or 5 '-end of the tyrosinamide (TA) aptamer and (ZnPPIX)-P-II/G-quadruplex linked to the 3 '- and 5 '-ends of the TA aptamer through a four-thymidine bridge. Effective photoinduced electron transfer (ET) from (ZnPPIX)-P-II/G-quadruplex to bipyridinium-functionalized tyrosinamide, TA-MV2+, bound to the TA aptamer units is demonstrated. The effectiveness of the primary ET quenching of (ZnPPIX)-P-II/G-quadruplex by TA-MV2+ controls the efficiency of the generation of TA-MV+.. The photosystem-controlled formation of TA-MV+. by the different photosystems dictates the secondary activation of the ET cascade corresponding to the ferredoxin-NADP(+) reductase (FNR)-catalysed reduction of NADP(+) to NADPH by TA-MV+., and the sequestered alcohol dehydrogenase catalysed reduction of acetophenone to 1-phenylethanol by NADPH.