A semi-artificial model of photosynthetic oxygen evolution and NADP+ reduction using thylakoid membrane proteins and a semiconductor

Abstract

We aim at developing a semi-artificial system for photosynthetic oxygen evolution by using thylakoid membrane proteins and inorganic semiconductors, such as ZnO and SnO2, as photosensitizer. In the first step of the present study, photoreduction of NADP+ was achieved and greatly increased over a control without thylakoid proteins. We attribute the accelerating effect to the interaction of proteins with the semiconductor, which may stabilize the radical ions formed by photoexcitation. Water oxidation in photosynthesis involves charge separation and charge accumulation. It may be possible to use inorganic semiconductors for the charge separation in combination with engineered proteins for charge accumulation. A preliminary scheme of this semi-artificial system is presented.