Natural photoenzymes

Several natural photoenzymes with activity controlled by light have been reported to date. Among them are DNA and (6-4) photoproduct photolyases, which are highly efficient light-driven DNA-repair enzymes [14, 15], protochlorophyllide reductase, which is an important enzyme in the chlorophyll biosynthesis pathway [16, 17], nitrile hydratase, which hydirates aliphatic and aromatic nitriles to the 

Bioinorganic Photochemistry Grazyna Stochel, Malgorzata Brindell, Wojciech Macyk, Zofia Stasicka, Konrad Szacilowski 2009 Grazyna Stochel, Malgorzata Brindell, Wojciech Macyk, Zofia Stasicka, Konrad Szacilowski. ISBN 978-1-405-16172-5 

Another enzymatic system with activity controlled by light is protochlorophyl-lide oxidoreductase (POR) [16, 17]. This enzyme catalyzes the reduction of the 

Niemeyer et al. have reported the design of quantum dot/enzyme nanohybrids that are capable of catalyzing an organic transformation upon optical excitation of semiconductor quantum dots (QDs) [31]. The hybrid device was composed of semiconductor CdS nanoparticles and cytochrome p450BSp enzyme. It has been proposed that irradiation of QDs leads to formation of excitons (h+-e pairs) that on dissociation generate superoxide and hydroxyl radicals in interfacial electron transfer process (see Chapter 7). These radicals in turn activate the enzyme adsorbed at the QD surface. The activated enzyme is able to catalyze mono-oxygenation of fatty acids, but has a lower activity than the native enzyme [31]. 

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