The chlorophyll biosynthetic enzyme NADPH:protochlorophyllide oxidoreductase, which catalyses a light-driven reaction involving hydride and proton transfers is examined. It is determined that prior excitation of the enzyme–substrate complex with a laser pulse induces a more favourable conformation of the active site and increases the catalytic efficiency of the coupled hydride and proton transfer reactions. Spectral changes in the mid-infrared after the absorption of one photon reveal significant conformational changes in the enzyme.
- Olga A. Sytina
- Derren J. Heyes
- Marie Louise Groot