In my group we study the function of photosystem II and the light-driven assembly of its water oxidation cluster. Special emphasis is given to the identification of the binding sites and modes of the two substrate waters and to the elucidation of the molecular mechanism of photosynthetic water oxidation.
We employ a variety of techniques including serial x-ray crystallography at free electron lasers, electron paramagnetic resonance (EPR), X-ray spectroscopy, time-resolved membrane inlet mass spectrometry, electrochemistry and quantum mechanical calculations.
In a second line of experiments, we develop within a biomimetic approach artificial water-splitting and nitrogen reducing catalysts that are made from earth-abundant elements. These are studied under various experimental conditions with a similar set of techniques, and assembled into lab scale devices. The ultimate goal is the construction of an ‘artificial leaf’ that uses sunlight to split water into O2 and H2, and of devices that utilize sunlight to reduce N2 to ammonia.
Svensk sammanfattningKey publications
- Cheah et al. (2020) Assessment of the manganese cluster's oxidation state via photoactivation of photosystem II microcrystals. Proc. Natl. Acad. Sci. USA 117, 141-145
- Kern, J, et al. (2019) Structures of the intermediates of Kok's photosynthetic water oxidation clock. Nature: 563, 421-425.
- Cox, N and Messinger, J (2013) Reflections on substrate water and dioxygen formation. Biochim Biophys Acta 1827, 1020-1030.
- Rapatskiy, L, et al. (2012) Detection of the water-binding sites of the oxygen-evolving complex of photosystem II using W-band 17O Electron-Electron Double Resonance-detected NMR spectroscopy. J. Am. Chem. Soc. 134: 16619-16634.
- Shevela, D, et al. (2011) Membrane-inlet mass spectrometry reveals a high driving force for oxygen production by photosystem II. Proc. Natl. Acad. Sci. USA 108: 3602-3607.