Universiteit Leiden

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Research project

Structure and regulation in photosynthesis

A sophisticated regulation network in plants and photosynthetic algae protects them against photodamage and ensures fitness in fluctuating environmental conditions. The research of Dr. Anjali Pandit focuses on the application of NMR spectroscopy to understand the underlying molecular processes. Photoregulation is essential for the organisms, but also sets an upper limit for their photosynthetic activity. By resolving the responsible structural mechanisms, we may find new ways to expand the limit and improve photosynthetic species for production of biomass and solar biofuels. Dr. Pandit has a background in biophysics of photosynthesis and participated in international solar biofuel initiatives as organizer of the HARVEST EU-network and co-editor of a white paper on solar fuels.

Contact
Anjali Pandit

In the photosynthetic membrane, protein nanomachines work together for the conversion of sunlight into biochemical energy. The photosynthetic machinery continuously adapts to fluctuating environmental light-intensity conditions in order to avoid photodamage at the water-splitting catalytic site of Photosystem II. To understand the molecular mechanisms of photosynthesis, atomic-resolution structures are central for describing the photophysical and photochemical functions. In natural photosynthesis, these functions are tightly integrated with regulatory processes on a larger scale involving molecular plasticity of photosynthetic multi-units and their supramolecular rearrangements in a dynamic, cellular network.

Manipulation of photoregulatory mechanisms can be a rational means for enhancing photosynthetic productivity of crop growth or algae biofuels 1,2. This approach is held back by the lack of high-resolution structural data describing the fundamentals of photoregulation by the interplay of atomic and (supra)molecular interactions in an active, biological membrane. Solid-state NMR holds great promise as key technique for this purpose.

By solid-state NMR, large biomolecules can be studied at atomic resolution and under near-native conditions without need for crystallization. MRI and HR-MAS NMR developments allow micro-imaging and metabolic profiling of intact systems. Together the techniques have the exciting potential to attain a high-resolution structural view of regulatory processes inside the photosynthetic machinery. To realize this goal, we develop NMR methods for solving structure and plasticity inside large photosystems, design novel membrane models to view their behavior in native-like environments and develop isotope-labeling approaches for photosynthetic organisms. To relate structure to function, NMR methods are complemented with optical spectroscopy and advanced modeling approaches.

1 PG Stephenson, CM Moore, MJ Terry, MV Zubkov and TS Bibby Improving photosynthesis for algal biofuels: toward a green revolution, Trends in Biotechnology 2011, Vol. 29, No. 12 DOI: 10.1016/j.tibtech.2011.06.005
2 EH Murchie and KK Niyogi Manipulation of Photoprotection to Improve Plant Photosynthesis, Plant Physiology 2011, Vol. 155, pp. 86–92 DOI: ​10.​1104/​pp.​110.​168831

Key publications

  1. Duffy, C.D.P., A. Pandit, A.V. Ruban, "Modeling the NMR signatures associated with the functional conformational switch in the major light-harvesting antenna of photosystem II in higher plants", Physical Chemistry Chemical Physics, vol. 16, no. 12, pp. 5571-5580, 2014. DOI: 10.1039/C3cp54971b

  2. Pandit, A., M. Reus, T. Morosinotto, R. Bassi, A.R. Holzwarth, H.J.M. de Groot, "An NMR comparison of the light-harvesting complex II (LHCII) in active and photoprotective states reveals subtle changes in the chlorophyll a ground-state electronic structures", Biochimica Et Biophysica Acta-Bioenergetics, vol. 1827, no. 6, pp. 738-744, Jun, 2013. DOI: 10.1016/J.Bbabio.2013.02.015

  3. Pandit, A., R.N. Frese, "Artificial Leaves: Towards bio-inspired solar energy converters", Comprehensive Renewable Energy, vol. 1.35: Elsevier Publ., pp. 657-677, 2012. DOI: 10.1016/B978-0-08-087872-0.00135-9

  4. Pandit, A., H.J.M. de Groot, "Solid-state NMR applied to photosynthetic light-harvesting complexes", Photosynthesis Research, vol. 111, no. 1-2, pp. 219-226, Mar, 2012. DOI: 10.1007/S11120-011-9674-9

  5. Pandit, A., N. Shirzad-Wasei, L.M. Wlodarczyk, H. van Roon, E.J. Boekema, J.P. Dekker, W.J. de Grip, "Assembly of the Major Light-Harvesting Complex II in Lipid Nanodiscs", Biophysical Journal, vol. 101, no. 10, pp. 2507-2515, Nov 16, 2011. DOI: 10.1016/J.Bpj.2011.09.055