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Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Unraveling the electronic structure of individual photosynthetic pigment-protein complexes
van Oijen AM1, Ketelaars, Kohler
1Centre for the Study of Excited States of Molecules, Department of Biophysics, Huygens Laboratory, Leiden University, Post Office Box 9504, 2300 RA Leiden, Netherlands.
Abstract:
Low-temperature single-molecule spectroscopic techniques were applied to a light-harvesting pigment-protein complex (LH2) from purple photosynthetic bacteria. The properties of the electronically excited states of the two circular assemblies (B800 and B850) of bacteriochlorophyll a (BChl a) pigment molecules in the individual complexes were revealed, without ensemble averaging. The results show that the excited states of the B800 ring of pigments are mainly localized on individual BChl a molecules. In contrast, the absorption of a photon by the B850 ring can be consistently described in terms of an excitation that is completely delocalized over the ring. This property may contribute to the high efficiency of energy transfer in these photosynthetic complexes.
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