The chlorophyll-protein complex CP43 is a proximal-antenna subunit important for excitation energy transfer from peripheral light-harvesting antenna to the Photosystem II (PSII) reaction centre. We report persistent spectral hole burning at 1.7K in the Qy(0,0) origin and Q y(1,0) vibrational satellite bands of chlorophyll a (chl a) in CP43 isolated from higher plants. The isolated CP43 is known to possess two quasi-degenerate 'red' trap states. We find persistent hole burning in the primary trap exhibits a photoconversion property, with a photoproduct located well outside its inhomogeneous distribution. This photoconversion of trap chl a molecules also occurs with non-selective white light illumination. The contribution of the 'red' states to CP43 absorption is discussed.

This work was supported by the Energy Biosciences Division, Office of Science, US Department of Energy (M.S.), by the MCYT in Spain (Grants PB98-1632 and PB2002-00031) (R.P.) and the Wenner-Gren Foundations (S.P. Å.)

Proceedings of the Fourteenth International Conference on Dynamical Processes in Excited States of Solids

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