Comparative studies of the S 0 and S 2 multiline electron paramagnetic resonance signals from the manganese cluster in Photosystem II

Abstract

Electron paramagnetic resonance (EPR) spectroscopy is one of the major techniques used to analyse the structure and function of the water oxidising complex (WOC) in Photosystem II. The discovery of an EPR signal from the S 0 state has opened the way for new experiments, aiming to characterise the S 0 state and elucidate the differences between the different S states. We present a review of the biochemical and biophysical characterisation of the S 0 state multiline signal that has evolved since its discovery, and compare these results to previous and recent data from the S 2 multiline signal. We also present some new data from the S 2 state reached on the second turnover of the enzyme.