Simulation of the isotropic EXAFS spectra for the S2 and S3 structures of the oxygen evolving complex in photosystem II

摘要: Most of the main features water oxidation in photosystem II are now well understood, including mechanism for O-O bond formation. For intermediate S2 and S3 structures there is also nearly complete agreement between quantum chemical modeling experiments. Given present high degree consensus these structures, it interest to go back previous suggestions concerning what happens S2-S3 transition. Analyses extended X-ray adsorption fine structure (EXAFS) experiments have indicated relatively large structural changes this transition, with distances sometimes larger than 0.3 A a change topology. In contrast, our density functional theory (DFT)(B3LYP) calculations on cluster model showed very small changes, less 0.1 A. It here found that DFT consistent EXAFS spectra states within normal errors DFT. The analysis suggests severe problems interpreting complicated systems.