The S-2 State of the Oxygen-Evolving Complex of Photosystem II Explored by QM/MM Dynamics: Spin Surfaces and Metastable States Suggest a Reaction Path Towards the S-3 State

摘要

Split and polish: Quantum mechanics/molecular mechanics simulations reveal the role of spin surfaces, kinetics, and thermodynamics on the interconversion between two structural models of the {Mn4CaO5} cluster (see picture) in the S2 state of the water-splitting Kok's cycle in photosystem-II. The results account for the temperature, illumination, and procedure dependence of historical EPR experiments and suggest a detailed pathway for the S2 to S3 transition. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.