Imperial College London

Professor Bill Rutherford FRS

Faculty of Natural SciencesDepartment of Life Sciences

Chair in Biochemistry of Solar Energy



+44 (0)20 7594 5329a.rutherford Website




702Sir Ernst Chain BuildingSouth Kensington Campus






BibTex format

author = {Saito, K and Rutherford, AW and Ishikita, H},
doi = {10.1038/ncomms9488},
journal = {Nature Communications},
title = {Energetics of proton release on the first oxidation step in the water-oxidizing enzyme},
url = {},
volume = {6},
year = {2015}

RIS format (EndNote, RefMan)

AB - In photosystem II (PSII), the Mn4CaO5 cluster catalyses the water splitting reaction. The crystal structure of PSII shows the presence of a hydrogen-bonded water molecule directly linked to O4. Here we show the detailed properties of the H-bonds associated with the Mn4CaO5 cluster using a quantum mechanical/molecular mechanical approach. When O4 is taken as a μ-hydroxo bridge acting as a hydrogen-bond donor to water539 (W539), the S0 redox state best describes the unusually short O4–OW539 distance (2.5 Å) seen in the crystal structure. We find that in S1, O4 easily releases the proton into a chain of eight strongly hydrogen-bonded water molecules. The corresponding hydrogen-bond network is absent for O5 in S1. The present study suggests that the O4-water chain could facilitate the initial deprotonation event in PSII. This unexpected insight is likely to be of real relevance to mechanistic models for water oxidation.
AU - Saito,K
AU - Rutherford,AW
AU - Ishikita,H
DO - 10.1038/ncomms9488
PY - 2015///
SN - 2041-1723
TI - Energetics of proton release on the first oxidation step in the water-oxidizing enzyme
T2 - Nature Communications
UR -
UR -
VL - 6
ER -