Closing Kok's cycle of nature's water oxidation catalysis

Y Guo, L He, Y Ding, L Kloo, DA Pantazis… - Nature …, 2024 - nature.com
Abstract The Mn4CaO5 (6) cluster in photosystem II catalyzes water splitting through the S i
state cycle (i= 0–4). Molecular O2 is formed and the natural catalyst is reset during the final …

Bicarbonate is a key regulator but not a substrate for O2 evolution in Photosystem II

DJ Vinyard, G Govindjee - Photosynthesis Research, 2024 - Springer
Photosystem II (PSII) uses light energy to oxidize water and to reduce plastoquinone in the
photosynthetic electron transport chain. O2 is produced as a byproduct. While most …

Mechanism of proton release during water oxidation in Photosystem II

F Allgöwer, MC Pöverlein, AW Rutherford… - Proceedings of the …, 2024 - pnas.org
Photosystem II (PSII) catalyzes light-driven water oxidation that releases dioxygen into our
atmosphere and provides the electrons needed for the synthesis of biomass. The catalysis …

Tuning Bro̷nsted Acidity by up to 12 pKa Units in a Redox-Active Nanopore Lined with Multifunctional Metal Sites

TJ Jones, KG Dutton, HS Dhattarwal… - Journal of the …, 2025 - ACS Publications
Electrostatic interactions, hydrogen bonding, and solvation effects can alter the free energies
of ionizable functional groups in proteins and other nanoporous architectures, allowing such …

Advances in cryo-electron microscopy (cryoEM) for structure-based drug discovery

P Rubach, KA Majorek, M Gucwa… - Expert Opinion on …, 2025 - Taylor & Francis
Introduction Macromolecular X-ray crystallography (XRC), nuclear magnetic resonance
(NMR), and cryo-electron microscopy (cryoEM) are the primary techniques for determining …

On the nature of high-spin forms in the S 2 state of the oxygen-evolving complex

MA Mermigki, M Drosou, DA Pantazis - Chemical Science, 2025 - pubs.rsc.org
The Mn4CaOx cluster of the oxygen-evolving complex (OEC) in photosystem II, the site of
biological water oxidation, adopts different forms as it progresses through the catalytic cycle …

Photosystem II: light-dependent oscillation of ligand composition at its active site

J Wang - Biological Crystallography, 2024 - journals.iucr.org
Recently, the conclusions drawn from crystallographic data about the number of oxygen
ligands associated with the CaMn4 cofactor in the oxygen-evolving center (OEC) of …

[HTML][HTML] Phe265 of the D1 protein is required to stabilize plastoquinone binding in the QB-binding site of photosystem II in Synechocystis sp. PCC 6803

TJ Brown, I Vass, TC Summerfield… - … and biophysical research …, 2024 - Elsevier
In Photosystem II electrons from water splitting pass through a primary quinone electron
acceptor (QA) to the secondary plastoquinone (QB). The D2 protein forms the Q A-binding …

Reaction Mechanism of the Terminal Plastoquinone QB in Photosystem II as Revealed by Time-Resolved Infrared Spectroscopy

Y Kato, H Ito, T Noguchi - Biochemistry, 2024 - ACS Publications
The secondary plastoquinone (PQ) electron acceptor QB in photosystem II (PSII) undergoes
a two-step photoreaction through electron transfer from the primary PQ electron acceptor …

[HTML][HTML] Structure of a mutated photosystem II complex reveals changes to the hydrogen-bonding network that affect proton egress during O–O bond formation

DA Flesher, J Shin, RJ Debus, GW Brudvig - Journal of Biological …, 2025 - Elsevier
Photosystem II (PSII) is the water-splitting enzyme of oxygenic photosynthesis. Using light
energy, PSII catalytically oxidizes two water molecules to fuel downstream metabolism …