ArticleProceedings of the National Academy of Sciences of the United States of America2012
Alternating electron and proton transfer steps in photosynthetic water oxidation.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 60 papers.
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60 citing papers in PubMed, 201 citations in OpenAlex.
- The structure of intact and active Photosystem II from Arabidopsis thaliana at 2.44 Å resolution.The New phytologist · 2026Article
- Interrelated Roles of Chloride and Bicarbonate in Regulating Electron Transport Across Photosystem II inPlants (Basel, Switzerland) · 2026Article
- Chloride dependence of photosystem II operation in the hypercarbonate-requiring cyanobacterium Limnospira maxima.Photosynthesis research · 2026Article
- Time-resolved Mn KThe Journal of biological chemistry · 2026Article
- Photoinhibition and protection of photosystem I.Plant & cell physiology · 2025Review
- Structure of the D1-Val185Asn mutated photosystem II complex with slow O-O bond formation reveals changes in the Cl1 water channel.Proceedings of the National Academy of Sciences of the United States of America · 2025Article
- Three rate-determining protein roles in photosynthetic ONature communications · 2025Article
- Structure, regulation and assembly of the photosynthetic electron transport chain.Nature reviews. Molecular cell biology · 2025Review
- The Low Oxidation State Paradigm is More Consistent with XFEL Observations of the S₃ → [S₄] → S₀ Transition in Photosystem II.Chemistry (Weinheim an der Bergstrasse, Germany) · 2025Article
- Electron Transfer Mechanism from the Oxygen-Evolving Complex to the Electron-Acceptor Tyrosine during the SACS omega · 2025Article
- An analysis of the structural changes of the oxygen evolving complex of Photosystem II in the SBiochimica et biophysica acta. Bioenergetics · 2025Review
- Observation of an Associative State in Aqueous Hydroxide.Journal of the American Chemical Society · 2025Article
- Mechanism of proton release during water oxidation in Photosystem II.Proceedings of the National Academy of Sciences of the United States of America · 2024Article
- Tracking the first electron transfer step at the donor side of oxygen-evolving photosystem II by time-resolved infrared spectroscopy.Photosynthesis research · 2024Article
- Exploring the interdependence of calcium and chloride activation of OPhotosynthesis research · 2024Article
- The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII.Current issues in molecular biology · 2024Article
- Structure Function Studies of Photosystem II Using X-Ray Free Electron Lasers.Annual review of biophysics · 2024Review
- Assignment of the slowly exchanging substrate water of nature's water-splitting cofactor.Proceedings of the National Academy of Sciences of the United States of America · 2024Article
- Review
- Comprehensive Evaluation of Models for Ammonia Binding to the Oxygen Evolving Complex of Photosystem II.The journal of physical chemistry. B · 2024Article
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Water oxidation by cyanobacteria, algae, and plants is pivotal in oxygenic photosynthesis, the process that powers life on Earth, and is the paradigm for engineering solar fuel-production systems. Each complete reaction cycle of photosynthetic water oxidation requires the removal of four electrons and four protons from the catalytic site, a manganese-calcium complex and its protein environment in photosystem II. In time-resolved photothermal beam deflection experiments, we monitored apparent volume changes of the photosystem II protein associated with charge creation by light-induced electron transfer (contraction) and charge-compensating proton relocation (expansion). Two previously invisible proton removal steps were detected, thereby filling two gaps in the basic reaction-cycle model of photosynthetic water oxidation. In the S(2) → S(3) transition of the classical S-state cycle, an intermediate is formed by deprotonation clearly before electron transfer to the oxidant (Y Z OX). The rate-determining elementary step (τ, approximately 30 µs at 20 °C) in the long-distance proton relocation toward the protein-water interface is characterized by a high activation energy (E(a) = 0.46 ± 0.05 eV) and strong H/D kinetic isotope effect (approximately 6). The characteristics of a proton transfer step during the S(0) → S(1) transition are similar (τ, approximately 100 µs; E(a) = 0.34 ± 0.08 eV; kinetic isotope effect, approximately 3); however, the proton removal from the Mn complex proceeds after electron transfer to . By discovery of the transient formation of two further intermediate states in the reaction cycle of photosynthetic water oxidation, a temporal sequence of strictly alternating removal of electrons and protons from the catalytic site is established.
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