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Glycerol Binding at the Narrow Channel of Photosystem II Stabilizes the Low-Spin S2 State of the Oxygen-Evolving Complex

Journal Article · · Photosynthesis Research
The oxygen-evolving complex (OEC) of photosystem II (PSII) cycles through redox intermediate states Si (i = 0–4) during the photochemical oxidation of water. The S2 state involves an equilibrium of two isomers including the low-spin S2 (LS-S2) state with its characteristic electron paramagnetic resonance (EPR) multiline signal centered at g = 2.0, and a high-spin S2 (HS-S2) state with its g = 4.1 EPR signal. The relative intensities of the two EPR signals change under experimental conditions that shift the HS-S2/LS-S2 state equilibrium. Here, we analyze the effect of glycerol on the relative stability of the LS-S2 and HS-S2 states when bound at the narrow channel of PSII, as reported in an X-ray crystal structure of cyanobacterial PSII. Our quantum mechanics/molecular mechanics (QM/MM) hybrid models of cyanobacterial PSII show that the glycerol molecule perturbs the hydrogen-bond network in the narrow channel, increasing the pKa of D1-Asp61 and stabilizing the LS-S2 state relative to the HS-S2 state. Here, the reported results are consistent with the absence of the HS-S2 state EPR signal in native cyanobacterial PSII EPR spectra and suggest that the narrow water channel hydrogen-bond network regulates the relative stability of OEC catalytic intermediates during water oxidation.
Research Organization:
Yale Univ., New Haven, CT (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division
Grant/Contract Number:
FG02-05ER15646; SC0001423
OSTI ID:
1860621
Journal Information:
Photosynthesis Research, Journal Name: Photosynthesis Research Journal Issue: 2 Vol. 152; ISSN 0166-8595
Publisher:
SpringerCopyright Statement
Country of Publication:
United States
Language:
English

References (59)

Two Interconvertible Structures that Explain the Spectroscopic Properties of the Oxygen-Evolving Complex of Photosystem II in the S 2 State journal August 2012
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 journal September 2013
The influence of polarization functions on molecular orbital hydrogenation energies journal January 1973
Chlorophyll a with a farnesyl tail in thermophilic cyanobacteria journal July 2017
The effect of temperature on the formation and decay of the multiline EPR signal species associated with photosynthetic oxygen evolution journal June 1983
EPR studies of the oxygen-evolving enzyme of Photosystem II journal October 1984
EPR spectroscopic observations of a manganese center associated with water oxidation in spinach chloroplasts journal November 1980
Et tu, Grotthuss! and other unfinished stories journal August 2006
Electron transfer pathways from the S 2 -states to the S 3 -states either after a Ca 2+ /Sr 2+ or a Cl − /I − exchange in Photosystem II from Thermosynechococcus elongatus journal June 2015
The low spin - high spin equilibrium in the S2-state of the water oxidizing enzyme journal May 2018
Temperature dependence of the high-spin S2 to S3 transition in Photosystem II: Mechanistic consequences journal June 2019
D1-S169A substitution of photosystem II reveals a novel S2-state structure journal December 2020
Proton exit pathways surrounding the oxygen evolving complex of photosystem II journal August 2021
Oxygen-evolving complex of Photosystem II: an analysis of second-shell residues and hydrogen-bonding networks journal April 2015
QM/MM study of the S2 to S3 transition reaction in the oxygen-evolving complex of photosystem II journal September 2015
Toward understanding the S2-S3 transition in the Kok cycle of Photosystem II: Lessons from Sr-substituted structure journal November 2021
NH 3 Binding to the S 2 State of the O 2 -Evolving Complex of Photosystem II: Analogue to H 2 O Binding during the S 2 → S 3 Transition journal September 2015
S 3 State of the O 2 -Evolving Complex of Photosystem II: Insights from QM/MM, EXAFS, and Femtosecond X-ray Diffraction journal February 2016
Requirement of Chloride for the Downhill Electron Transfer Pathway from the Water-Splitting Center in Natural Photosynthesis journal December 2021
Energetics of the S 2 State Spin Isomers of the Oxygen-Evolving Complex of Photosystem II journal January 2017
Insights into Proton-Transfer Pathways during Water Oxidation in Photosystem II journal September 2019
Mechanism of Water Delivery to the Active Site of Photosystem II along the S 2 to S 3 Transition journal January 2016
p K a of a Proton-Conducting Water Chain in Photosystem II journal May 2016
Location of Methanol on the S 2 State Mn Cluster in Photosystem II Studied by Proton Matrix Electron Nuclear Double Resonance journal January 2017
Early Binding of Substrate Oxygen Is Responsible for a Spectroscopically Distinct S 2 State in Photosystem II journal August 2019
Proton Isomers Rationalize the High- and Low-Spin Forms of the S 2 State Intermediate in the Water-Oxidizing Reaction of Photosystem II journal August 2019
Electron paramagnetic resonance properties of the S2 state of the oxygen-evolving complex of photosystem II journal August 1986
Evidence from FTIR Difference Spectroscopy That D1-Asp61 Influences the Water Reactions of the Oxygen-Evolving Mn 4 CaO 5 Cluster of Photosystem II journal April 2014
Structural Changes in the Oxygen-Evolving Complex of Photosystem II Induced by the S 1 to S 2 Transition: A Combined XRD and QM/MM Study journal October 2014
Effect of Near-Infrared Light on the S 2 -State of the Manganese Complex of Photosystem II from Synechococcus elongatus journal June 1998
The Affinities for the Two Substrate Water Binding Sites in the O 2 Evolving Complex of Photosystem II Vary Independently during S-State Turnover journal April 2000
Manganese Cluster in Photosynthesis:  Where Plants Oxidize Water to Dioxygen journal January 1996
Is Deprotonation of the Oxygen-Evolving Complex of Photosystem II during the S 1 → S 2 Transition Suppressed by Proton Quantum Delocalization? journal May 2021
Two Different Structures of the Oxygen-Evolving Complex in the Same Polypeptide Frameworks of Photosystem II journal January 2017
Differences in the Active Site of Water Oxidation among Photosynthetic Organisms journal September 2017
Crystal structure of oxygen-evolving photosystem II at a resolution of 1.9 Å journal April 2011
Native structure of photosystem II at 1.95 Å resolution viewed by femtosecond X-ray pulses journal November 2014
Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL journal February 2017
Structures of the intermediates of Kok’s photosynthetic water oxidation clock journal November 2018
High-resolution cryo-EM structure of photosystem II reveals damage from high-dose electron beams journal March 2021
pKa of the ligand water molecules in the oxygen-evolving Mn4CaO5 cluster in photosystem II journal July 2020
Oxygen-evolving complex of photosystem II: correlating structure with spectroscopy journal January 2014
A five-coordinate Mn( iv ) intermediate in biological water oxidation: spectroscopic signature and a pivot mechanism for water binding journal January 2016
The S 2 to S 3 transition for water oxidation in PSII (photosystem II), revisited journal January 2018
The ONIOM (our own N-layered integrated molecular orbital + molecular mechanics) method for the first singlet excited (S1) state photoisomerization path of a retinal protonated Schiff base journal August 2000
Ab initio effective core potentials for molecular calculations. Potentials for K to Au including the outermost core orbitals journal January 1985
Untangling the sequence of events during the S 2 → S 3 transition in photosystem II and implications for the water oxidation mechanism journal May 2020
Do crystallographic XFEL data support binding of a water molecule to the oxygen-evolving complex of photosystem II exposed to two flashes of light? journal June 2021
Reply to Wang et al.: Clear evidence of binding of Ox to the oxygen-evolving complex of photosystem II is best observed in the omit map journal June 2021
High-resolution cryo-electron microscopy structure of photosystem II from the mesophilic cyanobacterium, Synechocystis sp. PCC 6803 journal December 2021
Hole-vibronic coupling in oligothiophenes: impact of backbone torsional flexibility on relaxation energies
  • da Silva Filho, Demetrio A.; Coropceanu, Veaceslav; Fichou, Denis
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 365, Issue 1855 https://doi.org/10.1098/rsta.2007.2025
journal April 2007
QM/MM computational studies of substrate water binding to the oxygen-evolving centre of photosystem II
  • Sproviero, Eduardo M.; Shinopoulos, Katherine; Gascón, José A.
  • Philosophical Transactions of the Royal Society B: Biological Sciences, Vol. 363, Issue 1494 https://doi.org/10.1098/rstb.2007.2210
journal October 2007
Features and development of Coot journal March 2010
COOPERATION OF CHARGES IN PHOTOSYNTHETIC O 2 EVOLUTION–I. A LINEAR FOUR STEP MECHANISM journal June 1970
Structural isomers of the S 2 state in photosystem II: do they exist at room temperature and are they important for function? journal March 2019
Photosynthetic O2 Formation Tracked by Time-Resolved X-ray Experiments journal November 2005
An oxyl/oxo mechanism for oxygen-oxygen coupling in PSII revealed by an x-ray free-electron laser journal October 2019
The Structure of Photosystem II and the Mechanism of Water Oxidation in Photosynthesis journal April 2015
Progress Toward a Molecular Mechanism of Water Oxidation in Photosystem II journal May 2017