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Chapter
Refined Model of the Oxidation States and Structures of the Mn/Ca/Cl Cluster of the Oxygen Evolving Complex of Photosystem II
Central to the problem of photosynthetic oxygen evolution is the structure and function of the Mn/Ca/Cl complex that appears to be the locus of charge accumulation and water splitting. In the recent past our g...
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Chapter
Substrate Water 18O Exchange Kinetics in the S2 State of Photosystem II
The oxidation of water into molecular oxygen during photosynthesis is catalyzed by a subdomain of photosystem II (PSII) termed the water oxidizing complex (WOC). Contained within the WOC is a redox-active Mn/t...
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Chapter
Calcium and Chloride Cofactors of the Oxygen Evolving Complex - X-Ray Absorption Spectroscopy Evidence for A Mn/Ca/Cl Heteronuclear Cluster
The oxygen-evolving complex (OEC) of photosystem II (PSII) in green plants and algae contains a cluster of four Mn atoms in the active site, which catalyzes the oxidation of water to dioxygen. Along with Mn, Cl− ...
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Chapter
Mechanism of Photosynthetic Oxygen Production
This chapter deals with the mechanism of photosynthetic water oxidation that leads to O2 formation in Photosystem II (PS II). After a brief introduction to the structure and function of the PS II complex, the S-s...
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Article
Pulse EPR, 55Mn-ENDOR and ELDOR-detected NMR of the S2-state of the oxygen evolving complex in Photosystem II
Pulse EPR, 55Mn-ENDOR and ELDOR-detected NMR experiments were performed on the S2-state of the oxygen-evolving complex from spinach Photosystem II. The novel technique of random acquisition in ENDOR was used to s...
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Article
Interactions of photosystem II with bicarbonate, formate and acetate
In this study, we probe the effects of bicarbonate (hydrogencarbonate), BC, removal from photosystem II in spinach thylakoids by measuring flash-induced oxygen evolution patterns (FIOPs) with a Joliot-type ele...
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Chapter and Conference Paper
Structure of the Photosynthetic Mn4Ca Cluster Using X-ray Spectroscopy
Single crystals of Photosystem II (PSII) isolated from thermophilic cyanobacteria have been studied by X-ray diffraction (XRD) with resolutions between 3 and 3.8 Å (Ferreira et al. 2004; Loll et al. 2005). The...
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Chapter and Conference Paper
Effects of Chloride/Bromide Substitution on Substrate Water Exchange Rates in Photosystem II
The role of chloride in photosynthetic water oxidation is still under discussion since both its precise function and possible binding site are unresolved. In the present study the effects of Cl− on substrate wate...
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Chapter and Conference Paper
Oxygen Evolving Reactions by Synthetic Manganese Complexes
Four manganese complexes were screened for O2 formation under coherent experimental conditions. We identified several new oxygen evolving reactions and in one case 18O labelling with the expected isotope ratio in...
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Chapter and Conference Paper
Formate-Induced Release of Carbon Dioxide/ Hydrogencarbonate from Photosystem II
Using Membrane-Inlet Mass Spectrometry (Mims) We Confirm That Injections Of High Concentrations (100 Mm Final Concentration) Of Formate Into The Psii Samples Induce A Slow Release Of Carbon Dioxide/Hydrogencar...
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Chapter and Conference Paper
Substrate Water Bound to the S2-State of the Mn4OxCa Cluster in Photosystem II Studied by Advanced Pulse EPR Spectroscopy
In The Present Study, We Employed Several Advanced Pulse Epr Techniques To Detect Weak Hyperfine Couplings To Study Substrate Water Binding To The Mn4OXCa Cluster In The S2, State Of Photosystem Ii. Our Data Show...
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Chapter and Conference Paper
Electronic Structure and Oxidation State Changes in the Mn4Ca Cluster of Photosystem II
Oxygen-evolving complex (Mn4Ca cluster) of Photosystem II cycles through five intermediate states (Si-states, i = 0–4) before a molecule of dioxygen is released. During the Sstate transitions, electrons are extra...
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Chapter
Mass Spectrometry-Based Methods for Studying Kinetics and Dynamics in Biological Systems
In recent years, mass spectrometry (MS) has become one of the most widely used analytical techniques. MS allows studies on compounds ranging in size from single atoms to mega-Dalton biomolecular assemblies. Th...
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Article
Open AccessEffects of methanol on the S i -state transitions in photosynthetic water-splitting
From a chemical point of view methanol is one of the closest analogues of water. Consistent with this idea EPR spectroscopy studies have shown that methanol binds at—or at least very close to—the Mn4O ...
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Article
Special educational issue on ‘Basics and application of biophysical techniques in photosynthesis and related processes’
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Article
Special educational issue on ‘Basics and application of biophysical techniques in photosynthesis and related processes’—Part B
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Article
Open AccessOn-line mass spectrometry: membrane inlet sampling
Significant insights into plant photosynthesis and respiration have been achieved using membrane inlet mass spectrometry (MIMS) for the analysis of stable isotope distribution of gases. The MIMS approach is ba...
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Article
Open AccessIs Mn-Bound Substrate Water Protonated in the S 2 State of Photosystem II?
In spite of great progress in resolving the geometric structure of the water-splitting Mn4O x Ca cluster in photosystem II, the binding sites and modes of the two substrate water...
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Article
Agu Laisk, Ladislav Nedbal, and Govindjee (eds): Photosynthesis in silico. Understanding complexity from molecules to ecosystems
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Chapter and Conference Paper
An EPR and ENDOR Spectroscopic Investigation of the Ca2+-Depleted Oxygen-Evolving Complex of Photosystem II
Multifrequency EPR and 55Mn ENDOR spectroscopy were used to characterize the S2 ′ state of the Ca2+- depleted oxygen-evolving complex. The 55Mn ENDOR spectrum of the S2 ′ state is ...
