1997
The Tetranuclear Manganese Cluster in Photosystem II: Location and Magnetic Properties of the S2 State As Determined by Saturation−Recovery EPR Spectroscopy †
Koulougliotis D, Schweitzer R, Brudvig G. The Tetranuclear Manganese Cluster in Photosystem II: Location and Magnetic Properties of the S2 State As Determined by Saturation−Recovery EPR Spectroscopy †. Biochemistry 1997, 36: 9735-9746. PMID: 9245405, DOI: 10.1021/bi970326t.Peer-Reviewed Original ResearchConceptsFirst excited spin stateSpin-lattice relaxationSpin statesMagnetic propertiesExcited spin statesS2-state multiline EPRNuclear spin-lattice relaxationSpin-lattice relaxation propertiesEffective magnetic momentLine shapeUntreated photosystem IIMagnetic momentDifferent spin statesDipolar modelNear resonanceGround spin stateSaturation-recovery EPR spectroscopyNuclear relaxation processesLarmor frequencyOrbach mechanismGreater relaxation enhancementTemperature-dependent enhancementDipole-dipole interactionTetranuclear manganese clusterS2-state multiline EPR signal
1996
Reversible Binding of Nitric Oxide to Tyrosyl Radicals in Photosystem II. Nitric Oxide Quenches Formation of the S3 EPR Signal Species in Acetate-Inhibited Photosystem II†
Szalai V, Brudvig G. Reversible Binding of Nitric Oxide to Tyrosyl Radicals in Photosystem II. Nitric Oxide Quenches Formation of the S3 EPR Signal Species in Acetate-Inhibited Photosystem II†. Biochemistry 1996, 35: 15080-15087. PMID: 8942675, DOI: 10.1021/bi961117w.Peer-Reviewed Original ResearchConceptsS3 EPR signalOxygen-evolving complexMultiline EPR signalEPR signalS2 statePhotosystem IIManganese-depleted photosystem IIS2-state multiline EPR signalRedox-active tyrosinesPhotosystem II samplesRadical EPR signalSignal speciesNitric oxide (NO) bindsTyrosyl radicalsAmmonia resultsReversible bindingOxideYZDipolar interactionsRibonucleotide reductase
1987
Reactions of hydroxylamine with the electron-donor side of photosystem II.
Beck W, Brudvig G. Reactions of hydroxylamine with the electron-donor side of photosystem II. Biochemistry 1987, 26: 8285-95. PMID: 2831941, DOI: 10.1021/bi00399a040.Peer-Reviewed Original ResearchConceptsReaction of hydroxylamineMn complexesElectron donor sideO2-evolving centerCharge separationPSII membranesLow-temperature electron paramagnetic resonance (EPR) spectroscopyPhotosystem IIElectron paramagnetic resonance spectroscopyS2-state multiline EPR signalS1 stateTwo-electron reductionOne-electron photooxidationParamagnetic resonance spectroscopyN-methyl-substituted analoguesRadical oxidation productsO2 evolution activityMultiline EPR signalOxidation stateThylakoid membrane preparationsOxidation productsEvolution activityProlonged dark incubationEPR signalResonance spectroscopyFormation of the S2 state and structure of the Mn complex in photosystem II lacking the extrinsic 33 kilodalton polypeptide
Miller A, de Paula J, Brudvig G. Formation of the S2 state and structure of the Mn complex in photosystem II lacking the extrinsic 33 kilodalton polypeptide. Photosynthesis Research 1987, 12: 205-218. PMID: 24435688, DOI: 10.1007/bf00055121.Peer-Reviewed Original ResearchS2-state multiline EPR signalState multiline EPR signalStable charge separationPSII membranesMultiline EPR signalEPR signalCharge separationManganese sitesElectron paramagnetic resonance spectroscopyUntreated PSII membranesElectron transfer eventsParamagnetic resonance spectroscopyPhotosystem II membranesMn complexesElectron donorResonance spectroscopyS2 stateReaction centersExtrinsic polypeptidesHigh yieldsMagnetic propertiesPhotosystem IISeparationTemperature rangeSpectroscopy
1986
Binding of amines to the O2-evolving center of photosystem II.
Beck W, Brudvig G. Binding of amines to the O2-evolving center of photosystem II. Biochemistry 1986, 25: 6479-86. PMID: 3024709, DOI: 10.1021/bi00369a021.Peer-Reviewed Original ResearchConceptsO2-evolving centerMultiline EPR spectrumMultiline EPR signalEPR signalS2 statePSII membranesLow-temperature electron paramagnetic resonance (EPR) spectroscopyEPR spectraElectron paramagnetic resonance spectroscopyS2-state multiline EPR signalPhotosystem IIBinding of NH3Untreated PSII membranesDirect spectroscopic evidenceParamagnetic resonance spectroscopySpinach PSII membranesMn sitesBinding of aminesDifferent EPR signalsNH3 moleculesSpectroscopic evidencePrimary aminesSteric factorsParamagnetic sitesResonance spectroscopyEffect of the 17- and 23-kilodalton polypeptides, calcium, and chloride on electron transfer in photosystem II.
De Paula J, Li P, Miller A, Wu B, Brudvig G. Effect of the 17- and 23-kilodalton polypeptides, calcium, and chloride on electron transfer in photosystem II. Biochemistry 1986, 25: 6487-94. PMID: 3024710, DOI: 10.1021/bi00369a022.Peer-Reviewed Original ResearchConceptsS2-state multiline EPR signalMultiline EPR signalEPR signalPSII membranesPhotosystem II samplesS1 stateUntreated PSII membranesReaction centersElectron paramagnetic resonance measurementsChlorophyll moleculesPhotosystem II membranesStable charge separationParamagnetic resonance measurementsPhotosystem IIPSII samplesO2-evolving centerElectron transferCharge separationElectron donorNuclear hyperfine structureCytochrome b559Mn sitesResonance measurementsOxidationFraction of PSII
1985
Electron transfer in photosystem II at cryogenic temperatures.
De Paula J, Innes J, Brudvig G. Electron transfer in photosystem II at cryogenic temperatures. Biochemistry 1985, 24: 8114-20. PMID: 3004575, DOI: 10.1021/bi00348a042.Peer-Reviewed Original ResearchConceptsS2-state multiline EPR signalMultiline EPR signalElectron donationEPR signalS1 stateCytochrome b559Electron paramagnetic resonance spectroscopyParamagnetic resonance spectroscopyStable charge separationPhotosystem IIChemical oxidationChlorophyll cationElectron transferReaction center concentrationCharge separationElectron donorResonance spectroscopyS2 stateReaction centersTemperature rangeP680Signal speciesCenter concentrationB559Donation pathwayActive and resting states of the O2-evolving complex of photosystem II.
Beck W, De Paula J, Brudvig G. Active and resting states of the O2-evolving complex of photosystem II. Biochemistry 1985, 24: 3035-43. PMID: 2990539, DOI: 10.1021/bi00333a035.Peer-Reviewed Original ResearchConceptsO2-evolving complexEPR signalPSII membranesLow-temperature electron paramagnetic resonance (EPR) spectroscopyPhotosystem IIElectron paramagnetic resonance spectroscopyS2-state multiline EPR signalParamagnetic resonance spectroscopyS2 state EPR signalsMn sitesMultiline EPR signalSpinach photosystem IIThylakoid membranesCatalytic reductionChemical propertiesResonance spectroscopyDifferent hyperfine structureO2