Long-range electron–electron interaction and charge transfer in protein complexes: a numerical approach

2019 ◽  
Vol 21 (34) ◽  
pp. 18595-18604 ◽  
Author(s):  
David Gnandt ◽  
Thorsten Koslowski
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Protein Complexes ◽  
Numerical Approach ◽  
Pair Approximation ◽  
Electron Interaction ◽  
Coulomb Interactions ◽  
Electron Transfer Proteins ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Coulomb interactions in large electron transfer proteins can be addressed within a pair approximation. They have a profound effect on the thermodynamics and kinetics of charge transport.

scholarly journals The effects of the chemical environment of menaquinones in lipid monolayers on mercury electrodes on the thermodynamics and kinetics of their electrochemistry

2021 ◽  
Author(s):  
Karuppasamy Dharmaraj ◽  
Dirk Dattler ◽  
Heike Kahlert ◽  
Uwe Lendeckel ◽  
Felix Nagel ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Transfer Rate ◽  
Chemical Environment ◽  
Lipid Monolayers ◽  
Redox Potentials ◽  
Electron Transfer Rate ◽  
Thermodynamics And Kinetics ◽  
Mercury Electrodes ◽  
Kinetics Of

AbstractThe effects of the chemical environment of menaquinones (all-trans MK-4 and all-trans MK-7) incorporated in lipid monolayers on mercury electrodes have been studied with respect to the thermodynamics and kinetics of their electrochemistry. The chemical environment relates to the composition of lipid films as well as the adjacent aqueous phase. It could be shown that the addition of all-trans MK-4 to TMCL does not change the phase transition temperatures of TMCL. In case of DMPC monolayers, the presence of cholesterol has no effect on the thermodynamics (formal redox potentials) of all-trans MK-7, but the kinetics are affected. Addition of an inert electrolyte (sodium perchlorate; change of ionic strength) to the aqueous phase shifts the redox potentials of all-trans MK-7 only slightly. The formal redox potentials of all-trans MK-4 were determined in TMCL and nCL monolayers and found to be higher in nCL monolayers than in TMCL monolayers. The apparent electron transfer rate constants, transfer coefficients and activation energies of all-trans MK-4 in cardiolipins have been also determined. Most surprisingly, the apparent electron transfer rate constants of all-trans MK-4 exhibit an opposite pH dependence for TMCL and nCL films: the rate constants increase in TMCL films with increasing pH, but in nCL films they increase with decreasing pH. This study is a contribution to understand environmental effects on the redox properties of membrane bond redox systems. Graphical abstract

pH and Solvent H/D Isotope Effects on the Thermodynamics and Kinetics of Electron Transfer for Electrode-Immobilized Native and Urea-Unfolded Stellacyanin

Langmuir ◽  
2012 ◽  
Vol 28 (42) ◽  
pp. 15087-15094 ◽  
Author(s):  
Antonio Ranieri ◽  
Gianantonio Battistuzzi ◽  
Marco Borsari ◽  
Carlo Augusto Bortolotti ◽  
Giulia Di Rocco ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Isotope Effects ◽  
Thermodynamics And Kinetics ◽  
Kinetics Of

Entropy and enthalpy contributions to the kinetics of proton coupled electron transfer to the Mn4O4(O2PPh2)6 cubane

2014 ◽  
Vol 16 (24) ◽  
pp. 11843-11847
Author(s):  
Thomas G. Carrell ◽  
Paul F. Smith ◽  
Joseph Dennes ◽  
G. Charles Dismukes
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Hydrogen Atom ◽  
Water Oxidation ◽  
Proton Coupled Electron Transfer ◽  
Kinetics Of ◽  
Natural Photosynthesis

The reaction of a manganese-oxo cubane with hydrogen atom donors effectively models water oxidation and charge transfer in natural photosynthesis.

scholarly journals Electron-transfer studies involving flavodoxin and a natural redox partner, the iron protein of nitrogenase. Conformational constraints on protein-protein interactions and the kinetics of electron transfer within the protein complex

1988 ◽  
Vol 253 (2) ◽  
pp. 587-595 ◽  
Author(s):  
R N Thorneley ◽  
J Deistung
Keyword(s):  
Electron Transfer ◽  
Protein Interactions ◽  
Protein Complex ◽  
Protein Complexes ◽  
Linear Free Energy Relationship ◽  
Midpoint Potential ◽  
Linear Free Energy ◽  
Redox Partner ◽  
Fe Protein ◽  
Kinetics Of

The kinetics of electron-transfer reactions involving flavodoxins from Klebsiella pneumoniae (KpFld), Azotobacter chroococcum (AcFld), Anacystis nidulans (AnFld) and Megasphaera elsdenii (MeFld), the free, MgADP-bound and MgATP-bound forms of the Fe protein component of nitrogenase from K. pneumoniae [Kp2, Kp2(MgADP)2 and Kp2(MgATP)2] and Na2S2O4 were studied by stopped-flow spectrophotometry. Kinetic evidence was obtained for the formation of binary protein complexes involving KpFldSQ (semiquinone) with either Kp2(MgADP)2 (KD = 49 microM) or Kp2(MgATP)2 (KD = 13 microM) but not with Kp2 (KD greater than 730 microM). The binding of 2MgATP or 2MgADP to Kp2 therefore not only shifts the midpoint potential (Em) of the [4Fe-4S] centre from -200 mV to -320 mV or -350 mV respectively but also changes the affinity of Kp2 for KpFldSQ. Thermodynamically unfavourable electron from Kp2(MgADP)2 and Kp2(MgATP)2 to KpFldSQ occurs within the protein complexes with k = 1.2 s-1 (delta E = -72 mV) and 0.5 s-1 (delta E = -120 mV) respectively. Although AcFldSQ is reduced by Kp2, Kp2(MgADP)2 and Kp2(MgATP)2 (k = 8 x 10(3), 2.4 x 10(3) and 9 x 10(2) M-1.s-1 respectively), protein-complex formation is weak in each case (KD greater than 700 microM). Electron transfer in the physiologically important and thermodynamically favourable direction from Kp2FldHQ (hydroquinone) and AcFldHQ to Kp2ox.(MgADP)2 (the state of Kp2 that accepts electrons from FldHQ in the catalytic cycle of nitrogenase) is rapid (k greater than 10(6) M-1.s-1). The second-order rate constants for the reduction of KpFldSQ, AcFldSQ, AnFldSQ and MeFldSQ by SO2.- (active reductant formed by the predissociation of S2O4(2-) ion) exhibited the linear free-energy relationship predicted by the Marcus theory of electron transfer.

scholarly journals The Thermodynamics and Kinetics of Electron Transfer between Cytochromeb6fand Photosystem I in the Chlorophylld-dominated Cyanobacterium,Acaryochloris marina

2008 ◽  
Vol 283 (37) ◽  
pp. 25218-25226 ◽  
Author(s):  
Benjamin Bailleul ◽  
Xenie Johnson ◽  
Giovanni Finazzi ◽  
James Barber ◽  
Fabrice Rappaport ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photosystem I ◽  
Thermodynamics And Kinetics ◽  
Acaryochloris Marina ◽  
Kinetics Of
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