Proton and hydrogen currents in photosynthetic water oxidation. Academic Article

abstract

• The photosynthetic processes that lead to water oxidation involve an evolution in time from photon dynamics to photochemically-driven electron transfer to coupled electron/proton chemistry. The redox-active tyrosine, Y(Z), is the component at which the proton currents necessary for water oxidation are switched on. The thermodynamic and kinetic implications of this function for Y(Z) are discussed. These considerations also provide insight into the related roles of Y(Z) in preserving the high photochemical quantum efficiency in Photosystem II (PSII) and of conserving the highly oxidizing conditions generated by the photochemistry in the PSII reaction center. The oxidation of Y(Z) by P(680)(+) can be described well by a treatment that invokes proton coupling within the context of non-adiabatic electron transfer. The reduction of Y(.)(Z), however, appears to proceed by an adiabatic process that may have hydrogen-atom transfer character.

authors

• Tommos, Cecilia

published proceedings

• Biochim Biophys Acta

author list (cited authors)

• Tommos, C., & Babcock, G. T.

complete list of authors

• Tommos, C||Babcock, GT

publication date

• May 2000

publisher

• Elsevier  Publisher

published in

• Biochimica et Biophysica Acta: international journal of biochemistry and biophysics  Journal

keywords

• Electron Transport
• Hydrogen
• Hydrogen Bonding
• Hydrogen-Ion Concentration
• Kinetics
• Oxidation-Reduction
• Oxygen
• Photons
• Photosynthesis
• Photosynthetic Reaction Center Complex Proteins
• Photosystem Ii Protein Complex
• Protons
• Static Electricity
• Thermodynamics
• Tyrosine
• Water

PubMed Central ID

• 10812034

Digital Object Identifier (DOI)

• 10.1016/s0005-2728(00)00069-4

start page

• 199

end page

• 219

volume

• 1458

issue

• 1

URL

• http://dx.doi.org/10.1016/s0005-2728(00)00069-4