Version 1
: Received: 8 August 2024 / Approved: 8 August 2024 / Online: 12 August 2024 (03:31:23 CEST)
How to cite:
Santabarbara, S.; Casazza, A. P. Thermodynamic Factors Controlling Electron Transfer amongst the Terminal Electron Acceptors of Photosystem I: Insight from Kinetic Modelling. Preprints2024, 2024080661. https://doi.org/10.20944/preprints202408.0661.v1
Santabarbara, S.; Casazza, A. P. Thermodynamic Factors Controlling Electron Transfer amongst the Terminal Electron Acceptors of Photosystem I: Insight from Kinetic Modelling. Preprints 2024, 2024080661. https://doi.org/10.20944/preprints202408.0661.v1
Santabarbara, S.; Casazza, A. P. Thermodynamic Factors Controlling Electron Transfer amongst the Terminal Electron Acceptors of Photosystem I: Insight from Kinetic Modelling. Preprints2024, 2024080661. https://doi.org/10.20944/preprints202408.0661.v1
APA Style
Santabarbara, S., & Casazza, A. P. (2024). Thermodynamic Factors Controlling Electron Transfer amongst the Terminal Electron Acceptors of Photosystem I: Insight from Kinetic Modelling. Preprints. https://doi.org/10.20944/preprints202408.0661.v1
Chicago/Turabian Style
Santabarbara, S. and Anna Paola Casazza. 2024 "Thermodynamic Factors Controlling Electron Transfer amongst the Terminal Electron Acceptors of Photosystem I: Insight from Kinetic Modelling" Preprints. https://doi.org/10.20944/preprints202408.0661.v1
Abstract
Photosystem I is a key component of primary energy conversion in oxygenic photosynthesis. Electron transfer reactions in Photosystem I take place across two, parallel, electron transfer chains that converge after a few electron transfer steps, sharing both the terminal electron acceptors, that are a series of three Iron-Sulphur (Fe-S) clusters known as , and , and the terminal donor, . The two electron transfer chains show kinetic differences which are, due to their close geometrical symmetry, mainly attributable to the tuning of the physical-chemical reactivity of the bound cofactors, exerted by the protein surroundings. The factors controlling the rate of electron transfer between the terminal Fe-S clusters are still not fully understood because of the difficulties of monitoring these events directly. Here we present a discussion concerning the driving forces associated to electron transfer between and as well as and , employing a tunnelling-based description of the reaction rates coupled to the kinetic modelling of forward and recombination reactions. It is concluded that the reorganisation energy for oxidation shall be lower than 1 eV. Moreover, it is suggested that the analysis of mutants with altered redox properties can also provide useful information concerning the upstream, phylloquinone, cofactor energetics.
Keywords
electron transfer; standard gibbs free energy difference; reorganisation energy; tunnelling barrier; iron-sulphur cluster; (Phyllo)quinone
Subject
Biology and Life Sciences, Biophysics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
