Shallow Distance Dependence for Proton-Coupled Tyrosine Oxidation in Oligoproline Peptides.

  title={Shallow Distance Dependence for Proton-Coupled Tyrosine Oxidation in Oligoproline Peptides.},
  author={Brian Koronkiewicz and John R. Swierk and Kevin P. Regan and James M. Mayer},
  journal={Journal of the American Chemical Society},
We have explored the kinetic effect of increasing electron transfer distance in a biomimetic, proton coupled electron transfer system (PCET). Biological electron transfer is often simultaneous with proton transfer in order to avoid the high-energy, charged intermediates resulting from the stepwise transfer of protons and electrons. These concerted proton electron transfer (CPET) reactions are implicated in numerous biological electron transfer pathways. In many cases, proton transfer is coupled… 
4 Citations
Theoretical Study of Shallow Distance Dependence of Proton-Coupled Electron Transfer in Oligoproline Peptides.
This theory predicted a less shallow distance dependence of the PCET rate constant when imidazole rather than hydrogen phosphate serves as the proton acceptor, even though their pKa values are similar, and was subsequently validated experimentally, illustrating that long-range electron transfer processes can be tuned by modifying the nature of the propton acceptor in concerted PCET processes.
Proton-Coupled Electron Transfer: The Engine of Energy Conversion and Storage.
  • D. Nocera
  • Chemistry
    Journal of the American Chemical Society
  • 2022
The proper design of PCET in these systems facilitates their implementation in the areas of centralized large scale grid storage of electricity and decentralized energy storage/conversion using only sunlight, air and any water source to produce fuel and food within a sustainable cycle for the biogenic elements of C, N and P.
Towards practical applications in quantum computational biology
The applicability and promising directions of quantum computing in computational biology, genetics and bioinformatics is evaluated and discussed and attempts to indicate promising directions for further research in the emerging area of quantum computational biology.


Proton-coupled electron transfer of tyrosine oxidation: buffer dependence and parallel mechanisms.
A competition between three different PCET mechanisms is found, including a concerted PCET with water as the proton acceptor, which indeed shows a pH-dependence as earlier reported and a stepwise electron transfer−proton transfer that is pH-independent.
Long Range Proton-Coupled Electron Transfer Reactions of Bis(imidazole) Iron Tetraphenylporphyrins Linked to Benzoates.
The rate data and extensive molecular simulations show that the electronic coupling decay constant (β) depends on conformational flexibility and solvation associated with the linker domain, and this is the first analysis of β for a CPET reaction.
Long-range electron transfer in peptides. Tyrosine reduction of the indolyl radical: reaction mechanism, modulation of reaction rate, and physiological considerations
We have observed long-range electron transfer (LRET) across the oligoproline spacer from the tyrosine side chain to the indolyl cation radical derived from the 1-electron oxidation of
Thermochemistry of proton-coupled electron transfer reagents and its implications.
This issue discusses proton-coupled electron transfer or PCET processes, which are central to a great many chemical and biochemical processes, from biological catalysis and energy transduction, to bulk industrial chemical processes, to new approaches to solar energy conversion.
Activationless Multiple-Site Concerted Proton-Electron Tunneling.
Since the reaction proceeds without significant thermal activation energy, the rate constant indicates the magnitude of the electron/proton double tunneling probability, and this MS-CPET reaction thus occurs by tunneling of both the proton and electron, in different directions.
Proton-Coupled Electron Transfer in a Series of Ruthenium-Linked Tyrosines with Internal Bases: Evaluation of a Tunneling Model for Experimental Temperature-Dependent Kinetics.
A commonly employed theoretical model for proton tunneling which includes a harmonic distribution of proton donor-acceptor distances due to vibrational motions of the molecule is evaluated, and it is found that donor- acceptor compression is more facile in the compounds with shorter PT distance; however, this is contrary to independent calculations for the same compounds.
Concerted proton-electron transfer reactions in the Marcus inverted region
In inverted region behavior for proton-coupled electron transfer (PCET), Photochemical studies of anthracene-phenol-pyridine triads give rate constants for PCET charge recombination that are slower for the more thermodynamically favorable reactions.
Electron flow through metalloproteins.
Proton-coupled electron transfer in a model for tyrosine oxidation in photosystem II.
Theoretical calculations of a model for tyrosine oxidation in photosystem II are presented and indicate that the larger rate for single ET arises from a combination of factors, including the smaller solvent reorganization energy for ET and the averaging of the coupling for PCET over the reactant and product hydrogen vibrational wave functions.
Electron transfer through a prenucleated bimetalated alanine-based peptide helix.
A 22 residue alanine-based peptide with a tris(bipyridyl)ruthenium(II) amino acid near the middle of the peptide which can act as a photoinducible electron donor is synthesized.