Charge Transfer between [4Fe4S] Proteins and DNA Is Unidirectional: Implications for Biomolecular Signaling

Teo, Ruijie D.; Rousseau, Benjamin J.G.; Smithwick, Elizabeth R.; Felice, Rosa Di; Beratan, David N.; Migliore, Agostino

doi:10.1016/j.chempr.2019.05.016

Cited by 1 publication

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…γ/2 is the distance decay parameter, equal to 7.7 nm −1 . 54 This approximation has been extensively tested by Beratan and co-workers, 55,56 and a comparison with ab initio calculations 47,56 is given in Figure S5.…”

Section: Extracting Local Hopping Rates From Molecular Dynamics Simul...mentioning

confidence: 99%

“…γ/2 is the distance decay parameter, equal to 7.7 nm –1 . This approximation has been extensively tested by Beratan and co-workers, , and a comparison with ab initio calculations , is given in Figure S5. Taken together with the activation barriers obtained from the MD simulations, these equations yield the hopping times for all pairs within the Dutton radius in the protein, and the distribution of these times is plotted in Figure d, and the forward and backward rates are listed in Table S2.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Long-Range Conductivity in Proteins Mediated by Aromatic Residues

et al. 2023

View full text Add to dashboard Cite

Single-molecule measurements show that many proteins, lacking any redox cofactors, nonetheless exhibit electrical conductance on the order of a nanosiemen over 10 nm distances, implying that electrons can transit an entire protein in less than a nanosecond when subject to a potential difference of less than 1 V. This is puzzling because, for fast transport (i.e., a free energy barrier of zero), the hopping rate is determined by the reorganization energy of approximately 0.8 eV, and this sets the time scale of a single hop to at least 1 μs. Furthermore, the Fermi energies of typical metal electrodes are far removed from the energies required for sequential oxidation and reduction of the aromatic residues of the protein, which should further reduce the hopping current. Here, we combine all-atom molecular dynamics (MD) simulations of non-redox-active proteins (consensus tetratricopeptide repeats) with an electron transfer theory to demonstrate a molecular mechanism that can account for the unexpectedly fast electron transport. According to our MD simulations, the reorganization energy produced by the energy shift on charging (the Stokes shift) is close to the conventional value of 0.8 eV. However, the non-ergodic sampling of molecular configurations by the protein results in reaction-reorganization energies, extracted directly from the distribution of the electrostatic energy fluctuations, that are only ∼0.2 eV, which is small enough to enable long-range conductivity, without invoking quantum coherent transport. Using the MD values of the reorganization energies, we calculate a current decay with distance that is in agreement with experiment.

show abstract