Encyclopedia of Biophysics

Living Edition
| Editors: Gordon Roberts, Anthony Watts, European Biophysical Societies

Coupled Electron Transfer

  • Victor L. Davidson
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-35943-9_16-1

Synonyms

Definition

Coupled electron transfer is a process in which a relatively slow electron transfer reaction is preceded by a rapid but thermodynamically unfavorable nonelectron transfer reaction that is required to activate the system for electron transfer.

Basic Characteristics

Coupled electron transfer occurs when a relatively slow nonadiabatic (true electron transfer) reaction is preceded by a rapid but thermodynamically unfavorable, adiabatic (nonelectron transfer) reaction that is required to activate the system for electron transfer. Since the activated and unreactive states exist in an equilibrium that favors the unreactive state, the observed rate constant ( k obs) for the redox reaction under saturating conditions is an apparent value equal to the product of the true electron transfer rate constant ( k ET) and the equilibrium constant for the preceding reaction step (Eq. 1).
$$ {k}_{\mathrm{obs}}={k_{\mathrm{ET}}}^{\ast...
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References

  1. Davidson VL (2000) The effects of kinetic coupling on experimentally determined electron transfer parameters. Biochemistry 39:4924–4928CrossRefPubMedGoogle Scholar
  2. Davidson VL (2008) Protein control of true, gated and coupled electron transfer reactions. Acc Chem Res 41:730–738CrossRefPubMedPubMedCentralGoogle Scholar
  3. Harris TK, Davidson VL, Chen L et al (1994) Ionic strength dependence of the reaction between methanol dehydrogenase and cytochrome c-551i: evidence of conformationally coupled electron transfer. Biochemistry 33:12600–12608CrossRefPubMedGoogle Scholar
  4. Marcus RA, Sutin N (1985) Electron transfers in chemistry and biology. Biochim Biophys Acta 811:265–322CrossRefGoogle Scholar
  5. Sun D, Li X, Mathews FS, Davidson VL (2005) Site-directed mutagenesis of proline 94 to alanine in amicyanin converts a true electron transfer reaction into one that is kinetically coupled. Biochemistry 44:7200–7206CrossRefPubMedGoogle Scholar

Copyright information

© European Biophysical Societies' Association (EBSA) 2018

Authors and Affiliations

  1. 1.Burnett School of Biomedical Sciences, College of MedicineUniversity of Central FloridaOrlandoUSA