Photosynthesis Research

, Volume 22, Issue 3, pp 173–186 | Cite as

Electron tunneling pathways in proteins: influences on the transfer rate

  • David N. Beratan
  • José Nelson Onuchic
Theory Regular Paper


A strategy for calculating the tunneling matrix element dependence on the medium intervening between donor and acceptor in specific proteins is described. The scheme is based on prior studies of small molecules and is general enough to allow inclusion of through bond and through space contributions to the electronic tunneling interaction. This strategy should allow the prediction of relative electron transfer rates in a number of proteins. It will therefore serve as a design tool and will be explicitly testable, in contrast with calculations on single molecules. As an example, the method is applied to ruthenated myoglobin and the tunneling matrix elements are estimated. Quantitative improvements of the model are described and effects due to motion of the bridging protein are discussed. The method should be of use for designing target proteins having tailored electron transfer rates for production with site directed mutagenesis. The relevance of the technique to understanding certain photosynthetic reaction center electron transfer rates is discussed.

Key words

electronic coupling electron transfer pathways electron transfer theory electron tunneling nuclear tunneling protein mediated electronic coupling tunneling matrix element 


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Copyright information

© Kluwer Academic Publishers 1989

Authors and Affiliations

  • David N. Beratan
    • 1
  • José Nelson Onuchic
    • 2
  1. 1.Jet Propulsion LaboratoryCalifornia Institute of TechnologyPasadenaUSA
  2. 2.Instituto de Fisica e Quimica de São CarlosUniversidade de São PauloSão Carlos, SPBrazil

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