Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 2 February 2007:
Vol. 315. no. 5812, pp. 622 - 625
DOI: 10.1126/science.1134862
Prev | Table of Contents | Next

Reports

Coupling Coherence Distinguishes Structure Sensitivity in Protein Electron Transfer

Tatiana R. Prytkova, Igor V. Kurnikov,* David N. Beratan{dagger}

Quantum mechanical analysis of electron tunneling in nine thermally fluctuating cytochrome b562 derivatives reveals two distinct protein-mediated coupling limits. A structure-insensitive regime arises for redox partners coupled through dynamically averaged multiple-coupling pathways (in seven of the nine derivatives) where heme-edge coupling leads to the multiple-pathway regime. A structure-dependent limit governs redox partners coupled through a dominant pathway (in two of the nine derivatives) where axial-ligand coupling generates the single-pathway limit and slower rates. This two-regime paradigm provides a unified description of electron transfer rates in 26 ruthenium-modified heme and blue-copper proteins, as well as in numerous photosynthetic proteins.

Departments of Chemistry and Biochemistry, Duke University, Durham, NC 27708, USA.

* Present address: Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15219–3130, USA.

{dagger} To whom correspondence should be addressed. E-mail: david.beratan{at}duke.edu

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Mapping protein electron transfer pathways with QM/MM methods.
V. Guallar and F. Wallrapp (2008)
J R Soc Interface 5, 233-239
   Abstract »    Full Text »    PDF »
Tryptophan-Accelerated Electron Flow Through Proteins.
C. Shih, A. K. Museth, M. Abrahamsson, A. M. Blanco-Rodriguez, A. J. Di Bilio, J. Sudhamsu, B. R. Crane, K. L. Ronayne, M. Towrie, A. Vlcek Jr., et al. (2008)
Science 320, 1760-1762
   Abstract »    Full Text »    PDF »
Heme copper oxidases use tunneling pathways.
D. N. Beratan and I. A. Balabin (2008)
PNAS 105, 403-404
   Full Text »    PDF »
Nanosecond electron tunneling between the hemes in cytochrome bo3.
A. Jasaitis, M. P. Johansson, M. Wikstrom, M. H. Vos, and M. I. Verkhovsky (2007)
PNAS 104, 20811-20814
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)