A Caltech Library Service

Electron tunneling in structurally engineered proteins

Gray, Harry B. and Winkler, Jay R. (1997) Electron tunneling in structurally engineered proteins. Journal of Electroanalytical Chemistry, 438 (1-2). pp. 43-47. ISSN 1572-6657. doi:10.1016/S0022-0728(96)05024-3.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


Photosynthesis, respiration, nitrogen fixation, drug metabolism, DNA synthesis, and immune response are among the scores of biological processes that rely heavily on long-range (10 to 25 Å) protein electron-transfer (ET) reactions. Semiclassical theory predicts that the rates of these reactions depend on the reaction driving force −ΔG°, a nuclear reorganization parameter λ, and the electronic-coupling strength H_(AB) between reactants and products at the transition state: ET rates (k°_(ET)) reach their maximum values when the nuclear factor is optimized (−ΔG° = λ); these k_(ET)° values are limited only by the strength (H_(AB)^2) of the electronic interaction between the donor (D) and acceptor (A). Coupling-limited Cu^+ to Ru^(3+) and Fe^(2+) to Ru^(3+) ET rates have been extracted from kinetic studies on several Ru-modified proteins. In azurin, a blue copper protein, the distant D/A pairs are relatively well coupled (k°_(ET) decreases exponentially with R(CuRu); the decay constant is 1.1 Å^(−1)). In contrast to the extended peptides found in azurin and other β-sheet proteins, helical structures have tortuous covalent pathways owing to the curvature of the peptide backbone. The decay constants estimated from ET rates for D/A pairs separated by long sections of the α helix in myoglobin and the photosynthetic reaction center are between 1.25 and 1.6 Å^(−1).

Item Type:Article
Related URLs:
URLURL TypeDescription
Gray, Harry B.0000-0002-7937-7876
Winkler, Jay R.0000-0002-4453-9716
Additional Information:© 1997 Elsevier Science. Received 1 August 1996. Our work on electron transfer in proteins is supported by the National Science foundation, the National Institutes of Health, and the Arnold and Mabel Beckman Foundation.
Funding AgencyGrant Number
Arnold and Mabel Beckman FoundationUNSPECIFIED
Subject Keywords:Electron tunneling; Proteins; Electron transfer rate; Decay constant
Issue or Number:1-2
Record Number:CaltechAUTHORS:20170907-102343386
Persistent URL:
Official Citation:Harry B. Gray, Jay R. Winkler, Electron tunneling in structurally engineered proteins, Journal of Electroanalytical Chemistry, Volume 438, Issue 1, 1997, Pages 43-47, ISSN 1572-6657, (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:81241
Deposited By: Ruth Sustaita
Deposited On:07 Sep 2017 20:16
Last Modified:15 Nov 2021 19:42

Repository Staff Only: item control page