Long-range electron transfer in myoglobin.

Journal Article

The distance and driving-force dependences of electron transfer (ET) in a set of four surface-ruthenated myoglobins, in which the heme prosthetic group has been systematically replaced by a series of metalloporphyrins of differing excited-state redox potentials, have provided information on the magnitude [Hab(12.7 A) approximately 6.3 x 10(-3) cm-1] and decay [beta approximately 0.8 A-1, where kET alpha exp [-beta(d - do)]] of protein-mediated donor-acceptor electronic coupling. A reorganization energy lambda approximately 1.3 eV, due to coordination and solvation changes both at and between the ET sites, has been estimated using a rate expression that allows electron-vibration coupling to classical and quantum mechanical modes. The contribution to lambda from the porphyrin and peptide matrix is approximately 0.7 eV. Specific electron-tunneling pathways in the protein have been evaluated.

Full Text

Duke Authors

Cited Authors

  • Cowan, JA; Upmacis, RK; Beratan, DN; Onuchic, JN; Gray, HB

Published Date

  • 1988

Published In

Volume / Issue

  • 550 /

Start / End Page

  • 68 - 84

PubMed ID

  • 3245652

International Standard Serial Number (ISSN)

  • 0077-8923


  • eng

Conference Location

  • United States