Electron Tunneling in Proteins: Coupling Through a β Strand
Abstract
Electron coupling through a beta strand has been investigated by measurement of the intramolecular electron-transfer (ET) rates in ruthenium-modified derivatives of the beta barrel blue copper protein Pseudomonas aeruginosa azurin. Surface histidines, introduced on the methionine-121 beta strand by mutagenesis, were modified with a Ru(2,2'-bipyridine)2(imidazole)^2+ complex. The Cu+ to Ru^3+ rate constants yielded a distance-decay constant of 1.1 per angstrom, a value close to the distance-decay constant of 1.0 per angstrom predicted for electron tunneling through an idealized beta strand. Activationless ET rate constants in combination with a tunneling-pathway analysis of the structures of azurin and cytochrome c confirm that there is a generally efficient network for coupling the internal (native) redox center to the surface of both proteins.
Additional Information
© 1995 American Association for the Advancement of Science. 17 January 1995; accepted 23 March 1995. We thank D. R. Casimiro, K. Warncke, J. J. Regan, and J. N. Onuchic for helpful comments. Supported by NIH and NSF.Additional details
- Eprint ID
- 53841
- DOI
- 10.1126/science.7792598
- Resolver ID
- CaltechAUTHORS:20150116-145929070
- NIH
- NSF
- Created
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2015-01-17Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field