Session D6: Long-Distance Charge Transfer in Biological Systems

2:30 PM–5:30 PM, Monday, March 10, 2008
Morial Convention Center - RO4

Sponsoring Units: FIAP DPOLY
Chair: Nikolai Sergueev, University of Texas at Austin

Abstract: D6.00001 : Theory of Electron Transfer and Transport Pathways in Biomolecules

2:30 PM–3:06 PM

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Author:

  David Beratan
    (Duke University)

Electron transfer in proteins and nucleic acids occurs over large distances by a combination of short and long range tunneling mechanisms. Electron tunneling is facilitated by virtual oxidized and reduced states of the bridging macromolecule, and theoretical analysis reveals how a macromolecule's fold, energetics, and fluctuations influence the electron-transfer kinetics. Recent studies of protein electron transfer indicate when and why electron tunneling kinetics is sensitive to the structure of the protein's tunneling pathways. Electron transfer across protein-protein interfaces involves thin structured water layers that play a key role in tunneling mediation as well. Tunneling analysis that takes the dynamical fluctuations of the macromolecules into explicit account provides a unified view that links structure and function in protein electron transfer. In the case of DNA electron transport, a critical role is found for structural fluctuations and transport mediated by carrier injection to intervening bases, even at very short distances.