January 15, 1999Science
Electron Transfer Between Bases in Double Helical DNA
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Overview
Biophysical analysis reveals that base stacking and energetics govern electron transfer in double-helical DNA, indicating the pi-stack behaves as both an insulator and a wire.
Key Points
- To investigate how base stacking configurations and reactant energetics influence the kinetics and distance dependence of photoinduced electron transfer through the DNA pi-stack.
- Employed fluorescent adenine analogs that selectively oxidize guanine to probe charge transport across double-helical DNA.
- Evaluated photoinduced electron-transfer reaction kinetics across varying distance parameters and reactant stacking alignments.
- Values of beta, reflecting the distance dependence of electron transfer, ranged from 0.1 to 1.0 per angstrom.
- Strong base-stacking interactions yielded the fastest electron-transfer kinetics, favoring an intrastrand over an interstrand transport pathway.
- Reactant energetics substantially modulated charge transport distance dependence, demonstrating that the DNA pi-stack can transition between insulator-like and wire-like regimes.
Cite This Study
Kelley et al. (1999) studied this question.