Electron transfer in DNA? Competition by ultra-fast proton transfer?
Interstrand proton transfer, which is driven by the large changes in acidity or basicity that result from loss or uptake of an electron from or by a base in a base pair of DNA, can constitute a very powerful stop to the migration of holes or electrons in the direction of the DNA helix via the stacked bases. In theory, such a proton transfer could have the same rate (10(14) s[-1]) as the electron transfer. In base pair model systems, proton transfer rates up to 10(13) s(-1) have been measured. As a result of the existence of proton transfer barriers to electron transfer, the migration distance of the charge carriers in DNA is likely to be short, extending over only < or = 5 bp's (17 angstroms).
Steenken
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Max-Planck-Institut für Strahlenchemie, Mülheim, Germany.
D001482:Base Composition; D004247:DNA / Q000737:chemistry*; D004579:Electron Transport; D011522:Protons
D011522:Protons; D004247:DNA