TY - JOUR
T1 - Direct measurement of the dynamics of hole hopping in extended DNA G-tracts. an unbiased random walk
AU - Conron, Sarah M.Mickley
AU - Thazhathveetil, Arun K.
AU - Wasielewski, Michael R.
AU - Burin, Alexander L.
AU - Lewis, Frederick D.
PY - 2010/10/20
Y1 - 2010/10/20
N2 - We report the measurement of distance- and temperature-dependent rate constants for charge separation in capped hairpins in which a stilbene hole acceptor and hole donor are separated by A3Gn diblock polypurine sequences consisting of 3 adenines and 1-19 guanines. The longer diblock systems obey the simplest model for an unbiased random walk, providing a direct measurement of khop = 4.3 × 109 s -1 for a single reversible G-to-G hole hopping step, somewhat faster than the value of 1.2 × 109 s-1 calculated for A-tract hole hopping. The temperature dependence for hopping in A 3G13 provides values of Eact = 2.8 kcal/mol and A = 7 × 109 s-1, consistent with a weakly activated, conformationally gated process.
AB - We report the measurement of distance- and temperature-dependent rate constants for charge separation in capped hairpins in which a stilbene hole acceptor and hole donor are separated by A3Gn diblock polypurine sequences consisting of 3 adenines and 1-19 guanines. The longer diblock systems obey the simplest model for an unbiased random walk, providing a direct measurement of khop = 4.3 × 109 s -1 for a single reversible G-to-G hole hopping step, somewhat faster than the value of 1.2 × 109 s-1 calculated for A-tract hole hopping. The temperature dependence for hopping in A 3G13 provides values of Eact = 2.8 kcal/mol and A = 7 × 109 s-1, consistent with a weakly activated, conformationally gated process.
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U2 - 10.1021/ja106991f
DO - 10.1021/ja106991f
M3 - Article
C2 - 20863110
AN - SCOPUS:77958068669
VL - 132
SP - 14388
EP - 14390
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 41
ER -