Long-range charge hopping in DNA
Long-range charge hopping in DNA
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DOI：
10.1073/pnas.96.21.11713
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发表时间：
1999-10-12
影响因子：
11.1
通讯作者：
Jortner, J
中科院分区：
文献类型：
--
作者：
Bixon, M;Giese, B;Jortner, J
DNA中电荷迁移的基本机制与当前分子电子学和基于电化学的芯片技术的发展有关。DNA中空穴（正离子）多步跳跃运输的能量控制通过具有最低氧化电位的核碱基鸟嘌呤进行。鸟嘌呤阳离子的相对反应性和其中一条链中三个鸟嘌呤单元的电荷捕获的化学产率数据量化了跳跃、捕获和化学动力学参数。在300 K时，通过两个中间AT碱基对的超交换介导相互作用的空穴跳变速率估计为10(9)s（-1）。我们推测，当鸟嘌呤被单个AT碱基对隔开时，双分子的最大空穴跳迁距离为300 +/- 70埃。虽然我们遇到了DNA中空穴传输的限制，但由于胸腺嘧啶和胞嘧啶的还原电位的相似性，电子传输预计几乎是序列独立的。
The fundamental mechanisms of charge migration in DNA are pertinent for current developments in molecular electronics and electrochemistry-based chip technology. The energetic control of hole (positive ion) multistep hopping transport in DNA proceeds via the guanine, the nucleobase with the lowest oxidation potential. Chemical yield data for the relative reactivity of the guanine cations and of charge trapping by a triple guanine unit in one of the strands quantify the hopping, trapping, and chemical kinetic parameters. The hole-hopping rate for superexchange-mediated interactions via two intervening AT base pairs is estimated to be 10(9) s(-1) at 300 K. We infer that the maximal distance for hole hopping in the duplex with the guanine separated by a single AT base pair is 300 +/- 70 Angstrom. Although we encounter constraints for hole transport in DNA emerging from the number of the mediating AT base pairs, electron transport is expected to be nearly sequence independent because of the similarity of the reduction potentials of the thymine and of the cytosine.