Modulation of DNA mediated hole transport by novel substituents on DNA

DNA 上新型取代基对 DNA 介导的空穴传输的调节

• 批准号: 13450351
• 负责人: NAKATANI Kazuhiko
• 金额: $ 8.51万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13450351/
• 关键词: hole transport; DNA; cyclopropyl; ラジカルカチオン; ホール検出手法; ラジカルカオチン

While the mechanism of DNA mediated hole transport is a subject of controversy, it is now evident from remote guanine (G) oxidation of duplex DNAs containing a tethered oxidant that G radical cation (hole) migrates distance through DNA _<TT>-stack. Due to lower ionization potentials of GG and GGG than single G, these stacked G sites function as a thermodynamic sink of holes eventually producing, (piperidine labile sites. In principle, hole migration from hole donor to acceptor competes with hole trapping by water and/or oxygen. Therefore, overall efficiency of hole transfer is primarily determined by the rates of hole migration and hole trapping. When the rate of hole trapping is much slower than hole migration rate, equilibration of hole between donor and acceptor can be achieved. While the rate of hole migration can be attenuated by changing the potential energy gap between hole donor and acceptor, the modulation of hole transport efficiency by changing the rate of hole trapping has never been demonstrated. We report a novel hole-trapping nucleoside N2-cyclopropyl2'-deoxyguanosine 1 (dCPG), which possesses a cyclopropyl group on N2 as a radical-trapping device. One electron oxidation of dCPG by photoexcited riboflavine induces homolytic cyclopropane ring opening as evidenced by the formation of N2-(3-hydroxypropanoyl)dG 2. With the use of dCPG -containing duplex, we have demonstrated that dCPG efficiently terminates DNA mediated hole transport at its own site.

虽然 DNA 介导的空穴传输机制是一个有争议的话题，但现在从含有束缚氧化剂的双链 DNA 的远程鸟嘌呤 (G) 氧化可以明显看出，G 自由基阳离子（空穴）通过 DNA _<TT>-stack 迁移距离。由于 GG 和 GGG 的电离势比单个 G 更低，这些堆叠的 G 位点充当最终产生空穴的热力学汇（哌啶不稳定位点）。原则上，从空穴供体到受体的空穴迁移与水和/或空穴捕获的空穴竞争。因此，空穴转移的总体效率主要由空穴迁移和空穴捕获速率决定。当空穴捕获速率远慢于空穴迁移速率时，可以实现供体和受体之间的空穴平衡。空穴迁移速率可以通过改变空穴供体和受体之间的势能间隙来减弱，但通过改变空穴捕获速率来调节空穴传输效率尚未得到证实。我们报道了一种新型空穴捕获核苷N2-环丙基2'-。脱氧鸟苷 1 (dCPG)，在 N2 上具有环丙基作为自由基捕获装置，光激发核黄素对 dCPG 的一个电子氧化可诱导均裂。 N2-(3-羟基丙酰基)dG 2 的形成证明了环丙烷开环。通过使用含有 dCPG 的双链体，我们证明 dCPG 在其自身位点有效终止 DNA 介导的空穴传输。

项目成果

Nakatani, K. et al.: "Recognition of Guanine-Guanine Mismatch by Dimeric Form of 2-Amino-1,8-naphthyridine"J. Am. Chem. Soc.. 123・50. 12650-12657 (2001)

Nakatani, K. 等：“2-氨基-1,8-萘啶二聚体的鸟嘌呤-鸟嘌呤错配的识别”J. Am. Soc. 123・50 (2001)。

Nakatani, K. et al.: "Design of Hole-Trapping Nucleobase : Termination of DNA Mediated Hole Transport at N^2-Cyclopropyldeoxyguanosine"J. Am. Chem. Soc.. 123・39. 9681-9682 (2001)

Nakatani, K. 等：“空穴捕获核碱基的设计：N^2-环丙基脱氧鸟苷的 DNA 介导的空穴传输”J. Am. 123・39 (2001)。

Nakatani, K. et al.: "Guanine of the Third Strand of C.G^*G Triplex Serves as an Effective Hole Trap"J. Am. Chem. Soc.. 123・49. 9681-9682 (2001)

Nakatani, K. 等：“C.G^*G 三链体的鸟嘌呤作为有效的空穴陷阱”J. Soc. 123・49 (2001)。

Nakatani, K. et al.: "Suppression of DNA-Mediated Charge Transport by BamH I Binding"Chem. Bio.. 9. 361-366 (2002)

Nakatani, K. 等人：“BamH I 结合抑制 DNA 介导的电荷传输”Chem。

Nakatani, K., Sando, S., Kumasawa, H., Kikuchi, J., Saito, I.: "Recognition of Guanine-Guanine Mismatch by Dimeric Form of 2-Amino-l, 8-naphthyridine"J. Am. Chem. Soc. 123. 12650-12657 (2001)

Nakatani, K.、Sando, S.、Kumasawa, H.、Kikuchi, J.、Saito, I.：“通过 2-氨基-1, 8-萘啶二聚形式识别鸟嘌呤-鸟嘌呤错配”J.