[1] Si WeiYang HaojieJi AnpingLi Kun, Sha JingjieLiu Lei, Chen Yunfei,. Electrophoresis of poly(dT)20 through α-hemolysin nanoporein high concentration potassium chloride solution [J]. Journal of Southeast University (English Edition), 2016, 32 (4): 496-501. [doi:10.3969/j.issn.1003-7985.2016.04.017]

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Electrophoresis of poly(dT)₂₀ through α-hemolysin nanoporein high concentration potassium chloride solution()

高浓度氯化钾盐溶液中poly(dT)₂₀ 在α溶血素纳米孔内的电泳动力学

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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:

32

Issue:

2016 4

Page:

496-501

Research Field:

Mechanical Engineering

Publishing date:

2016-12-20

Info

Title:

Electrophoresis of poly(dT)₂₀ through α-hemolysin nanoporein high concentration potassium chloride solution

高浓度氯化钾盐溶液中poly(dT)₂₀ 在α溶血素纳米孔内的电泳动力学

Author(s):

Si WeiYang HaojieJi AnpingLi Kun, Sha JingjieLiu Lei, Chen Yunfei

School of Mechanical Engineering, Southeast University, Nanjing 211189, China
Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Nanjing 211189, China

司伟, 杨浩杰, 纪安平, 李堃, 沙菁刘磊陈云飞

东南大学机械工程学院, 南京 211189; 江苏省微纳生物医疗器械设计与制造重点实验室, 南京 211189

Keywords:

nanopore;  transport speed;  ionic current;  electrophoresis

纳米孔;  过孔速度;  离子电流;  电泳

PACS:

TH789;Q786

DOI:

10.3969/j.issn.1003-7985.2016.04.017

Abstract:

Experiments of poly(dT)₂₀ electrophoresis through α-hemolysin nanopores were performed to unveil the electrophoretic transport mechanism of DNA through nanopores in high concentration potassium chloride solution. It is found that there are two obvious current blockades induced by poly(dT)₂₀ translocation and collision events. Both blockade currents increase linearly with the applied bias voltage. However, the normalized blockade currents are almost kept the same although variable bias voltages are applied. The collision time of poly(dT)₂₀ in the luminal site of the pore remains constant for different voltages. The translocation speed of poly(dT)₂₀ through the nanopore decreases with the increase of bias voltage. It is because as the potential increases, the drag force on the homopolymer helps it to crumple into a cluster much easier due to the poor stacking of thymine residues compared with homopolymers consisting of other nucleotides. Molecular dynamics simulations further confirm the experimental results. Increasing the applied bias voltage can slow down the translocation velocity of the flexible poly(dT)₂₀, which favors increasing the precision of single molecule detection by using nanopores.

为了揭示高浓度盐溶液中DNA穿过纳米孔时的动力学行为, 实验研究了poly(dT)₂₀电泳穿过α溶血素纳米孔的输运机理.实验结果表明, 阻塞电流主要由DNA的过孔事件和碰撞事件引起.2种事件引发的阻塞电流都随着外加电势的增加而线性增加.尽管外加电势存在差异, 归一化之后的阻塞电流幅值却都保持不变.此外, poly(dT)₂₀的碰撞事件持续时间并不受电压影响, 而过孔时间却随着外加电势的增加而相应延长.这是由于胸腺嘧啶的堆叠效应较差, 相比较其他碱基而言, 在强电场力作用下, poly(dT)₂₀更容易发生蜷曲, 导致过孔阻力增加.分子动力学模拟也进一步对实验结果进行了验证.研究结果表明, 增加跨膜电势差有助于降低柔性poly(dT)₂₀的过孔速度, 从而提高单分子的检测精度.

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Memo

Memo:

Biographies: Si Wei(1989—), male, graduate; Chen Yunfei(corresponding author), male, doctor, professor, yunfeichen@seu.edu.cn.
Foundation items: The National Natural Science Foundation of China(No.51435003, 51375092), Research Program of Chongqing Municipal Education Commission(No.KJ1401030), the Research & Innovation Program for Graduate Student in Universities of Jiangsu Province(No.KYLX_0100), the Scientific Research Foundation of Graduate School of Southeast University(No.YBJJ1540).
Citation: Si Wei, Yang Haojie, Ji Anping, et al.Electrophoresis of poly(dT)₂₀ through α-hemolysin nanopore in high concentration potassium chloride solution[J].Journal of Southeast University(English Edition), 2016, 32(4):496-501.DOI:10.3969/j.issn.1003-7985.2016.04.017.

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