Charge, Diffusion, and Current Fluctuations of Single-Stranded DNA Trapped in an MspA Nanopore

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• 作者：Stephen J. Fleming¹ ; Bo Lu¹ ; Jene A. Golovchenko¹ ; ² ; ^{golovchenko@physics.harvard.edu}
• 刊名：Biophysical Journal
• 出版年：2017
• 出版时间：24 January 2017
• 年：2017
• 卷：112
• 期：2
• 页码：368-375
• 全文大小：1371 K
• 卷排序：112

文摘

We report effective charges and diffusion constants of several different single-stranded DNA oligonucleotides trapped in an MspA nanopore. Nucleotide identity is found to have a substantial influence on effective charges and diffusion constants. These quantities are determined from escape time experiments for a DNA molecule attached to a NeutrAvidin molecule that, unlike the DNA, does not pass through the pore. Correlations are reported between oligonucleotide effective charges and current blockages, and between their diffusion constants and DNA-induced current blockage fluctuations. We also report an unanticipated source of current fluctuations that reflects a discrete blockage current level structure. We posit that this is associated with interactions between the NeutrAvidin molecule and the MspA nanopore.