Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom.
Nano Lett. 2013 Jun 12;13(6):2500-5. doi: 10.1021/nl400560r. Epub 2013 May 23.
The electrophoretic translocation of polynucleotides through nanopores may permit direct single-molecule nucleic acid sequencing. Here we describe the translocation of ssRNA heteropolymers (91-6083 bases) through the α-hemolysin nanopore. Translocation of these long ssRNAs is characterized by surprisingly long, almost complete ionic current blockades with durations averaging milliseconds per base (at +180 mV). The event durations decrease exponentially with increased transmembrane potential but are largely unaffected by the presence of urea. When the ssRNA is coupled at the 3' end to streptavidin, which cannot translocate through the pore, permanent blockades are observed, supporting our conclusion that the transient blockades arise from ssRNA translocation.
多核苷酸通过纳米孔的电泳转移可能允许直接进行单分子核酸测序。在这里，我们描述了 ssRNA 杂聚物（91-6083 个碱基）通过α-溶血素纳米孔的转移。这些长 ssRNA 的转移特征是令人惊讶的长，几乎完全的离子电流阻断，阻断持续时间平均为每个碱基毫秒（在+180 mV 时）。事件持续时间随跨膜电位的增加呈指数下降，但几乎不受脲的存在影响。当 ssRNA 在 3' 端与链霉亲和素偶联时，由于链霉亲和素不能通过孔转移，因此观察到永久阻断，这支持了我们的结论，即瞬态阻断来自 ssRNA 的转移。
