Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019-0065, USA.
Electrophoresis. 2011 Nov;32(21):3034-41. doi: 10.1002/elps.201100216. Epub 2011 Oct 14.
The effect of acidic pH on the translocation of single-stranded DNA through the α-hemolysin pore is investigated. Two significantly different types of events, i.e. deep blockades and shallow blockades, are observed at low pH. The residence times of the shallow blockades are not significantly different from those of the DNA translocation events obtained at or near physiological pH, whereas the deep blockades have much larger residence times and blockage amplitudes. With a decrease in the pH of the electrolyte solution, the percentage of the deep blockades in the total events increases. Furthermore, the mean residence time of these long-lived events is dependent on the length of DNA, and also varies with the nucleotide base, suggesting that they are appropriate for use in DNA analysis. In addition to being used as an effective approach to affect DNA translocation in the nanopore, manipulation of the pH of the electrolyte solution provides a potential means to greatly enhance the sensitivity of nanopore stochastic sensing.
研究了酸性 pH 值对单链 DNA 通过α-溶血素孔迁移的影响。在低 pH 值下观察到两种明显不同类型的事件，即深阻塞和浅阻塞。浅阻塞的停留时间与在生理 pH 值或接近生理 pH 值时获得的 DNA 迁移事件的停留时间没有显著差异，而深阻塞的停留时间和阻塞幅度要大得多。随着电解质溶液 pH 值的降低，深阻塞在总事件中的比例增加。此外，这些长寿命事件的平均停留时间取决于 DNA 的长度，并且也随核苷酸碱基而变化，表明它们适合用于 DNA 分析。除了被用作影响纳米孔中 DNA 迁移的有效方法之外，电解质溶液 pH 值的操纵还提供了一种极大提高纳米孔随机传感灵敏度的潜在方法。
