Spectrally resolved single-molecule electrometry.
Spectrally resolved single-molecule electrometry.
复制标题
光谱解析单分子静电测量法。
DOI：
10.1063/1.5008936
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Madhavi Krishnan
中科院分区：
文献类型：
--
作者：
F. Ruggeri;Madhavi Krishnan
逃逸时间电测法是最近发展起来的一种实验技术，它提供了测量单个生物分子在溶液中的有效电荷的能力，具有亚基本电荷精度。该方法依赖于测量单个带电的大分子或分子物种的平均逃逸时间，这些分子或分子物种暂时被限制在静电流体陷阱中。将实验结果与分子静电学平均场模型的预测进行了比较，发现所测得的有效电荷甚至反映了分子的构象，如折叠或无序状态，以及无序蛋白质或聚电解质中电荷的不均匀分布。在这里，我们演示了在相同的实验条件下，在单一的同时测量中，使用光谱维度来区分单个分子或分子物种之间的微小电荷差异的能力。使用一个光谱通道进行参考测量，这种光物理可区分性基本上消除了对关键实验参数的准确知识的需要，否则通过对实验装置的密集表征来获得。作为例子，我们展示了检测双链∼片段长度的微小差异(DNA5%)的能力，以及内在无序蛋白质--胸腺素原α中的单一氨基酸交换。
Escape-time electrometry is a recently developed experimental technique that offers the ability to measure the effective electrical charge of a single biomolecule in solution with sub-elementary charge precision. The approach relies on measuring the average escape-time of a single charged macromolecule or molecular species transiently confined in an electrostatic fluidic trap. Comparing the experiments with the predictions of a mean-field model of molecular electrostatics, we have found that the measured effective charge even reports on molecular conformation, e.g., folded or disordered state, and non-uniform charge distribution in disordered proteins or polyelectrolytes. Here we demonstrate the ability to use the spectral dimension to distinguish minute differences in electrical charge between individual molecules or molecular species in a single simultaneous measurement, under identical experimental conditions. Using one spectral channel for referenced measurement, this kind of photophysical distinguishability essentially eliminates the need for accurate knowledge of key experimental parameters, otherwise obtained through intensive characterization of the experimental setup. As examples, we demonstrate the ability to detect small differences (∼5%) in the length of double-stranded DNA fragments as well as single amino acid exchange in an intrinsically disordered protein, prothymosin α.
影响因子：
6.1
作者：
Kamerlin SC;Sharma PK;Prasad RB;Warshel A
通讯作者：
Warshel A
影响因子：
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作者：
Thompson, David B.;Cronican, James J.;Liu, David R.
通讯作者：
Liu, David R.