Single Molecule Imaging of Protein Molecules in Nanopores
Single Molecule Imaging of Protein Molecules in Nanopores
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DOI：
10.1021/ac902487c
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发表时间：
2010-01-15
影响因子：
7.4
通讯作者：
Yeung, Edward S.
中科院分区：
文献类型：
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作者：
Ma, Changbei;Yeung, Edward S.
在单分子水平上研究了单个蛋白质分子和纳米多孔聚碳酸酯膜之间的相互作用。蛋白质的包埋具有尺寸选择性，并且取决于膜孔径。仅略大于蛋白质最大尺寸的孔径不足以侵入孔中。对于给定的蛋白质，在给定深度发现的分子数量随着孔径的减小而减少。此外，随着深度的增加，对于给定尺寸的孔隙，分子数量迅速减少。深度相关的直方图很好地拟合了一维扩散模型。然而，即使孔径是蛋白质大小的 10 倍，也观察到高度受限的运动，导致扩散系数异常小。我们还证明了 BSA 和血红蛋白的深度分布存在细微差异，它们的分子量几乎相同，但分子形状略有不同。这些结果为尺寸排阻色谱和膜过滤的详细机制提供了独特的见解。
The interactions between single protein molecules and nanoporous polycarbonate membranes were investigated at the single molecule level. Entrapment of proteins was shown to be size selective and was dependent on the membrane pore diameter. A pore size that is only slightly larger than the maximum dimension of the proteins was inadequate for intrusion into the pores. For a given protein, the number of molecules found at a given depth decreased as the pore size decreased. In addition, as the depth increased, for a given size pore, the number of molecules decreased rapidly. The depth-dependent histograms nicely fit a one-dimensional diffusion model. However, a highly restricted motion was observed even when the pore diameter was 10 times the size of the protein, resulting in anomalously small diffusion coefficients. We also demonstrated the subtle differences in depth distribution among BSA and hemoglobin that have nearly the same molecular weight but slightly different molecular shapes. These results give unique insights into the detailed mechanism of size-exclusion chromatography and membrane filtration.