Estimation of Shape, Volume, and Dipole Moment of Individual Proteins Freely Transiting a Synthetic Nanopore
| Autor: | Michael Mayer, Mitu C. Acharjee, Santoshi Nandivada, Jared Houghtaling, Olivia M. Eggenberger, Adam R. Hall, Jiali Li, Cuifeng Ying, Aziz Fennouri |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Rotation Lipid Bilayers Electric Conductivity General Engineering Proteins General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Translation (geometry) 01 natural sciences Finite element method 0104 chemical sciences Diffusion Nanopores Dipole Nanopore Chemical physics Electric field Moment (physics) General Materials Science 0210 nano-technology Lipid bilayer |
| Zdroj: | ACS Nano. 13:5231-5242 |
| ISSN: | 1936-086X 1936-0851 |
| DOI: | 10.1021/acsnano.8b09555 |
| Popis: | This paper demonstrates that high-bandwidth current recordings in combination with low-noise silicon nitride nanopores make it possible to determine the molecular volume, approximate shape, and dipole moment of single native proteins in solution without the need for labeling, tethering, or other chemical modifications of these proteins. The analysis is based on current modulations caused by the translation and rotation of single proteins through a uniform electric field inside of a nanopore. We applied this technique to nine proteins and show that the measured protein parameters agree well with reference values but only if the nanopore walls were coated with a nonstick fluid lipid bilayer. One potential challenge with this approach is that an untethered protein is able to diffuse laterally while transiting a nanopore, which generates increasingly asymmetric disruptions in the electric field as it approaches the nanopore walls. These "off-axis" effects add an additional noise-like element to the electrical recordings, which can be exacerbated by nonspecific interactions with pore walls that are not coated by a fluid lipid bilayer. We performed finite element simulations to quantify the influence of these effects on subsequent analyses. Examining the size, approximate shape, and dipole moment of unperturbed, native proteins in aqueous solution on a single-molecule level in real time while they translocate through a nanopore may enable applications such as identifying or characterizing proteins in a mixture, or monitoring the assembly or disassembly of transient protein complexes based on their shape, volume, or dipole moment. |
| Databáze: | OpenAIRE |
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