Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy
DNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg<sup>2+</sup...
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doaj-32e89deb9b9e456faabdaaa7cf8a2e3d2021-08-26T14:07:09ZengMDPI AGMolecules1420-30492021-08-01264798479810.3390/molecules26164798Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force MicroscopyYang Xin0Amir Ardalan Zargariantabrizi1Guido Grundmeier2Adrian Keller3Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, GermanyTechnical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, GermanyTechnical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, GermanyTechnical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, GermanyDNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg<sup>2+</sup> ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg<sup>2+</sup> concentrations, however, present a serious limitation in such experiments as they may interfere with the reactions and processes under investigation. Therefore, we here evaluate three approaches to efficiently immobilize DONs at mica surfaces under essentially Mg<sup>2+</sup>-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni<sup>2+</sup>, poly-<span style="font-variant: small-caps;">l</span>-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni<sup>2+</sup> shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg<sup>2+</sup>-mediated adsorption in terms of surface coverage, depending on the employed solution. For 3D six-helix bundles, less pronounced differences between the individual strategies are observed. Our results provide some general guidance for the immobilization of DONs at mica surfaces under Mg<sup>2+</sup>-free conditions and may aid future in situ AFM studies.https://www.mdpi.com/1420-3049/26/16/4798DNA origamiDNA nanotechnologyadsorptionmicaatomic force microscopy |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Yang Xin Amir Ardalan Zargariantabrizi Guido Grundmeier Adrian Keller |
spellingShingle |
Yang Xin Amir Ardalan Zargariantabrizi Guido Grundmeier Adrian Keller Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy Molecules DNA origami DNA nanotechnology adsorption mica atomic force microscopy |
author_facet |
Yang Xin Amir Ardalan Zargariantabrizi Guido Grundmeier Adrian Keller |
author_sort |
Yang Xin |
title |
Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy |
title_short |
Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy |
title_full |
Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy |
title_fullStr |
Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy |
title_full_unstemmed |
Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy |
title_sort |
magnesium-free immobilization of dna origami nanostructures at mica surfaces for atomic force microscopy |
publisher |
MDPI AG |
series |
Molecules |
issn |
1420-3049 |
publishDate |
2021-08-01 |
description |
DNA origami nanostructures (DONs) are promising substrates for the single-molecule investigation of biomolecular reactions and dynamics by in situ atomic force microscopy (AFM). For this, they are typically immobilized on mica substrates by adding millimolar concentrations of Mg<sup>2+</sup> ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg<sup>2+</sup> concentrations, however, present a serious limitation in such experiments as they may interfere with the reactions and processes under investigation. Therefore, we here evaluate three approaches to efficiently immobilize DONs at mica surfaces under essentially Mg<sup>2+</sup>-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni<sup>2+</sup>, poly-<span style="font-variant: small-caps;">l</span>-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni<sup>2+</sup> shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg<sup>2+</sup>-mediated adsorption in terms of surface coverage, depending on the employed solution. For 3D six-helix bundles, less pronounced differences between the individual strategies are observed. Our results provide some general guidance for the immobilization of DONs at mica surfaces under Mg<sup>2+</sup>-free conditions and may aid future in situ AFM studies. |
topic |
DNA origami DNA nanotechnology adsorption mica atomic force microscopy |
url |
https://www.mdpi.com/1420-3049/26/16/4798 |
work_keys_str_mv |
AT yangxin magnesiumfreeimmobilizationofdnaorigaminanostructuresatmicasurfacesforatomicforcemicroscopy AT amirardalanzargariantabrizi magnesiumfreeimmobilizationofdnaorigaminanostructuresatmicasurfacesforatomicforcemicroscopy AT guidogrundmeier magnesiumfreeimmobilizationofdnaorigaminanostructuresatmicasurfacesforatomicforcemicroscopy AT adriankeller magnesiumfreeimmobilizationofdnaorigaminanostructuresatmicasurfacesforatomicforcemicroscopy |
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1721191196831776768 |