Adsorption of Polyelectrolyte versus Surface Charge:  in Situ Single-Molecule Atomic Force Microscopy Experiments on Similarly, Oppositely, and Heterogeneously Charged Surfaces†

2007 ◽  
Vol 111 (29) ◽  
pp. 8597-8604 ◽  
Author(s):  
Yuri Roiter ◽  
Sergiy Minko
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Charge ◽  
Single Molecule ◽  
Force Microscopy ◽  
Charged Surfaces ◽  
Atomic Force

scholarly journals Magnesium-Free Immobilization of DNA Origami Nanostructures at Mica Surfaces for Atomic Force Microscopy

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4798
Author(s):  
Yang Xin ◽  
Amir Ardalan Zargariantabrizi ◽  
Guido Grundmeier ◽  
Adrian Keller
Keyword(s):  
Atomic Force Microscopy ◽  
Single Molecule ◽  
Pure Water ◽  
Dna Origami ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Individual ◽  
Individual Strategies ◽  
Phosphate Buffered Saline

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 Mg2+ ions to the sample solution, which enable the adsorption of the negatively charged DONs at the like-charged mica surface. These non-physiological Mg2+ 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 Mg2+-free conditions. These approaches rely on the pre-adsorption of different multivalent cations, i.e., Ni2+, poly-l-lysine (PLL), and spermidine (Spdn). DON adsorption is studied in phosphate-buffered saline (PBS) and pure water. In general, Ni2+ shows the worst performance with heavily deformed DONs. For 2D DON triangles, adsorption at PLL- and in particular Spdn-modified mica may outperform even Mg2+-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 Mg2+-free conditions and may aid future in situ AFM studies.

In situ monitoring of single molecule binding reactions with time-lapse atomic force microscopy on functionalized DNA origami

Nanoscale ◽  
2011 ◽  
Vol 3 (6) ◽  
pp. 2481 ◽  
Author(s):  
Na Wu ◽  
Xingfei Zhou ◽  
Daniel M. Czajkowsky ◽  
Ming Ye ◽  
Dongdong Zeng ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Single Molecule ◽  
Time Lapse ◽  
Dna Origami ◽  
In Situ Monitoring ◽  
Force Microscopy ◽  
Atomic Force

In situ single molecule detection of insulin receptors on erythrocytes from a type 1 diabetes ketoacidosis patient by atomic force microscopy

The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7407-7416 ◽  
Author(s):  
Lu Zhang ◽  
Jiang Pi ◽  
Qiping Shi ◽  
Jiye Cai ◽  
Peihui Yang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Type 1 Diabetes ◽  
Single Molecule ◽  
Insulin Receptors ◽  
Single Molecule Detection ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecule Interactions

A method to investigate the single molecule interactions between insulin and insulin receptor in erythrocytes from healthy volunteer and type 1 diabetes ketoacidosis (T1-DKA) patient was introduced using atomic force microscopy (AFM).

Single-molecule imaging of DNA polymerase I (Klenow fragment) activity by atomic force microscopy

Nanoscale ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 5842-5846 ◽  
Author(s):  
J. Chao ◽  
P. Zhang ◽  
Q. Wang ◽  
N. Wu ◽  
F. Zhang ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Dna Polymerase ◽  
Single Molecule ◽  
Klenow Fragment ◽  
Dna Polymerase I ◽  
Single Molecule Level ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polymerase I

Observing DNA replicationin situat the single-molecule level by atomic force microscopy.

In Situ Detection of Liver Cancer Biomarkers with Atomic Force Microscopy at a Single-molecule Level

2013 ◽  
Vol 42 (10) ◽  
pp. 1154-1156 ◽  
Author(s):  
Bochong Tang ◽  
Min Li ◽  
Xiao Zhang ◽  
Jiaojiao Wang ◽  
Peng Xie ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Liver Cancer ◽  
Single Molecule ◽  
Cancer Biomarkers ◽  
Single Molecule Level ◽  
Force Microscopy ◽  
Atomic Force ◽  
In Situ Detection

Atomic Force Microscopy (AFM) for Topography and Recognition Imaging at Single Molecule Level

2013 ◽  
pp. 102-112
Author(s):  
Memed Duman ◽  
Andreas Ebner ◽  
Christian Rankl ◽  
Jilin Tang ◽  
Lilia A. Chtcheglova ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Single Molecule ◽  
Single Molecule Level ◽  
Force Microscopy ◽  
Atomic Force ◽  
Recognition Imaging

scholarly journals Atomic Force Microscopy Investigation of the Interactions between the MCM Helicase and DNA

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 687
Author(s):  
Amna Abdalla Mohammed Khalid ◽  
Pietro Parisse ◽  
Barbara Medagli ◽  
Silvia Onesti ◽  
Loredana Casalis
Keyword(s):  
Atomic Force Microscopy ◽  
Nucleic Acid ◽  
Single Molecule ◽  
Protein Complex ◽  
The Other ◽  
Contour Length ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mcm Complex ◽  
Dna Double Helix

The MCM (minichromosome maintenance) protein complex forms an hexameric ring and has a key role in the replication machinery of Eukaryotes and Archaea, where it functions as the replicative helicase opening up the DNA double helix ahead of the polymerases. Here, we present a study of the interaction between DNA and the archaeal MCM complex from Methanothermobacter thermautotrophicus by means of atomic force microscopy (AFM) single molecule imaging. We first optimized the protocol (surface treatment and buffer conditions) to obtain AFM images of surface-equilibrated DNA molecules before and after the interaction with the protein complex. We discriminated between two modes of interaction, one in which the protein induces a sharp bend in the DNA, and one where there is no bending. We found that the presence of the MCM complex also affects the DNA contour length. A possible interpretation of the observed behavior is that in one case the hexameric ring encircles the dsDNA, while in the other the nucleic acid wraps on the outside of the ring, undergoing a change of direction. We confirmed this topographical assignment by testing two mutants, one affecting the N-terminal β-hairpins projecting towards the central channel, and thus preventing DNA loading, the other lacking an external subdomain and thus preventing wrapping. The statistical analysis of the distribution of the protein complexes between the two modes, together with the dissection of the changes of DNA contour length and binding angle upon interaction, for the wild type and the two mutants, is consistent with the hypothesis. We discuss the results in view of the various modes of nucleic acid interactions that have been proposed for both archaeal and eukaryotic MCM complexes.

Substrate Specificity of Sugar Transport by Rabbit SGLT1:  Single-Molecule Atomic Force Microscopy versus Transport Studies†

Biochemistry ◽  
2007 ◽  
Vol 46 (10) ◽  
pp. 2797-2804 ◽  
Author(s):  
Theeraporn Puntheeranurak ◽  
Barbara Wimmer ◽  
Francisco Castaneda ◽  
Hermann J. Gruber ◽  
Peter Hinterdorfer ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Substrate Specificity ◽  
Single Molecule ◽  
Sugar Transport ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transport Studies
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