Magnetic Tweezers: Development and Use in Single-Molecule Research

Gaire, Santosh; Fabian, Roberto; Pegg, Ian L.; Sarkar, Abhijit

doi:10.2144/btn-2021-0104

Cited by 9 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results reported here build upon previous research in our lab on custom horizontal magnetic tweezers. The design of the tweezers, as well as the steps we took to calibrate it, are described in detail in [ 37 , 38 , 39 , 40 , 41 ]. Extensive testing and calibration of the tweezers suggests that the single molecule data generated by the system are reproducible and free of systematic biases.…”

Section: Discussionmentioning

confidence: 99%

“…We performed all single-molecule micromanipulation experiments using the horizontal magnetic tweezers (or transverse magnetic tweezers), discussed in references [ 39 , 41 ]—see schematics in Figure 5 . In brief, we start by functionalizing λ-DNA (N3011S, New England Biolabs, Ipswich, MA, USA), which involves ligating biotinylated DNA oligomers (five biotins) complementary to 12 base polynucleotide overhangs to each end of the DNA molecule.…”

Section: Methodsmentioning

confidence: 99%

“… Schematic of our experiment. ( a ) The horizontal magnetic tweezers, modified from [ 41 ]. ( b ) The buffer exchange system.…”

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

Micromechanical Study of Hyperacetylated Nucleosomes Using Single Molecule Transverse Magnetic Tweezers

Gaire

Fabian

Adhikari

et al. 2023

IJMS

Self Cite

View full text Add to dashboard Cite

Nucleosomes are stable complexes of DNA and histone proteins that are essential for the proper functioning of the genome. These structures must be unwrapped and disassembled for processes such as gene expression, replication, and repair. Histone post-translational modifications (PTMs) are known to play a significant role in regulating the structural changes of nucleosomes. However, the underlying mechanisms by which these modifications function remain unclear. In this study, we report the results of single molecule micromanipulation experiments on DNA–protein complexes composed of hyperacetylated histone proteins using transverse magnetic tweezers. The experiments were conducted by pre-extending λ-DNA with a force less than 4 pN before introducing hyperacetylated histones into the sample chamber. The DNA shortened as the histones formed complexes with it and the nucleosome arrays were then exposed to increasing tension, resulting in quantized changes in the DNA’s extension with step sizes of (integral multiples of) ~50 nm. We also compared results of experiments using PTM histones and native histones with data collected for both types of histones for the same force ranges (2–80 pN) and loading rates. Our data show that hyperacetylated nucleosomes require an unbinding force of around ~2.5 pN, which is similar to that required for native histones. Moreover, we identified clear differences between the step-size distributions of native and hyperacetylated histones and found that in contrast to tethers reconstituted with native histones, the majority of nucleosomes in tethers compacted with hyperacetylated histones underwent disassembly at forces significantly lower than 6 pN.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Micromechanical Study of Hyperacetylated Nucleosomes Using Single Molecule Transverse Magnetic Tweezers

Gaire

Fabian

Adhikari

et al. 2023

IJMS

Self Cite

View full text Add to dashboard Cite

show abstract

“…This technique is used in single molecular studies. 322,323 A study using magnetic beads-based single molecule detector assay revealed high mechanical stability and lifetime of vinculin-talin and vinculin-α-catenin interfaces, indicating their role in mechanosensing and mechanotransduction. 324 Rotational magnetic spectroscopy, a modified MT-based technique, has been used to study the local viscoelastic responses of the living cells under mechanical stress.…”

Section: Mts and Optical Traps/tweezers (Ots)mentioning

confidence: 99%

“…MT‐based approaches are used to study in vitro mechanics and dynamics of biomolecules. This technique is used in single molecular studies 322,323 . A study using magnetic beads‐based single molecule detector assay revealed high mechanical stability and lifetime of vinculin‐talin and vinculin‐α‐catenin interfaces, indicating their role in mechanosensing and mechanotransduction 324 .…”

Section: Techniques For Studying Mechano‐epigeneticsmentioning

confidence: 99%

Mechanotransduction and epigenetic modulations of chromatin: Role of mechanical signals in gene regulation

Mishra,

Chakraborty,

Niharika

et al. 2024

J of Cellular Biochemistry

View full text Add to dashboard Cite

Mechanical forces may be generated within a cell due to tissue stiffness, cytoskeletal reorganization, and the changes (even subtle) in the cell's physical surroundings. These changes of forces impose a mechanical tension within the intracellular protein network (both cytosolic and nuclear). Mechanical tension could be released by a series of protein–protein interactions often facilitated by membrane lipids, lectins and sugar molecules and thus generate a type of signal to drive cellular processes, including cell differentiation, polarity, growth, adhesion, movement, and survival. Recent experimental data have accentuated the molecular mechanism of this mechanical signal transduction pathway, dubbed mechanotransduction. Mechanosensitive proteins in the cell's plasma membrane discern the physical forces and channel the information to the cell interior. Cells respond to the message by altering their cytoskeletal arrangement and directly transmitting the signal to the nucleus through the connection of the cytoskeleton and nucleoskeleton before the information despatched to the nucleus by biochemical signaling pathways. Nuclear transmission of the force leads to the activation of chromatin modifiers and modulation of the epigenetic landscape, inducing chromatin reorganization and gene expression regulation; by the time chemical messengers (transcription factors) arrive into the nucleus. While significant research has been done on the role of mechanotransduction in tumor development and cancer progression/metastasis, the mechanistic basis of force‐activated carcinogenesis is still enigmatic. Here, in this review, we have discussed the various cues and molecular connections to better comprehend the cellular mechanotransduction pathway, and we also explored the detailed role of some of the multiple players (proteins and macromolecular complexes) involved in mechanotransduction. Thus, we have described an avenue: how mechanical stress directs the epigenetic modifiers to modulate the epigenome of the cells and how aberrant stress leads to the cancer phenotype.

show abstract

Characterization of single synthetic polymers via magnetic tweezers

Xie,

Zhou,

Mao

et al. 2023

Journal of Polymer Science

View full text Add to dashboard Cite

Due to the ability to perform the parallel measurement of multiple single chains and exert precise control over stretching force in the sub‐nanonewton regime, magnetic tweezers (MT) are a suitable tool to study the individual chain conformations and inherent behaviors of polymers. Herein, we examined the applications of MT in studying single synthetic polymers, distinct from previous reviews focusing on biological polymers such as DNAs. We first presented an overview of the technical aspects of MT, including the imaging setup, the algorithm of three‐dimensional single particle tracking, the configuration of magnets, the calibration and control of magnetic forces, the assembly of flow cells, and the polymer tethering methods. Then, we discussed selected examples highlighting the utilization of MT in studying the chain conformation, mechanical properties, ion and ligands effect, regime transition mechanism, and polymerization dynamics of single synthetic polymers. We envision that MT can serve as a powerful toolbox for delving into the structure–property correlations at the single chain level, which provides quantitative validations for building the theoretical models of synthetic polymers. In the end, we contemplated potential avenues and opportunities for future research in this domain.

show abstract

Magnetic Tweezers: Development and Use in Single-Molecule Research

Cited by 9 publications

References 43 publications

Micromechanical Study of Hyperacetylated Nucleosomes Using Single Molecule Transverse Magnetic Tweezers

Micromechanical Study of Hyperacetylated Nucleosomes Using Single Molecule Transverse Magnetic Tweezers

Mechanotransduction and epigenetic modulations of chromatin: Role of mechanical signals in gene regulation

Characterization of single synthetic polymers via magnetic tweezers

Contact Info

Product

Resources

About