1
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Carlucci LA, Johnson KC, Thomas WE. FimH-mannose noncovalent bonds survive minutes to hours under force. Biophys J 2024; 123:3038-3050. [PMID: 38961621 PMCID: PMC11427783 DOI: 10.1016/j.bpj.2024.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/10/2024] [Accepted: 07/01/2024] [Indexed: 07/05/2024] Open
Abstract
The adhesin FimH is expressed by commensal Escherichia coli and is implicated in urinary tract infections, where it mediates adhesion to mannosylated glycoproteins on urinary and intestinal epithelial cells in the presence of a high-shear fluid environment. The FimH-mannose bond exhibits catch behavior in which bond lifetime increases with force, because tensile force induces a transition in FimH from a compact native to an elongated activated conformation with a higher affinity to mannose. However, the lifetime of the activated state of FimH has not been measured under force. Here we apply multiplexed magnetic tweezers to apply a preload force to activate FimH bonds with yeast mannan, then we measure the lifetime of these activated bonds under a wide range of forces above and below the preload force. A higher fraction of FimH-mannan bonds were activated above than below a critical preload force, confirming the FimH catch bond behavior. Once activated, FimH detached from mannose with multi-state kinetics, suggesting the existence of two bound states with a 20-fold difference in dissociation rates. The average lifetime of activated FimH-mannose bonds was 1000 to 10,000 s at forces of 30-70 pN. Structural explanations of the two bound states and the high force resistance provide insights into structural mechanisms for long-lived, force-resistant biomolecular interactions.
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Affiliation(s)
- Laura A Carlucci
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Keith C Johnson
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Wendy E Thomas
- Department of Bioengineering, University of Washington, Seattle, Washington.
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2
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Csányi MC, Sziklai D, Feller T, Hársfalvi J, Kellermayer M. Cryptic Extensibility in von Willebrand Factor Revealed by Molecular Nanodissection. Int J Mol Sci 2024; 25:7296. [PMID: 39000402 PMCID: PMC11242059 DOI: 10.3390/ijms25137296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/19/2024] [Accepted: 06/29/2024] [Indexed: 07/16/2024] Open
Abstract
Von Willebrand factor (VWF) is a multimer with a variable number of protomers, each of which is a head-to-head dimer of two multi-domain monomers. VWF responds to shear through the unfolding and extension of distinct domains, thereby mediating platelet adhesion and aggregation to the injured blood vessel wall. VWF's C1-6 segment uncoils and then the A2 domain unfolds and extends in a hierarchical and sequential manner. However, it is unclear whether there is any reservoir of further extensibility. Here, we explored the presence of cryptic extensibility in VWF by nanodissecting individual, pre-stretched multimers with atomic force microscopy (AFM). The AFM cantilever tip was pressed into the surface and moved in a direction perpendicular to the VWF axis. It was possible to pull out protein loops from VWF, which resulted in a mean contour length gain of 217 nm. In some cases, the loop became cleaved, and a gap was present along the contour. Frequently, small nodules appeared in the loops, indicating that parts of the nanodissected VWF segment remained folded. After analyzing the nodal structure, we conclude that the cryptic extensibility lies within the C1-6 and A1-3 regions. Cryptic extensibility may play a role in maintaining VWF's functionality in extreme shear conditions.
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Affiliation(s)
- Mária Csilla Csányi
- Institute of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó u. 37-47, H1094 Budapest, Hungary; (M.C.C.)
| | - Dominik Sziklai
- Institute of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó u. 37-47, H1094 Budapest, Hungary; (M.C.C.)
| | - Tímea Feller
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS29JT, UK
| | - Jolán Hársfalvi
- Institute of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó u. 37-47, H1094 Budapest, Hungary; (M.C.C.)
| | - Miklós Kellermayer
- Institute of Biophysics and Radiation Biology, Semmelweis University, Tűzoltó u. 37-47, H1094 Budapest, Hungary; (M.C.C.)
- HUNREN-SE Biophysical Virology Group, Tűzoltó Str. 37-47, H1094 Budapest, Hungary
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3
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Tapia-Rojo R, Mora M, Garcia-Manyes S. Single-molecule magnetic tweezers to probe the equilibrium dynamics of individual proteins at physiologically relevant forces and timescales. Nat Protoc 2024; 19:1779-1806. [PMID: 38467905 PMCID: PMC7616092 DOI: 10.1038/s41596-024-00965-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 12/18/2023] [Indexed: 03/13/2024]
Abstract
The reversible unfolding and refolding of proteins is a regulatory mechanism of tissue elasticity and signalling used by cells to sense and adapt to extracellular and intracellular mechanical forces. However, most of these proteins exhibit low mechanical stability, posing technical challenges to the characterization of their conformational dynamics under force. Here, we detail step-by-step instructions for conducting single-protein nanomechanical experiments using ultra-stable magnetic tweezers, which enable the measurement of the equilibrium conformational dynamics of single proteins under physiologically relevant low forces applied over biologically relevant timescales. We report the basic principles determining the functioning of the magnetic tweezer instrument, review the protein design strategy and the fluid chamber preparation and detail the procedure to acquire and analyze the unfolding and refolding trajectories of individual proteins under force. This technique adds to the toolbox of single-molecule nanomechanical techniques and will be of particular interest to those interested in proteins involved in mechanosensing and mechanotransduction. The procedure takes 4 d to complete, plus an additional 6 d for protein cloning and production, requiring basic expertise in molecular biology, surface chemistry and data analysis.
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Affiliation(s)
- Rafael Tapia-Rojo
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, London, UK.
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King's College London, London, UK.
| | - Marc Mora
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, London, UK.
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King's College London, London, UK.
| | - Sergi Garcia-Manyes
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, London, UK.
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King's College London, London, UK.
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4
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Rahmati N, Keshavarz Motamed P, Maftoon N. Numerical study of ultra-large von Willebrand factor multimers in coagulopathy. Biomech Model Mechanobiol 2024; 23:737-756. [PMID: 38217745 DOI: 10.1007/s10237-023-01803-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/30/2023] [Indexed: 01/15/2024]
Abstract
An excessive von Willebrand factor (VWF) secretion, coupled with a moderate to severe deficiency of ADAMTS13 activity, serves as a linking mechanism between inflammation to thrombosis. The former facilitates platelet adhesion to the vessel wall and the latter is required to cleave VWF multimers. As a result, the ultra-large VWF (UL-VWF) multimers released by Weibel-Palade bodies remain uncleaved. In this study, using a computational model based on first principles, we quantitatively show how the uncleaved UL-VWF multimers interact with the blood cells to initiate microthrombosis. We observed that platelets first adhere to unfolded and stretched uncleaved UL-VWF multimers anchored to the microvessel wall. By the end of this initial adhesion phase, the UL-VWF multimers and platelets make a mesh-like trap in which the red blood cells increasingly accumulate to initiate a gradually growing microthrombosis. Although high-shear rate and blood flow velocity are required to activate platelets and unfold the UL-VWFs, during the initial adhesion phase, the blood velocity drastically drops after thrombosis, and as a result, the wall shear stress is elevated near UL-VWF roots, and the pressure drops up to 6 times of the healthy condition. As the time passes, these trends progressively continue until the microthrombosis fully develops and the effective size of the microthrombosis and these flow quantities remain almost constant. Our findings quantitatively demonstrate the potential role of UL-VWF in coagulopathy.
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Affiliation(s)
- Nahid Rahmati
- Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Pouyan Keshavarz Motamed
- Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada
| | - Nima Maftoon
- Department of Systems Design Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
- Centre for Bioengineering and Biotechnology, University of Waterloo, Waterloo, ON, Canada.
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5
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de la Torre M, Pomorski A. Investigation of metal ion binding biomolecules one molecule at a time. Front Chem 2024; 12:1378447. [PMID: 38680456 PMCID: PMC11045889 DOI: 10.3389/fchem.2024.1378447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/22/2024] [Indexed: 05/01/2024] Open
Abstract
Metal ions can perform multiple roles ranging from regulatory to structural and are crucial for cell function. While some metal ions like Na+ are ubiquitously present at high concentrations, other ions, especially Ca2+ and transition metals, such as Zn2+ or Cu+/2+ are regulated. The concentrations above or below the physiological range cause severe changes in the behavior of biomolecules that bind them and subsequently affect the cell wellbeing. This has led to the development of specialized protocols to study metal ion binding biomolecules in bulk conditions that mimic the cell environment. Recently, there is growing evidence of influence of post-transcriptional and post-translational modifications on the affinity of the metal ion binding sites. However, such targets are difficult to obtain in amounts required for classical biophysical experiments. Single molecule techniques have revolutionized the field of biophysics, molecular and structural biology. Their biggest advantage is the ability to observe each molecule's interaction independently, without the need for synchronization. An additional benefit is its extremely low sample consumption. This feature allows characterization of designer biomolecules or targets obtained coming from natural sources. All types of biomolecules, including proteins, DNA and RNA were characterized using single molecule methods. However, one group is underrepresented in those studies. These are the metal ion binding biomolecules. Single molecule experiments often require separate optimization, due to extremely different concentrations used during the experiments. In this review we focus on single molecule methods, such as single molecule FRET, nanopores and optical tweezers that are used to study metal ion binding biomolecules. We summarize various examples of recently characterized targets and reported experimental conditions. Finally, we discuss the potential promises and pitfalls of single molecule characterization on metal ion binding biomolecules.
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Affiliation(s)
| | - Adam Pomorski
- Department of Chemical Biology, Faculty of Biotechnology, University of Wrocław, Wrocław, Poland
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6
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Tapia-Rojo R, Alonso-Caballero A, Badilla CL, Fernandez JM. Identical sequences, different behaviors: Protein diversity captured at the single-molecule level. Biophys J 2024; 123:814-823. [PMID: 38409780 PMCID: PMC10995423 DOI: 10.1016/j.bpj.2024.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/07/2024] [Accepted: 02/22/2024] [Indexed: 02/28/2024] Open
Abstract
The classical "one sequence, one structure, one function" paradigm has shaped much of our intuition of how proteins work inside the cell. Partially due to the insight provided by bulk biochemical assays, individual biomolecules are often assumed to behave as identical entities, and their characterization relies on ensemble averages that flatten any conformational diversity into a unique phenotype. While the emergence of single-molecule techniques opened the gates to interrogating individual molecules, technical shortcomings typically limit the duration of these measurements, which precludes a complete characterization of an individual protein and, hence, capturing the heterogeneity among molecular populations. Here, we introduce an ultrastable magnetic tweezers design, which enables us to measure the folding dynamics of a single protein during several uninterrupted days with high temporal and spatial resolution. Thanks to this instrumental development, we fully characterize the nanomechanics of two proteins with a very distinct force response, the talin R3IVVI domain and protein L. Days-long recordings on the same protein individual accumulate thousands of folding transitions with submicrosecond resolution, allowing us to reconstruct their free energy landscapes and describe how they evolve with force. By mapping the nanomechanical identity of many different protein individuals, we directly capture their molecular diversity as a quantifiable dispersion on their force response and folding kinetics. By significantly expanding the measurable timescales, our instrumental development offers a tool for profiling individual molecules, opening the gates to directly characterizing biomolecular heterogeneity.
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Affiliation(s)
- Rafael Tapia-Rojo
- Department of Biological Sciences, Columbia University, New York, New York.
| | | | - Carmen L Badilla
- Department of Biological Sciences, Columbia University, New York, New York
| | - Julio M Fernandez
- Department of Biological Sciences, Columbia University, New York, New York
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7
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Bauer MS, Gruber S, Hausch A, Melo MCR, Gomes PSFC, Nicolaus T, Milles LF, Gaub HE, Bernardi RC, Lipfert J. Single-molecule force stability of the SARS-CoV-2-ACE2 interface in variants-of-concern. NATURE NANOTECHNOLOGY 2024; 19:399-405. [PMID: 38012274 DOI: 10.1038/s41565-023-01536-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 09/26/2023] [Indexed: 11/29/2023]
Abstract
Mutations in SARS-CoV-2 have shown effective evasion of population immunity and increased affinity to the cellular receptor angiotensin-converting enzyme 2 (ACE2). However, in the dynamic environment of the respiratory tract, forces act on the binding partners, which raises the question of whether not only affinity but also force stability of the SARS-CoV-2-ACE2 interaction might be a selection factor for mutations. Using magnetic tweezers, we investigate the impact of amino acid substitutions in variants of concern (Alpha, Beta, Gamma and Delta) and on force-stability and bond kinetic of the receptor-binding domain-ACE2 interface at a single-molecule resolution. We find a higher affinity for all of the variants of concern (>fivefold) compared with the wild type. In contrast, Alpha is the only variant of concern that shows higher force stability (by 17%) compared with the wild type. Using molecular dynamics simulations, we rationalize the mechanistic molecular origins of this increase in force stability. Our study emphasizes the diversity of contributions to the transmissibility of variants and establishes force stability as one of the several factors for fitness. Understanding fitness advantages opens the possibility for the prediction of probable mutations, allowing a rapid adjustment of therapeutics, vaccines and intervention measures.
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Affiliation(s)
- Magnus S Bauer
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Sophia Gruber
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | - Adina Hausch
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
- Center for Protein Assemblies, TUM School of Natural Sciences, Technical University of Munich, Munich, Germany
| | | | | | - Thomas Nicolaus
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | - Lukas F Milles
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Hermann E Gaub
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | | | - Jan Lipfert
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany.
- Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
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8
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Ali A, Kim H, Torati SR, Kang Y, Reddy V, Kim K, Yoon J, Lim B, Kim C. Magnetic Lateral Ladder for Unidirectional Transport of Microrobots: Design Principles and Potential Applications of Cells-on-Chip. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305528. [PMID: 37845030 DOI: 10.1002/smll.202305528] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/23/2023] [Indexed: 10/18/2023]
Abstract
Functionalized microrobots, which are directionally manipulated in a controlled and precise manner for specific tasks, face challenges. However, magnetic field-based controls constrain all microrobots to move in a coordinated manner, limiting their functions and independent behaviors. This article presents a design principle for achieving unidirectional microrobot transport using an asymmetric magnetic texture in the shape of a lateral ladder, which the authors call the "railway track." An asymmetric magnetic energy distribution along the axis allows for the continuous movement of microrobots in a fixed direction regardless of the direction of the magnetic field rotation. The authors demonstrated precise control and simple utilization of this method. Specifically, by placing magnetic textures with different directionalities, an integrated cell/particle collector can collect microrobots distributed in a large area and move them along a complex trajectory to a predetermined location. The authors can leverage the versatile capabilities offered by this texture concept, including hierarchical isolation, switchable collection, programmable pairing, selective drug-response test, and local fluid mixing for target objects. The results demonstrate the importance of microrobot directionality in achieving complex individual control. This novel concept represents significant advancement over conventional magnetic field-based control technology and paves the way for further research in biofunctionalized microrobotics.
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Affiliation(s)
- Abbas Ali
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - Hyeonseol Kim
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - Sri Ramulu Torati
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
- Center for Bioelectronics, Old Dominion University, Norfolk, VA, 23508, USA
| | - Yumin Kang
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - Venu Reddy
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
- Nanotechnology Research Center, SRKR Engineering College, Bhimavaram, Andhra Pradesh, 534204, India
| | - Keonmok Kim
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - Jonghwan Yoon
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - Byeonghwa Lim
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
| | - CheolGi Kim
- Department of Physics and Chemistry, DGIST, Daegu, 42988, Republic of Korea
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9
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Tapia-Rojo R. Construction and operation of high-resolution magnetic tape head tweezers for measuring single-protein dynamics under force. Methods Enzymol 2024; 694:83-107. [PMID: 38492959 DOI: 10.1016/bs.mie.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
Mechanical forces are critical to protein function across many biological contexts-from bacterial adhesion to muscle mechanics and mechanotransduction processes. Hence, understanding how mechanical forces govern protein activity has developed into a central scientific question. In this context, single-molecule magnetic tweezers has recently emerged as a valuable experimental tool, offering the capability to measure single proteins over physiologically relevant forces and timescales. In this chapter, we present a detailed protocol for the assembly and operation of our magnetic tape head tweezers instrument, specifically tailored to investigate protein dynamics. Our instrument boasts a simplified microscope design and incorporates a magnetic tape head as the force-generating apparatus, facilitating precise force control and enhancing its temporal stability, enabling the study of single protein mechanics over extended timescales spanning several hours or even days. Moreover, its straightforward and cost-effective design ensures its accessibility to the wider scientific community. We anticipate that this technique will attract widespread interest within the growing field of mechanobiology and expect that this chapter will provide facilitated accessibility to this technology.
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10
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Sun H, Le S, Guo Z, Chen H. Exploring the free energy landscape of proteins using magnetic tweezers. Methods Enzymol 2024; 694:237-261. [PMID: 38492953 DOI: 10.1016/bs.mie.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
Proteins fold to their native states by searching through the free energy landscapes. As single-domain proteins are the basic building block of multiple-domain proteins or protein complexes composed of subunits, the free energy landscapes of single-domain proteins are of critical importance to understand the folding and unfolding processes of proteins. To explore the free energy landscapes of proteins over large conformational space, the stability of native structure is perturbed by biochemical or mechanical means, and the conformational transition process is measured. In single molecular manipulation experiments, stretching force is applied to proteins, and the folding and unfolding transitions are recorded by the extension time course. Due to the broad force range and long-time stability of magnetic tweezers, the free energy landscape over large conformational space can be obtained. In this article, we describe the magnetic tweezers instrument design, protein construct design and preparation, fluid chamber preparation, common-used measuring protocols including force-ramp and force-jump measurements, and data analysis methods to construct the free energy landscape. Single-domain cold shock protein is introduced as an example to build its free energy landscape by magnetic tweezers measurements.
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Affiliation(s)
- Hao Sun
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China
| | - Shimin Le
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Xiamen University, Xiamen, P.R. China
| | - Zilong Guo
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China.
| | - Hu Chen
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China; Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Xiamen University, Xiamen, P.R. China.
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11
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Dulin D. An Introduction to Magnetic Tweezers. Methods Mol Biol 2024; 2694:375-401. [PMID: 37824014 DOI: 10.1007/978-1-0716-3377-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Magnetic tweezers are a single-molecule force and torque spectroscopy technique that enable the mechanical interrogation in vitro of biomolecules, such as nucleic acids and proteins. They use a magnetic field originating from either permanent magnets or electromagnets to attract a magnetic particle, thus stretching the tethering biomolecule. They nicely complement other force spectroscopy techniques such as optical tweezers and atomic force microscopy (AFM) as they operate as a very stable force clamp, enabling long-duration experiments over a very broad range of forces spanning from 10 fN to 1 nN, with 1-10 milliseconds time and sub-nanometer spatial resolution. Their simplicity, robustness, and versatility have made magnetic tweezers a key technique within the field of single-molecule biophysics, being broadly applied to study the mechanical properties of, e.g., nucleic acids, genome processing molecular motors, protein folding, and nucleoprotein filaments. Furthermore, magnetic tweezers allow for high-throughput single-molecule measurements by tracking hundreds of biomolecules simultaneously both in real-time and at high spatiotemporal resolution. Magnetic tweezers naturally combine with surface-based fluorescence spectroscopy techniques, such as total internal reflection fluorescence microscopy, enabling correlative fluorescence and force/torque spectroscopy on biomolecules. This chapter presents an introduction to magnetic tweezers including a description of the hardware, the theory behind force calibration, its spatiotemporal resolution, combining it with other techniques, and a (non-exhaustive) overview of biological applications.
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Affiliation(s)
- David Dulin
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
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12
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Lin YY, Brouns T, Kolbeck PJ, Vanderlinden W, Lipfert J. High-yield ligation-free assembly of DNA constructs with nucleosome positioning sequence repeats for single-molecule manipulation assays. J Biol Chem 2023; 299:104874. [PMID: 37257819 PMCID: PMC10404619 DOI: 10.1016/j.jbc.2023.104874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/08/2023] [Accepted: 05/16/2023] [Indexed: 06/02/2023] Open
Abstract
Force and torque spectroscopy have provided unprecedented insights into the mechanical properties, conformational transitions, and dynamics of DNA and DNA-protein complexes, notably nucleosomes. Reliable single-molecule manipulation measurements require, however, specific and stable attachment chemistries to tether the molecules of interest. Here, we present a functionalization strategy for DNA that enables high-yield production of constructs for torsionally constrained and very stable attachment. The method is based on two subsequent PCRs: first ∼380 bp long DNA strands are generated that contain multiple labels, which are used as "megaprimers" in a second PCR to generate ∼kbp long double-stranded DNA constructs with multiple labels at the respective ends. To achieve high-force stability, we use dibenzocyclooctyne-based click chemistry for covalent attachment to the surface and biotin-streptavidin coupling to the bead. The resulting tethers are torsionally constrained and extremely stable under load, with an average lifetime of 70 ± 3 h at 45 pN. The high yield of the approach enables nucleosome reconstitution by salt dialysis on the functionalized DNA, and we demonstrate proof-of-concept measurements on nucleosome assembly statistics and inner turn unwrapping under force. We anticipate that our approach will facilitate a range of studies of DNA interactions and nucleoprotein complexes under forces and torques.
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Affiliation(s)
- Yi-Yun Lin
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany; Soft Condensed Matter and Biophysics, Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands
| | - Tine Brouns
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany; Division of Molecular Imaging and Photonics, KU Leuven, Leuven, Belgium
| | - Pauline J Kolbeck
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany; Soft Condensed Matter and Biophysics, Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands
| | - Willem Vanderlinden
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany; Soft Condensed Matter and Biophysics, Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
| | - Jan Lipfert
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany; Soft Condensed Matter and Biophysics, Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
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13
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Gallego P, Garcia-Bonete MJ, Trillo-Muyo S, Recktenwald CV, Johansson MEV, Hansson GC. The intestinal MUC2 mucin C-terminus is stabilized by an extra disulfide bond in comparison to von Willebrand factor and other gel-forming mucins. Nat Commun 2023; 14:1969. [PMID: 37031240 PMCID: PMC10082768 DOI: 10.1038/s41467-023-37666-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/20/2023] [Indexed: 04/10/2023] Open
Abstract
The MUC2 mucin polymer is the main building unit of the intestinal mucus layers separating intestinal microbiota from the host epithelium. The MUC2 mucin is a large glycoprotein with a C-terminal domain similar to the MUC5AC and MUC5B mucins and the von Willebrand factor (VWF). A structural model of the C-terminal part of MUC2, MUC2-C, was generated by combining Cryo-electron microscopy, AlphaFold prediction, information of its glycosylation, and small angle X-ray scattering information. The globular VWD4 assembly in the N-terminal of MUC2-C is followed by 3.5 linear VWC domains that form an extended flexible structure before the C-terminal cystine-knot. All gel-forming mucins and VWF form tail-tail disulfide-bonded dimers in their C-terminal cystine-knot domain, but interestingly the MUC2 mucin has an extra stabilizing disulfide bond on the N-terminal side of the VWD4 domain, likely essential for a stable intestinal mucus barrier.
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Affiliation(s)
- Pablo Gallego
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Maria-Jose Garcia-Bonete
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Sergio Trillo-Muyo
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Christian V Recktenwald
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Malin E V Johansson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden
| | - Gunnar C Hansson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30, Gothenburg, Sweden.
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14
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Gokulu IS, Banta S. Biotechnology applications of proteins functionalized with DNA oligonucleotides. Trends Biotechnol 2023; 41:575-585. [PMID: 36115723 DOI: 10.1016/j.tibtech.2022.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 10/14/2022]
Abstract
The functionalization of proteins with DNA through the formation of covalent bonds enables a wide range of biotechnology advancements. For example, single-molecule analytical methods rely on bioconjugated DNA as elastic biolinkers for protein immobilization. Labeling proteins with DNA enables facile protein identification, as well as spatial and temporal organization and control of protein within DNA-protein networks. Bioconjugation reactions can target native, engineered, and non-canonical amino acids (NCAAs) within proteins. In addition, further protein engineering via the incorporation of peptide tags and self-labeling proteins can also be used for conjugation reactions. The selection of techniques will depend on application requirements such as yield, selectivity, conjugation position, potential for steric hindrance, cost, commercial availability, and potential impact on protein function.
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Affiliation(s)
- Ipek Simay Gokulu
- Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA
| | - Scott Banta
- Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, NY 10027, USA.
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15
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Tapia-Rojo R, Mora M, Board S, Walker J, Boujemaa-Paterski R, Medalia O, Garcia-Manyes S. Enhanced statistical sampling reveals microscopic complexity in the talin mechanosensor folding energy landscape. NATURE PHYSICS 2023; 19:52-60. [PMID: 36660164 PMCID: PMC7614079 DOI: 10.1038/s41567-022-01808-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Statistical mechanics can describe the major conformational ensembles determining the equilibrium free-energy landscape of a folding protein. The challenge is to capture the full repertoire of low-occurrence conformations separated by high kinetic barriers that define complex landscapes. Computationally, enhanced sampling methods accelerate the exploration of molecular rare events. However, accessing the entire protein's conformational space in equilibrium experiments requires technological developments to enable extended observation times. We developed single-molecule magnetic tweezers to capture over a million individual transitions as a single talin protein unfolds and refolds under force in equilibrium. When observed at classically-probed timescales, talin folds in an apparently uncomplicated two-state manner. As the sampling time extends from minutes to days, the underlying energy landscape exhibits gradually larger signatures of complexity, involving a finite number of well-defined rare conformations. A fluctuation analysis allows us to propose plausible structures of each low-probability conformational state. The physiological relevance of each distinct conformation can be connected to the binding of the cytoskeletal protein vinculin, suggesting an extra layer of complexity in talin-mediated mechanotransduction. More generally, our experiments directly test the fundamental notion that equilibrium dynamics depend on the observation timescale.
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Affiliation(s)
- Rafael Tapia-Rojo
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- Corresponding authors: , ,
| | - Marc Mora
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- Corresponding authors: , ,
| | - Stephanie Board
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Jane Walker
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Rajaa Boujemaa-Paterski
- Department of Biochemistry, Zurich University, Winterhurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Ohad Medalia
- Department of Biochemistry, Zurich University, Winterhurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Sergi Garcia-Manyes
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- Corresponding authors: , ,
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16
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Beedle AEM, Garcia-Manyes S. The role of single protein elasticity in mechanobiology. NATURE REVIEWS. MATERIALS 2023; 8:10-24. [PMID: 37469679 PMCID: PMC7614781 DOI: 10.1038/s41578-022-00488-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/07/2022] [Indexed: 07/21/2023]
Abstract
In addition to biochemical signals and genetic considerations, mechanical forces are rapidly emerging as a master regulator of human physiology. Yet the molecular mechanisms that regulate force-induced functionalities across a wide range of scales, encompassing the cell, tissue or organ levels, are comparatively not so well understood. With the advent, development and refining of single molecule nanomechanical techniques, enabling to exquisitely probe the conformational dynamics of individual proteins under the effect of a calibrated force, we have begun to acquire a comprehensive knowledge on the rich plethora of physicochemical principles that regulate the elasticity of single proteins. Here we review the major advances underpinning our current understanding of how the elasticity of single proteins regulates mechanosensing and mechanotransduction. We discuss the present limitations and future challenges of such a prolific and burgeoning field.
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Affiliation(s)
- Amy EM Beedle
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- Institute for Bioengineering of Catalonia (IBEC), the Barcelona Institute of Technology (BIST), 08028 Barcelona, Spain
| | - Sergi Garcia-Manyes
- Department of Physics, Randall Centre for Cell and Molecular Biophysics, Centre for the Physical Science of Life and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- Single Molecule Mechanobiology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
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17
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Csányi MC, Salamon P, Feller T, Bozó T, Hársfalvi J, Kellermayer MSZ. Structural hierarchy of mechanical extensibility in human von Willebrand factor multimers. Protein Sci 2023; 32:e4535. [PMID: 36478480 PMCID: PMC9798247 DOI: 10.1002/pro.4535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022]
Abstract
The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80- to 120-nm-long protomeric units and plays a fundamental role in mediating platelet function at high shear. The exact nature of the shear-induced structural transitions have remained elusive; uncovering them requires the high-resolution quantitative analysis of gradually extended VWF. Here, we stretched human blood-plasma-derived VWF with molecular combing and analyzed the axial structure of the elongated multimers with atomic force microscopy. Protomers extended through structural intermediates that could be grouped into seven distinct topographical classes. Protomer extension thus progresses through the uncoiling of the C1-6 domain segment, rearrangements among the N-terminal VWF domains, and unfolding and elastic extension of the A2 domain. The least and most extended protomer conformations were localized at the ends and the middle of the multimer, respectively, revealing an apparent necking phenomenon characteristic of plastic-material behavior. The structural hierarchy uncovered here is likely to provide a spatial control mechanism to the complex functions of VWF.
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Affiliation(s)
- Mária Csilla Csányi
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
| | - Pál Salamon
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary,Present address:
Department of BioengineeringSapientia Hungarian University of TransylvaniaMiercurea CiucRomania
| | - Tímea Feller
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary,Present address:
Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic MedicineUniversity of LeedsLeedsUK
| | - Tamás Bozó
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
| | - Jolán Hársfalvi
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
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18
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Rief M, Žoldák G. Single-molecule mechanical studies of chaperones and their clients. BIOPHYSICS REVIEWS 2022; 3:041301. [PMID: 38505517 PMCID: PMC10903372 DOI: 10.1063/5.0098033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 09/12/2022] [Indexed: 03/21/2024]
Abstract
Single-molecule force spectroscopy provides access to the mechanics of biomolecules. Recently, magnetic and laser optical tweezers were applied in the studies of chaperones and their interaction with protein clients. Various aspects of the chaperone-client interactions can be revealed based on the mechanical probing strategies. First, when a chaperone is probed under load, one can examine the inner workings of the chaperone while it interacts with and works on the client protein. Second, when protein clients are probed under load, the action of chaperones on folding clients can be studied in great detail. Such client folding studies have given direct access to observing actions of chaperones in real-time, like foldase, unfoldase, and holdase activity. In this review, we introduce the various single molecule mechanical techniques and summarize recent single molecule mechanical studies on heat shock proteins, chaperone-mediated folding on the ribosome, SNARE folding, and studies of chaperones involved in the folding of membrane proteins. An outlook on significant future developments is given.
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Affiliation(s)
- Matthias Rief
- Center for Functional Protein Assemblies (CPA), Physik Department, Technische Universität München, Ernst-Otto-Fischer-Str., 8, D-85748 Garching, Germany
| | - Gabriel Žoldák
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P. J. Šafárik University, Trieda SNP 1, 040 11 Košice, Slovakia
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19
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Zhong BL, Vachharajani VT, Dunn AR. Facile detection of mechanical forces across proteins in cells with STReTCh. CELL REPORTS METHODS 2022; 2:100278. [PMID: 36160040 PMCID: PMC9499875 DOI: 10.1016/j.crmeth.2022.100278] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/25/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
Numerous proteins experience and respond to mechanical forces as an integral part of their cellular functions, but measuring these forces remains a practical challenge. Here, we present a compact, 11-kDa molecular tension sensor termed STReTCh (sensing tension by reactive tag characterization). Unlike existing genetically encoded tension sensors, STReTCh does not rely on experimentally demanding measurements based on Förster resonance energy transfer and is compatible with typical fix-and-stain protocols. Using a magnetic tweezers assay, we calibrate the STReTCh module and show that it responds to physiologically relevant, piconewton forces. As proof of concept, we use an extracellular STReTCh-based sensor to visualize cell-generated forces at integrin-based adhesion complexes. In addition, we incorporate STReTCh into vinculin, a cytoskeletal adaptor protein, and show that STReTCh reports on forces transmitted between the cytoskeleton and cellular adhesion complexes. These data illustrate the utility of STReTCh as a tool for visualizing molecular-scale forces in biological systems.
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Affiliation(s)
- Brian L. Zhong
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | | | - Alexander R. Dunn
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
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20
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A conformational transition of the D'D3 domain primes von Willebrand factor for multimerization. Blood Adv 2022; 6:5198-5209. [PMID: 36069828 PMCID: PMC9631632 DOI: 10.1182/bloodadvances.2022006978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/17/2022] [Indexed: 11/26/2022] Open
Abstract
Magnetic tweezers reveal a pH-dependent destabilization of the D3 interface priming VWF for multimerization by exposing Cys1099 and Cys1142. The stability of the D3 interface is increased by FVIII, suggesting a binding site within the D3 submodules.
Von Willebrand factor (VWF) is a multimeric plasma glycoprotein that is critically involved in hemostasis. Biosynthesis of long VWF concatemers in the endoplasmic reticulum and the trans-Golgi is still not fully understood. We use the single-molecule force spectroscopy technique magnetic tweezers to analyze a previously hypothesized conformational change in the D′D3 domain crucial for VWF multimerization. We find that the interface formed by submodules C8-3, TIL3, and E3 wrapping around VWD3 can open and expose 2 buried cysteines, Cys1099 and Cys1142, that are vital for multimerization. By characterizing the conformational change at varying levels of force, we can quantify the kinetics of the transition and stability of the interface. We find a pronounced destabilization of the interface on lowering the pH from 7.4 to 6.2 and 5.5. This is consistent with initiation of the conformational change that enables VWF multimerization at the D′D3 domain by a decrease in pH in the trans-Golgi network and Weibel-Palade bodies. Furthermore, we find a stabilization of the interface in the presence of coagulation factor VIII, providing evidence for a previously hypothesized binding site in submodule C8-3. Our findings highlight the critical role of the D′D3 domain in VWF biosynthesis and function, and we anticipate our methodology to be applicable to study other, similar conformational changes in VWF and beyond.
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21
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Chakraborty S, Chaudhuri D, Chaudhuri D, Singh V, Banerjee S, Chowdhury D, Haldar S. Connecting conformational stiffness of the protein with energy landscape by a single experiment. NANOSCALE 2022; 14:7659-7673. [PMID: 35546109 DOI: 10.1039/d1nr07582a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The structure-function dynamics of a protein as a flexible polymer is essential to describe its biological functions. Here, using single-molecule magnetic tweezers, we have studied the effect of ionic strength on the folding mechanics of protein L, and probed its folding-associated physical properties by re-measuring the same protein in a range of ammonium sulfate concentrations from 150 mM to 650 mM. We observed an electrolyte-dependent conformational dynamics and folding landscape of the protein in a single experiment. Salt increases the refolding kinetics, while decreasing the unfolding kinetics under force, which in turn modifies the barrier heights towards the folded state. Additionally, salt enhances the molecular compaction by decreasing the Kuhn length of the protein polymer from 1.18 nm to 0.58 nm, which we have explained by modifying the freely jointed chain model. Finally, we correlated polymer chain physics to the folding dynamics, and thus provided an analytical framework for understanding compaction-induced folding mechanics across a range of ionic strengths from a single experiment.
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Affiliation(s)
- Soham Chakraborty
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Deep Chaudhuri
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Dyuti Chaudhuri
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Vihan Singh
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Souradeep Banerjee
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Debojyoti Chowdhury
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
| | - Shubhasis Haldar
- Department of Biological Sciences, Ashoka University, Sonepat, Haryana 131029, India.
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22
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Engineered Molecular Therapeutics Targeting Fibrin and the Coagulation System: a Biophysical Perspective. Biophys Rev 2022; 14:427-461. [PMID: 35399372 PMCID: PMC8984085 DOI: 10.1007/s12551-022-00950-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/25/2022] [Indexed: 02/07/2023] Open
Abstract
The coagulation cascade represents a sophisticated and highly choreographed series of molecular events taking place in the blood with important clinical implications. One key player in coagulation is fibrinogen, a highly abundant soluble blood protein that is processed by thrombin proteases at wound sites, triggering self-assembly of an insoluble protein hydrogel known as a fibrin clot. By forming the key protein component of blood clots, fibrin acts as a structural biomaterial with biophysical properties well suited to its role inhibiting fluid flow and maintaining hemostasis. Based on its clinical importance, fibrin is being investigated as a potentially valuable molecular target in the development of coagulation therapies. In this topical review, we summarize our current understanding of the coagulation cascade from a molecular, structural and biophysical perspective. We highlight single-molecule studies on proteins involved in blood coagulation and report on the current state of the art in directed evolution and molecular engineering of fibrin-targeted proteins and polymers for modulating coagulation. This biophysical overview will help acclimatize newcomers to the field and catalyze interdisciplinary work in biomolecular engineering toward the development of new therapies targeting fibrin and the coagulation system.
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23
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Abstract
In the dynamic environment of the airways, where SARS-CoV-2 infections are initiated by binding to human host receptor ACE2, mechanical stability of the viral attachment is a crucial fitness advantage. Using single-molecule force spectroscopy techniques, we mimic the effect of coughing and sneezing, thereby testing the force stability of SARS-CoV-2 RBD:ACE2 interaction under physiological conditions. Our results reveal a higher force stability of SARS-CoV-2 binding to ACE2 compared to SARS-CoV-1, causing a possible fitness advantage. Our assay is sensitive to blocking agents preventing RBD:ACE2 bond formation. It will thus provide a powerful approach to investigate the modes of action of neutralizing antibodies and other agents designed to block RBD binding to ACE2 that are currently developed as potential COVID-19 therapeutics. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are initiated by attachment of the receptor-binding domain (RBD) on the viral Spike protein to angiotensin-converting enzyme-2 (ACE2) on human host cells. This critical first step occurs in dynamic environments, where external forces act on the binding partners and avidity effects play an important role, creating an urgent need for assays that can quantitate SARS-CoV-2 interactions with ACE2 under mechanical load. Here, we introduce a tethered ligand assay that comprises the RBD and the ACE2 ectodomain joined by a flexible peptide linker. Using magnetic tweezers and atomic force spectroscopy as highly complementary single-molecule force spectroscopy techniques, we investigate the RBD:ACE2 interaction over the whole physiologically relevant force range. We combine the experimental results with steered molecular dynamics simulations and observe and assign fully consistent unbinding and unfolding events across the three techniques, enabling us to establish ACE2 unfolding as a molecular fingerprint. Measuring at forces of 2 to 5 pN, we quantify the force dependence and kinetics of the RBD:ACE2 bond in equilibrium. We show that the SARS-CoV-2 RBD:ACE2 interaction has higher mechanical stability, larger binding free energy, and a lower dissociation rate compared to SARS-CoV-1, which helps to rationalize the different infection patterns of the two viruses. By studying how free ACE2 outcompetes tethered ACE2, we show that our assay is sensitive to prevention of bond formation by external binders. We expect our results to provide a way to investigate the roles of viral mutations and blocking agents for targeted pharmaceutical intervention.
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24
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Direct observation of chaperone-modulated talin mechanics with single-molecule resolution. Commun Biol 2022; 5:307. [PMID: 35379917 PMCID: PMC8979947 DOI: 10.1038/s42003-022-03258-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 03/11/2022] [Indexed: 12/18/2022] Open
Abstract
Talin as a critical focal adhesion mechanosensor exhibits force-dependent folding dynamics and concurrent interactions. Being a cytoplasmic protein, talin also might interact with several cytosolic chaperones; however, the roles of chaperones in talin mechanics remain elusive. To address this question, we investigated the force response of a mechanically stable talin domain with a set of well-known unfoldase (DnaJ, DnaK) and foldase (DnaKJE, DsbA) chaperones, using single-molecule magnetic tweezers. Our findings demonstrate that chaperones could affect adhesion proteins’ stability by changing their folding mechanics; while unfoldases reduce their unfolding force from ~11 pN to ~6 pN, foldase shifts it upto ~15 pN. Since talin is mechanically synced within 2 pN force ranges, these changes are significant in cellular conditions. Furthermore, we determined that chaperones directly reshape the energy landscape of talin: unfoldases decrease the unfolding barrier height from 26.8 to 21.7 kBT, while foldases increase it to 33.5 kBT. We reconciled our observations with eukaryotic Hsp70 and Hsp40 and observed their similar function of decreasing the talin unfolding barrier. Quantitative mapping of this chaperone-induced talin folding landscape directly illustrates that chaperones perturb the adhesion protein stability under physiological force, thereby, influencing their force-dependent interactions and adhesion dynamics. Chakraborty et al. uses single-molecule magnetic tweezers to investigate the chaperone-modulated talin protein mechanics. The results showed that chaperones are involved in the regulation of talin folding/unfolding under mechanical force with some chaperones stabilizing talin and increasing the force, whereas others destabilize it and reduce the force.
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25
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Liao S, Sun M, Zhan J, Xu M, Yao L. Advances in the Biological Application of Force-Induced Remnant Magnetization Spectroscopy. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27072072. [PMID: 35408471 PMCID: PMC9000611 DOI: 10.3390/molecules27072072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/15/2022] [Accepted: 03/22/2022] [Indexed: 11/16/2022]
Abstract
Biomolecules participate in various physiological and pathological processes through intermolecular interactions generally driven by non-covalent forces. In the present review, the force-induced remnant magnetization spectroscopy (FIRMS) is described and illustrated as a novel method to measure non-covalent forces. During the FIRMS measurement, the molecular magnetic probes are magnetized to produce an overall magnetization signal. The dissociation under the interference of external force yields a decrease in the magnetic signal, which is recorded and collected by atomic magnetometer in a spectrum to study the biological interactions. Furthermore, the recent FIRMS development with various external mechanical forces and magnetic probes is summarized.
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Affiliation(s)
- Shuyu Liao
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing 100190, China; (S.L.); (M.S.); (J.Z.); (M.X.)
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengxue Sun
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing 100190, China; (S.L.); (M.S.); (J.Z.); (M.X.)
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinxiu Zhan
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing 100190, China; (S.L.); (M.S.); (J.Z.); (M.X.)
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Min Xu
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing 100190, China; (S.L.); (M.S.); (J.Z.); (M.X.)
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Yao
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing 100190, China; (S.L.); (M.S.); (J.Z.); (M.X.)
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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26
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Abstract
Single-molecule magnetic tweezers deliver magnetic force and torque to single target molecules, permitting the study of dynamic changes in biomolecular structures and their interactions. Because the magnetic tweezer setups can generate magnetic fields that vary slowly over tens of millimeters-far larger than the nanometer scale of the single molecule events being observed-this technique can maintain essentially constant force levels during biochemical experiments while generating a biologically meaningful force on the order of 1-100 pN. When using bead-tether constructs to pull on single molecules, smaller magnetic beads and shorter submicrometer tethers improve dynamic response times and measurement precision. In addition, employing high-speed cameras, stronger light sources, and a graphics programming unit permits true high-resolution single-molecule magnetic tweezers that can track nanometer changes in target molecules on a millisecond or even submillisecond time scale. The unique force-clamping capacity of the magnetic tweezer technique provides a way to conduct measurements under near-equilibrium conditions and directly map the energy landscapes underlying various molecular phenomena. High-resolution single-molecule magnetic tweezers can thus be used to monitor crucial conformational changes in single-protein molecules, including those involved in mechanotransduction and protein folding. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Hyun-Kyu Choi
- Wallace H. Coulter Department of Biomedical Engineering and Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Hyun Gyu Kim
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea;
| | - Min Ju Shon
- Department of Physics and School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science & Technology (POSTECH), Pohang, South Korea;
| | - Tae-Young Yoon
- School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, South Korea;
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27
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Beshay PE, Cortes-Medina MG, Menyhert MM, Song JW. The biophysics of cancer: emerging insights from micro- and nanoscale tools. ADVANCED NANOBIOMED RESEARCH 2022; 2:2100056. [PMID: 35156093 PMCID: PMC8827905 DOI: 10.1002/anbr.202100056] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cancer is a complex and dynamic disease that is aberrant both biologically and physically. There is growing appreciation that physical abnormalities with both cancer cells and their microenvironment that span multiple length scales are important drivers for cancer growth and metastasis. The scope of this review is to highlight the key advancements in micro- and nano-scale tools for delineating the cause and consequences of the aberrant physical properties of tumors. We focus our review on three important physical aspects of cancer: 1) solid mechanical properties, 2) fluid mechanical properties, and 3) mechanical alterations to cancer cells. Beyond posing physical barriers to the delivery of cancer therapeutics, these properties are also known to influence numerous biological processes, including cancer cell invasion and migration leading to metastasis, and response and resistance to therapy. We comment on how micro- and nanoscale tools have transformed our fundamental understanding of the physical dynamics of cancer progression and their potential for bridging towards future applications at the interface of oncology and physical sciences.
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Affiliation(s)
- Peter E Beshay
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210
| | | | - Miles M Menyhert
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210
| | - Jonathan W Song
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210
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28
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Zhao YC, Wang H, Wang Y, Lou J, Ju LA. The N-terminal autoinhibitory module of the A1 domain in von Willebrand factor stabilizes the mechanosensor catch bond. RSC Chem Biol 2022; 3:707-720. [PMID: 35755187 PMCID: PMC9175105 DOI: 10.1039/d2cb00010e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/07/2022] [Indexed: 12/29/2022] Open
Abstract
The N-AIM of VWF-A1 forms a Rotini-like structure, therefore partially autoinhibit VWF-A1–GPIbα interaction. The N-AIM acts as a defending sword to protect and stabilize the VWF-A1 structure under harsh environments.
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Affiliation(s)
- Yunduo Charles Zhao
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW 2008, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW 2006, Australia
| | - Haoqing Wang
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW 2008, Australia
- Heart Research Institute, Newtown, NSW 2042, Australia
| | - Yao Wang
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW 2008, Australia
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, NSW 2052, Australia
| | - Jizhong Lou
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Lining Arnold Ju
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW 2008, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW 2006, Australia
- Heart Research Institute, Newtown, NSW 2042, Australia
- The University of Sydney Nano Institute (Sydney Nano), The University of Sydney, Camperdown, NSW 2006, Australia
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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29
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Carlucci LA, Thomas WE. Modification to axial tracking for mobile magnetic microspheres. BIOPHYSICAL REPORTS 2021; 1:100031. [PMID: 35965968 PMCID: PMC9371438 DOI: 10.1016/j.bpr.2021.100031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 11/04/2021] [Indexed: 11/30/2022]
Abstract
Three-dimensional particle tracking is a routine experimental procedure for various biophysical applications including magnetic tweezers. A common method for tracking the axial position of particles involves the analysis of diffraction rings whose pattern depends sensitively on the axial position of the bead relative to the focal plane. To infer the axial position, the observed rings are compared with reference images of a bead at known axial positions. Often the precision or accuracy of these algorithms is measured on immobilized beads over a limited axial range, while many experiments are performed using freely mobile beads. This inconsistency raises the possibility of incorrect estimates of experimental uncertainty. By manipulating magnetic beads in a bidirectional magnetic tweezer setup, we evaluated the error associated with tracking mobile magnetic beads and found that the error of tracking a moving magnetic bead increases by almost an order of magnitude compared to the error of tracking a stationary bead. We found that this additional error can be ameliorated by excluding the center-most region of the diffraction ring pattern from tracking analysis. Evaluation of the limitations of a tracking algorithm is essential for understanding the error associated with a measurement. These findings promise to bring increased resolution to three-dimensional bead tracking of magnetic microspheres.
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Affiliation(s)
- Laura A. Carlucci
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Wendy E. Thomas
- Department of Bioengineering, University of Washington, Seattle, Washington
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30
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Piccolo JG, Méndez Harper J, McCalla D, Xu W, Miller S, Doan J, Kovari D, Dunlap D, Finzi L. Force spectroscopy with electromagnetic tweezers. JOURNAL OF APPLIED PHYSICS 2021; 130:134702. [PMID: 38681504 PMCID: PMC11055633 DOI: 10.1063/5.0060276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/07/2021] [Indexed: 05/01/2024]
Abstract
Force spectroscopy using magnetic tweezers (MTs) is a powerful method to probe the physical characteristics of single polymers. Typically, molecules are functionalized for specific attachment to a glass surface at one end and a micrometer-scale paramagnetic bead at the other end. By applying an external magnetic field, multiple molecules can be stretched and twisted simultaneously without exposure to potentially damaging radiation. The majority of MTs utilize mobile, permanent magnets to produce forces on the beads (and the molecule under test). However, translating and rotating the permanent magnets may require expensive precision actuators, limit the rate at which force can be changed, and may induce vibrations that disturb tether dynamics and bead tracking. Alternatively, the magnetic field can be produced with an electromagnet, which allows fast force modulation and eliminates motor-associated vibration. Here, we describe a low-cost quadrapolar electromagnetic tweezer design capable of manipulating DNA-tethered MyOne paramagnetic beads with forces as high as 15 pN. The solid-state nature of the generated B-field modulated along two axes is convenient for accessing the range of forces and torques relevant for studying the activity of DNA motor enzymes like polymerases and helicases. Our design specifically leverages technology available at an increasing number of university maker spaces and student-run machine shops. Thus, it is an accessible tool for undergraduate education that is applicable to a wide range of biophysical research questions.
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Affiliation(s)
- Joseph G. Piccolo
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Joshua Méndez Harper
- Department of Earth Science, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403, USA
| | - Derrica McCalla
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Wenxuan Xu
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Sam Miller
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Jessie Doan
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Dan Kovari
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - David Dunlap
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
| | - Laura Finzi
- Department of Physics, Emory University, 400 Dowman Dr., Atlanta, Georgia 30322, USA
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31
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Petrosyan R, Narayan A, Woodside MT. Single-Molecule Force Spectroscopy of Protein Folding. J Mol Biol 2021; 433:167207. [PMID: 34418422 DOI: 10.1016/j.jmb.2021.167207] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/11/2021] [Accepted: 08/11/2021] [Indexed: 10/20/2022]
Abstract
The use of force probes to induce unfolding and refolding of single molecules through the application of mechanical tension, known as single-molecule force spectroscopy (SMFS), has proven to be a powerful tool for studying the dynamics of protein folding. Here we provide an overview of what has been learned about protein folding using SMFS, from small, single-domain proteins to large, multi-domain proteins. We highlight the ability of SMFS to measure the energy landscapes underlying folding, to map complex pathways for native and non-native folding, to probe the mechanisms of chaperones that assist with native folding, to elucidate the effects of the ribosome on co-translational folding, and to monitor the folding of membrane proteins.
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Affiliation(s)
- Rafayel Petrosyan
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Abhishek Narayan
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - Michael T Woodside
- Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
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32
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van der Sleen LM, Tych KM. Bioconjugation Strategies for Connecting Proteins to DNA-Linkers for Single-Molecule Force-Based Experiments. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2424. [PMID: 34578744 PMCID: PMC8464727 DOI: 10.3390/nano11092424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 01/10/2023]
Abstract
The mechanical properties of proteins can be studied with single molecule force spectroscopy (SMFS) using optical tweezers, atomic force microscopy and magnetic tweezers. It is common to utilize a flexible linker between the protein and trapped probe to exclude short-range interactions in SMFS experiments. One of the most prevalent linkers is DNA due to its well-defined properties, although attachment strategies between the DNA linker and protein or probe may vary. We will therefore provide a general overview of the currently existing non-covalent and covalent bioconjugation strategies to site-specifically conjugate DNA-linkers to the protein of interest. In the search for a standardized conjugation strategy, considerations include their mechanical properties in the context of SMFS, feasibility of site-directed labeling, labeling efficiency, and costs.
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Affiliation(s)
| | - Katarzyna M. Tych
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands;
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33
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Tian F, Tong B, Sun L, Shi S, Zheng B, Wang Z, Dong X, Zheng P. N501Y mutation of spike protein in SARS-CoV-2 strengthens its binding to receptor ACE2. eLife 2021; 10:e69091. [PMID: 34414884 PMCID: PMC8455130 DOI: 10.7554/elife.69091] [Citation(s) in RCA: 210] [Impact Index Per Article: 70.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 08/19/2021] [Indexed: 12/18/2022] Open
Abstract
SARS-CoV-2 has been spreading around the world for the past year. Recently, several variants such as B.1.1.7 (alpha), B.1.351 (beta), and P.1 (gamma), which share a key mutation N501Y on the receptor-binding domain (RBD), appear to be more infectious to humans. To understand the underlying mechanism, we used a cell surface-binding assay, a kinetics study, a single-molecule technique, and a computational method to investigate the interaction between these RBD (mutations) and ACE2. Remarkably, RBD with the N501Y mutation exhibited a considerably stronger interaction, with a faster association rate and a slower dissociation rate. Atomic force microscopy (AFM)-based single-molecule force microscopy (SMFS) consistently quantified the interaction strength of RBD with the mutation as having increased binding probability and requiring increased unbinding force. Molecular dynamics simulations of RBD-ACE2 complexes indicated that the N501Y mutation introduced additional π-π and π-cation interactions that could explain the changes observed by force microscopy. Taken together, these results suggest that the reinforced RBD-ACE2 interaction that results from the N501Y mutation in the RBD should play an essential role in the higher rate of transmission of SARS-CoV-2 variants, and that future mutations in the RBD of the virus should be under surveillance.
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Affiliation(s)
- Fang Tian
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing UniversityNanjingChina
| | - Bei Tong
- Institute of Botany, Jiangsu Province and Chinese Academy of SciencesNanjingChina
| | - Liang Sun
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing UniversityNanjingChina
| | - Shengchao Shi
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing UniversityNanjingChina
| | - Bin Zheng
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing UniversityNanjingChina
| | - Zibin Wang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing UniversityNanjingChina
| | - Xianchi Dong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing UniversityNanjingChina
- Engineering Research Center of Protein and Peptide Medicine, Ministry of EducationNanjingChina
| | - Peng Zheng
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing UniversityNanjingChina
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34
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Alegre-Cebollada J. Protein nanomechanics in biological context. Biophys Rev 2021; 13:435-454. [PMID: 34466164 PMCID: PMC8355295 DOI: 10.1007/s12551-021-00822-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/05/2021] [Indexed: 12/20/2022] Open
Abstract
How proteins respond to pulling forces, or protein nanomechanics, is a key contributor to the form and function of biological systems. Indeed, the conventional view that proteins are able to diffuse in solution does not apply to the many polypeptides that are anchored to rigid supramolecular structures. These tethered proteins typically have important mechanical roles that enable cells to generate, sense, and transduce mechanical forces. To fully comprehend the interplay between mechanical forces and biology, we must understand how protein nanomechanics emerge in living matter. This endeavor is definitely challenging and only recently has it started to appear tractable. Here, I introduce the main in vitro single-molecule biophysics methods that have been instrumental to investigate protein nanomechanics over the last 2 decades. Then, I present the contemporary view on how mechanical force shapes the free energy of tethered proteins, as well as the effect of biological factors such as post-translational modifications and mutations. To illustrate the contribution of protein nanomechanics to biological function, I review current knowledge on the mechanobiology of selected muscle and cell adhesion proteins including titin, talin, and bacterial pilins. Finally, I discuss emerging methods to modulate protein nanomechanics in living matter, for instance by inducing specific mechanical loss-of-function (mLOF). By interrogating biological systems in a causative manner, these new tools can contribute to further place protein nanomechanics in a biological context.
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35
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Maciuba K, Zhang F, Kaiser CM. Facile tethering of stable and unstable proteins for optical tweezers experiments. Biophys J 2021; 120:2691-2700. [PMID: 33989618 DOI: 10.1016/j.bpj.2021.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/14/2021] [Accepted: 05/05/2021] [Indexed: 10/21/2022] Open
Abstract
Single-molecule force spectroscopy with optical tweezers has emerged as a powerful tool for dissecting protein folding. The requirement to stably attach "molecular handles" to specific points in the protein of interest by preparative biochemical techniques is a limiting factor in applying this methodology, especially for large or unstable proteins that are difficult to produce and isolate. Here, we present a streamlined approach for creating stable and specific attachments using autocatalytic covalent tethering. The high specificity of coupling allowed us to tether ribosome-nascent chain complexes, demonstrating its suitability for investigating complex macromolecular assemblies. We combined this approach with cell-free protein synthesis, providing a facile means of preparing samples for single-molecule force spectroscopy. The workflow eliminates the need for biochemical protein purification during sample preparation for single-molecule measurements, making structurally unstable proteins amenable to investigation by this powerful single-molecule technique. We demonstrate the capabilities of this approach by carrying out pulling experiments with an unstructured domain of elongation factor G that had previously been refractory to analysis. Our approach expands the pool of proteins amenable to folding studies, which should help to reduce existing biases in the currently available set of protein folding models.
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Affiliation(s)
- Kevin Maciuba
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
| | - Fan Zhang
- Department of Biology, Johns Hopkins University, Baltimore, Maryland
| | - Christian M Kaiser
- Department of Biology, Johns Hopkins University, Baltimore, Maryland; Department of Biophysics, Johns Hopkins University, Baltimore, Maryland.
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36
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Arce NA, Cao W, Brown AK, Legan ER, Wilson MS, Xu ER, Berndt MC, Emsley J, Zhang XF, Li R. Activation of von Willebrand factor via mechanical unfolding of its discontinuous autoinhibitory module. Nat Commun 2021; 12:2360. [PMID: 33883551 PMCID: PMC8060278 DOI: 10.1038/s41467-021-22634-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 03/16/2021] [Indexed: 01/05/2023] Open
Abstract
Von Willebrand factor (VWF) activates in response to shear flow to initiate hemostasis, while aberrant activation could lead to thrombosis. Above a critical shear force, the A1 domain of VWF becomes activated and captures platelets via the GPIb-IX complex. Here we show that the shear-responsive element controlling VWF activation resides in the discontinuous autoinhibitory module (AIM) flanking A1. Application of tensile force in a single-molecule setting induces cooperative unfolding of the AIM to expose A1. The AIM-unfolding force is lowered by truncating either N- or C-terminal AIM region, type 2B VWD mutations, or binding of a ristocetin-mimicking monoclonal antibody, all of which could activate A1. Furthermore, the AIM is mechanically stabilized by the nanobody that comprises caplacizumab, the only FDA-approved anti-thrombotic drug to-date that targets VWF. Thus, the AIM is a mechano-regulator of VWF activity. Its conformational dynamics may define the extent of VWF autoinhibition and subsequent activation under force.
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Affiliation(s)
- Nicholas A Arce
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Wenpeng Cao
- Department of Bioengineering, Department of Mechanical Engineering & Mechanics, Lehigh University, Bethlehem, PA, USA
| | - Alexander K Brown
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Emily R Legan
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Moriah S Wilson
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Emma-Ruoqi Xu
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Michael C Berndt
- Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Jonas Emsley
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - X Frank Zhang
- Department of Bioengineering, Department of Mechanical Engineering & Mechanics, Lehigh University, Bethlehem, PA, USA.
| | - Renhao Li
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA.
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37
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Nanopores: a versatile tool to study protein dynamics. Essays Biochem 2021; 65:93-107. [PMID: 33296461 DOI: 10.1042/ebc20200020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Proteins are the active workhorses in our body. These biomolecules perform all vital cellular functions from DNA replication and general biosynthesis to metabolic signaling and environmental sensing. While static 3D structures are now readily available, observing the functional cycle of proteins - involving conformational changes and interactions - remains very challenging, e.g., due to ensemble averaging. However, time-resolved information is crucial to gain a mechanistic understanding of protein function. Single-molecule techniques such as FRET and force spectroscopies provide answers but can be limited by the required labelling, a narrow time bandwidth, and more. Here, we describe electrical nanopore detection as a tool for probing protein dynamics. With a time bandwidth ranging from microseconds to hours, nanopore experiments cover an exceptionally wide range of timescales that is very relevant for protein function. First, we discuss the working principle of label-free nanopore experiments, various pore designs, instrumentation, and the characteristics of nanopore signals. In the second part, we review a few nanopore experiments that solved research questions in protein science, and we compare nanopores to other single-molecule techniques. We hope to make electrical nanopore sensing more accessible to the biochemical community, and to inspire new creative solutions to resolve a variety of protein dynamics - one molecule at a time.
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38
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Stannard A, Mora M, Beedle AE, Castro-López M, Board S, Garcia-Manyes S. Molecular Fluctuations as a Ruler of Force-Induced Protein Conformations. NANO LETTERS 2021; 21:2953-2961. [PMID: 33765390 PMCID: PMC7610714 DOI: 10.1021/acs.nanolett.1c00051] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Molecular fluctuations directly reflect the underlying energy landscape. Variance analysis examines protein dynamics in several biochemistry-driven approaches, yet measurement of probe-independent fluctuations in proteins exposed to mechanical forces remains only accessible through steered molecular dynamics simulations. Using single molecule magnetic tweezers, here we conduct variance analysis to show that individual unfolding and refolding transitions occurring in dynamic equilibrium in a single protein under force are hallmarked by a change in the protein's end-to-end fluctuations, revealing a change in protein stiffness. By unfolding and refolding three structurally distinct proteins under a wide range of constant forces, we demonstrate that the associated change in protein compliance to reach force-induced thermodynamically stable states scales with the protein's contour length increment, in agreement with the sequence-independent freely jointed chain model of polymer physics. Our findings will help elucidate the conformational dynamics of proteins exposed to mechanical force at high resolution which are of central importance in mechanosensing and mechanotransduction.
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Affiliation(s)
- Andrew Stannard
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Marc Mora
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Amy E.M. Beedle
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Marta Castro-López
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
| | - Stephanie Board
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
| | - Sergi Garcia-Manyes
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King’s College London, Strand, WC2R 2LS London, United Kingdom
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, London, UK
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39
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Belyaev AV. Intradimer forces and their implication for conformations of von Willebrand factor multimers. Biophys J 2021; 120:899-911. [PMID: 33524374 DOI: 10.1016/j.bpj.2021.01.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/31/2020] [Accepted: 01/19/2021] [Indexed: 10/22/2022] Open
Abstract
The largest blood glycoprotein von Willebrand factor (VWF) responds to hydrodynamic stresses in the bloodstream with abrupt conformation changes, thus increasing its adhesivity to platelets and collagen. Arterial and microvascular hemostasis relies on mechanical and physicochemical properties of this macromolecule. Recently, it was discovered that the mechanical properties of VWF are controlled by multiple pH-dependent interactions with opposite trends within dimeric subunits. In this work, computer simulations reveal the effect of these intradimer forces on the conformation of VWF multimers in various hydrodynamic conditions. A coarse-grained computer model of VWF has been proposed and parameterized to give a good agreement with experimental data. The simulations suggest that strong attraction between VWF D4 domains increases the resistance to elongation under shear stress, whereas even intermediate attraction between VWF C domains contributes to VWF compaction in nonsheared fluid. It is hypothesized that the detailed subdimer dynamics of VWF concatamers may be one of the biophysical regulators of initial hemostasis and arterial thrombosis.
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Affiliation(s)
- Aleksey V Belyaev
- Lomonosov Moscow State University, Faculty of Physics, Moscow, Russia; IRC Mathematical modelling in Biomedicine, S.M. Nikolskii Mathematical Institute, RUDN University, Moscow, Russia.
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40
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Yang J, Wu Z, Long Q, Huang J, Hong T, Liu W, Lin J. Insights Into Immunothrombosis: The Interplay Among Neutrophil Extracellular Trap, von Willebrand Factor, and ADAMTS13. Front Immunol 2020; 11:610696. [PMID: 33343584 PMCID: PMC7738460 DOI: 10.3389/fimmu.2020.610696] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 11/02/2020] [Indexed: 12/24/2022] Open
Abstract
Both neutrophil extracellular traps (NETs) and von Willebrand factor (VWF) are essential for thrombosis and inflammation. During these processes, a complex series of events, including endothelial activation, NET formation, VWF secretion, and blood cell adhesion, aggregation and activation, occurs in an ordered manner in the vasculature. The adhesive activity of VWF multimers is regulated by a specific metalloprotease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13). Increasing evidence indicates that the interaction between NETs and VWF contributes to arterial and venous thrombosis as well as inflammation. Furthermore, contents released from activated neutrophils or NETs induce the reduction of ADAMTS13 activity, which may occur in both thrombotic microangiopathies (TMAs) and acute ischemic stroke (AIS). Recently, NET is considered as a driver of endothelial damage and immunothrombosis in COVID-19. In addition, the levels of VWF and ADAMTS13 can predict the mortality of COVID-19. In this review, we summarize the biological characteristics and interactions of NETs, VWF, and ADAMTS13, and discuss their roles in TMAs, AIS, and COVID-19. Targeting the NET-VWF axis may be a novel therapeutic strategy for inflammation-associated TMAs, AIS, and COVID-19.
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Affiliation(s)
- Junxian Yang
- Research Department of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Zhiwei Wu
- Research Department of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Quan Long
- Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jiaqi Huang
- Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Tiantian Hong
- Research Department of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Wang Liu
- Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
| | - Jiangguo Lin
- Research Department of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China.,Institute of Biomechanics/School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China
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41
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Müller DJ, Dumitru AC, Lo Giudice C, Gaub HE, Hinterdorfer P, Hummer G, De Yoreo JJ, Dufrêne YF, Alsteens D. Atomic Force Microscopy-Based Force Spectroscopy and Multiparametric Imaging of Biomolecular and Cellular Systems. Chem Rev 2020; 121:11701-11725. [PMID: 33166471 DOI: 10.1021/acs.chemrev.0c00617] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During the last three decades, a series of key technological improvements turned atomic force microscopy (AFM) into a nanoscopic laboratory to directly observe and chemically characterize molecular and cell biological systems under physiological conditions. Here, we review key technological improvements that have established AFM as an analytical tool to observe and quantify native biological systems from the micro- to the nanoscale. Native biological systems include living tissues, cells, and cellular components such as single or complexed proteins, nucleic acids, lipids, or sugars. We showcase the procedures to customize nanoscopic chemical laboratories by functionalizing AFM tips and outline the advantages and limitations in applying different AFM modes to chemically image, sense, and manipulate biosystems at (sub)nanometer spatial and millisecond temporal resolution. We further discuss theoretical approaches to extract the kinetic and thermodynamic parameters of specific biomolecular interactions detected by AFM for single bonds and extend the discussion to multiple bonds. Finally, we highlight the potential of combining AFM with optical microscopy and spectroscopy to address the full complexity of biological systems and to tackle fundamental challenges in life sciences.
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Affiliation(s)
- Daniel J Müller
- Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule (ETH) Zürich, Mattenstrasse 28, 4056 Basel, Switzerland
| | - Andra C Dumitru
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Cristina Lo Giudice
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - Hermann E Gaub
- Applied Physics, Ludwig-Maximilians-Universität Munich, Amalienstrasse 54, 80799 München, Germany
| | - Peter Hinterdorfer
- Institute of Biophysics, Johannes Kepler University of Linz, Gruberstrasse 40, 4020 Linz, Austria
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics and Department of Physics, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
| | - James J De Yoreo
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States.,Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
| | - David Alsteens
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCLouvain), Croix du Sud, 4-5, bte L7.07.07, B-1348 Louvain-la-Neuve, Belgium
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42
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Gruber S, Löf A, Sedlak SM, Benoit M, Gaub HE, Lipfert J. Designed anchoring geometries determine lifetimes of biotin-streptavidin bonds under constant load and enable ultra-stable coupling. NANOSCALE 2020; 12:21131-21137. [PMID: 33079117 DOI: 10.1039/d0nr03665j] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The small molecule biotin and the homotetrameric protein streptavidin (SA) form a stable and robust complex that plays a pivotal role in many biotechnological and medical applications. In particular, the SA-biotin linkage is frequently used in single-molecule force spectroscopy (SMFS) experiments. Recent data suggest that SA-biotin bonds show strong directional dependence and a broad range of multi-exponential lifetimes under load. Here, we investigate engineered SA variants with different valencies and a unique tethering point under constant forces using a magnetic tweezers assay. We observed orders-of-magnitude differences in the lifetimes under force, which we attribute to the distinct force-loading geometries in the different SA variants. Lifetimes showed exponential dependencies on force, with extrapolated lifetimes at zero force that are similar for the different SA variants and agree with parameters determined from constant-speed dynamic SMFS experiments. We identified an especially long-lived tethering geometry that will facilitate ultra-stable SMFS experiments.
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Affiliation(s)
- Sophia Gruber
- Department of Physics and Center for NanoScience, LMU Munich, Germany.
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43
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44
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Abstract
Manipulation of individual molecules with optical tweezers provides a powerful means of interrogating the structure and folding of proteins. Mechanical force is not only a relevant quantity in cellular protein folding and function, but also a convenient parameter for biophysical folding studies. Optical tweezers offer precise control in the force range relevant for protein folding and unfolding, from which single-molecule kinetic and thermodynamic information about these processes can be extracted. In this review, we describe both physical principles and practical aspects of optical tweezers measurements and discuss recent advances in the use of this technique for the study of protein folding. In particular, we describe the characterization of folding energy landscapes at high resolution, studies of structurally complex multidomain proteins, folding in the presence of chaperones, and the ability to investigate real-time cotranslational folding of a polypeptide.
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Affiliation(s)
- Carlos Bustamante
- Department of Molecular and Cell Biology, Department of Physics, Howard Hughes Medical Institute, and Kavli Energy NanoScience Institute, University of California, Berkeley, California 94720, USA;
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Lisa Alexander
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Kevin Maciuba
- Cell, Molecular, Developmental Biology, and Biophysics Graduate Program, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - Christian M Kaiser
- Department of Biology and Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, USA;
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45
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Mandal SS. Force Spectroscopy on Single Molecules of Life. ACS OMEGA 2020; 5:11271-11278. [PMID: 32478214 PMCID: PMC7254507 DOI: 10.1021/acsomega.0c00814] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/29/2020] [Indexed: 05/02/2023]
Abstract
Biomolecules such as nucleic acids and proteins constitute the cells and its organelles that form the crucial components in all living organisms. They are associated with a variety of cellular processes during which they undergo conformational orientations. The structural rearrangements resulting from protein-protein, protein-DNA, and protein-drug interactions vary in spatial and temporal length scales. Force is one of the important key factors which regulate these interactions. The magnitude of the force can vary from sub-piconewtons to several thousands of piconewtons. Single-molecule force spectroscopy acts as a powerful tool which is capable of investigating mechanical stability and conformational rearrangements arising in biomolecules due to the above interactions. Real-time observation of conformational dynamics including access to rare or transient states and the estimation of mean dwell times using these tools aids in the kinetic analysis of these interactions. In this review, we highlight the capabilities of common force spectroscopy techniques such as optical tweezers, magnetic tweezers, and atomic force microscopy with case studies on emerging applications.
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Affiliation(s)
- Soumit S Mandal
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Tirupati 517507, India
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46
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Lansakara TI, Morris HS, Singh P, Kohen A, Tivanski AV. Rigid Double-Stranded DNA Linkers for Single Molecule Enzyme-Drug Interaction Measurements Using Molecular Recognition Force Spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4174-4183. [PMID: 32233509 DOI: 10.1021/acs.langmuir.9b03495] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Single-molecule studies can reveal the distribution of states and interactions between ligand-enzyme complexes not accessible for most studies that measure a large ensemble average response of many molecules. Furthermore, in some biological applications, the information regarding the outliers, not the average of measured properties, can be more important. The high spatial and force resolution provided by atomic force microscopy (AFM) under physiological conditions has been utilized in this study to quantify the force-distance relations of enzyme-drug interactions. Different immobilization techniques of the protein to a surface and the drug to AFM tip were quantitatively compared to improve the accuracy and precision of the measurement. Protein that is directly bound to the surface, forming a monolayer, was compared to enzyme molecules bound to the surface with rigid double-stranded (ds) DNA spacers. These surfaces immobilization techniques were studied with the drug bound directly to the AFM tip and drug bound via flexible poly(ethylene glycol) and rigid dsDNA linkers. The activity of the enzyme was found to be not significantly altered by immobilization methods relative to its activity in solution. The findings indicate that the approach for studying drug-enzyme interaction based on rigid dsDNA linker on the surface and either flexible or rigid linker on the tip affords straightforward, highly specific, reproducible, and accurate force measurements with a potential for single-molecule level studies. The method could facilitate in-depth examination of a broad spectrum of biological targets and potential drugs.
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Affiliation(s)
| | - Holly S Morris
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Priyanka Singh
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Amnon Kohen
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Alexei V Tivanski
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
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47
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Abstract
The complex of the small molecule biotin and the homotetrameric protein streptavidin is key to a broad range of biotechnological applications. Therefore, the behavior of this extraordinarily high-affinity interaction under mechanical force is intensively studied by single-molecule force spectroscopy. Recently, steered molecular dynamics simulations have identified a low force pathway for the dissociation of biotin from streptavidin, which involves partial unfolding of the N-terminal β-sheet structure of monovalent streptavidin's functional subunit. Based on these results, we now introduced two mutations (T18C,A33C) in the functional subunit of monovalent streptavidin to establish a switchable connection (disulfide bridge) between the first two β-strands to prevent this unfolding. In atomic force microscopy-based single-molecule force spectroscopy experiments, we observed unbinding forces of about 350 pN (at a force-loading rate of 10 nN s-1) for pulling a single biotin out of an N-terminally anchored monovalent streptavidin binding pocket - about 1.5-fold higher compared with what has been reported for N-terminal force loading of native monovalent streptavidin. Upon addition of a reducing agent, the unbinding forces dropped back to 200 pN, as the disulfide bridge was destroyed. Switching from reducing to oxidizing buffer conditions, the inverse effect was observed. Our work illustrates how the mechanics of a receptor-ligand system can be tuned by engineering the receptor protein far off the ligand-binding pocket.
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Affiliation(s)
- Leonard C Schendel
- Lehrstuhl für Angewandte Physik and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany.
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48
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Sedlak SM, Schendel LC, Gaub HE, Bernardi RC. Streptavidin/biotin: Tethering geometry defines unbinding mechanics. SCIENCE ADVANCES 2020; 6:eaay5999. [PMID: 32232150 PMCID: PMC7096159 DOI: 10.1126/sciadv.aay5999] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/03/2020] [Indexed: 05/26/2023]
Abstract
Macromolecules tend to respond to applied forces in many different ways. Chemistry at high shear forces can be intriguing, with relatively soft bonds becoming very stiff in specific force-loading geometries. Largely used in bionanotechnology, an important case is the streptavidin (SA)/biotin interaction. Although SA's four subunits have the same affinity, we find that the forces required to break the SA/biotin bond depend strongly on the attachment geometry. With AFM-based single-molecule force spectroscopy (SMFS), we measured unbinding forces of biotin from different SA subunits to range from 100 to more than 400 pN. Using a wide-sampling approach, we carried out hundreds of all-atom steered molecular dynamics (SMD) simulations for the entire system, including molecular linkers. Our strategy revealed the molecular mechanism that causes a fourfold difference in mechanical stability: Certain force-loading geometries induce conformational changes in SA's binding pocket lowering the energy barrier, which biotin has to overcome to escape the pocket.
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Affiliation(s)
- Steffen M. Sedlak
- Lehrstuhl für Angewandte Physik and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
| | - Leonard C. Schendel
- Lehrstuhl für Angewandte Physik and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
| | - Hermann E. Gaub
- Lehrstuhl für Angewandte Physik and Center for NanoScience, Ludwig-Maximilians-Universität München, Amalienstr. 54, 80799 Munich, Germany
| | - Rafael C. Bernardi
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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49
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Dahal N, Nowitzke J, Eis A, Popa I. Binding-Induced Stabilization Measured on the Same Molecular Protein Substrate Using Single-Molecule Magnetic Tweezers and Heterocovalent Attachments. J Phys Chem B 2020; 124:3283-3290. [DOI: 10.1021/acs.jpcb.0c00167] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Narayan Dahal
- Department of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, Wisconsin 53211, United States
| | - Joel Nowitzke
- Department of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, Wisconsin 53211, United States
| | - Annie Eis
- Department of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, Wisconsin 53211, United States
| | - Ionel Popa
- Department of Physics, University of Wisconsin-Milwaukee, 3135 North Maryland Avenue, Milwaukee, Wisconsin 53211, United States
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50
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Extreme mechanical stability in protein complexes. Curr Opin Struct Biol 2020; 60:124-130. [DOI: 10.1016/j.sbi.2019.11.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 11/14/2019] [Accepted: 11/27/2019] [Indexed: 12/21/2022]
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