1
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Khare E, Grewal DS, Buehler MJ. Bond clusters control rupture force limit in shear loaded histidine-Ni 2+ metal-coordinated proteins. NANOSCALE 2023; 15:8578-8588. [PMID: 37092811 DOI: 10.1039/d3nr01287e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Dynamic noncovalent interactions are pivotal to the structure and function of biological proteins and have been used in bioinspired materials for similar roles. Metal-coordination bonds, in particular, are especially tunable and enable control over static and dynamic properties when incorporated into synthetic materials. Despite growing efforts to engineer metal-coordination bonds to produce strong, tough, and self-healing materials, the systematic characterization of the exact contribution of these bonds towards mechanical strength and the effect of geometric arrangements is missing, limiting the full design potential of these bonds. In this work, we engineer the cooperative rupture of metal-coordination bonds to increase the rupture strength of metal-coordinated peptide dimers. Utilizing all-atom steered molecular dynamics simulations on idealized bidentate histidine-Ni2+ coordinated peptides, we show that histidine-Ni2+ bonds can rupture cooperatively in groups of two to three bonds. We find that there is a strength limit, where adding additional coordination bonds does not contribute to the additional increase in the protein rupture strength, likely due to the highly heterogeneous rupture behavior exhibited by the coordination bonds. Further, we show that this coordination bond limit is also found natural metal-coordinated biological proteins. Using these insights, we quantitatively suggest how other proteins can be rationally designed with dynamic noncovalent interactions to exhibit cooperative bond breaking behavior. Altogether, this work provides a quantitative analysis of the cooperativity and intrinsic strength limit for metal-coordination bonds with the aim of advancing clear guiding molecular principles for the mechanical design of metal-coordinated materials.
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Affiliation(s)
- Eesha Khare
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, 33 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - Darshdeep S Grewal
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, 33 Massachusetts Avenue, Cambridge, MA 02139, USA.
| | - Markus J Buehler
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, 33 Massachusetts Avenue, Cambridge, MA 02139, USA.
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2
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Collagen-like Motifs of SasG: A Novel Fold for Protein Mechanical Strength. J Mol Biol 2023; 435:167980. [PMID: 36708761 DOI: 10.1016/j.jmb.2023.167980] [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: 10/18/2022] [Revised: 01/11/2023] [Accepted: 01/19/2023] [Indexed: 01/26/2023]
Abstract
The Staphylococcus aureus surface protein G (SasG) is associated with host colonisation and biofilm formation. As colonisation occurs at the liquid-substrate interface bacteria are subject to a myriad of external forces and, presumably as a consequence, SasG displays extreme mechanical strength. This mechanical phenotype arises from the B-domain; a repetitive region composed of alternating E and G5 subdomains. These subdomains have an unusual structure comprising collagen-like regions capped by triple-stranded β-sheets. To identify the determinants of SasG mechanical strength, we characterised the mechanical phenotype and thermodynamic stability of 18 single substitution variants of a pseudo-wildtype protein. Visualising the mechanically-induced transition state at a residue-level by ϕ-value analysis reveals that the main force-bearing regions are the N- and C-terminal 'Mechanical Clamps' and their side-chain interactions. This is tailored by contacts at the pseudo-hydrophobic core interface. We also describe a novel mechanical motif - the collagen-like region and show that glycine to alanine substitutions, analogous to those found in Osteogenesis Imperfecta (brittle bone disease), result in a significantly reduced mechanical strength.
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3
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Wang Z, Wang M, Zhao Z, Zheng P. Quantification of carboxylate-bridged di-zinc site stability in protein due ferri by single-molecule force spectroscopy. Protein Sci 2023; 32:e4583. [PMID: 36718829 PMCID: PMC9926469 DOI: 10.1002/pro.4583] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/16/2023] [Accepted: 01/27/2023] [Indexed: 02/01/2023]
Abstract
Carboxylate-bridged diiron proteins belong to a protein family involved in different physiological processes. These proteins share the conservative EXXH motif, which provides the carboxylate bridge and is critical for metal binding. Here, we choose de novo-designed single-chain due ferri protein (DFsc), a four-helical protein with two EXXH motifs as a model protein, to study the stability of the carboxylate-bridged di-metal binding site. The mechanical and kinetic properties of the di-Zn site in DFsc were obtained by atomic force microscopy-based single-molecule force spectroscopy. Zn-DFsc showed a considerable rupture force of ~200 pN, while the apo-protein is mechanically labile. In addition, multiple rupture pathways were observed with different probabilities, indicating the importance of the EXXH-based carboxylate-bridged metal site. These results demonstrate carboxylate-bridged di-metal site is mechanically stable and improve our understanding of this important type of metalloprotein.
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Affiliation(s)
- Zhiyi Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical EngineeringNanjing UniversityNanjingPeople's Republic of China
| | - Mengdie Wang
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical EngineeringNanjing UniversityNanjingPeople's Republic of China
| | - Zhongxin Zhao
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical EngineeringNanjing UniversityNanjingPeople's Republic of China
| | - Peng Zheng
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical EngineeringNanjing UniversityNanjingPeople's Republic of China
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4
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Cheirdaris D, Krokidis MG, Kasti M, Vrahatis AG, Exarchos T, Vlamos P. Setting Up a Bio-AFM to Study Protein Misfolding in Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1423:1-10. [PMID: 37525028 DOI: 10.1007/978-3-031-31978-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
The clinical pathology of neurodegenerative diseases suggests that earlier onset and progression are related to the accumulation of protein aggregates due to misfolding. A prominent way to extract useful information regarding single-molecule studies of protein misfolding at the nanoscale is by capturing the unbinding molecular forces through forced mechanical tension generated and monitored by an atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS). This AFM-driven process results in an amount of data in the form of force versus molecular extension plots (force-distance curves), the statistical analysis of which can provide insights into the underlying energy landscape and assess a number of characteristic elastic and kinetic molecular parameters of the investigated sample. This chapter outlines the setup of a bio-AFM-based SMFS technique for single-molecule probing. The infrastructure used as a reference for this presentation is the Bruker ForceRobot300.
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Affiliation(s)
- Dionysios Cheirdaris
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
| | - Marios G Krokidis
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
| | - Marianne Kasti
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
| | - Aristidis G Vrahatis
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
| | - Themistoklis Exarchos
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
| | - Panagiotis Vlamos
- Bioinformatics and Human Electrophysiology Laboratory, Department of Informatics, Ionian University, Corfu, Greece
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5
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Fernández-Ramírez MDC, Ng KKS, Menéndez M, Laurents DV, Hervás R, Carrión-Vázquez M. Expanded Conformations of Monomeric Tau Initiate Its Amyloidogenesis. Angew Chem Int Ed Engl 2022; 62:e202209252. [PMID: 36542681 DOI: 10.1002/anie.202209252] [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: 06/26/2022] [Revised: 11/30/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
Understanding early amyloidogenesis is key to rationally develop therapeutic strategies. Tau protein forms well-characterized pathological deposits but its aggregation mechanism is still poorly understood. Using single-molecule force spectroscopy based on a mechanical protection strategy, we studied the conformational landscape of the monomeric tau repeat domain (tau-RD244-368 ). We found two sets of conformational states, whose frequency is influenced by mutations and the chemical context. While pathological mutations Δ280K and P301L and a pro-amyloidogenic milieu favored expanded conformations and destabilized local structures, an anti-amyloidogenic environment promoted a compact ensemble, including a conformer whose topology might mask two amyloidogenic segments. Our results reveal that to initiate aggregation, monomeric tau-RD244-368 decreases its polymorphism adopting expanded conformations. This could account for the distinct structures found in vitro and across tauopathies.
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Affiliation(s)
- María Del Carmen Fernández-Ramírez
- Instituto Cajal, IC-CSIC, Avda. Doctor Arce 37, 28002, Madrid, Spain.,Current address: Center for Alzheimer's and Neurodegenerative Diseases, Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kevin Kan-Shing Ng
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.,School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Margarita Menéndez
- Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, 28006, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Respiratorias (CIBERES), Spain
| | - Douglas V Laurents
- Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, 28006, Madrid, Spain
| | - Rubén Hervás
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.,School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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6
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Liang X, Shiomi K, Nakajima K. Study of the Dynamic Viscoelasticity of Single Poly( N-isopropylacrylamide) Chains Using Atomic Force Microscopy. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Xiaobin Liang
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo152-8552, Japan
| | - Kohei Shiomi
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo152-8552, Japan
| | - Ken Nakajima
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo152-8552, Japan
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7
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Goult BT, von Essen M, Hytönen VP. The mechanical cell - the role of force dependencies in synchronising protein interaction networks. J Cell Sci 2022; 135:283155. [PMID: 36398718 PMCID: PMC9845749 DOI: 10.1242/jcs.259769] [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] [Indexed: 11/19/2022] Open
Abstract
The role of mechanical signals in the proper functioning of organisms is increasingly recognised, and every cell senses physical forces and responds to them. These forces are generated both from outside the cell or via the sophisticated force-generation machinery of the cell, the cytoskeleton. All regions of the cell are connected via mechanical linkages, enabling the whole cell to function as a mechanical system. In this Review, we define some of the key concepts of how this machinery functions, highlighting the critical requirement for mechanosensory proteins, and conceptualise the coupling of mechanical linkages to mechanochemical switches that enables forces to be converted into biological signals. These mechanical couplings provide a mechanism for how mechanical crosstalk might coordinate the entire cell, its neighbours, extending into whole collections of cells, in tissues and in organs, and ultimately in the coordination and operation of entire organisms. Consequently, many diseases manifest through defects in this machinery, which we map onto schematics of the mechanical linkages within a cell. This mapping approach paves the way for the identification of additional linkages between mechanosignalling pathways and so might identify treatments for diseases, where mechanical connections are affected by mutations or where individual force-regulated components are defective.
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Affiliation(s)
- Benjamin T. Goult
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, Kent, UK,Authors for correspondence (; )
| | - Magdaléna von Essen
- Faculty of Medicine and Health Technology, Tampere University, FI-33100 Tampere, Finland
| | - Vesa P. Hytönen
- Faculty of Medicine and Health Technology, Tampere University, FI-33100 Tampere, Finland,Fimlab Laboratories, FI-33520 Tampere, Finland,Authors for correspondence (; )
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8
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Lei H, Zhang J, Li Y, Wang X, Qin M, Wang W, Cao Y. Histidine-Specific Bioconjugation for Single-Molecule Force Spectroscopy. ACS NANO 2022; 16:15440-15449. [PMID: 35980082 DOI: 10.1021/acsnano.2c07298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Atomic force microscopy (AFM) based single-molecule force spectroscopy (SMFS) is a powerful tool to study the mechanical properties of proteins. In these experiments, site-specific immobilization of proteins is critical, as the tether determines the direction and amplitude of forces applied to the protein of interest. However, existing methods are mainly based on thiol chemistry or specific protein tags, which cannot meet the need of many challenging experiments. Here, we developed a histidine-specific phosphorylation strategy to covalently anchor proteins to an AFM cantilever tip or the substrate via their histidine tag or surface-exposed histidine residues. The formed covalent linkage was mechanically stable with rupture forces of over 1.3 nN. This protein immobilization method considerably improved the pickup rate and data quality of SMFS experiments. We further demonstrated the use of this method to explore the pulling-direction-dependent mechanical stability of green fluorescent protein and the unfolding of the membrane protein archaerhodopsin-3.
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Affiliation(s)
- Hai Lei
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University 163 Xianlin Road, Nanjing 210023, People's Republic of China
| | - Junsheng Zhang
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
| | - Ying Li
- Institute of Advanced Materials and Flexible Electronics (IAMFE), School of Chemistry and Materials Science, Nanjing University of Information Science & Technology 219 Ningliu Road, Nanjing, 210044, People's Republic of China
| | - Xin Wang
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
| | - Meng Qin
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
| | - Wei Wang
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
| | - Yi Cao
- Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructure, Department of Physics, Nanjing University 22 Hankou Road, Nanjing 210093, People's Republic of China
- Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University 163 Xianlin Road, Nanjing 210023, People's Republic of China
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, People's Republic of China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan 250021, People's Republic of China
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9
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Nandi T, Ainavarapu SRK. Native Salt Bridges Are a Key Regulator of Ubiquitin's Mechanical Stability. J Phys Chem B 2022; 126:3505-3511. [PMID: 35535497 DOI: 10.1021/acs.jpcb.2c00972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although it is known that various intramolecular interactions determine protein mechanical stability, a detailed molecular-level understanding of the key regulators of protein mechanical stability is still lacking. Here, we present evidence for salt bridges in ubiquitin as important intramolecular interactions that can affect protein mechanical stability. Ubiquitin has two salt bridges: one relatively surface-exposed (SB1:K11-E34) and the other relatively buried (SB2:K27-D52). Ubiquitin is a reversible post-translational modifier and is stable mechanically (Favgu = 185 pN). On breaking SB1, the mechanical stability of ubiquitin is slightly enhanced (Favgu = 193 pN). In contrast, the mechanical stability significantly decreased upon breaking SB2 (Favgu = 158 pN). These results suggest that SB1 are SB2 are regulators of the mechanical stability of ubiquitin. Interestingly, the mechanical stability decreased further (Favgu = 145 pN) for the double salt bridge (DB) null variant. Monte Carlo simulations elucidate that the main regulating factor is the spontaneous unfolding rate constant (ku0), being the highest for the DB null variant followed by the SB2 null variant, and it remains unaltered for the SB1 null variant, while the native-to-transition-state distance (xu) remains unchanged. Our study provides mechanistic understanding on how two native salt bridges can independently regulate the mechanical stability in a protein, which has implications in designing protein-based robust biomaterials in the future.
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Affiliation(s)
- Tathagata Nandi
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Sri Rama Koti Ainavarapu
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
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10
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Gil-Redondo JC, Weber A, Toca-Herrera JL. Measuring (biological) materials mechanics with atomic force microscopy. 3. Mechanical unfolding of biopolymers. Microsc Res Tech 2022; 85:3025-3036. [PMID: 35502131 PMCID: PMC9543778 DOI: 10.1002/jemt.24136] [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: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 11/28/2022]
Abstract
Biopolymers, such as polynucleotides, polypeptides and polysaccharides, are macromolecules that direct most of the functions in living beings. Studying the mechanical unfolding of biopolymers provides important information about their molecular elasticity and mechanical stability, as well as their energy landscape, which is especially important in proteins, since their three‐dimensional structure is essential for their correct activity. In this primer, we present how to study the mechanical properties of proteins with atomic force microscopy and how to obtain information about their stability and energetic landscape. In particular, we discuss the preparation of polyprotein constructs suitable for AFM single molecule force spectroscopy (SMFS), describe the parameters used in our force‐extension SMFS experiments and the models and equations employed in the analysis of the data. As a practical example, we show the effect of the temperature on the unfolding force, the distance to the transition state, the unfolding rate at zero force, the height of the transition state barrier, and the spring constant of the protein for a construct containing nine repeats of the I27 domain from the muscle protein titin.
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Affiliation(s)
- Juan Carlos Gil-Redondo
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - Andreas Weber
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
| | - José L Toca-Herrera
- Institute of Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna (BOKU), Vienna, Austria
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11
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Ferenczy GG, Kellermayer M. Contribution of Hydrophobic Interactions to Protein Mechanical Stability. Comput Struct Biotechnol J 2022; 20:1946-1956. [PMID: 35521554 PMCID: PMC9062142 DOI: 10.1016/j.csbj.2022.04.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 04/07/2022] [Accepted: 04/17/2022] [Indexed: 11/26/2022] Open
Abstract
The role of hydrophobic and polar interactions in providing thermodynamic stability to folded proteins has been intensively studied, but the relative contribution of these interactions to the mechanical stability is less explored. We used steered molecular dynamics simulations with constant-velocity pulling to generate force-extension curves of selected protein domains and monitor hydrophobic surface unravelling upon extension. Hydrophobic contribution was found to vary between one fifth and one third of the total force while the rest of the contribution is attributed primarily to hydrogen bonds. Moreover, hydrophobic force peaks were shifted towards larger protein extensions with respect to the force peaks attributed to hydrogen bonds. The higher importance of hydrogen bonds compared to hydrophobic interactions in providing mechanical resistance is in contrast with the relative importance of the hydrophobic interactions in providing thermodynamic stability of proteins. The different contributions of these interactions to the mechanical stability are explained by the steeper free energy dependence of hydrogen bonds compared to hydrophobic interactions on the relative positions of interacting atoms. Comparative analyses for several protein domains revealed that the variation of hydrophobic forces is modest, while the contribution of hydrogen bonds to the force peaks becomes increasingly important for mechanically resistant protein domains.
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12
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Neel BL, Nisler CR, Walujkar S, Araya-Secchi R, Sotomayor M. Elastic versus brittle mechanical responses predicted for dimeric cadherin complexes. Biophys J 2022; 121:1013-1028. [PMID: 35151631 PMCID: PMC8943749 DOI: 10.1016/j.bpj.2022.02.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/02/2022] [Accepted: 02/07/2022] [Indexed: 12/15/2022] Open
Abstract
Cadherins are a superfamily of adhesion proteins involved in a variety of biological processes that include the formation of intercellular contacts, the maintenance of tissue integrity, and the development of neuronal circuits. These transmembrane proteins are characterized by ectodomains composed of a variable number of extracellular cadherin (EC) repeats that are similar but not identical in sequence and fold. E-cadherin, along with desmoglein and desmocollin proteins, are three classical-type cadherins that have slightly curved ectodomains and engage in homophilic and heterophilic interactions through an exchange of conserved tryptophan residues in their N-terminal EC1 repeat. In contrast, clustered protocadherins are straighter than classical cadherins and interact through an antiparallel homophilic binding interface that involves overlapped EC1 to EC4 repeats. Here we present molecular dynamics simulations that model the adhesive domains of these cadherins using available crystal structures, with systems encompassing up to 2.8 million atoms. Simulations of complete classical cadherin ectodomain dimers predict a two-phased elastic response to force in which these complexes first softly unbend and then stiffen to unbind without unfolding. Simulated α, β, and γ clustered protocadherin homodimers lack a two-phased elastic response, are brittle and stiffer than classical cadherins and exhibit complex unbinding pathways that in some cases involve transient intermediates. We propose that these distinct mechanical responses are important for function, with classical cadherin ectodomains acting as molecular shock absorbers and with stiffer clustered protocadherin ectodomains facilitating overlap that favors binding specificity over mechanical resilience. Overall, our simulations provide insights into the molecular mechanics of single cadherin dimers relevant in the formation of cellular junctions essential for tissue function.
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Affiliation(s)
- Brandon L Neel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Collin R Nisler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago, Chile
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio.
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13
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Nandi T, Koti Ainavarapu SR. Reconstruction of the Free Energy Profile for SUMO1 from Nonequilibrium Single-Molecule Pulling Experiments. J Phys Chem B 2022; 126:2168-2172. [PMID: 35271281 DOI: 10.1021/acs.jpcb.1c08596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Free energy profiles form the cornerstone in the study of protein folding and function. In this study, the free energy profile of SUMO1 protein is directly reconstructed using an extension of the Jarzynski equality from atomic force microscope (AFM) based single-molecule force spectroscopy (SMFS) experiments. SUMO1 is a ubiquitin-like posttranslational modifier protein having a β clamp motif in its structure, imparting it with mechanical stability. We use the Jarzynski equality to obtain the equilibrium free energy profile from repeated nonequilibrium single-molecule pulling experiments. Indeed, the free energy values determined by the Jarzynski equality are lesser than the normal work average at all extensions. The free energy profiles constructed for the two velocities (100 and 400 nm/s) overlap with each other. The unfolding free energy barrier is estimated to be ∼7.5 kcal/mol. We anticipate that the Jarzynski equality can be applied in a similar manner to other ubiquitin-like proteins to extract their differences in the free energy profile, and hence, the effect of sequence diversity of structurally homologous proteins on the free energy landscape can be studied.
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Affiliation(s)
- Tathagata Nandi
- Department of Chemical Sciences, Tata Institute of Fundamental Research Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
| | - Sri Rama Koti Ainavarapu
- Department of Chemical Sciences, Tata Institute of Fundamental Research Dr. Homi Bhabha Road, Colaba, Mumbai 400005, India
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14
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Wang H, Zhou F, Guo Y, Ju LA. Micropipette-based biomechanical nanotools on living cells. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2022; 51:119-133. [PMID: 35171346 PMCID: PMC8964576 DOI: 10.1007/s00249-021-01587-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 08/30/2021] [Accepted: 12/13/2021] [Indexed: 12/14/2022]
Abstract
Mechanobiology is an emerging field at the interface of biology and mechanics, investigating the roles of mechanical forces within biomolecules, organelles, cells, and tissues. As a highlight, the recent advances of micropipette-based aspiration assays and dynamic force spectroscopies such as biomembrane force probe (BFP) provide unprecedented mechanobiological insights with excellent live-cell compatibility. In their classic applications, these assays measure force-dependent ligand-receptor-binding kinetics, protein conformational changes, and cellular mechanical properties such as cortical tension and stiffness. In recent years, when combined with advanced microscopies in high spatial and temporal resolutions, these biomechanical nanotools enable characterization of receptor-mediated cell mechanosensing and subsequent organelle behaviors at single-cellular and molecular level. In this review, we summarize the latest developments of these assays for live-cell mechanobiology studies. We also provide perspectives on their future upgrades with multimodal integration and high-throughput capability.
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Affiliation(s)
- Haoqing Wang
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia.,Heart Research Institute, Newtown, NSW, Australia
| | - Fang Zhou
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW, Australia
| | - Yuze Guo
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW, Australia
| | - Lining Arnold Ju
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Darlington, NSW, Australia. .,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia. .,Heart Research Institute, Newtown, NSW, Australia.
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15
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Kaur V, Garg S, Rakshit S. Instantaneous splicing and excision of inteins to synthesize polyproteins on a substrate with tunable linkers. SOFT MATTER 2022; 18:602-608. [PMID: 34928293 DOI: 10.1039/d1sm01469b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nature has adapted chimeric polyproteins to achieve superior and multiplexed functionality in a single protein. However, the hurdles in in vitro synthesis have restricted the biomimicry of and subsequent fundamental studies on the structure-function relationship of polyproteins. Recombinant expression of polyproteins and the synthesis of polyproteins via the enzyme-mediated repetitive digestion and ligation of individual protein domains have been widely practiced. However, recombinant expression often suffers from an in vitro refolding process, whereas enzyme-assisted peptide conjugation results in heterogeneous products, primarily due to enzymatic re-digestion, and prolonged and multistep reactions. Moreover, both methods incorporate enzyme-recognition residues of varying lengths as artifacts at interdomain linkers. The linkers, although tiny, regulate the spatiotemporal conformations of the polyproteins differentially and tune the folding dynamics, stability, and functions of the constituent protein. In an attempt to leave no string behind at the interdomain junctions, here, we develop a 'splice and excise' synthetic route for polyproteins on a substrate using two orthogonal split inteins. Inteins self-excise and conjugate the protein units covalently and instantaneously, without any cofactors, and incorporate a single cysteine or serine residue at the interdomain junctions.
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Affiliation(s)
- Veerpal Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, 140306, Punjab, India.
| | - Surbhi Garg
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, 140306, Punjab, India.
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, 140306, Punjab, India.
- Centre for Protein Science Design and Engineering, Indian Institute of Science Education and Research Mohali, 140306, Punjab, India
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16
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Schönfelder J, Alonso-Caballero A, Perez-Jimenez R. Mechanochemical Evolution of Disulfide Bonds in Proteins. Methods Mol Biol 2022; 2376:283-300. [PMID: 34845615 DOI: 10.1007/978-1-0716-1716-8_15] [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: 06/13/2023]
Abstract
Disulfide bonds play a pivotal role in the mechanical stability of proteins. Numerous proteins that are known to be exposed to mechanical forces in vivo contain disulfide bonds. The presence of cryptic disulfide bonds in a protein structure may be related to its resistance to an applied mechanical force. Disulfide bonds in proteins tend to be highly conserved but their evolution might be directly related to the evolution of the protein mechanical stability. Hence, tracking the evolution of disulfide bonds in a protein can help to derive crucial stability/function correlations in proteins that are exposed to mechanical forces. Phylogenic analysis and ancestral sequence reconstruction (ASR) allow tracking the evolution of proteins from the past ancestors to our modern days and also establish correlations between proteins from different species. In addition, ASR can be combined with single-molecule force spectroscopy (smFS) to investigate the mechanical properties of proteins including the occurrence and function of disulfide bonds. Here we present a detailed protocol to study the mechanochemical evolution of proteins using a fragment of the giant muscle protein titin as example. The protocol can be easily adapted to AFS studies of any resurrected mechanical force bearing protein of interest.
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Affiliation(s)
- Jörg Schönfelder
- CIC nanoGUNE, San Sebastián, Spain
- IMDEA Nanosciences, Madrid, Spain
| | | | - Raul Perez-Jimenez
- CIC nanoGUNE, San Sebastián, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.
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17
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Besleaga A, Apetrei A, Sirghi L. Atomic force spectroscopy with magainin 1 functionalized tips and biomimetic supported lipid membranes. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2022; 51:29-40. [PMID: 35031815 DOI: 10.1007/s00249-021-01580-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 08/11/2021] [Accepted: 12/04/2021] [Indexed: 06/14/2023]
Abstract
Antimicrobial peptides are molecules synthesized by living organisms as the first line of defense against bacteria, fungi, parasites, or viruses. Since their biological activity is based on destabilization of the microbial membranes, a study of direct interaction forces between antimicrobial peptides and biomimetic membranes is very important for understanding the molecular mechanisms of their action. Herein, we use atomic force spectroscopy to probe the interaction between atomic force microscopy (AFM) tips functionalized with magainin 1 and supported lipid bilayers (SLBs) mimicking electrically uncharged membranes of normal eukaryotic cells and negatively charged membranes of bacterial cells. The investigations performed on negatively charged SLBs showed that the magainin 1 functionalized AFM tips are quickly adsorbed into the SLBs when they approach, while they adhere strongly to the lipid membrane when retracted. On contrary, same investigations performed on neutral SLBs showed mechanical resistance of the lipid membrane to the tip breakthrough and negligible adhesion force at detachment.
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Affiliation(s)
- Alexandra Besleaga
- Iasi Plasma Advanced Research Center (IPARC), Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Blvd. Carol I nr. 11, 700506, Iasi, Romania
| | - Aurelia Apetrei
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, 700506, Iasi, Romania
| | - Lucel Sirghi
- Iasi Plasma Advanced Research Center (IPARC), Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Blvd. Carol I nr. 11, 700506, Iasi, Romania.
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18
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Pandey S, Xiang Y, Friedrich D, Leng Y, Mao H. Direct Measurement of Intermolecular Mechanical Force for Nonspecific Interactions between Small Molecules. J Phys Chem Lett 2021; 12:11316-11322. [PMID: 34780182 PMCID: PMC8778946 DOI: 10.1021/acs.jpclett.1c03142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mechanical force can evaluate intramolecular interactions in macromolecules. Because of the rapid motion of small molecules, it is extremely challenging to measure mechanical forces of nonspecific intermolecular interactions. Here, we used optical tweezers to directly examine the intermolecular mechanical force (IMMF) of nonspecific interactions between two cholesterols. We found that IMMFs of dimeric cholesterol complexes were dependent on the orientation of the interaction. The surprisingly high IMMF in cholesterol dimers (∼30 pN) is comparable to the mechanical stability of DNA secondary structures. Using Hess-like cycles, we quantified that changes in free energy of solubilizing cholesterol (ΔGsolubility) by β-cyclodextrin (βCD) and methylated βCD (Me-βCD) were as low as -16 and -27 kcal/mol, respectively. Compared to the ΔGsolubility of cholesterols in water (5.1 kcal/mol), these values indicated that cyclodextrins can easily solubilize cholesterols. Our results demonstrated that the IMMF can serve as a generic and multipurpose variable to dissect nonspecific intermolecular interactions among small molecules into orientational components.
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Affiliation(s)
- Shankar Pandey
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Yuan Xiang
- Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
| | - Dirk Friedrich
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Yongsheng Leng
- Department of Mechanical and Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
| | - Hanbin Mao
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
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19
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Mothi N, Muñoz V. Protein Folding Dynamics as Diffusion on a Free Energy Surface: Rate Equation Terms, Transition Paths, and Analysis of Single-Molecule Photon Trajectories. J Phys Chem B 2021; 125:12413-12425. [PMID: 34735144 DOI: 10.1021/acs.jpcb.1c05401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rates of protein (un)folding are often described as diffusion on the projection of a hyperdimensional energy landscape onto a few (ideally one) order parameters. Testing such an approximation by experiment requires resolving the reactive transition paths of individual molecules, which is now becoming feasible with advanced single-molecule spectroscopic techniques. This has also sparked the interest of theorists in better understanding reactive transition paths. Here we focus on these issues aiming to establish (i) practical guidelines for the mechanistic interpretation of transition path times (TPT) and (ii) methods to extract the free energy surface and protein dynamics from the maximum likelihood analysis of photon trajectories (MLA-PT). We represent the (un)folding rates as diffusion on a 1D free energy surface with the FRET efficiency as a reaction coordinate proxy. We then perform diffusive kinetic simulations on surfaces with two minima and a barrier, but with different shapes (curvatures, barrier height, and symmetry), coupled to stochastic simulations of photon emissions that reproduce current SM-FRET experiments. From the analysis of transition paths, we find that the TPT is inversely proportional to the barrier height (difference in free energy between minimum and barrier top) for any given surface shape, and that dividing the TPT into climb and descent segments provides key information about the barrier's symmetry. We also find that the original MLA-PT procedure used to determine the TPT from experiments underestimates its value, particularly for the cases with smaller barriers (e.g., fast folders), and we suggest a simple strategy to correct for this bias. Importantly, we also demonstrate that photon trajectories contain enough information to extract the 1D free energy surface's shape and dynamics (if TPT is >4-5-fold longer than the interphoton time) using the MLA-PT directly implemented with a diffusive free energy surface model. When dealing with real (unknown) experimental data, the comparison between the likelihoods of the free energy surface and discrete kinetic three-state models can be used to evaluate the statistical significance of the estimated free energy surface.
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Affiliation(s)
- Nivin Mothi
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California, Merced, 95343 California, United States.,Chemistry and Chemical Biology Graduate Program, University of California, Merced, 95343 California, United States
| | - Victor Muñoz
- NSF-CREST Center for Cellular and Biomolecular Machines (CCBM), University of California, Merced, 95343 California, United States.,Chemistry and Chemical Biology Graduate Program, University of California, Merced, 95343 California, United States.,Department of Bioengineering, University of California, Merced, 95343 California, United States
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20
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Du Q, Wu Y, Tang S, Ren M, Fu Z. Influences of ultrasonic treatment on structure and functional properties of salt‐soluble protein from
Moringa oleifera
seeds. Int J Food Sci Technol 2021. [DOI: 10.1111/ijfs.15254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Qiu‐Han Du
- Institute of Light Industry and Food Engineering Guangxi University Nanning 530004 China
| | - Yan‐Hui Wu
- Institute of Light Industry and Food Engineering Guangxi University Nanning 530004 China
| | - Shi‐Qi Tang
- Institute of Light Industry and Food Engineering Guangxi University Nanning 530004 China
| | - Min‐Hong Ren
- Institute of Light Industry and Food Engineering Guangxi University Nanning 530004 China
| | - Zhen Fu
- Institute of Light Industry and Food Engineering Guangxi University Nanning 530004 China
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21
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Grahame DAS, Dupuis JH, Bryksa BC, Tanaka T, Yada RY. Improving the alkaline stability of pepsin through rational protein design using renin, an alkaline-stable aspartic protease, as a structural and functional reference. Enzyme Microb Technol 2021; 150:109871. [PMID: 34489030 DOI: 10.1016/j.enzmictec.2021.109871] [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: 04/13/2021] [Revised: 06/28/2021] [Accepted: 07/12/2021] [Indexed: 10/20/2022]
Abstract
The present study sought to identify the structural determinants of aspartic protease structural stability and activity at elevated pH. Various hypotheses have been published regarding the features responsible for the unusual alkaline structural stability of renin, however, few structure-function studies have verified these claims. Using pepsin as a model system, and renin as a template for functional and structural alkaline stability, a rational re-design of pepsin was undertaken to identify residues contributing to the alkaline instability of pepsin-like aspartic proteases in regards to both structure and function. We constructed 13 mutants based on this strategy. Among them, mutants D159 L and D60A led to an increase in activity at elevated pH levels (p ≤ 0.05) and E4V and H53F were shown to retain native-like structure at elevated pH (p ≤ 0.05). Previously suggested carboxyl groups Asp11, Asp118, and Glu13 were individually shown not to be responsible for the structural instability or lack of activity at neutral pH in pepsin. The importance of the β-barrel to structural stability was highlighted as the majority of the stabilizing residues identified, and 39% of the weakly conserved residues in the N-terminal lobe, were located in β-sheet strands of the barrel. The results of the present study indicate that alkaline stabilization of pepsin will require reduction of electrostatic repulsions and an improved understanding of the role of the hydrogen bonding network of the characteristic β-barrel.
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Affiliation(s)
- Douglas A S Grahame
- Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - John H Dupuis
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Brian C Bryksa
- Department of Food Science, Ontario Agricultural College, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Takuji Tanaka
- Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada
| | - Rickey Y Yada
- Food, Nutrition, and Health Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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22
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Applications of atomic force microscopy in modern biology. Emerg Top Life Sci 2021; 5:103-111. [PMID: 33600596 DOI: 10.1042/etls20200255] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/25/2020] [Accepted: 01/22/2021] [Indexed: 01/20/2023]
Abstract
Single-molecule force spectroscopy (SMFS) is an emerging tool to investigate mechanical properties of biomolecules and their responses to mechanical forces, and one of the most-used techniques for mechanical manipulation is the atomic force microscope (AFM). AFM was invented as an imaging tool which can be used to image biomolecules in sub-molecular resolution in physiological conditions. It can also be used as a molecular force probe for applying mechanical forces on biomolecules. In this brief review, we will provide exciting examples from recent literature which show how the advances in AFM have enabled us to gain deep insights into mechanical properties and mechanobiology of biomolecules. AFM has been applied to study mechanical properties of cells, tissues, microorganisms, viruses as well as biological macromolecules such as proteins. It has found applications in biomedical fields like cancer biology, where it has been used both in the diagnostic phases as well as drug discovery. AFM has been able to answer questions pertaining to mechanosensing by neurons, and mechanical changes in viruses during infection by the viral particles as well as the fundamental processes such as cell division. Fundamental questions related to protein folding have also been answered by SMFS like determination of energy landscape properties of variety of proteins and their correlation with their biological functions. A multipronged approach is needed to diversify the research, as a combination with optical spectroscopy and computer-based steered molecular dynamic simulations along with SMFS can help us gain further insights into the field of biophysics and modern biology.
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23
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Hervás R, Del Carmen Fernández-Ramírez M, Galera-Prat A, Suzuki M, Nagai Y, Bruix M, Menéndez M, Laurents DV, Carrión-Vázquez M. Divergent CPEB prion-like domains reveal different assembly mechanisms for a generic amyloid-like fold. BMC Biol 2021; 19:43. [PMID: 33706787 PMCID: PMC7953810 DOI: 10.1186/s12915-021-00967-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 01/25/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Amyloids are ordered, insoluble protein aggregates, characterized by a cross-β sheet quaternary structure in which molecules in a β-strand conformation are stacked along the filament axis via intermolecular interactions. While amyloids are typically associated with pathological conditions, functional amyloids have also been identified and are present in a wide variety of organisms ranging from bacteria to humans. The cytoplasmic polyadenylation element-binding (CPEB) prion-like protein is an mRNA-binding translation regulator, whose neuronal isoforms undergo activity-dependent aggregation, a process that has emerged as a plausible biochemical substrate for memory maintenance. CPEB aggregation is driven by prion-like domains (PLD) that are divergent in sequence across species, and it remains unknown whether such divergent PLDs follow a similar aggregating assembly pathway. Here, we describe the amyloid-like features of the neuronal Aplysia CPEB (ApCPEB) PLD and compare them to those of the Drosophila ortholog, Orb2 PLD. RESULTS Using in vitro single-molecule and bulk biophysical methods, we find transient oligomers and mature amyloid-like filaments that suggest similarities in the late stages of the assembly pathway for both ApCPEB and Orb2 PLDs. However, while prior to aggregation the Orb2 PLD monomer remains mainly as a random coil in solution, ApCPEB PLD adopts a diversity of conformations comprising α-helical structures that evolve to coiled-coil species, indicating structural differences at the beginning of their amyloid assembly pathways. CONCLUSION Our results indicate that divergent PLDs of CPEB proteins from different species retain the ability to form a generic amyloid-like fold through different assembly mechanisms.
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Affiliation(s)
- Rubén Hervás
- Instituto Cajal, IC-CSIC, Avda. Doctor Arce 37, E-28002, Madrid, Spain. .,Present address: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
| | | | | | - Mari Suzuki
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.,Present address: Diabetic Neuropathy Project, Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, Japan
| | - Yoshitaka Nagai
- Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.,Present address: Department of Neurology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan
| | - Marta Bruix
- Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, E-28006, Madrid, Spain
| | - Margarita Menéndez
- Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, E-28006, Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Respiratorias (CIBERES), C/ Monforte de Lemos 3-5, 28029, Madrid, Spain
| | - Douglas V Laurents
- Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, E-28006, Madrid, Spain
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24
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Ding Y, Apostolidou D, Marszalek P. Mechanical Stability of a Small, Highly-Luminescent Engineered Protein NanoLuc. Int J Mol Sci 2020; 22:E55. [PMID: 33374567 PMCID: PMC7801952 DOI: 10.3390/ijms22010055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 12/19/2020] [Accepted: 12/20/2020] [Indexed: 11/16/2022] Open
Abstract
NanoLuc is a bioluminescent protein recently engineered for applications in molecular imaging and cellular reporter assays. Compared to other bioluminescent proteins used for these applications, like Firefly Luciferase and Renilla Luciferase, it is ~150 times brighter, more thermally stable, and smaller. Yet, no information is known with regards to its mechanical properties, which could introduce a new set of applications for this unique protein, such as a novel biomaterial or as a substrate for protein activity/refolding assays. Here, we generated a synthetic NanoLuc derivative protein that consists of three connected NanoLuc proteins flanked by two human titin I91 domains on each side and present our mechanical studies at the single molecule level by performing Single Molecule Force Spectroscopy (SMFS) measurements. Our results show each NanoLuc repeat in the derivative behaves as a single domain protein, with a single unfolding event occurring on average when approximately 72 pN is applied to the protein. Additionally, we performed cyclic measurements, where the forces applied to a single protein were cyclically raised then lowered to allow the protein the opportunity to refold: we observed the protein was able to refold to its correct structure after mechanical denaturation only 16.9% of the time, while another 26.9% of the time there was evidence of protein misfolding to a potentially non-functional conformation. These results show that NanoLuc is a mechanically moderately weak protein that is unable to robustly refold itself correctly when stretch-denatured, which makes it an attractive model for future protein folding and misfolding studies.
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Affiliation(s)
- Yue Ding
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, USA; (Y.D.); (D.A.)
- Department of Engineering Mechanics, SVL, Xi’an Jiaotong University, Xi’an 710049, China
| | - Dimitra Apostolidou
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, USA; (Y.D.); (D.A.)
| | - Piotr Marszalek
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, USA; (Y.D.); (D.A.)
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25
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Pang X, Tang B. Role of the copper ion in pseudoazurin during the mechanical unfolding process. Int J Biol Macromol 2020; 166:213-220. [PMID: 33172612 DOI: 10.1016/j.ijbiomac.2020.10.149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/19/2020] [Accepted: 10/19/2020] [Indexed: 11/15/2022]
Abstract
Metalloproteins require the corresponding metal cofactors to exert their proper function. The presence of metal cofactors in the metalloprotein makes it more difficult to investigate its folding and unfolding process. In this study, we employed atomic-force-microscopy-based single-molecule force spectroscopy to reveal the unfolding process of pseudoazurin (PAZ) that belongs to blue copper proteins. Our study shows that holo-PAZ requires a higher rupture force for mechanical unfolding comparing with the apo-PAZ. This result demonstrates that the copper atom not only enables PAZ access to transfer electron, but should also have an influence on its stability. The results also suggest that the electronic configuration of the metal cofactors has a striking effect on the strength of the organometallic bonds. Moreover, the results also reveal that there is an intermediate state during the unfolding process of PAZ. This study provides insight into the characteristics of metalloproteins and leads to a better knowledge of their interaction at the individual molecule level.
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Affiliation(s)
- Xiangchao Pang
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China; Hunan Province Key Laboratory of Materials Surface & Interface Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China; Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Bin Tang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, China.
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26
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Campos LA, Sadqi M, Muñoz V. Lessons about Protein Folding and Binding from Archetypal Folds. Acc Chem Res 2020; 53:2180-2188. [PMID: 32914959 DOI: 10.1021/acs.accounts.0c00322] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The function of proteins as biological nanomachines relies on their ability to fold into complex 3D structures, bind selectively to partners, and undergo conformational changes on cue. The native functional structures, and the rates of interconversion between conformational states (folded-unfolded, bound-free), are all encoded in the physical chemistry of their amino acid sequence. However, despite extensive research over decades, this code has proven difficult to fully crack, in terms of both prediction and understanding the molecular mechanisms at play.Earlier work on single-domain proteins reported a commonality of slow rates (10-2-102 s-1) and simple behavior in both kinetic and thermodynamic unfolding experiments, which suggested the process was all-or-none and thereby analogous to a chemical reaction (e.g., A ⇄ B). In the absence of a first-principles pre-exponential factor for protein (un)folding dynamics, the rates could only be interpreted in relative terms, e.g., the changes induced by mutation, and hence, neither the height of nor the entropic contribution to the free energy barriers was known. The rates were also many orders of magnitude too slow for direct atomistic simulations, and the computational focus was on predicting rate changes induced by mutation via coarse grained simulations. However, even the effects of mutation proved to be strikingly homogeneous with all experimental data clustering at ∼1/3 of the free energy perturbation recovered on folding and ∼2/3 on unfolding.The implementation of ultrafast kinetic methods turned the field upside down because they allowed researchers to measure the time scales of elementary (un)folding motions, which set the pre-exponential factor for protein conformational transitions at ∼1 μs. In parallel, we and others set out to investigate the simplest possible protein structures capable of autonomous folding, which we defined as archetypal folds. The rationale was to recapitulate the hierarchical organization of protein structure, starting from the bottom up. The study of fold archetypes ended up opening new research avenues in protein (un)folding, but also making unexpected connections with the folding upon binding of intrinsically disordered proteins and suggesting their functioning as conformational rheostats.This Account describes our work on the kinetic, thermodynamic, mechanistic, and functional analysis of fold archetypes. We first discuss the kinetic studies, emphasizing their impact on our understanding of (un)folding rates, of barrierless (downhill) folding, and as benchmarks for atomistic simulations. We continue with the thermodynamic analysis, introducing the differential scanning calorimetry, multiprobe, and NMR approaches that we developed to dissect their gradual, minimally cooperative (un)folding transitions and to probe the underlying mechanisms with unprecedented detail. The last two sections cover single-molecule analyses and some recent, mostly computational, results on the exploration of possible biological and technological roles for the gradual conformational transitions of fold archetypes.
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Affiliation(s)
- Luis Alberto Campos
- Centro Nacional de Biotecnologı́a (CNB-CSIC), Darwin 3, Campus de Cantoblanco, 28049 Madrid, Spain
- Unidad Asociada de Nanobiotecnologı́a IMDEA Nanociencia-CNB, 28049 Madrid, Spain
| | - Mourad Sadqi
- Department of Bioengineering, University of California, Merced, California 95343, United States
- NSF-CREST Center for Cellular and Biomolecular Machines, University of California, Merced, California 95343, United States
| | - Victor Muñoz
- Department of Bioengineering, University of California, Merced, California 95343, United States
- NSF-CREST Center for Cellular and Biomolecular Machines, University of California, Merced, California 95343, United States
- IMDEA Nanociencia, Ciudad Universitaria Cantoblanco, Faraday 9, 28049 Madrid, Spain
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27
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Baudouin F, Nogueira TL, van der Mijnsbrugge A, Frederix S, Redl A, Morel MH. Mechanochemical activation of gluten network development during dough mixing. J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2020.110035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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28
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Mykuliak VV, Sikora M, Booth JJ, Cieplak M, Shalashilin DV, Hytönen VP. Mechanical Unfolding of Proteins-A Comparative Nonequilibrium Molecular Dynamics Study. Biophys J 2020; 119:939-949. [PMID: 32822586 PMCID: PMC7474207 DOI: 10.1016/j.bpj.2020.07.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 02/02/2023] Open
Abstract
Mechanical signals regulate functions of mechanosensitive proteins by inducing structural changes that are determinant for force-dependent interactions. Talin is a focal adhesion protein that is known to extend under mechanical load, and it has been shown to unfold via intermediate states. Here, we compared different nonequilibrium molecular dynamics (MD) simulations to study unfolding of the talin rod. We combined boxed MD (BXD), steered MD, and umbrella sampling (US) techniques and provide free energy profiles for unfolding of talin rod subdomains. We conducted BXD, steered MD, and US simulations at different detail levels and demonstrate how these different techniques can be used to study protein unfolding under tension. Unfolding free energy profiles determined by BXD suggest that the intermediate states in talin rod subdomains are stabilized by force during unfolding, and US confirmed these results.
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Affiliation(s)
- Vasyl V Mykuliak
- Faculty of Medicine and Health Technology and BioMediTech, Tampere University, Tampere, Finland; Fimlab Laboratories, Tampere, Finland
| | - Mateusz Sikora
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | | | - Marek Cieplak
- Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | | | - Vesa P Hytönen
- Faculty of Medicine and Health Technology and BioMediTech, Tampere University, Tampere, Finland; Fimlab Laboratories, Tampere, Finland.
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29
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Liu Y, Vancso GJ. Polymer single chain imaging, molecular forces, and nanoscale processes by Atomic Force Microscopy: The ultimate proof of the macromolecular hypothesis. Prog Polym Sci 2020. [DOI: 10.1016/j.progpolymsci.2020.101232] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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30
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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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31
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Bureau HR, Quirk S, Hernandez R. The relative stability of trpzip1 and its mutants determined by computation and experiment. RSC Adv 2020; 10:6520-6535. [PMID: 35495997 PMCID: PMC9049704 DOI: 10.1039/d0ra00920b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 02/04/2020] [Indexed: 11/21/2022] Open
Abstract
The single-point mutations of tprzip1 are indicated at left, and their relative energetics are compared at right.
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32
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Mora M, Stannard A, Garcia-Manyes S. The nanomechanics of individual proteins. Chem Soc Rev 2020; 49:6816-6832. [DOI: 10.1039/d0cs00426j] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This tutorial review provides an overview of the single protein force spectroscopy field, including the main techniques and the basic tools for analysing the data obtained from the single molecule experiments.
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Affiliation(s)
- Marc Mora
- Department of Physics and Randall Centre for Cell and Molecular Biophysics
- King's College London
- London
- UK
- The Francis Crick Institute
| | - Andrew Stannard
- Department of Physics and Randall Centre for Cell and Molecular Biophysics
- King's College London
- London
- UK
- The Francis Crick Institute
| | - Sergi Garcia-Manyes
- Department of Physics and Randall Centre for Cell and Molecular Biophysics
- King's College London
- London
- UK
- The Francis Crick Institute
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33
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Qiu W, Patil A, Hu F, Liu XY. Hierarchical Structure of Silk Materials Versus Mechanical Performance and Mesoscopic Engineering Principles. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1903948. [PMID: 31657136 DOI: 10.1002/smll.201903948] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/27/2019] [Indexed: 05/21/2023]
Abstract
A comprehensive review on the five levels of hierarchical structures of silk materials and the correlation with macroscopic properties/performance of the silk materials, that is, the toughness, strain-stiffening, etc., is presented. It follows that the crystalline binding force turns out to be very important in the stabilization of silk materials, while the β-crystallite networks or nanofibrils and the interactions among helical nanofibrils are two of the most essential structural elements, which to a large extent determine the macroscopic performance of various forms of silk materials. In this context, the characteristic structural factors such as the orientation, size, and density of β-crystallites are very crucial. It is revealed that the formation of these structural elements is mainly controlled by the intermolecular nucleation of β-crystallites. Consequently, the rational design and reconstruction of silk materials can be implemented by controlling the molecular nucleation via applying sheering force and seeding (i.e., with carbon nanotubes). In general, the knowledge of the correlation between hierarchical structures and performance provides an understanding of the structural reasons behind the fascinating behaviors of silk materials.
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Affiliation(s)
- Wu Qiu
- Research Institution for Biomimetics and Soft Matter, Fujian Key Provincial Laboratory for Soft Functional Materials Research, College of Physical Science and Technology & College of Materials, Xiamen University, Xiamen, 361005, P. R. China
| | - Aniruddha Patil
- Research Institution for Biomimetics and Soft Matter, Fujian Key Provincial Laboratory for Soft Functional Materials Research, College of Physical Science and Technology & College of Materials, Xiamen University, Xiamen, 361005, P. R. China
| | - Fan Hu
- Research Institution for Biomimetics and Soft Matter, Fujian Key Provincial Laboratory for Soft Functional Materials Research, College of Physical Science and Technology & College of Materials, Xiamen University, Xiamen, 361005, P. R. China
- Advanced Soft Matter Group, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft, 2629 HZ, The Netherlands
| | - Xiang Yang Liu
- Research Institution for Biomimetics and Soft Matter, Fujian Key Provincial Laboratory for Soft Functional Materials Research, College of Physical Science and Technology & College of Materials, Xiamen University, Xiamen, 361005, P. R. China
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
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Xia J, Zuo J, Li H. Single molecule force spectroscopy reveals that the oxidation state of cobalt ions plays an important role in enhancing the mechanical stability of proteins. NANOSCALE 2019; 11:19791-19796. [PMID: 31612899 DOI: 10.1039/c9nr06912g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Engineered bi-histidine (biHis)-based metal chelation is a general and robust method to enhance the mechanical stability of proteins. Here we used single molecule force spectroscopy techniques to investigate the effect of binding of Co2+/Co3+ on the mechanical stability of an engineered biHis mutant of protein GB1, G6-53. We found that the binding of Co2+/Co3+ can lead to an enhancement of the mechanical stability of G6-53, but the degree of enhancement is drastically different. The binding of Co2+ can only lead to marginal enhancement of G6-53's mechanical stability, while Co3+ has a much stronger effect. This large difference is likely due to the large difference in thermodynamic stability and kinetic lability of Co2+ and Co3+ complexes. These results opened up new avenues towards fine tuning the mechanical properties of proteins.
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Affiliation(s)
- Jiahao Xia
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada. and Key Laboratory of Organic Optoelectronic and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing, 10084, P. R. China
| | - Jiacheng Zuo
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
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Gunnoo M, Cazade PA, Orlowski A, Chwastyk M, Liu H, Ta DT, Cieplak M, Nash M, Thompson D. Steered molecular dynamics simulations reveal the role of Ca 2+ in regulating mechanostability of cellulose-binding proteins. Phys Chem Chem Phys 2019; 20:22674-22680. [PMID: 30132772 DOI: 10.1039/c8cp00925b] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The conversion of cellulosic biomass into biofuels requires degradation of the biomass into fermentable sugars. The most efficient natural cellulase system for carrying out this conversion is an extracellular multi-enzymatic complex named the cellulosome. In addition to temperature and pH stability, mechanical stability is important for functioning of cellulosome domains, and experimental techniques such as Single Molecule Force Spectroscopy (SMFS) have been used to measure the mechanical strength of several cellulosomal proteins. Molecular dynamics computer simulations provide complementary atomic-resolution quantitative maps of domain mechanical stability for identification of experimental leads for protein stabilization. In this study, we used multi-scale steered molecular dynamics computer simulations, benchmarked against new SMFS measurements, to measure the intermolecular contacts that confer high mechanical stability to a family 3 Carbohydrate Binding Module protein (CBM3) derived from the archetypal Clostridium thermocellum cellulosome. Our data predicts that electrostatic interactions in the calcium binding pocket modulate the mechanostability of the cellulose-binding module, which provides an additional design rule for the rational re-engineering of designer cellulosomes for biotechnology. Our data offers new molecular insights into the origins of mechanostability in cellulose binding domains and gives leads for synthesis of more robust cellulose-binding protein modules. On the other hand, simulations predict that insertion of a flexible strand can promote alternative unfolding pathways and dramatically reduce the mechanostability of the carbohydrate binding module, which gives routes to rational design of tailormade fingerprint complexes for force spectroscopy experiments.
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Affiliation(s)
- Melissabye Gunnoo
- Department of Physics, Bernal Institute, University of Limerick, V94 T9PX, Ireland.
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36
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Grasso G, Rebella M, Morbiducci U, Tuszynski JA, Danani A, Deriu MA. The Role of Structural Polymorphism in Driving the Mechanical Performance of the Alzheimer's Beta Amyloid Fibrils. Front Bioeng Biotechnol 2019; 7:83. [PMID: 31106199 PMCID: PMC6499180 DOI: 10.3389/fbioe.2019.00083] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/03/2019] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's Disease (AD) is related with the abnormal aggregation of amyloid β-peptides Aβ1−40 and Aβ1−42, the latter having a polymorphic character which gives rise to U- or S-shaped fibrils. Elucidating the role played by the nanoscale-material architecture on the amyloid fibril stability is a crucial breakthrough to better understand the pathological nature of amyloid structures and to support the rational design of bio-inspired materials. The computational study here presented highlights the superior mechanical behavior of the S-architecture, characterized by a Young's modulus markedly higher than the U-shaped architecture. The S-architecture showed a higher mechanical resistance to the enforced deformation along the fibril axis, consequence of a better interchain hydrogen bonds' distribution. In conclusion, this study, focusing the attention on the pivotal multiscale relationship between molecular phenomena and material properties, suggests the S-shaped Aβ1−42 species as a target of election in computational screen/design/optimization of effective aggregation modulators.
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Affiliation(s)
- Gianvito Grasso
- Istituto Dalle Molle di studi sull'Intelligenza Artificiale, Scuola Universitaria Professionale della Svizzera Italiana, Università della Svizzera Italiana, Manno, Switzerland
| | - Martina Rebella
- Polito BioMEDLab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Umberto Morbiducci
- Polito BioMEDLab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Jack A Tuszynski
- Polito BioMEDLab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy.,Department of Physics, University of Alberta, Edmonton AB, Canada
| | - Andrea Danani
- Istituto Dalle Molle di studi sull'Intelligenza Artificiale, Scuola Universitaria Professionale della Svizzera Italiana, Università della Svizzera Italiana, Manno, Switzerland
| | - Marco A Deriu
- Istituto Dalle Molle di studi sull'Intelligenza Artificiale, Scuola Universitaria Professionale della Svizzera Italiana, Università della Svizzera Italiana, Manno, Switzerland
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37
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Wang WB, Zhu JZ, Li XY, Li CH, Su JG, Li JY. Enhancement of protein mechanical stability: Correlated deformations are handcuffed by ligand binding. J Chem Phys 2019; 150:155102. [PMID: 31005084 DOI: 10.1063/1.5054932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
As revealed by previous experiments, protein mechanical stability can be effectively regulated by ligand binding with the binding site distant from the force-bearing region. However, the mechanism for such long-range allosteric control of protein mechanics is still largely unknown. In this work, we use protein topology-based elastic network model (ENM) and all-atomic steered molecular dynamics (SMD) simulations to study the impact of ligand binding on protein mechanical stability in two systems, i.e., GB1 and CheY-binding P2-domain of CheA (CBDCheA). Both ENM and SMD results show that the ligand binding has considerable and negligible effects on the mechanical stability of these two proteins, respectively. These results are consistent with the experimental observations. A physical mechanism for the enhancement of protein mechanical stability was then proposed: the correlated deformations of the force-bearing region and the binding site are handcuffed by the binding of ligand. The handcuff effect suppresses the propagation of internal force in the force-bearing region, thus improving the resistance to the loading force. Our study indicates that ENM method can effectively identify the structure motifs allosterically related to the deformation in the force bearing region, as well as the force propagation pathway within the structure of the studied proteins. Hence, it should be helpful to understand the molecular origin of the different mechanical properties in response to ligand binding for GB1 and CBDCheA.
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Affiliation(s)
- Wei Bu Wang
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Jian Zhuo Zhu
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Xing Yuan Li
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Chun Hua Li
- College of Life Science and Bioengineering, Beijing University of Technology, Beijing 100124, China
| | - Ji Guo Su
- Key Laboratory for Microstructural Material Physics of Hebei Province, College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Jing Yuan Li
- Institute of Quantitative Biology and Department of Physics, Zhejiang University, Hangzhou 310027, China
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38
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Galvanetto N, Perissinotto A, Pedroni A, Torre V. Fodis: Software for Protein Unfolding Analysis. Biophys J 2019; 114:1264-1266. [PMID: 29590583 DOI: 10.1016/j.bpj.2018.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 01/22/2018] [Accepted: 02/06/2018] [Indexed: 10/17/2022] Open
Abstract
The folding dynamics of proteins at the single-molecule level has been studied with single-molecule force spectroscopy experiments for 20 years, but a common standardized method for the analysis of the collected data and for sharing among the scientific community members is still not available. We have developed a new open-source tool-Fodis-for the analysis of the force-distance curves obtained in single-molecule force spectroscopy experiments, providing almost automatic processing, analysis, and classification of the obtained data. Our method provides also a classification of the possible unfolding pathways and the structural heterogeneity present during the unfolding of proteins.
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Affiliation(s)
| | | | - Andrea Pedroni
- International School for Advanced Studies (SISSA), Trieste, Italy
| | - Vincent Torre
- International School for Advanced Studies (SISSA), Trieste, Italy; Cixi Institute of Biomedical Engineering, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Zhejiang, People's Republic of China; Center of Systems Medicine, Chinese Academy of Medical Sciences, Suzhou Institute of Systems Medicine, Suzhou Industrial Park, Suzhou, Jiangsu, People's Republic of China
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39
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Nathwani B, Shih WM, Wong WP. Force Spectroscopy and Beyond: Innovations and Opportunities. Biophys J 2018; 115:2279-2285. [PMID: 30447991 PMCID: PMC6302248 DOI: 10.1016/j.bpj.2018.10.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 10/08/2018] [Accepted: 10/25/2018] [Indexed: 12/26/2022] Open
Abstract
Life operates at the intersection of chemistry and mechanics. Over the years, we have made remarkable progress in understanding life from a biochemical perspective and the mechanics of life at the single-molecule scale. Yet the full integration of physical and mechanical models into mainstream biology has been impeded by technical and conceptual barriers, including limitations in our ability to 1) easily measure and apply mechanical forces to biological systems, 2) scale these measurements from single-molecule characterization to more complex biomolecular systems, and 3) model and interpret biophysical data in a coherent way across length scales that span single molecules to cells to multicellular organisms. In this manuscript, through a look at historical and recent developments in force spectroscopy techniques and a discussion of a few exemplary open problems in cellular biomechanics, we aim to identify research opportunities that will help us reach our goal of a more complete and integrated understanding of the role of force and mechanics in biological systems.
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Affiliation(s)
- Bhavik Nathwani
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts.
| | - William M Shih
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts
| | - Wesley P Wong
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts; Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, Massachusetts.
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40
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De-la-Torre P, Choudhary D, Araya-Secchi R, Narui Y, Sotomayor M. A Mechanically Weak Extracellular Membrane-Adjacent Domain Induces Dimerization of Protocadherin-15. Biophys J 2018; 115:2368-2385. [PMID: 30527337 PMCID: PMC6302040 DOI: 10.1016/j.bpj.2018.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/01/2018] [Accepted: 11/05/2018] [Indexed: 10/27/2022] Open
Abstract
The cadherin superfamily of proteins is defined by the presence of extracellular cadherin (EC) "repeats" that engage in protein-protein interactions to mediate cell-cell adhesion, cell signaling, and mechanotransduction. The extracellular domains of nonclassical cadherins often have a large number of EC repeats along with other subdomains of various folds. Protocadherin-15 (PCDH15), a protein component of the inner-ear tip link filament essential for mechanotransduction, has 11 EC repeats and a membrane adjacent domain (MAD12) of atypical fold. Here we report the crystal structure of a pig PCDH15 fragment including EC10, EC11, and MAD12 in a parallel dimeric arrangement. MAD12 has a unique molecular architecture and folds as a ferredoxin-like domain similar to that found in the nucleoporin protein Nup54. Analytical ultracentrifugation experiments along with size-exclusion chromatography coupled to multiangle laser light scattering and small-angle x-ray scattering corroborate the crystallographic dimer and show that MAD12 induces parallel dimerization of PCDH15 near its membrane insertion point. In addition, steered molecular dynamics simulations suggest that MAD12 is mechanically weak and may unfold before tip-link rupture. Sequence analyses and structural modeling predict the existence of similar domains in cadherin-23, protocadherin-24, and the "giant" FAT and CELSR cadherins, indicating that some of them may also exhibit MAD-induced parallel dimerization.
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Affiliation(s)
- Pedro De-la-Torre
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Deepanshu Choudhary
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Structural Biophysics, Section for Neutron and X-ray Science, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Yoshie Narui
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio.
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Abstract
Polyproteins, individual protein units joined covalently in tandem, have evolved as a promising tool for measuring the dynamic folding of biomacromolecules in single-molecule force spectroscopy. However, the synthetic routes to prepare polyproteins have been a bottleneck, and urge development of in vitro methods to knit individual protein units covalently into polyprotein. Employing two enzymes of orthogonal functionalities periodically in sequence, we synthesized monodispersed polyproteins on a solid surface. We used Sortase A (SrtA), the enzyme known for sequence specific transpeptidation, to staple protein units covalently through peptide bonds. Exploiting the sequence-specific peptide cleaving ability of TEV protease, we controlled the progress of the reaction to one attachment at a time. Finally, with unique design of the unit proteins we control the orientation of proteins in polyprotein. This simple conjugation has the potential to staple proteins with different functionalities and from different expression systems, in any number in the polyprotein and, above all, via irreversible peptide bonds. Multiple chimeric constructs can also be synthesized with interchangeable protein units.
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Affiliation(s)
- S. Garg
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - G. S. Singaraju
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - S. Yenghkom
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - S. Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
- Centre for Protein Science Design and Engineering, Indian Institute of Science Education and Research Mohali, Punjab, India
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42
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Johnson KC, Thomas WE. How Do We Know when Single-Molecule Force Spectroscopy Really Tests Single Bonds? Biophys J 2018; 114:2032-2039. [PMID: 29742396 PMCID: PMC5961468 DOI: 10.1016/j.bpj.2018.04.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 03/16/2018] [Accepted: 04/02/2018] [Indexed: 01/04/2023] Open
Abstract
Single-molecule force spectroscopy makes it possible to measure the mechanical strength of single noncovalent receptor-ligand-type bonds. A major challenge in this technique is to ensure that measurements reflect bonds between single biomolecules because the molecules cannot be directly observed. This perspective evaluates different methodologies for identifying and reducing the contribution of multiple molecule interactions to single-molecule measurements to help the reader design experiments or assess publications in the single-molecule force spectroscopy field. We apply our analysis to the large body of literature that purports to measure the strength of single bonds between biotin and streptavidin as a demonstration that measurements are only reproducible when the most reliable methods for ensuring single molecules are used.
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Affiliation(s)
- 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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43
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Mykuliak VV, Haining AWM, von Essen M, del Río Hernández A, Hytönen VP. Mechanical unfolding reveals stable 3-helix intermediates in talin and α-catenin. PLoS Comput Biol 2018; 14:e1006126. [PMID: 29698481 PMCID: PMC5940241 DOI: 10.1371/journal.pcbi.1006126] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/08/2018] [Accepted: 04/06/2018] [Indexed: 11/18/2022] Open
Abstract
Mechanical stability is a key feature in the regulation of structural scaffolding proteins and their functions. Despite the abundance of α-helical structures among the human proteome and their undisputed importance in health and disease, the fundamental principles of their behavior under mechanical load are poorly understood. Talin and α-catenin are two key molecules in focal adhesions and adherens junctions, respectively. In this study, we used a combination of atomistic steered molecular dynamics (SMD) simulations, polyprotein engineering, and single-molecule atomic force microscopy (smAFM) to investigate unfolding of these proteins. SMD simulations revealed that talin rod α-helix bundles as well as α-catenin α-helix domains unfold through stable 3-helix intermediates. While the 5-helix bundles were found to be mechanically stable, a second stable conformation corresponding to the 3-helix state was revealed. Mechanically weaker 4-helix bundles easily unfolded into a stable 3-helix conformation. The results of smAFM experiments were in agreement with the findings of the computational simulations. The disulfide clamp mutants, designed to protect the stable state, support the 3-helix intermediate model in both experimental and computational setups. As a result, multiple discrete unfolding intermediate states in the talin and α-catenin unfolding pathway were discovered. Better understanding of the mechanical unfolding mechanism of α-helix proteins is a key step towards comprehensive models describing the mechanoregulation of proteins.
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Affiliation(s)
- Vasyl V. Mykuliak
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Alexander William M. Haining
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Magdaléna von Essen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
| | - Armando del Río Hernández
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, United Kingdom
- * E-mail: (AdRH); (VPH)
| | - Vesa P. Hytönen
- Faculty of Medicine and Life Sciences and BioMediTech, University of Tampere, Finland and Fimlab Laboratories, Tampere, Finland
- * E-mail: (AdRH); (VPH)
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Naranjo T, Cerrón F, Nieto-Ortega B, Latorre A, Somoza Á, Ibarra B, Pérez EM. Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions. Chem Sci 2017; 8:6037-6041. [PMID: 28989633 PMCID: PMC5625567 DOI: 10.1039/c7sc03044d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 07/29/2017] [Indexed: 11/26/2022] Open
Abstract
Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.
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Affiliation(s)
- Teresa Naranjo
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Fernando Cerrón
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Belén Nieto-Ortega
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Alfonso Latorre
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
| | - Álvaro Somoza
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
- Nanobiotecnología (IMDEA-Nanociencia) , Unidad Asociada al Centro Nacional de Biotecnología (CSIC) , 28049 , Madrid , Spain
| | - Borja Ibarra
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
- Nanobiotecnología (IMDEA-Nanociencia) , Unidad Asociada al Centro Nacional de Biotecnología (CSIC) , 28049 , Madrid , Spain
| | - Emilio M Pérez
- IMDEA Nanociencia , C/Faraday 9, Ciudad Universitaria de Cantoblanco , 28049 , Madrid , Spain . ;
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Walder R, LeBlanc MA, Van Patten WJ, Edwards DT, Greenberg JA, Adhikari A, Okoniewski SR, Sullan RMA, Rabuka D, Sousa MC, Perkins TT. Rapid Characterization of a Mechanically Labile α-Helical Protein Enabled by Efficient Site-Specific Bioconjugation. J Am Chem Soc 2017; 139:9867-9875. [PMID: 28677396 DOI: 10.1021/jacs.7b02958] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS) is a powerful yet accessible means to characterize mechanical properties of biomolecules. Historically, accessibility relies upon the nonspecific adhesion of biomolecules to a surface and a cantilever and, for proteins, the integration of the target protein into a polyprotein. However, this assay results in a low yield of high-quality data, defined as the complete unfolding of the polyprotein. Additionally, nonspecific surface adhesion hinders studies of α-helical proteins, which unfold at low forces and low extensions. Here, we overcame these limitations by merging two developments: (i) a polyprotein with versatile, genetically encoded short peptide tags functionalized via a mechanically robust Hydrazino-Pictet-Spengler ligation and (ii) the efficient site-specific conjugation of biomolecules to PEG-coated surfaces. Heterobifunctional anchoring of this polyprotein construct and DNA via copper-free click chemistry to PEG-coated substrates and a strong but reversible streptavidin-biotin linkage to PEG-coated AFM tips enhanced data quality and throughput. For example, we achieved a 75-fold increase in the yield of high-quality data and repeatedly probed the same individual polyprotein to deduce its dynamic force spectrum in just 2 h. The broader utility of this polyprotein was demonstrated by measuring three diverse target proteins: an α-helical protein (calmodulin), a protein with internal cysteines (rubredoxin), and a computationally designed three-helix bundle (α3D). Indeed, at low loading rates, α3D represents the most mechanically labile protein yet characterized by AFM. Such efficient SMFS studies on a commercial AFM enable the rapid characterization of macromolecular folding over a broader range of proteins and a wider array of experimental conditions (pH, temperature, denaturants). Further, by integrating these enhancements with optical traps, we demonstrate how efficient bioconjugation to otherwise nonstick surfaces can benefit diverse single-molecule studies.
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Affiliation(s)
- Robert Walder
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | | | - William J Van Patten
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | - Devin T Edwards
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | | | - Ayush Adhikari
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | - Stephen R Okoniewski
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | - Ruby May A Sullan
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
| | - David Rabuka
- Catalent Biologics-West , Emeryville, California 94608, United States
| | | | - Thomas T Perkins
- JILA, National Institute of Standards and Technology and University of Colorado , Boulder, Colorado 80309, United States
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46
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Impact of ultrasonic treatment on an emulsion system stabilized with soybean protein isolate and lecithin: Its emulsifying property and emulsion stability. Food Hydrocoll 2017. [DOI: 10.1016/j.foodhyd.2016.10.024] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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He C, Li H. Staphylokinase Displays Surprisingly Low Mechanical Stability. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:1077-1083. [PMID: 28040904 DOI: 10.1021/acs.langmuir.6b04425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Single-molecule force spectroscopy (SMFS) and molecular dynamics (MD) simulations have revealed that shear topology is an important structural feature for mechanically stable proteins. Proteins containing a β-grasp fold display the typical shear topology and are generally of significant mechanical stability. In an effort to experimentally identify mechanically strong proteins using single-molecule atomic force microscopy, we found that staphylokinase (SAK), which has a typical β-grasp fold and was predicted to be mechanically stable in coarse-grained MD simulations, displays surprisingly low mechanical stability. At a pulling speed of 400 nm/s, SAK unfolds at ∼60 pN, making it the mechanically weakest protein among the β-grasp fold proteins that have been characterized experimentally. In contrast, its structural homologous protein streptokinase β domain displays significant mechanical stability under the same experimental condition. Our results showed that the large malleability of native-state SAK is largely responsible for its low mechanical stability. The molecular origin of this large malleability of SAK remains unknown. Our results reveal a hidden complexity in protein mechanics and call for a detailed investigation into the molecular determinants of the protein mechanical malleability.
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Affiliation(s)
- Chengzhi He
- Department of Chemistry, University of British Columbia , Vancouver, BC V6T 1Z1, Canada
| | - Hongbin Li
- Department of Chemistry, University of British Columbia , Vancouver, BC V6T 1Z1, Canada
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Stauch T, Dreuw A. Advances in Quantum Mechanochemistry: Electronic Structure Methods and Force Analysis. Chem Rev 2016; 116:14137-14180. [PMID: 27767298 DOI: 10.1021/acs.chemrev.6b00458] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In quantum mechanochemistry, quantum chemical methods are used to describe molecules under the influence of an external force. The calculation of geometries, energies, transition states, reaction rates, and spectroscopic properties of molecules on the force-modified potential energy surfaces is the key to gain an in-depth understanding of mechanochemical processes at the molecular level. In this review, we present recent advances in the field of quantum mechanochemistry and introduce the quantum chemical methods used to calculate the properties of molecules under an external force. We place special emphasis on quantum chemical force analysis tools, which can be used to identify the mechanochemically relevant degrees of freedom in a deformed molecule, and spotlight selected applications of quantum mechanochemical methods to point out their synergistic relationship with experiments.
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Affiliation(s)
- Tim Stauch
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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Wołek K, Gómez-Sicilia À, Cieplak M. Determination of contact maps in proteins: A combination of structural and chemical approaches. J Chem Phys 2016; 143:243105. [PMID: 26723590 DOI: 10.1063/1.4929599] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Contact map selection is a crucial step in structure-based molecular dynamics modelling of proteins. The map can be determined in many different ways. We focus on the methods in which residues are represented as clusters of effective spheres. One contact map, denoted as overlap (OV), is based on the overlap of such spheres. Another contact map, named Contacts of Structural Units (CSU), involves the geometry in a different way and, in addition, brings chemical considerations into account. We develop a variant of the CSU approach in which we also incorporate Coulombic effects such as formation of the ionic bridges and destabilization of possible links through repulsion. In this way, the most essential and well defined contacts are identified. The resulting residue-residue contact map, dubbed repulsive CSU (rCSU), is more sound in its physico-chemical justification than CSU. It also provides a clear prescription for validity of an inter-residual contact: the number of attractive atomic contacts should be larger than the number of repulsive ones - a feature that is not present in CSU. However, both of these maps do not correlate well with the experimental data on protein stretching. Thus, we propose to use rCSU together with the OV map. We find that the combined map, denoted as OV+rCSU, performs better than OV. In most situations, OV and OV+rCSU yield comparable folding properties but for some proteins rCSU provides contacts which improve folding in a substantial way. We discuss the likely residue-specificity of the rCSU contacts. Finally, we make comparisons to the recently proposed shadow contact map, which is derived from different principles.
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Affiliation(s)
- Karol Wołek
- Institute of Physics, Polish Academy of Science, Al. Lotników 32/46, 02-668 Warsaw, Poland
| | - Àngel Gómez-Sicilia
- Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), Av. Doctor Arce, 37, 28002 Madrid, Spain
| | - Marek Cieplak
- Institute of Physics, Polish Academy of Science, Al. Lotników 32/46, 02-668 Warsaw, Poland
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The Power of Force: Insights into the Protein Folding Process Using Single-Molecule Force Spectroscopy. J Mol Biol 2016; 428:4245-4257. [PMID: 27639437 DOI: 10.1016/j.jmb.2016.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 09/07/2016] [Accepted: 09/07/2016] [Indexed: 01/03/2023]
Abstract
One of the major challenges in modern biophysics is observing and understanding conformational changes during complex molecular processes, from the fundamental protein folding to the function of molecular machines. Single-molecule techniques have been one of the major driving forces of the huge progress attained in the last few years. Recent advances in resolution of the experimental setups, aided by theoretical developments and molecular dynamics simulations, have revealed a much higher degree of complexity inside these molecular processes than previously reported using traditional ensemble measurements. This review sums up the evolution of these developments and gives an outlook on prospective discoveries.
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