1
|
Mesbah I, Habermann B, Rico F. MechanoProDB: a web-based database for exploring the mechanical properties of proteins. Database (Oxford) 2024; 2024:baae047. [PMID: 38837788 DOI: 10.1093/database/baae047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/19/2024] [Accepted: 05/17/2024] [Indexed: 06/07/2024]
Abstract
The mechanical stability of proteins is crucial for biological processes. To understand the mechanical functions of proteins, it is important to know the protein structure and mechanical properties. Protein mechanics is usually investigated through force spectroscopy experiments and simulations that probe the forces required to unfold the protein of interest. While there is a wealth of data in the literature on force spectroscopy experiments and steered molecular dynamics simulations of forced protein unfolding, this information is spread and difficult to access by non-experts. Here, we introduce MechanoProDB, a novel web-based database resource for collecting and mining data obtained from experimental and computational works. MechanoProDB provides a curated repository for a wide range of proteins, including muscle proteins, adhesion molecules and membrane proteins. The database incorporates relevant parameters that provide insights into the mechanical stability of proteins and their conformational stability such as the unfolding forces, energy landscape parameters and contour lengths of unfolding steps. Additionally, it provides intuitive annotations of the unfolding pathways of each protein, allowing users to explore the individual steps during mechanical unfolding. The user-friendly interface of MechanoProDB allows researchers to efficiently navigate, search and download data pertaining to specific protein folds or experimental conditions. Users can visualize protein structures using interactive tools integrated within the database, such as Mol*, and plot available data through integrated plotting tools. To ensure data quality and reliability, we have carefully manually verified and curated the data currently available on MechanoProDB. Furthermore, the database also features an interface that enables users to contribute new data and annotations, promoting community-driven comprehensiveness. The freely available MechanoProDB aims to streamline and accelerate research in the field of mechanobiology and biophysics by offering a unique platform for data sharing and analysis. MechanoProDB is freely available at https://mechanoprodb.ibdm.univ-amu.fr.
Collapse
Affiliation(s)
- Ismahene Mesbah
- Aix Marseille Univ, INSERM, DyNaMo, Turing Center of Living Systems (CENTURI), Marseille 13009, France
| | - Bianca Habermann
- Aix Marseille Univ, CNRS, IBDM UMR7288, Turing Center of Living Systems (CENTURI), Marseille 13009, France
| | - Felix Rico
- Aix Marseille Univ, INSERM, DyNaMo, Turing Center of Living Systems (CENTURI), Marseille 13009, France
| |
Collapse
|
2
|
Hu Y, Li H, Zhang C, Feng J, Wang W, Chen W, Yu M, Liu X, Zhang X, Liu Z. DNA-based ForceChrono probes for deciphering single-molecule force dynamics in living cells. Cell 2024:S0092-8674(24)00517-8. [PMID: 38838668 DOI: 10.1016/j.cell.2024.05.008] [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: 02/13/2024] [Revised: 04/15/2024] [Accepted: 05/02/2024] [Indexed: 06/07/2024]
Abstract
Understanding cellular force transmission dynamics is crucial in mechanobiology. We developed the DNA-based ForceChrono probe to measure force magnitude, duration, and loading rates at the single-molecule level within living cells. The ForceChrono probe circumvents the limitations of in vitro single-molecule force spectroscopy by enabling direct measurements within the dynamic cellular environment. Our findings reveal integrin force loading rates of 0.5-2 pN/s and durations ranging from tens of seconds in nascent adhesions to approximately 100 s in mature focal adhesions. The probe's robust and reversible design allows for continuous monitoring of these dynamic changes as cells undergo morphological transformations. Additionally, by analyzing how mutations, deletions, or pharmacological interventions affect these parameters, we can deduce the functional roles of specific proteins or domains in cellular mechanotransduction. The ForceChrono probe provides detailed insights into the dynamics of mechanical forces, advancing our understanding of cellular mechanics and the molecular mechanisms of mechanotransduction.
Collapse
Affiliation(s)
- Yuru Hu
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Hongyun Li
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China.
| | - Chen Zhang
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Jingjing Feng
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Wenxu Wang
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Wei Chen
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Miao Yu
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Xinping Liu
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China
| | - Xinghua Zhang
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China.
| | - Zheng Liu
- The Institute for Advanced Studies, TaiKang Center for Life and Medical Sciences, Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Wuhan University, Wuhan, Hubei Province 430072, China.
| |
Collapse
|
3
|
Sun Y, Liu X, Huang W, Le S, Yan J. Structural domain in the Titin N2B-us region binds to FHL2 in a force-activation dependent manner. Nat Commun 2024; 15:4496. [PMID: 38802383 DOI: 10.1038/s41467-024-48828-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/15/2024] [Indexed: 05/29/2024] Open
Abstract
Titin N2B unique sequence (N2B-us) is a 572 amino acid sequence that acts as an elastic spring to regulate muscle passive elasticity. It is thought to lack stable tertiary structures and is a force-bearing region that is regulated by mechanical stretching. In this study, the conformation of N2B-us and its interaction with four-and-a-half LIM domain protein 2 (FHL2) are investigated using AlphaFold2 predictions and single-molecule experimental validation. Surprisingly, a stable alpha/beta structural domain is predicted and confirmed in N2B-us that can be mechanically unfolded at forces of a few piconewtons. Additionally, more than twenty FHL2 LIM domain binding sites are predicted to spread throughout N2B-us. Single-molecule manipulation experiments reveals the force-dependent binding of FHL2 to the N2B-us structural domain. These findings provide insights into the mechano-sensing functions of N2B-us and its interactions with FHL2.
Collapse
Affiliation(s)
- Yuze Sun
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Xuyao Liu
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Wenmao Huang
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Shimin Le
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Centre for Biological Imaging Sciences, National University of Singapore, Singapore, Singapore.
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, China.
| |
Collapse
|
4
|
Liu Y, Song D, Li S, Guo Z, Zheng P. Click Chemistry-Based Force Spectroscopy Revealed Enhanced Binding Dynamics of Phosphorylated HMGB1 to Cisplatin-DNA. J Am Chem Soc 2024; 146:13126-13132. [PMID: 38696488 DOI: 10.1021/jacs.4c00224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2024]
Abstract
Cisplatin, a cornerstone in cancer chemotherapy, is known for its DNA-binding capacity and forms lesions that lead to cancer cell death. However, the repair of these lesions compromises cisplatin's effectiveness. This study investigates how phosphorylation of HMGB1, a nuclear protein, modifies its binding to cisplatin-modified DNA (CP-DNA) and thus protects it from repair. Despite numerous methods for detecting protein-DNA interactions, quantitative approaches for understanding their molecular mechanism remain limited. Here, we applied click chemistry-based single-molecule force spectroscopy, achieving high-precision quantification of the interaction between phosphorylated HMGB1 and CP-DNA. This method utilizes a synergy of click chemistry and enzymatic ligation for precise DNA-protein immobilization and interaction in the system. Our results revealed that HMGB1 binds to CP-DNA with a significantly high rupture force of ∼130 pN, stronger than most natural DNA-protein interactions and varying across different DNA sequences. Moreover, Ser14 is identified as the key phosphorylation site, enhancing the interaction's kinetic stability by 35-fold. This increase in stability is attributed to additional hydrogen bonding suggested by molecular dynamics (MD) simulations. Our findings not only reveal the important role of phosphorylated HMGB1 in potentially improving cisplatin's therapeutic efficacy but also provide a precise method for quantifying protein-DNA interactions.
Collapse
Affiliation(s)
- Yutong Liu
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Dongfan Song
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Senmiao Li
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Peng Zheng
- State Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| |
Collapse
|
5
|
Yuan L, Sun H, Ma X, Wang Y, Guo Z, Qi X, Le S, Chen H. Ligand-dependent folding and unfolding dynamics and free energy landscapes of acylphosphatase. SOFT MATTER 2024; 20:3780-3786. [PMID: 38639061 DOI: 10.1039/d4sm00131a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Acylphosphatase (AcP) is an enzyme which catalyses the hydrolysis of acylphosphate. The binding with the phosphate ion (Pi) assumes significance in preserving both the stability and enzymatic activity of AcP. While previous studies using single molecule force spectroscopy explored the mechanical properties of AcP, the influence of Pi on its folding and unfolding dynamic behaviors remains unexplored. In this work, using stable magnetic tweezers, we measured and compared the force-dependent folding and unfolding rates of AcP in the Tris buffer and phosphate buffer within a force range from 2 pN to 40 pN. We found that Pi exerts no discernible effect on the folding dynamics but consistently decreases the force-dependent unfolding rate of AcP by a constant ratio across the entire force spectrum. The free energy landscapes of AcP in the absence and presence of Pi are constructed. Our results reveal that Pi selectively binds to the native state of AcP, stabilizing it and suggesting the general properties of specific ligand-receptor interactions.
Collapse
Affiliation(s)
- Li Yuan
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, Xiamen 361005, China.
| | - Hao Sun
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| | - Xuening Ma
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, Xiamen 361005, China.
| | - Yang Wang
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| | - Zilong Guo
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| | - Xingyu Qi
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, Xiamen 361005, China.
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| | - Shimin Le
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, Xiamen 361005, China.
| | - Hu Chen
- Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Department of Physics, Xiamen University, Xiamen 361005, China.
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325000, China
| |
Collapse
|
6
|
Truong DT, Ho K, Pham DQH, Chwastyk M, Nguyen-Minh T, Nguyen MT. Treatment of flexibility of protein backbone in simulations of protein-ligand interactions using steered molecular dynamics. Sci Rep 2024; 14:10475. [PMID: 38714683 PMCID: PMC11076533 DOI: 10.1038/s41598-024-59899-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Accepted: 04/16/2024] [Indexed: 05/10/2024] Open
Abstract
To ensure that an external force can break the interaction between a protein and a ligand, the steered molecular dynamics simulation requires a harmonic restrained potential applied to the protein backbone. A usual practice is that all or a certain number of protein's heavy atoms or Cα atoms are fixed, being restrained by a small force. This present study reveals that while fixing both either all heavy atoms and or all Cα atoms is not a good approach, while fixing a too small number of few atoms sometimes cannot prevent the protein from rotating under the influence of the bulk water layer, and the pulled molecule may smack into the wall of the active site. We found that restraining the Cα atoms under certain conditions is more relevant. Thus, we would propose an alternative solution in which only the Cα atoms of the protein at a distance larger than 1.2 nm from the ligand are restrained. A more flexible, but not too flexible, protein will be expected to lead to a more natural release of the ligand.
Collapse
Affiliation(s)
- Duc Toan Truong
- Laboratory for Chemical Computation and Modeling, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, 70000, Vietnam
- Faculty of Applied Technology, School of Technology, Van Lang University, Ho Chi Minh City, 70000, Vietnam
| | - Kiet Ho
- Institute for Computational Science and Technology (ICST), Quang Trung Software City, Ho Chi Minh City, 70000, Vietnam
| | | | - Mateusz Chwastyk
- Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Thai Nguyen-Minh
- University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, 70000, Vietnam
| | - Minh Tho Nguyen
- Laboratory for Chemical Computation and Modeling, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, 70000, Vietnam.
- Faculty of Applied Technology, School of Technology, Van Lang University, Ho Chi Minh City, 70000, Vietnam.
| |
Collapse
|
7
|
Zhao D, Zhang Z, Wei Z, Zhao J, Li T, Yan X. A Crown-Ether-Based Elastomer Bearing Loop Structures with Dissipating Characteristics and Enhanced Mechanical Performance. Angew Chem Int Ed Engl 2024; 63:e202402394. [PMID: 38499462 DOI: 10.1002/anie.202402394] [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] [Received: 02/02/2024] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 03/20/2024]
Abstract
Loops are prevalent topological structures in cross-linked polymer networks, resulting from the folding of polymer chains back onto themselves. Traditionally, they have been considered as defects that compromise the mechanical properties of the network, leading to extensive efforts in synthesis to prevent their formation. In this study, we introduce the inclusion of cyclic dibenzo-24-crown-8 (DB24C8) moieties within the polymer network strands to form CCNs, and surprisingly, these loops enhance the mechanical performances of the network, leading to tough elastomers. The toughening effect can be attributed to the unique cyclic structure of DB24C8. The relatively small size and the presence of rigid phenyl rings provide the loops with relatively stable conformations, allowing for substantial energy dissipation upon the application of force. Furthermore, the DB24C8 rings possess a broad range of potential conformations, imparting the materials with exceptional elasticity. The synergistic combination of these two features effectively toughens the materials, resulting in a remarkable 66-fold increase in toughness compared to the control sample of covalent networks. Moreover, the mechanical properties, particularly the recovery performance of the network, can be effectively tuned by introducing guests to bind with DB24C8, such as potassium ions and secondary ammonium salts.
Collapse
Affiliation(s)
- Dong Zhao
- Wenzhou Key Laboratory of Biophysics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, P. R. China
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Zhaoming Zhang
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Zhiyou Wei
- Wenzhou Key Laboratory of Biophysics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, P. R. China
| | - Jun Zhao
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| | - Tao Li
- Wenzhou Key Laboratory of Biophysics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325001, P. R. China
| | - Xuzhou Yan
- School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
| |
Collapse
|
8
|
Hartmann B, Fleischhauer L, Nicolau M, Jensen THL, Taran FA, Clausen-Schaumann H, Reuten R. Profiling native pulmonary basement membrane stiffness using atomic force microscopy. Nat Protoc 2024; 19:1498-1528. [PMID: 38429517 DOI: 10.1038/s41596-024-00955-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 11/27/2023] [Indexed: 03/03/2024]
Abstract
Mammalian cells sense and react to the mechanics of their immediate microenvironment. Therefore, the characterization of the biomechanical properties of tissues with high spatial resolution provides valuable insights into a broad variety of developmental, homeostatic and pathological processes within living organisms. The biomechanical properties of the basement membrane (BM), an extracellular matrix (ECM) substructure measuring only ∼100-400 nm across, are, among other things, pivotal to tumor progression and metastasis formation. Although the precise assignment of the Young's modulus E of such a thin ECM substructure especially in between two cell layers is still challenging, biomechanical data of the BM can provide information of eminent diagnostic potential. Here we present a detailed protocol to quantify the elastic modulus of the BM in murine and human lung tissue, which is one of the major organs prone to metastasis. This protocol describes a streamlined workflow to determine the Young's modulus E of the BM between the endothelial and epithelial cell layers shaping the alveolar wall in lung tissues using atomic force microscopy (AFM). Our step-by-step protocol provides instructions for murine and human lung tissue extraction, inflation of these tissues with cryogenic cutting medium, freezing and cryosectioning of the tissue samples, and AFM force-map recording. In addition, it guides the reader through a semi-automatic data analysis procedure to identify the pulmonary BM and extract its Young's modulus E using an in-house tailored user-friendly AFM data analysis software, the Center for Applied Tissue Engineering and Regenerative Medicine processing toolbox, which enables automatic loading of the recorded force maps, conversion of the force versus piezo-extension curves to force versus indentation curves, calculation of Young's moduli and generation of Young's modulus maps, where the pulmonary BM can be identified using a semi-automatic spatial filtering tool. The entire protocol takes 1-2 d.
Collapse
Affiliation(s)
- Bastian Hartmann
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany
- Center for Nanoscience, Munich, Germany
| | - Lutz Fleischhauer
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany
- Center for Nanoscience, Munich, Germany
| | - Monica Nicolau
- Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg, Germany
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Thomas Hartvig Lindkær Jensen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Pathology, Rigshospitalet, Copenhagen, Denmark
| | - Florin-Andrei Taran
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Hauke Clausen-Schaumann
- Munich University of Applied Sciences, Center for Applied Tissue Engineering and Regenerative Medicine - CANTER, Munich, Germany.
- Center for Nanoscience, Munich, Germany.
| | - Raphael Reuten
- Experimental and Clinical Pharmacology and Toxicology, Medical Faculty, University of Freiburg, Freiburg, Germany.
- Department of Obstetrics and Gynecology, Medical Center, University of Freiburg, Freiburg, Germany.
| |
Collapse
|
9
|
Yang H, Zhou D, Zhou Z, Duan M, Yu H. Mechanistic Insight into the Mechanical Unfolding of the Integral Membrane Diacylglycerol Kinase. JACS AU 2024; 4:1422-1435. [PMID: 38665647 PMCID: PMC11040704 DOI: 10.1021/jacsau.3c00829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/29/2024] [Accepted: 03/01/2024] [Indexed: 04/28/2024]
Abstract
The essential forces stabilizing membrane proteins and governing their folding and unfolding are difficult to decipher. Single-molecule atomic force spectroscopy mechanically unfolds individual membrane proteins and quantifies their dynamics and energetics. However, it remains challenging to structurally assign unfolding intermediates precisely and to deduce dominant interactions between specific residues that facilitate either the localized stabilization of these intermediates or the global assembly of membrane proteins. Here, we performed force spectroscopy experiments and multiscale molecular dynamics simulations to study the unfolding pathway of diacylglycerol kinase (DGK), a small trimeric multispan transmembrane enzyme. The remarkable agreement between experiments and simulations allowed precise structural assignment and interaction analysis of unfolding intermediates, bypassing existing limitations on structural mapping, and thus provided mechanistic explanations for the formation of these states. DGK unfolding was found to proceed with structural segments varying in size that do not correlate with its secondary structure. We identified intermolecular side-chain packing interactions as one of the major contributions to the stability of unfolding intermediates. Mutagenesis creating packing defects induced a dramatic decrease in the mechano-stability of corresponding intermediates and also in the thermo-stability of DGK trimer, in good agreement with predictions from simulations. Hence, the molecular determinants of the mechano- and thermo-stability of a membrane protein can be identified at residue resolution. The accurate structural assignment established and microscopic mechanism revealed in this work may substantially expand the scope of single-molecule studies of membrane proteins.
Collapse
Affiliation(s)
- Huiying Yang
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Daihong Zhou
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Zhangyi Zhou
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| | - Mojie Duan
- Innovation
Academy for Precision Measurement Science and Technology, Chinese
Academy of Sciences, Wuhan 430071, China
| | - Hao Yu
- School
of Physics, Huazhong University of Science
and Technology, Wuhan 430074, China
| |
Collapse
|
10
|
Stroik D, Gregorich ZR, Raza F, Ge Y, Guo W. Titin: roles in cardiac function and diseases. Front Physiol 2024; 15:1385821. [PMID: 38660537 PMCID: PMC11040099 DOI: 10.3389/fphys.2024.1385821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
The giant protein titin is an essential component of muscle sarcomeres. A single titin molecule spans half a sarcomere and mediates diverse functions along its length by virtue of its unique domains. The A-band of titin functions as a molecular blueprint that defines the length of the thick filaments, the I-band constitutes a molecular spring that determines cell-based passive stiffness, and various domains, including the Z-disk, I-band, and M-line, serve as scaffolds for stretch-sensing signaling pathways that mediate mechanotransduction. This review aims to discuss recent insights into titin's functional roles and their relationship to cardiac function. The role of titin in heart diseases, such as dilated cardiomyopathy and heart failure with preserved ejection fraction, as well as its potential as a therapeutic target, is also discussed.
Collapse
Affiliation(s)
- Dawson Stroik
- Cellular and Molecular Pathology Program, Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
| | - Zachery R. Gregorich
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
| | - Farhan Raza
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Wei Guo
- Cellular and Molecular Pathology Program, Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
| |
Collapse
|
11
|
Gao C, Zhang E, Bian X, Li Q, Wang C, Yang G, Jiang M, Chen G. One-Pot Fabrication of Supramolecular Synthetic Protein Hydrogel with Tissue-like Integrated Dynamic Features. Biomacromolecules 2024; 25:2065-2074. [PMID: 38386431 DOI: 10.1021/acs.biomac.3c01451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Protein-incorporated soft networks have received remarkable attention during the past several years. They possess desirable properties similar to native tissues and organs and exhibit unique advantages in applications. However, fabrication of protein-based hydrogels usually suffers from complex protein mutation and modification or chemical synthesis, which limited the scale and yield of production. Meanwhile, the lack of rationally designed noncovalent interactions in networks may result in a deficiency of the dynamic features of materials. Therefore, a highly efficient method is needed to include supramolecular interactions into protein hydrogel to generate a highly dynamic hydrogel possessing integrated tissue-like properties. Here, we report the design and construction of native protein-based supramolecular synthetic protein hydrogels through a simple and efficient one-pot polymerization of acrylamide and ligand monomers in the presence of a ligand-binding protein. The supramolecular interactions in the network yield integrated dynamic properties, including remarkable stretchability over 10,000% of their original length, ultrafast self-healing abilities within 3-4 s, tissue-like fast stress relaxation, satisfactory ability of adhesion to different living and nonliving substrates, injectability, and high biocompatibility. Furthermore, this material demonstrated potential as a biosensor to monitor small finger movements. This strategy provides a new avenue for fabricating synthetic protein hydrogels with integrated features.
Collapse
Affiliation(s)
- Chendi Gao
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Ensong Zhang
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Xinyu Bian
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Qiaoran Li
- Biomass Molecular Engineering Center and Department of Materials Science and Engineering, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Chunming Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medicine & Department of Pharmaceutical Sciences, Faculty of Health Science, University of Macau, Taipa, Macau SAR 999078, China
| | - Guang Yang
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
- Biomass Molecular Engineering Center and Department of Materials Science and Engineering, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Ming Jiang
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| | - Guosong Chen
- The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200433, China
| |
Collapse
|
12
|
Baptista de Oliveira Medeiros H, de Brito Fontana H, Herzog W. A low-cost 2-D sarcomere model to demonstrate titin-related mechanisms for force production. ADVANCES IN PHYSIOLOGY EDUCATION 2024; 48:92-96. [PMID: 38059284 DOI: 10.1152/advan.00090.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 10/06/2023] [Accepted: 12/04/2023] [Indexed: 12/08/2023]
Abstract
Given the recently proposed three-filament theory of muscle contraction, we present a low-cost physical sarcomere model aimed at illustrating the role of titin in the production of active force in skeletal muscle. With inexpensive materials, it is possible to illustrate actin-myosin cross-bridge interactions between the thick and thin filaments and demonstrate the two different mechanisms by which titin is thought to contribute to active and passive muscle force. Specifically, the model illustrates how titin, a molecule with springlike properties, may increase its stiffness by binding free calcium upon muscle activation and reducing its extensible length by attaching itself to actin, resulting in the greater force-generating capacity after an active than a passive elongation that has been observed experimentally. The model is simple to build and manipulate, and demonstration to high school students was shown to result in positive perception and improved understanding of the otherwise complex titin-related mechanisms of force production in skeletal and cardiac muscles.NEW & NOTEWORTHY Our physical sarcomere model illustrates not only the classic view of muscle contraction, the sliding filament and cross-bridge theories, but also the newly discovered role of titin in force regulation, called the three-filament theory. The model allows for easy visualization of the role of titin in muscle contraction and aids in explaining complex muscle properties that are not captured by the traditional cross-bridge theory.
Collapse
Affiliation(s)
| | - Heiliane de Brito Fontana
- Musculoskeletal Biomechanics Research Group, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
- Biological Sciences Center, Morphological Sciences Department, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Walter Herzog
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
13
|
Jacobson DR, Perkins TT. Quantifying a light-induced energetic change in bacteriorhodopsin by force spectroscopy. Proc Natl Acad Sci U S A 2024; 121:e2313818121. [PMID: 38324569 PMCID: PMC10873598 DOI: 10.1073/pnas.2313818121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 12/26/2023] [Indexed: 02/09/2024] Open
Abstract
Ligand-induced conformational changes are critical to the function of many membrane proteins and arise from numerous intramolecular interactions. In the photocycle of the model membrane protein bacteriorhodopsin (bR), absorption of a photon by retinal triggers a conformational cascade that results in pumping a proton across the cell membrane. While decades of spectroscopy and structural studies have probed this photocycle in intricate detail, changes in intramolecular energetics that underlie protein motions have remained elusive to experimental quantification. Here, we measured these energetics on the millisecond time scale using atomic-force-microscopy-based single-molecule force spectroscopy. Precisely, timed light pulses triggered the bR photocycle while we measured the equilibrium unfolding and refolding of the terminal 8-amino-acid region of bR's G-helix. These dynamics changed when the EF-helix pair moved ~9 Å away from this end of the G helix during the "open" portion of bR's photocycle. In ~60% of the data, we observed abrupt light-induced destabilization of 3.4 ± 0.3 kcal/mol, lasting 38 ± 3 ms. The kinetics and pH-dependence of this destabilization were consistent with prior measurements of bR's open phase. The frequency of light-induced destabilization increased with the duration of illumination and was dramatically reduced in the triple mutant (D96G/F171C/F219L) thought to trap bR in its open phase. In the other ~40% of the data, photoexcitation unexpectedly stabilized a longer-lived putative misfolded state. Through this work, we establish a general single-molecule force spectroscopy approach for measuring ligand-induced energetics and lifetimes in membrane proteins.
Collapse
Affiliation(s)
- David R. Jacobson
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO80309
| | - Thomas T. Perkins
- JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO80309
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO80309
| |
Collapse
|
14
|
Tapia-Rojo R. Construction and operation of high-resolution magnetic tape head tweezers for measuring single-protein dynamics under force. Methods Enzymol 2024; 694:83-107. [PMID: 38492959 DOI: 10.1016/bs.mie.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
Mechanical forces are critical to protein function across many biological contexts-from bacterial adhesion to muscle mechanics and mechanotransduction processes. Hence, understanding how mechanical forces govern protein activity has developed into a central scientific question. In this context, single-molecule magnetic tweezers has recently emerged as a valuable experimental tool, offering the capability to measure single proteins over physiologically relevant forces and timescales. In this chapter, we present a detailed protocol for the assembly and operation of our magnetic tape head tweezers instrument, specifically tailored to investigate protein dynamics. Our instrument boasts a simplified microscope design and incorporates a magnetic tape head as the force-generating apparatus, facilitating precise force control and enhancing its temporal stability, enabling the study of single protein mechanics over extended timescales spanning several hours or even days. Moreover, its straightforward and cost-effective design ensures its accessibility to the wider scientific community. We anticipate that this technique will attract widespread interest within the growing field of mechanobiology and expect that this chapter will provide facilitated accessibility to this technology.
Collapse
|
15
|
Suhail A, Banerjee A, Rajesh R. Dissipation and recovery in collagen fibrils under cyclic loading: A molecular dynamics study. Phys Rev E 2024; 109:024411. [PMID: 38491641 DOI: 10.1103/physreve.109.024411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 01/22/2024] [Indexed: 03/18/2024]
Abstract
The hysteretic behavior exhibited by collagen fibrils, when subjected to cyclic loading, is known to result in both dissipation as well as accumulation of residual strain. On subsequent relaxation, partial recovery has also been reported. Cross-links have been considered to play a key role in overall mechanical properties. Here, we modify an existing coarse-grained molecular dynamics model for collagen fibril with initially cross-linked collagen molecules, which is known to reproduce the response to uniaxial strain, by incorporating reformation of cross-links to allow for possible recovery of the fibril. Using molecular dynamics simulations, we show that our model successfully replicates the key features observed in experimental data, including the movement of hysteresis loops, the time evolution of residual strains and energy dissipation, as well as the recovery observed during relaxation. We also show that the characteristic cycle number, describing the approach toward steady state, has a value similar to that in experiments. We also emphasize the vital role of the degree of cross-linking on the key features of the macroscopic response to cyclic loading.
Collapse
Affiliation(s)
- Amir Suhail
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | | | - R Rajesh
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| |
Collapse
|
16
|
Yuan R, Zhang Z, Wu G, Zhang Y, Sha J, Chen Y, Si W. Unfolding of protein using MoS 2/SnS 2heterostructure for nanopore-based sequencing. NANOTECHNOLOGY 2024; 35:135501. [PMID: 38118165 DOI: 10.1088/1361-6528/ad177f] [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: 10/16/2023] [Accepted: 12/20/2023] [Indexed: 12/22/2023]
Abstract
Protein sequencing is crucial for understanding the complex mechanisms driving biological functions. However, proteins are usually folded in their native state and the mechanism of fast protein conformation transitions still remains unclear, which make protein sequencing challenging. Molecular dynamics simulations with accurate force field are now able to observe the entire folding/unfolding process, providing valuable insights into protein folding mechanisms. Given that proteins can be unfolded, nanopore technology shows great potential for protein sequencing. In this study, we proposed to use MoS2/SnS2heterostructures to firstly unfold proteins and then detect them by a nanopore in the heterostructural membrane. All-atom molecular dynamics simulations performed in this work provided rich atomic-level information for a comprehensive understanding of protein unfolding process and mechanism on the MoS2/SnS2heterostructure, it was found that the strong binding of protein to SnS2nanostripe and hydrogen bond breaking were the main reasons for unfolding the protein on the heterostructure. After the protein was fully unfolded, it was restrained on the nanostripe because of the affinity of protein to the SnS2nanostripe. Thus by integrating the proposed unfolding technique with nanopore technology, detection of linear unfolded peptide was realized in this work, allowing for the identification of protein components, which is essential for sequencing proteins in the near future.
Collapse
Affiliation(s)
- Runyi Yuan
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| | - Zhen Zhang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| | - Gensheng Wu
- School of Mechanical and Electronic Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China
| | - Yin Zhang
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| | - Jingjie Sha
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| | - Yunfei Chen
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| | - Wei Si
- Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, School of Mechanical Engineering, Southeast University, Nanjing 211100, People's Republic of China
| |
Collapse
|
17
|
Mierke CT. Magnetic tweezers in cell mechanics. Methods Enzymol 2024; 694:321-354. [PMID: 38492957 DOI: 10.1016/bs.mie.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
The chapter provides an overview of the applications of magnetic tweezers in living cells. It discusses the advantages and disadvantages of magnetic tweezers technology with a focus on individual magnetic tweezers configurations, such as electromagnetic tweezers. Solutions to the disadvantages identified are also outlined. The specific role of magnetic tweezers in the field of mechanobiology, such as mechanosensitivity, mechano-allostery and mechanotransduction are also emphasized. The specific usage of magnetic tweezers in mechanically probing cells via specific cell surface receptors, such as mechanosensitive channels is discussed and why mechanical probing has revealed the opening and closing of the channels. Finally, the future direction of magnetic tweezers is presented.
Collapse
Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth System Sciences, Peter Debye Institute for Soft Matter Physics, Biological Physics Division, Leipzig University, Leipzig, Germany.
| |
Collapse
|
18
|
Sun H, Le S, Guo Z, Chen H. Exploring the free energy landscape of proteins using magnetic tweezers. Methods Enzymol 2024; 694:237-261. [PMID: 38492953 DOI: 10.1016/bs.mie.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
Proteins fold to their native states by searching through the free energy landscapes. As single-domain proteins are the basic building block of multiple-domain proteins or protein complexes composed of subunits, the free energy landscapes of single-domain proteins are of critical importance to understand the folding and unfolding processes of proteins. To explore the free energy landscapes of proteins over large conformational space, the stability of native structure is perturbed by biochemical or mechanical means, and the conformational transition process is measured. In single molecular manipulation experiments, stretching force is applied to proteins, and the folding and unfolding transitions are recorded by the extension time course. Due to the broad force range and long-time stability of magnetic tweezers, the free energy landscape over large conformational space can be obtained. In this article, we describe the magnetic tweezers instrument design, protein construct design and preparation, fluid chamber preparation, common-used measuring protocols including force-ramp and force-jump measurements, and data analysis methods to construct the free energy landscape. Single-domain cold shock protein is introduced as an example to build its free energy landscape by magnetic tweezers measurements.
Collapse
Affiliation(s)
- Hao Sun
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China
| | - Shimin Le
- Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Xiamen University, Xiamen, P.R. China
| | - Zilong Guo
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China.
| | - Hu Chen
- Center of Biomedical Physics, Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, P.R. China; Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Lab for Soft Functional Materials Research, Xiamen University, Xiamen, P.R. China.
| |
Collapse
|
19
|
Mora M, Tapia-Rojo R, Garcia-Manyes S. Unfolding and Refolding Proteins Using Single-Molecule AFM. Methods Mol Biol 2024; 2694:339-354. [PMID: 37824012 DOI: 10.1007/978-1-0716-3377-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Single-molecule atomic force microscopy (AFM) allows capturing the conformational dynamics of an individual molecule under force. In this chapter, we describe a protocol for conducting a protein nanomechanical experiment using AFM, covering both the force-extension and force-clamp modes. Combined, these experiments provide an integrated vista of the molecular mechanisms-and their associated kinetics-underpinning the mechanical unfolding and refolding of individual proteins when exposed to mechanical load.
Collapse
Affiliation(s)
- Marc Mora
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King's College London, London, UK
| | - Rafael Tapia-Rojo
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King's College London, London, UK
| | - Sergi Garcia-Manyes
- Department of Physics, Randall Centre for Cell and Molecular Biophysics and London Centre for Nanotechnology, King's College London, London, UK.
| |
Collapse
|
20
|
Feng Y, Roos WH. Atomic Force Microscopy: An Introduction. Methods Mol Biol 2024; 2694:295-316. [PMID: 37824010 DOI: 10.1007/978-1-0716-3377-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Imaging of nano-sized particles and sample features is crucial in a variety of research fields, for instance, in biological sciences, where it is paramount to investigate structures at the single particle level. Often, two-dimensional images are not sufficient, and further information such as topography and mechanical properties are required. Furthermore, to increase the biological relevance, it is desired to perform the imaging in close to physiological environments. Atomic force microscopy (AFM) meets these demands in an all-in-one instrument. It provides high-resolution images including surface height information leading to three-dimensional information on sample morphology. AFM can be operated both in air and in buffer solutions. Moreover, it has the capacity to determine protein and membrane material properties via the force spectroscopy mode. Here we discuss the principles of AFM operation and provide examples of how biomolecules can be studied. New developments in AFM are discussed, and by including approaches such as bimodal AFM and high-speed AFM (HS-AFM), we show how AFM can be used to study a variety of static and dynamic single biomolecules and biomolecular assemblies.
Collapse
Affiliation(s)
- Yuzhen Feng
- Moleculaire Biofysica, Zernike instituut, Rijksuniversiteit Groningen, Groningen, the Netherlands
| | - Wouter H Roos
- Moleculaire Biofysica, Zernike instituut, Rijksuniversiteit Groningen, Groningen, the Netherlands.
| |
Collapse
|
21
|
Ukraintsev E, Rezek B. Non-contact non-resonant atomic force microscopy method for measurements of highly mobile molecules and nanoparticles. Ultramicroscopy 2023; 253:113816. [PMID: 37531754 DOI: 10.1016/j.ultramic.2023.113816] [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: 11/07/2022] [Revised: 04/13/2023] [Accepted: 07/25/2023] [Indexed: 08/04/2023]
Abstract
Atomic force microscopy (AFM) is nowadays indispensable versatile scanning probe method widely employed for fundamental and applied research in physics, chemistry, biology as well as industrial metrology. Conventional AFM systems can operate in various environments such as ultra-high vacuum, electrolyte solutions, or controlled gas atmosphere. Measurements in ambient air are prevalent due to their technical simplicity; however, there are drawbacks such as formation of water meniscus that greatly increases attractive interaction (adhesion) between the tip and the sample, reduced spatial resolution, and too strong interactions leading to tip and/or sample modifications. Here we show how the attractive forces in AFM under ambient conditions can be used with advantage to probe surface properties in a very sensitive way even on highly mobile molecules and nanoparticles. We introduce a stable non-contact non-resonant (NCNR) AFM method which enables to reliably perform measurements in the attractive force regime even in air by controlling the tip position in the intimate surface vicinity without touching it. We demonstrate proof-of-concept results on helicene-based macrocycles, DNA on mica, and nanodiamonds on SiO2. We compare the results with other conventional AFM regimes, showing NCNR advantages such as higher spatial resolution, reduced tip contamination, and negligible sample modification. We analyze principle physical and chemical mechanisms influencing the measurements, discuss issues of stability and various possible method implementations. We explain how the NCNR method can be applied in any AFM system by a mere software modification. The method thus opens a new research field for measurements of highly sensitive and mobile nanoscale objects under air and other environments.
Collapse
Affiliation(s)
- Egor Ukraintsev
- Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6, 166 27, Czech Republic.
| | - Bohuslav Rezek
- Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6, 166 27, Czech Republic
| |
Collapse
|
22
|
Karna D, Mano E, Ji J, Kawamata I, Suzuki Y, Mao H. Chemo-mechanical forces modulate the topology dynamics of mesoscale DNA assemblies. Nat Commun 2023; 14:6459. [PMID: 37833326 PMCID: PMC10575982 DOI: 10.1038/s41467-023-41604-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 09/06/2023] [Indexed: 10/15/2023] Open
Abstract
The intrinsic complexity of many mesoscale (10-100 nm) cellular machineries makes it challenging to elucidate their topological arrangement and transition dynamics. Here, we exploit DNA origami nanospring as a model system to demonstrate that tens of piconewton linear force can modulate higher-order conformation dynamics of mesoscale molecular assemblies. By switching between two chemical structures (i.e., duplex and tetraplex DNA) in the junctions of adjacent origami modules, the corresponding stretching or compressing chemo-mechanical stress reversibly flips the backbone orientations of the DNA nanosprings. Both coarse-grained molecular dynamics simulations and atomic force microscopy measurements reveal that such a backbone conformational switch does not alter the right-handed chirality of the nanospring helix. This result suggests that mesoscale helical handedness may be governed by the torque, rather than the achiral orientation, of nanospring backbones. It offers a topology-based caging/uncaging concept to present chemicals in response to environmental cues in solution.
Collapse
Affiliation(s)
- Deepak Karna
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Eriko Mano
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8578, Japan
| | - Jiahao Ji
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA
| | - Ibuki Kawamata
- Department of Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8579, Japan.
| | - Yuki Suzuki
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 6-3 Aramaki-aza Aoba, Aoba-ku, Sendai, 980-8578, Japan.
- Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu, 514-8507, Japan.
| | - Hanbin Mao
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242, USA.
| |
Collapse
|
23
|
Mioduszewski Ł. Choosing the right density for a concentrated protein system like gluten in a coarse-grained model. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:583-591. [PMID: 37378869 PMCID: PMC10618313 DOI: 10.1007/s00249-023-01667-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/05/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023]
Abstract
Large coarse-grained simulations are often conducted with an implicit solvent, which makes it hard to assess the water content of the sample and the effective concentration of the system. Here the number and the size of cavities and entanglements in the system, together with density profiles, are used to asses the homogeneity and interconnectedness of gluten. This is a continuation of an earlier article, "Viscoelastic properties of wheat gluten in a molecular dynamics study" (Mioduszewski and Cieplak 2021b). It turns out there is a wide range of densities (between 1 residue per cubic nanometer and 3 residues/nm[Formula: see text]) where the system is interconnected, but not homogeneous: there are still large empty spaces, surrounded by an entangled protein network. Those findings should be of importance to any coarse-grained simulation of large protein systems.
Collapse
Affiliation(s)
- Łukasz Mioduszewski
- Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszyński University, Wóycickiego 1/3, 01-938, Warsaw, Poland.
| |
Collapse
|
24
|
Elias-Mordechai M, David N, Oren S, Georgia Pelah M, Jopp J, Fichtman B, Harel A, Berkovich R, Sal-Man N. A single filament biomechanical study of the enteropathogenic Escherichia coli Type III secretion system reveals a high elastic aspect ratio. NANOSCALE 2023; 15:15027-15037. [PMID: 37668452 DOI: 10.1039/d3nr01953e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Type III secretion systems (T3SSs) are syringe-like protein complexes used by some of the most harmful bacterial pathogens to infect host cells. While the T3SS filament, a long hollow conduit that bridges between bacteria and host cells, has been characterized structurally, very little is known about its physical properties. These filaments should endure shear and normal stresses imposed by the viscous mucosal flow during infection within the intestinal tract. We used atomic force microscopy (AFM) to probe the longitudinal and radial mechanical response of individual T3SS filaments by pulling on filaments extending directly from bacterial surfaces and later pressing into filaments that were detached from the bacteria. The measured longitudinal elastic moduli were higher by about two orders of magnitude than the radial elastic moduli. These proportions are commensurate with the role of the T3SS filament, which requires horizontal flexibility while maintaining its structural integrity to withstand intense stresses during infection.
Collapse
Affiliation(s)
- Moran Elias-Mordechai
- Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
| | - Nofar David
- Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
| | - Sonia Oren
- Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
| | - Maya Georgia Pelah
- Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
| | - Jürgen Jopp
- The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Boris Fichtman
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Amnon Harel
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
| | - Ronen Berkovich
- Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
- The Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Neta Sal-Man
- Department of Microbiology, Immunology, and Genetics, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.
| |
Collapse
|
25
|
Khurshid B, Lesniewska E, Polacchi L, L'Héronde M, Jackson DJ, Motreuil S, Thomas J, Bardeau JF, Wolf SE, Vielzeuf D, Perrin J, Marin F. In situ mapping of biomineral skeletal proteins by molecular recognition imaging with antibody-functionalized AFM tips. Acta Biomater 2023; 168:198-209. [PMID: 37490960 DOI: 10.1016/j.actbio.2023.07.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 07/27/2023]
Abstract
Spatial localizing of skeletal proteins in biogenic minerals remains a challenge in biomineralization research. To address this goal, we developed a novel in situ mapping technique based on molecular recognition measurements via atomic force microscopy (AFM), which requires three steps: (1) the development and purification of a polyclonal antibody elicited against the target protein, (2) its covalent coupling to a silicon nitride AFM tip ('functionalization'), and (3) scanning of an appropriately prepared biomineral surface. We applied this approach to a soluble shell protein - accripin11 - recently identified as a major component of the calcitic prisms of the fan mussel Pinna nobilis [1]. Multiple tests reveal that accripin11 is evenly distributed at the surface of the prisms and also present in the organic sheaths surrounding the calcitic prisms, indicating that this protein is both intra- and inter-crystalline. We observed that the adhesion force in transverse sections is about twice higher than in longitudinal sections, suggesting that accripin11 may exhibit preferred orientation in the biomineral. To our knowledge, this is the first time that a protein is localized by molecular recognition atomic force microscopy with antibody-functionalized tips in a biogenic mineral. The 'pros' and 'cons' of this methodology are discussed in comparison with more 'classical' approaches like immunogold. This technique, which leaves the surface to analyze clean, might prove useful for clinical tests on non-pathological (bone, teeth) or pathological (kidney stone) biomineralizations. Studies using implants with protein-doped calcium phosphate coating can also benefit from this technology. STATEMENT OF SIGNIFICANCE: Our paper deals with an unconventional technical approach for localizing proteins that are occluded in biominerals. This technique relies on the use of molecular recognition atomic force microscopy with antibody-functionalized tips. Although such approach has been employed in other system, this is the very first time that it is developed for biominerals. In comparison to more classical approaches (such as immunogold), AFM microscopy with antibody-functionalized tips allows higher magnification and keeps the scanned surface clean for other biophysical characterizations. Our method has a general scope as it can be applied in human health, for non-pathological (bone, teeth) and pathological (kidney stone) biomineralizations as well as for bone implants coated with protein-doped calcium phosphate.
Collapse
Affiliation(s)
- Benazir Khurshid
- Laboratoire Biogéosciences, UMR CNRS-EPHE 6282, University of Burgundy, Dijon, France; Synchrotron SOLEIL, Beamline ANATOMIX, Saint-Aubin, Gif-sur-Yvette, France
| | - Eric Lesniewska
- Laboratoire Interdisciplinaire Carnot de Bourgogne (ICB), UMR CNRS 6303, University of Burgundy, Dijon, France
| | - Luca Polacchi
- IPANEMA, USR3461, CNRS/MCC, Saint-Aubin, Gif-sur-Yvette, France; CR2P UMR7207, Muséum National d'Histoire Naturelle, Paris, France
| | - Maëva L'Héronde
- IPANEMA, USR3461, CNRS/MCC, Saint-Aubin, Gif-sur-Yvette, France
| | - Daniel J Jackson
- Department of Geobiology, Georg-August University of Göttingen, Göttingen, Germany
| | - Sébastien Motreuil
- Laboratoire Biogéosciences, UMR CNRS-EPHE 6282, University of Burgundy, Dijon, France
| | - Jérôme Thomas
- Laboratoire Biogéosciences, UMR CNRS-EPHE 6282, University of Burgundy, Dijon, France
| | | | - Stephan E Wolf
- Institute of Glass and Ceramics, Dpt. Materials Science & Engineering, Friedrich-Alexander-University, Erlangen, Germany
| | | | - Jonathan Perrin
- Synchrotron SOLEIL, Beamline ANATOMIX, Saint-Aubin, Gif-sur-Yvette, France
| | - Frédéric Marin
- Laboratoire Biogéosciences, UMR CNRS-EPHE 6282, University of Burgundy, Dijon, France.
| |
Collapse
|
26
|
Chu J, Romero A, Taulbee J, Aran K. Development of Single Molecule Techniques for Sensing and Manipulation of CRISPR and Polymerase Enzymes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300328. [PMID: 37226388 PMCID: PMC10524706 DOI: 10.1002/smll.202300328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/20/2023] [Indexed: 05/26/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and polymerases are powerful enzymes and their diverse applications in genomics, proteomics, and transcriptomics have revolutionized the biotechnology industry today. CRISPR has been widely adopted for genomic editing applications and Polymerases can efficiently amplify genomic transcripts via polymerase chain reaction (PCR). Further investigations into these enzymes can reveal specific details about their mechanisms that greatly expand their use. Single-molecule techniques are an effective way to probe enzymatic mechanisms because they may resolve intermediary conformations and states with greater detail than ensemble or bulk biosensing techniques. This review discusses various techniques for sensing and manipulation of single biomolecules that can help facilitate and expedite these discoveries. Each platform is categorized as optical, mechanical, or electronic. The methods, operating principles, outputs, and utility of each technique are briefly introduced, followed by a discussion of their applications to monitor and control CRISPR and Polymerases at the single molecule level, and closing with a brief overview of their limitations and future prospects.
Collapse
Affiliation(s)
- Josephine Chu
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Andres Romero
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Jeffrey Taulbee
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Kiana Aran
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
- Cardea, San Diego, CA, 92121, USA
- University of California Berkeley, Berkeley, CA, 94720, USA
| |
Collapse
|
27
|
Zheng B, Xiao Y, Tong B, Mao Y, Ge R, Tian F, Dong X, Zheng P. S373P Mutation Stabilizes the Receptor-Binding Domain of the Spike Protein in Omicron and Promotes Binding. JACS AU 2023; 3:1902-1910. [PMID: 37502147 PMCID: PMC10369413 DOI: 10.1021/jacsau.3c00142] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 07/29/2023]
Abstract
A cluster of several newly occurring mutations on Omicron is found at the β-core region of the spike protein's receptor-binding domain (RBD), where mutation rarely happened before. Notably, the binding of SARS-CoV-2 to human receptor ACE2 via RBD happens in a dynamic airway environment, where mechanical force caused by coughing or sneezing occurs. Thus, we used atomic force microscopy-based single-molecule force spectroscopy (AFM-SMFS) to measure the stability of RBDs and found that the mechanical stability of Omicron RBD increased by ∼20% compared with the wild type. Molecular dynamics (MD) simulations revealed that Omicron RBD showed more hydrogen bonds in the β-core region due to the closing of the α-helical motif caused primarily by the S373P mutation. In addition to a higher unfolding force, we showed a higher dissociation force between Omicron RBD and ACE2. This work reveals the mechanically stabilizing effect of the conserved mutation S373P for Omicron and the possible evolution trend of the β-core region of RBD.
Collapse
Affiliation(s)
- Bin Zheng
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Yuelong Xiao
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Bei Tong
- Institute
of Botany, Jiangsu Province and Chinese
Academy of Sciences, Nanjing, Jiangsu 210014, China
| | - Yutong Mao
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Rui Ge
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Fang Tian
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Xianchi Dong
- State
Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210023, China
- Engineering
Research Center of Protein and Peptide Medicine, Ministry of Education, Nanjing, Jiangsu 210023, China
| | - Peng Zheng
- State
Key Laboratory of Coordination Chemistry, Chemistry and Biomedicine
Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China
| |
Collapse
|
28
|
Fernandez M, Shkumatov AV, Liu Y, Stulemeijer C, Derclaye S, Efremov R, Hallet B, Alsteens D. AFM-based force spectroscopy unravels stepwise formation of the DNA transposition complex in the widespread Tn3 family mobile genetic elements. Nucleic Acids Res 2023; 51:4929-4941. [PMID: 37026471 PMCID: PMC10250215 DOI: 10.1093/nar/gkad241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/03/2023] [Accepted: 03/23/2023] [Indexed: 04/08/2023] Open
Abstract
Transposon Tn4430 belongs to a widespread family of bacterial transposons, the Tn3 family, which plays a prevalent role in the dissemination of antibiotic resistance among pathogens. Despite recent data on the structural architecture of the transposition complex, the molecular mechanisms underlying the replicative transposition of these elements are still poorly understood. Here, we use force-distance curve-based atomic force microscopy to probe the binding of the TnpA transposase of Tn4430 to DNA molecules containing one or two transposon ends and to extract the thermodynamic and kinetic parameters of transposition complex assembly. Comparing wild-type TnpA with previously isolated deregulated TnpA mutants supports a stepwise pathway for transposition complex formation and activation during which TnpA first binds as a dimer to a single transposon end and then undergoes a structural transition that enables it to bind the second end cooperatively and to become activated for transposition catalysis, the latter step occurring at a much faster rate for the TnpA mutants. Our study thus provides an unprecedented approach to probe the dynamic of a complex DNA processing machinery at the single-particle level.
Collapse
Affiliation(s)
- Maricruz Fernandez
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Alexander V Shkumatov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Yun Liu
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Claire Stulemeijer
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Sylvie Derclaye
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Rouslan G Efremov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Bernard Hallet
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - David Alsteens
- NanoBioPhysics lab, Louvain Institute of Biomolecular Science and Technology, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| |
Collapse
|
29
|
Fu L, Li L, Bian Q, Xue B, Jin J, Li J, Cao Y, Jiang Q, Li H. Cartilage-like protein hydrogels engineered via entanglement. Nature 2023; 618:740-747. [PMID: 37344650 DOI: 10.1038/s41586-023-06037-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 03/31/2023] [Indexed: 06/23/2023]
Abstract
Load-bearing tissues, such as muscle and cartilage, exhibit high elasticity, high toughness and fast recovery, but have different stiffness (with cartilage being significantly stiffer than muscle)1-8. Muscle achieves its toughness through finely controlled forced domain unfolding-refolding in the muscle protein titin, whereas articular cartilage achieves its high stiffness and toughness through an entangled network comprising collagen and proteoglycans. Advancements in protein mechanics and engineering have made it possible to engineer titin-mimetic elastomeric proteins and soft protein biomaterials thereof to mimic the passive elasticity of muscle9-11. However, it is more challenging to engineer highly stiff and tough protein biomaterials to mimic stiff tissues such as cartilage, or develop stiff synthetic matrices for cartilage stem and progenitor cell differentiation12. Here we report the use of chain entanglements to significantly stiffen protein-based hydrogels without compromising their toughness. By introducing chain entanglements13 into the hydrogel network made of folded elastomeric proteins, we are able to engineer highly stiff and tough protein hydrogels, which seamlessly combine mutually incompatible mechanical properties, including high stiffness, high toughness, fast recovery and ultrahigh compressive strength, effectively converting soft protein biomaterials into stiff and tough materials exhibiting mechanical properties close to those of cartilage. Our study provides a general route towards engineering protein-based, stiff and tough biomaterials, which will find applications in biomedical engineering, such as osteochondral defect repair, and material sciences and engineering.
Collapse
Affiliation(s)
- Linglan Fu
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Lan Li
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Branch of National Clinical Research Center for Orthopedics, Drum Tower Hospital affiliated to Medical School of Nanjing University, Nanjing, People's Republic of China
| | - Qingyuan Bian
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Bin Xue
- National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, Nanjing, People's Republic of China
| | - Jing Jin
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Branch of National Clinical Research Center for Orthopedics, Drum Tower Hospital affiliated to Medical School of Nanjing University, Nanjing, People's Republic of China
| | - Jiayu Li
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Yi Cao
- National Laboratory of Solid State Microstructures, Department of Physics, Nanjing University, Nanjing, People's Republic of China
| | - Qing Jiang
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Branch of National Clinical Research Center for Orthopedics, Drum Tower Hospital affiliated to Medical School of Nanjing University, Nanjing, People's Republic of China
| | - Hongbin Li
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada.
| |
Collapse
|
30
|
Kaur V, Garg S, Rakshit S. Polyprotein synthesis: a journey from the traditional pre-translational method to modern post-translational approaches for single-molecule force spectroscopy. Chem Commun (Camb) 2023. [PMID: 37183922 DOI: 10.1039/d3cc01756g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Polyproteins, an array of protein units of similar or differential functions in tandem, have been extensively utilized by organisms, unicellular or multicellular, as concentrators of the myriad of molecular activities. Most eukaryotic proteins, two-thirds in unicellular organisms, and more than 80% in metazoans, are polyproteins. Although the use of polyproteins continues to evolve in nature, our understanding of the structure-function-property of polyproteins is still limited. Cumbersome recombinant strategies and the lack of convenient in vitro synthetic routes of polyproteins have been rate-determining factors in the progress. However, in this review we have discussed the revolutionary journey of polyprotein synthesis with a major focus on surface-based structure-function-property studies, especially using force spectroscopy at the single-molecule level.
Collapse
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
| |
Collapse
|
31
|
Grande V, Schuld J, van der Ven PFM, Gruss OJ, Fürst DO. Filamin-A-interacting protein 1 (FILIP1) is a dual compartment protein linking myofibrils and microtubules during myogenic differentiation and upon mechanical stress. Cell Tissue Res 2023:10.1007/s00441-023-03776-4. [PMID: 37178194 DOI: 10.1007/s00441-023-03776-4] [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] [Received: 02/02/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
Variations in the gene encoding filamin-A-interacting protein 1 (FILIP1) were identified to be associated with a combination of neurological and muscular symptoms. While FILIP1 was shown to regulate motility of brain ventricular zone cells, a process important for corticogenesis, the function of the protein in muscle cells has been less well characterized. The expression of FILIP1 in regenerating muscle fibres predicted a role in early muscle differentiation. Here we analysed expression and localization of FILIP1 and its binding partners filamin-C (FLNc) and microtubule plus-end-binding protein EB3 in differentiating cultured myotubes and adult skeletal muscle. Prior to the development of cross-striated myofibrils, FILIP1 is associated with microtubules and colocalizes with EB3. During further myofibril maturation its localization changes, and FILIP1 localizes to myofibrillar Z-discs together with the actin-binding protein FLNc. Forced contractions of myotubes by electrical pulse stimulation (EPS) induce focal disruptions in myofibrils and translocation of both proteins from Z-discs to these lesions, suggesting a role in induction and/or repair of these structures. The immediate proximity of tyrosylated, dynamic microtubules and EB3 to lesions implies that also these play a role in these processes. This implication is supported by the fact that in nocodazole-treated myotubes that lack functional microtubules, the number of lesions induced by EPS is significantly reduced. In summary, we here show that FILIP1 is a cytolinker protein that is associated with both microtubules and actin filaments, and might play a role in the assembly of myofibrils and their stabilization upon mechanical stress to protect them from damage.
Collapse
Affiliation(s)
- Valentina Grande
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Julia Schuld
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Peter F M van der Ven
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany
| | - Oliver J Gruss
- Institute of Genetics, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115, Bonn, Germany
| | - Dieter O Fürst
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121, Bonn, Germany.
| |
Collapse
|
32
|
Aufderhorst-Roberts A, Cussons S, Brockwell DJ, Dougan L. Diversity of viscoelastic properties of an engineered muscle-inspired protein hydrogel. SOFT MATTER 2023; 19:3167-3178. [PMID: 37067782 DOI: 10.1039/d2sm01225a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Folded protein hydrogels are prime candidates as tuneable biomaterials but it is unclear to what extent their mechanical properties have mesoscopic, as opposed to molecular origins. To address this, we probe hydrogels inspired by the muscle protein titin and engineered to the polyprotein I275, using a multimodal rheology approach. Across multiple protocols, the hydrogels consistently exhibit power-law viscoelasticity in the linear viscoelastic regime with an exponent β = 0.03, suggesting a dense fractal meso-structure, with predicted fractal dimension df = 2.48. In the nonlinear viscoelastic regime, the hydrogel undergoes stiffening and energy dissipation, indicating simultaneous alignment and unfolding of the folded proteins on the nanoscale. Remarkably, this behaviour is highly reversible, as the value of β, df and the viscoelastic moduli return to their equilibrium value, even after multiple cycles of deformation. This highlights a previously unrevealed diversity of viscoelastic properties that originate on both at the nanoscale and the mesoscopic scale, providing powerful opportunities for engineering novel biomaterials.
Collapse
Affiliation(s)
- Anders Aufderhorst-Roberts
- Department of Physics, Centre for Materials Physics, University of Durham, Durham, DH1 3LE, UK
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK.
| | - Sophie Cussons
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Brockwell
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Lorna Dougan
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK.
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| |
Collapse
|
33
|
Rudra S, Chauhan K, Singh AR, Kumar S. Force-induced melting of DNA hairpin: Unfolding pathways and phase diagrams. Phys Rev E 2023; 107:054501. [PMID: 37328992 DOI: 10.1103/physreve.107.054501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/27/2023] [Indexed: 06/18/2023]
Abstract
Using the exact enumeration technique, we have studied the force-induced melting of a DNA hairpin on the face centered cubic lattice for two different sequences which differ in terms of loop closing base pairs. The melting profiles obtained from the exact enumeration technique is consistent with the Gaussian network model and Langevin dynamics simulations. Probability distribution analysis based on the exact density of states revealed the microscopic details of the opening of the hairpin. We showed the existence of intermediate states near the melting temperature. We further showed that different ensembles used to model single-molecule force spectroscopy setups may give different force-temperature diagrams. We delineate the possible reasons for the observed discrepancies.
Collapse
Affiliation(s)
- Sumitra Rudra
- Department of Physics, Banaras Hindu University, Varanasi 221005, India
| | - Keerti Chauhan
- Department of Physics, Banaras Hindu University, Varanasi 221005, India
| | - Amit Raj Singh
- Department of Physics, Graphic Era Hill University, Dehradun 248002, India
| | - Sanjay Kumar
- Department of Physics, Banaras Hindu University, Varanasi 221005, India
| |
Collapse
|
34
|
Anderson MS. Lateral force separation of biopolymers using an atomic force microscope. BIOMICROFLUIDICS 2023; 17:034102. [PMID: 37252431 PMCID: PMC10219682 DOI: 10.1063/5.0153116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 05/03/2023] [Indexed: 05/31/2023]
Abstract
The lateral force separation of long chain biomolecules is demonstrated using an atomic force microscope (AFM). This is achieved by using an AFM tip to pull molecules away from the edge of a nanofluidic solution. By monitoring the torsion on the AFM cantilever, a characteristic force-distance signal is produced when long chain molecules separate and detach from the solvent edge. This lateral force separation using AFM (LFS-AFM) is demonstrated on egg albumin proteins and synthetic DNA strands. The detected length of the protein and nucleotide biopolymers was consistent with their calculated molecular contour length. LFS AFM provides separation and detection of single polymer strands that has potential applications in biochemical analysis, paleontology, and life detection.
Collapse
|
35
|
Linke WA. Stretching the story of titin and muscle function. J Biomech 2023; 152:111553. [PMID: 36989971 DOI: 10.1016/j.jbiomech.2023.111553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
The discovery of the giant protein titin, also known as connectin, dates almost half a century back. In this review, I recapitulate major advances in the discovery of the titin filaments and the recognition of their properties and function until today. I briefly discuss how our understanding of the layout and interactions of titin in muscle sarcomeres has evolved and review key facts about the titin sequence at the gene (TTN) and protein levels. I also touch upon properties of titin important for the stability of the contractile units and the assembly and maintenance of sarcomeric proteins. The greater part of my discussion centers around the mechanical function of titin in skeletal muscle. I cover milestones of research on titin's role in stretch-dependent passive tension development, recollect the reasons behind the enormous elastic diversity of titin, and provide an update on the molecular mechanisms of titin elasticity, details of which are emerging even now. I reflect on current knowledge of how muscle fibers behave mechanically if titin stiffness is removed and how titin stiffness can be dynamically regulated, such as by posttranslational modifications or calcium binding. Finally, I highlight novel and exciting, but still controversially discussed, insight into the role titin plays in active tension development, such as length-dependent activation and contraction from longer muscle lengths.
Collapse
Affiliation(s)
- Wolfgang A Linke
- Institute of Physiology II, University of Münster, Germany; Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Germany; German Centre for Cardiovascular Research, Berlin, Germany.
| |
Collapse
|
36
|
Abstract
Many elastomeric proteins, which play important roles in a wide range of biological processes, exist as parallel/antiparallelly arranged dimers or multimers to perform their mechanobiological functions. For example, in striated muscle sarcomeres, the giant muscle protein titin exists as hexameric bundles to mediate the passive elasticity of muscles. However, it has not been possible to directly probe the mechanical properties of such parallelly arranged elastomeric proteins. And it remains unknown if the knowledge obtained from single-molecule force spectroscopy studies can be directly extrapolated to such parallelly/antiparallelly arranged systems. Here, we report the development of atomic force microscopy (AFM)-based two-molecule force spectroscopy to directly probe the mechanical properties of two elastomeric proteins that are arranged in parallel. We developed a twin-molecule approach to allow two parallelly arranged elastomeric proteins to be picked up and stretched simultaneously in an AFM experiment. Our results clearly revealed the mechanical features of such parallelly arranged elastomeric proteins during force-extension measurements and allowed for the determination of mechanical unfolding forces of proteins in such an experimental setting. Our study provides a general and robust experimental strategy to closely mimic the physiological condition of such parallel elastomeric protein multimers.
Collapse
Affiliation(s)
- Jiacheng Zuo
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| |
Collapse
|
37
|
El-Kirat-Chatel S, Varbanov M, Retourney C, Salles E, Risler A, Brunel JM, Beaussart A. AFM reveals the interaction and nanoscale effects imposed by squalamine on Staphylococcus epidermidis. Colloids Surf B Biointerfaces 2023; 226:113324. [PMID: 37146477 DOI: 10.1016/j.colsurfb.2023.113324] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 04/07/2023] [Accepted: 04/21/2023] [Indexed: 05/07/2023]
Abstract
The Gram-positive bacterium Staphylococcus epidermidis is responsible for important nosocomial infections. With the continuous emergence of antibiotic-resistant strains, the search for new treatments has been amplified in the last decades. A potential candidate against multidrug-resistant bacteria is squalamine, a natural aminosterol discovered in dogfish sharks. Despite its broad-spectrum efficiency, little is known about squalamine mode of action. Here, we used atomic force microscopy (AFM) imaging to decipher the effect of squalamine on S. epidermidis morphology, revealing the peptidoglycan structure at the bacterial surface after the drug action. Single-molecule force spectroscopy with squalamine-decorated tips shows that squalamine binds to the cell surface via the spermidine motif, most likely through electrostatic interactions between the amine groups of the molecule and the negatively-charged bacterial cell wall. We demonstrated that - although spermidine is sufficient for the initial attachment of squalamine to S. epidermidis - the integrity of the molecule needs to be conserved for its antimicrobial action. A deeper analysis of the AFM force-distance signatures suggests the implication of the accumulation-associated protein (Aap), one of the main adhesins of S. epidermidis, in the initial binding of squalamine to the bacterial cell wall. This work highlights that AFM -combined with microbiological assays at the bacterial suspension scale- is a valuable approach to better understand the molecular mechanisms behind the efficiency of squalamine antibacterial activity.
Collapse
Affiliation(s)
| | - Mihayl Varbanov
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France; Laboratoire de Virologie, CHRU de Nancy Brabois, F-54500 Vandœuvre-lès-Nancy, France
| | | | - Elsa Salles
- Université de Lorraine, CNRS, LIEC, F-57000 Metz, France
| | - Arnaud Risler
- Université de Lorraine, CNRS, L2CM, F-54000 Nancy, France
| | - Jean-Michel Brunel
- UMR_MD1, U-1261, Aix Marseille Université, INSERM, SSA, MCT, Marseille, France
| | | |
Collapse
|
38
|
Dumas L, Marfoglia M, Yang B, Hijazi M, Larabi AN, Lau K, Pojer F, Nash MA, Barth P. Uncovering and engineering the mechanical properties of the adhesion GPCR ADGRG1 GAIN domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.05.535724. [PMID: 37066252 PMCID: PMC10104041 DOI: 10.1101/2023.04.05.535724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Key cellular functions depend on the transduction of extracellular mechanical signals by specialized membrane receptors including adhesion G-protein coupled receptors (aGPCRs). While recently solved structures support aGPCR activation through shedding of the extracellular GAIN domain, the molecular mechanisms underpinning receptor mechanosensing remain poorly understood. When probed using single-molecule atomic force spectroscopy and molecular simulations, ADGRG1 GAIN dissociated from its tethered agonist at forces significantly higher than other reported signaling mechanoreceptors. Strong mechanical resistance was achieved through specific structural deformations and force propagation pathways under mechanical load. ADGRG1 GAIN variants computationally designed to lock the alpha and beta subdomains and rewire mechanically-induced structural deformations were found to modulate the GPS-Stachel rupture forces. Our study provides unprecedented insights into the molecular underpinnings of GAIN mechanical stability and paves the way for engineering mechanosensors, better understanding aGPCR function, and informing drug-discovery efforts targeting this important receptor class.
Collapse
|
39
|
Chai Z, Gu S, Lykotrafitis G. Dynamics of the axon plasma membrane skeleton. SOFT MATTER 2023; 19:2514-2528. [PMID: 36939651 DOI: 10.1039/d2sm01602h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
It was recently revealed via super-resolution microscopy experiments that the axon plasma membrane skeleton (APMS) comprises a series of periodically arranged azimuthal actin rings connected via longitudinal spectrin filaments forming an orthotropic network. The common perception is that APMS enhances structural stability of the axon but its impact on axon deformation is unknown. To investigate the response of the APMS to extension, we introduce a coarse-grain molecular dynamics model consisting of actin particles forming rings and chains of particles representing spectrin tetramers with repeats than can unfold. We observe that the shape of force-extension curve is initially linear and the force level depends on the extension rate. Even during the initial deformation stage, unfolding of spectrin repeats occurs, but the saw-tooth shape of the corresponding force-extension curve observed in the case of one spectrin tetramer does not appear in the case of the entire APMS. The reason is that spectrin unfolding is not synchronized across filaments during extension. If actin-spectrin associations remain intact, the force-extension response reaches a perfectly plastic region because of increased spectrin unfolding frequency. However, when actin-spectrin links dissociate, which can happen at moderate and high extension rates, APMS softens and the resistance force decreases linearly as the axon elongates until it reaches a point where the APMS is completely severed. Furthermore, when the ring-to-ring distance is maintained fixed under stretch, the resistance force relaxes exponentially as a function of time due to additional unfolding of spectrin tetramers following the Kelvin-Voigt representation of the Zener model.
Collapse
Affiliation(s)
- Zhaojie Chai
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA.
| | - Shiju Gu
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
| | - George Lykotrafitis
- Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA.
- Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA
| |
Collapse
|
40
|
Ma XY, Kang X, Su CX, Chen YQ, Sun HM. Effects of water chemistry on microfabric and micromechanical properties evolution of coastal sediment: A centrifugal model study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161343. [PMID: 36596424 DOI: 10.1016/j.scitotenv.2022.161343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/22/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Water chemistry alteration induced strength weakening of natural sediment, which leads to the differential settlement of infrastructures in coastal areas, has caused numerous disasters and engineering failures. To thoroughly understand the underlying mechanisms of how water chemistry influences the microfabric and mechanical properties evolution of coastal sediments, herein, the authors adopted centrifuge test, X-ray diffraction (XRD), and atomic force microscope (AFM) to quantitatively study the structure anisotropy index (i.e., orientation index (OI)), micromorphological property (i.e., root mean square height (Sq)), and micromechanics (i.e., microscale apparent modulus) of clay sediments in different water chemistry conditions and gravity gradients. The results show that the change rule of OI is: OIsaline > OIalkaline > OIwater > OIacid, along the vertical sedimentary depth. Randomly distributed clay flocs and loose flocculated soil skeleton (mainly consisted by edge-to-face (EF) and edge-to-edge (EE) contact of the kaolinite platelets) are associated with the acidic water chemical conditions. The action of supergravity and face-to-face (FF) repulsive contact mode lead to high degree of anisotropy of kaolinite sediments in alkaline environment. Clay platelets are compacted closely under the synergetic effect of centrifugal pressure and prevailing van der Waals attraction (reduction of electric double layer repulsion) in saline environment. The change of 1/Sq is highly consistent with the change of OI at different depths in different water chemical environments. Along the sedimentary depth (i.e., transition from the normal gravity (1 g) to supergravity (8000 g)), the microscale apparent modulus of kaolinite sediment was found to be the highest in alkaline environment. As the water chemistry changes from alkaline to acidic, however, the microscale apparent modulus of kaolinite aggregate decreased, and it showed the smallest in the saline environment.
Collapse
Affiliation(s)
- Xiong-Ying Ma
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China; National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China; College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Xin Kang
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China; National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China; College of Civil Engineering, Hunan University, Changsha 410082, China.
| | - Chen-Xi Su
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China; National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China; College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Yong-Qing Chen
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China; National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China; College of Civil Engineering, Hunan University, Changsha 410082, China
| | - He-Mei Sun
- Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, China; National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha 410082, China; College of Civil Engineering, Hunan University, Changsha 410082, China
| |
Collapse
|
41
|
Paiva TO, Geoghegan JA, Dufrêne YF. High-force catch bonds between the Staphylococcus aureus surface protein SdrE and complement regulator factor H drive immune evasion. Commun Biol 2023; 6:302. [PMID: 36944849 PMCID: PMC10030832 DOI: 10.1038/s42003-023-04660-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/02/2023] [Indexed: 03/23/2023] Open
Abstract
The invasive bacterial pathogen Staphylococcus aureus recruits the complement regulatory protein factor H (fH) to its surface to evade the human immune system. Here, we report the identification of an extremely high-force catch bond used by the S. aureus surface protein SdrE to efficiently capture fH under mechanical stress. We find that increasing the external force applied to the SdrE-fH complex prolongs the lifetime of the bond at an extraordinary high force, 1,400 pN, above which the bond lifetime decreases as an ordinary slip bond. This catch-bond behavior originates from a variation of the dock, lock and latch interaction, where the SdrE ligand binding domains undergo conformational changes under stress, enabling the formation of long-lived hydrogen bonds with fH. The binding mechanism dissected here represents a potential target for new therapeutics against multidrug-resistant S. aureus strains.
Collapse
Affiliation(s)
- Telmo O Paiva
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, L7.07.07, B-1348, Louvain-la-Neuve, Belgium
| | - Joan A Geoghegan
- Institute of Microbiology and Infection, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Yves F Dufrêne
- Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, L7.07.07, B-1348, Louvain-la-Neuve, Belgium.
| |
Collapse
|
42
|
Scher Y, Lauber Bonomo O, Pal A, Reuveni S. Microscopic theory of adsorption kinetics. J Chem Phys 2023; 158:094107. [PMID: 36889971 DOI: 10.1063/5.0121359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Adsorption is the accumulation of a solute at an interface that is formed between a solution and an additional gas, liquid, or solid phase. The macroscopic theory of adsorption dates back more than a century and is now well-established. Yet, despite recent advancements, a detailed and self-contained theory of single-particle adsorption is still lacking. Here, we bridge this gap by developing a microscopic theory of adsorption kinetics, from which the macroscopic properties follow directly. One of our central achievements is the derivation of the microscopic version of the seminal Ward-Tordai relation, which connects the surface and subsurface adsorbate concentrations via a universal equation that holds for arbitrary adsorption dynamics. Furthermore, we present a microscopic interpretation of the Ward-Tordai relation that, in turn, allows us to generalize it to arbitrary dimension, geometry, and initial conditions. The power of our approach is showcased on a set of hitherto unsolved adsorption problems to which we present exact analytical solutions. The framework developed herein sheds fresh light on the fundamentals of adsorption kinetics, which opens new research avenues in surface science with applications to artificial and biological sensing and to the design of nano-scale devices.
Collapse
Affiliation(s)
- Yuval Scher
- School of Chemistry, Center for the Physics and Chemistry of Living Systems, Ratner Institute for Single Molecule Chemistry, and the Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Ofek Lauber Bonomo
- School of Chemistry, Center for the Physics and Chemistry of Living Systems, Ratner Institute for Single Molecule Chemistry, and the Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Arnab Pal
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India
| | - Shlomi Reuveni
- School of Chemistry, Center for the Physics and Chemistry of Living Systems, Ratner Institute for Single Molecule Chemistry, and the Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, 6997801 Tel Aviv, Israel
| |
Collapse
|
43
|
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.
Collapse
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
| |
Collapse
|
44
|
Jin T, Coley CW, Alexander-Katz A. Adsorption of Biomimetic Amphiphilic Heteropolymers onto Graphene and Its Derivatives. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c02413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Affiliation(s)
- Tianyi Jin
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Connor W. Coley
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alfredo Alexander-Katz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
45
|
Li T, Dufresne ER, Kröger M, Heyden S. Siloxane Molecules: Nonlinear Elastic Behavior and Fracture Characteristics. Macromolecules 2023; 56:1303-1310. [PMID: 36874533 PMCID: PMC9979691 DOI: 10.1021/acs.macromol.2c02576] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/17/2023] [Indexed: 02/10/2023]
Abstract
Fracture phenomena in soft materials span multiple length and time scales. This poses a major challenge in computational modeling and predictive materials design. To pass quantitatively from molecular to continuum scales, a precise representation of the material response at the molecular level is vital. Here, we derive the nonlinear elastic response and fracture characteristics of individual siloxane molecules using molecular dynamics (MD) studies. For short chains, we find deviations from classical scalings for both the effective stiffness and mean chain rupture times. A simple model of a nonuniform chain of Kuhn segments captures the observed effect and agrees well with MD data. We find that the dominating fracture mechanism depends on the applied force scale in a nonmonotonic fashion. This analysis suggests that common polydimethylsiloxane (PDMS) networks fail at cross-linking points. Our results can be readily lumped into coarse-grained models. Although focusing on PDMS as a model system, our study presents a general procedure to pass beyond the window of accessible rupture times in MD studies employing mean first passage time theory, which can be exploited for arbitrary molecular systems.
Collapse
Affiliation(s)
- Tianchi Li
- Soft and Living Materials, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Eric R Dufresne
- Soft and Living Materials, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Martin Kröger
- Polymer Physics, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland.,Magnetism and Interface Physics, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Stefanie Heyden
- Soft and Living Materials, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| |
Collapse
|
46
|
Zhou P, Ding L, Yan Y, Wang Y, Su B. Recent advances in label-free imaging of cell-matrix adhesions. Chem Commun (Camb) 2023; 59:2341-2351. [PMID: 36744880 DOI: 10.1039/d2cc06499e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cell-matrix adhesions play an essential role in mediating and regulating many biological processes. The adhesion receptors, typically transmembrane integrins, provide dynamic correlations between intracellular environments and extracellular matrixes (ECMs) by bi-directional signaling. In-depth investigations of cell-matrix adhesion and integrin-mediated cell adhesive force are of great significance in biology and medicine. The emergence of advanced imaging techniques and principles has facilitated the understanding of the molecular composition and structure dynamics of cell-matrix adhesions, especially the label-free imaging methods that can be used to study living cell dynamics without immunofluorescence staining. This highlight article aims to give an overview of recent developments in imaging cell-matrix adhesions in a label-free manner. Electrochemiluminescence microscopy (ECLM) and surface plasmon resonance microscopy (SPRM) are briefly introduced and their applications in imaging analysis of cell-matrix adhesions are summarized. Then we highlight the advances in mapping cell-matrix adhesion force based on molecular tension probes and fluorescence microscopy (collectively termed as MTFM). The biomaterials including polyethylene glycol (PEG), peptides and DNA for constructing tension probes in MTFM are summarized. Finally, the outlook and perspectives on the further developments of cell-matrix adhesion imaging are presented.
Collapse
Affiliation(s)
- Ping Zhou
- Key Laboratory of Excited-State Materials of Zhejiang Province, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
| | - Lurong Ding
- Key Laboratory of Excited-State Materials of Zhejiang Province, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
| | - Yajuan Yan
- Key Laboratory of Excited-State Materials of Zhejiang Province, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
| | - Yafeng Wang
- Key Laboratory of Excited-State Materials of Zhejiang Province, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
| | - Bin Su
- Key Laboratory of Excited-State Materials of Zhejiang Province, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
47
|
Rivera M, Mjaavatten A, Smith SB, Baez M, Wilson CAM. Temperature dependent mechanical unfolding and refolding of a protein studied by thermo-regulated optical tweezers. Biophys J 2023; 122:513-521. [PMID: 36587240 PMCID: PMC9941719 DOI: 10.1016/j.bpj.2022.12.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 06/15/2022] [Accepted: 12/23/2022] [Indexed: 01/01/2023] Open
Abstract
Temperature is a useful system variable to gather kinetic and thermodynamic information from proteins. Usually, free energy and the associated entropic and enthalpic contributions are obtained by quantifying the conformational equilibrium based on melting experiments performed in bulk conditions. Such experiments are suitable only for those small single-domain proteins whose side reactions of irreversible aggregation are unlikely to occur. Here, we avoid aggregation by pulling single-protein molecules in a thermo-regulated optical tweezers. Thus, we are able to explore the temperature dependence of the thermodynamic and kinetic parameters of MJ0366 from Methanocaldococcus jannaschii at the single-molecule level. By performing force-ramp experiments between 2°C and 40°C, we found that MJ0366 has a nonlinear dependence of free energy with temperature and a specific heat change of 2.3 ± 1.2 kcal/mol∗K. These thermodynamic parameters are compatible with a two-state unfolding/refolding mechanism for MJ0366. However, the kinetics measured as a function of the temperature show a complex behavior, suggesting a three-state folding mechanism comprising a high-energy intermediate state. The combination of two perturbations, temperature and force, reveals a high-energy species in the folding mechanism of MJ0366 not detected in force-ramp experiments at constant temperature.
Collapse
Affiliation(s)
- Maira Rivera
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile; ANID - Millennium Science Initiative Program - Millennium Institute for Integrative Biology (iBio), Santiago, Chile; Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
| | | | | | - Mauricio Baez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
| | - Christian A M Wilson
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.
| |
Collapse
|
48
|
Ramirez MP, Rajaganapathy S, Hagerty AR, Hua C, Baxter GC, Vavra J, Gordon WR, Muretta JM, Salapaka MV, Ervasti JM. Phosphorylation alters the mechanical stiffness of a model fragment of the dystrophin homologue utrophin. J Biol Chem 2023; 299:102847. [PMID: 36587764 PMCID: PMC9922815 DOI: 10.1016/j.jbc.2022.102847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 12/30/2022] Open
Abstract
Duchenne muscular dystrophy is a lethal muscle wasting disease caused by the absence of the protein dystrophin. Utrophin is a dystrophin homologue currently under investigation as a protein replacement therapy for Duchenne muscular dystrophy. Dystrophin is hypothesized to function as a molecular shock absorber that mechanically stabilizes the sarcolemma. While utrophin is homologous with dystrophin from a molecular and biochemical perspective, we have recently shown that full-length utrophin expressed in eukaryotic cells is stiffer than what has been reported for dystrophin fragments expressed in bacteria. In this study, we show that differences in expression system impact the mechanical stiffness of a model utrophin fragment encoding the N terminus through spectrin repeat 3 (UtrN-R3). We also demonstrate that UtrN-R3 expressed in eukaryotic cells was phosphorylated while bacterial UtrN-R3 was not detectably phosphorylated. Using atomic force microscopy, we show that phosphorylated UtrN-R3 exhibited significantly higher unfolding forces compared to unphosphorylated UtrN-R3 without altering its actin-binding activity. Consistent with the effect of phosphorylation on mechanical stiffness, mutating the phosphorylated serine residues on insect eukaryotic protein to alanine decreased its stiffness to levels not different from unphosphorylated bacterial protein. Taken together, our data suggest that the mechanical properties of utrophin may be tuned by phosphorylation, with the potential to improve its efficacy as a protein replacement therapy for dystrophinopathies.
Collapse
Affiliation(s)
- Maria Paz Ramirez
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Sivaraman Rajaganapathy
- Department of Electrical and Computer Engineering, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Anthony R Hagerty
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Cailong Hua
- Department of Electrical and Computer Engineering, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Gloria C Baxter
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Joseph Vavra
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Wendy R Gordon
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Joseph M Muretta
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - Murti V Salapaka
- Department of Electrical and Computer Engineering, University of Minnesota - Twin Cities, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota - Twin Cities, Minneapolis, MN, USA.
| |
Collapse
|
49
|
Li H. Single Molecule Force Spectroscopy Studies on Metalloproteins: Opportunities and Challenges. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:1345-1353. [PMID: 36647634 DOI: 10.1021/acs.langmuir.2c03332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Metalloproteins play important roles in a wide range of biological processes. Elucidating the mechanisms via which metalloproteins fold and constitute their metal centers is critical to the understanding of the functions and dynamics of metalloproteins. Owing to its superior force and length resolution, single-molecule force spectroscopy (SMFS) has evolved into a powerful tool to probe the unfolding and folding mechanisms of metalloproteins at the single level by forcing metalloproteins to unfold and then refold along a reaction coordinate defined by the applied stretching force. The folding of metalloproteins is complex and involves two interwound processes, the folding of the polypeptide chain and the constitution of the metal center. Experimental studies of the folding of metalloproteins are challenging. SMFS studies have allowed researchers to directly probe the folding and unfolding of metalloproteins at the single-molecule level and the effect of metal centers on the folding-unfolding energy landscape of metalloproteins. New mechanistic insights on the folding and unfolding of some metalloproteins have been obtained, demonstrating the power and unique advantages that SMFS techniques may offer. In this Perspective, using calcium-binding proteins and small iron-sulfur proteins as examples, I provide a concise overview of the information and insights that SMFS studies have provided to understand the folding and unfolding of metalloproteins. I also discuss the opportunities and challenges that are present in this fast-progressing area of research.
Collapse
Affiliation(s)
- Hongbin Li
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| |
Collapse
|
50
|
Cao N, Cai W, Qian L, Nie Z, Mao C, Cui S. Emulating Titin by a Multidomain DNA Structure. ACS Macro Lett 2023; 12:59-64. [PMID: 36573670 DOI: 10.1021/acsmacrolett.2c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Titin, a giant protein containing multiple tandem domains, is essential in maintaining the superior mechanical performance of muscle. The consecutive and reversible unfolding and refolding of the domains are crucial for titin to serve as a modular spring. Since the discovery of the mechanical features of a single titin molecule, the exploration of biomimetic materials with titin-emulating modular structures has been an active field. However, it remains a challenge to prepare these modular polymers on a large scale due to the complex synthesis process. In this study, we propose modular DNA with multiple hairpins (MH-DNA) as the fundamental block for the bottom-up design of advanced materials. By analyzing the unfolding and refolding dynamics of modular hairpins by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), we find that MH-DNA shows comparable stability to those of polyproteins like titin. The unique low hysteresis of modular hairpin makes it an ideal molecular spring with remarkable mechanical efficiency. On the basis of the well-established DNA synthesis techniques, we anticipate that MH-DNA can be used as a promising building block for advanced materials with a combination of superior structural stability, considerable extensibility, and high mechanical efficiency.
Collapse
Affiliation(s)
- Nanpu Cao
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Wanhao Cai
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Lu Qian
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| | - Zhou Nie
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
| | - Chengde Mao
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Shuxun Cui
- College of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, China
| |
Collapse
|