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Kumar R, Dutta S. Exploring the unfolding pathways of protein families using Elastic Network Model. Sci Rep 2024; 14:23905. [PMID: 39397155 PMCID: PMC11471764 DOI: 10.1038/s41598-024-75436-8] [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: 04/19/2024] [Accepted: 10/04/2024] [Indexed: 10/15/2024] Open
Abstract
We explore how a protein's native structure determines its unfolding process. We examine how the local structural features, like shear, and the global structural properties, like the number of soft modes, change during unfolding. Simulations are performed using a Gaussian Network Model (GNM) with bond breaking for both thermal and force-induced unfolding scenarios. We find that unfolding starts in areas of high shear in the native structure and progressively spreads to the low shear regions. Interestingly, analysis of single domain protein families (Chymotrypsin inhibitor and Barnase) reveal that proteins with distinct unfolding pathways exhibit divergent behavior of the number of soft modes during unfolding. This suggests that the number of soft modes might be a valuable tool for understanding thermal unfolding pathways. Additionally, we found a strong link between a protein's overall structural similarity (TM-score) and its unfolding pathways, highlighting the importance of the native structure in determining how a protein unfolds.
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Affiliation(s)
- Ranjan Kumar
- Department of Physics, Birla Institute of Technology and Science, Pilani, Rajasthan, 333031, India
| | - Sandipan Dutta
- Department of Physics, Birla Institute of Technology and Science, Pilani, Rajasthan, 333031, India.
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2
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Bauer J, Žoldák G. Interpretation of Single-Molecule Force Experiments on Proteins Using Normal Mode Analysis. NANOMATERIALS 2021; 11:nano11112795. [PMID: 34835560 PMCID: PMC8624234 DOI: 10.3390/nano11112795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 11/25/2022]
Abstract
Single-molecule force spectroscopy experiments allow protein folding and unfolding to be explored using mechanical force. Probably the most informative technique for interpreting the results of these experiments at the structural level makes use of steered molecular dynamics (MD) simulations, which can explicitly model the protein under load. Unfortunately, this technique is computationally expensive for many of the most interesting biological molecules. Here, we find that normal mode analysis (NMA), a significantly cheaper technique from a computational perspective, allows at least some of the insights provided by MD simulation to be gathered. We apply this technique to three non-homologous proteins that were previously studied by force spectroscopy: T4 lysozyme (T4L), Hsp70 and the glucocorticoid receptor domain (GCR). The NMA results for T4L and Hsp70 are compared with steered MD simulations conducted previously, and we find that we can recover the main results. For the GCR, which did not undergo MD simulation, our approach identifies substructures that correlate with experimentally identified unfolding intermediates. Overall, we find that NMA can make a valuable addition to the analysis toolkit for the structural analysis of single-molecule force experiments on proteins.
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Affiliation(s)
- Jacob Bauer
- Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
- Correspondence: (J.B.); (G.Ž.); Tel.: +421-55-234-2242 (G.Ž.)
| | - Gabriel Žoldák
- Center for Interdisciplinary Biosciences, P. J. Šafárik University, Technology and Innovation Park, Trieda SNP 1, 041 54 Košice, Slovakia
- Correspondence: (J.B.); (G.Ž.); Tel.: +421-55-234-2242 (G.Ž.)
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3
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Cheng Q, Joung I, Lee J, Kuwajima K, Lee J. Exploring the Folding Mechanism of Small Proteins GB1 and LB1. J Chem Theory Comput 2019; 15:3432-3449. [DOI: 10.1021/acs.jctc.8b01163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qianyi Cheng
- Department of Chemistry, University of Memphis, Memphis, Tennessee 38152, United States
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - InSuk Joung
- Department of Chemistry, Kangwon National University, Chuncheon 24341, South Korea
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - Juyong Lee
- Department of Chemistry, Kangwon National University, Chuncheon 24341, South Korea
| | - Kunihiro Kuwajima
- Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, South Korea
| | - Jooyoung Lee
- Center for In Silico Protein Science, Korea Institute for Advanced Study, Seoul 02455, South Korea
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul 02455, South Korea
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4
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Modeling of Protein Structural Flexibility and Large-Scale Dynamics: Coarse-Grained Simulations and Elastic Network Models. Int J Mol Sci 2018; 19:ijms19113496. [PMID: 30404229 PMCID: PMC6274762 DOI: 10.3390/ijms19113496] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 12/13/2022] Open
Abstract
Fluctuations of protein three-dimensional structures and large-scale conformational transitions are crucial for the biological function of proteins and their complexes. Experimental studies of such phenomena remain very challenging and therefore molecular modeling can be a good alternative or a valuable supporting tool for the investigation of large molecular systems and long-time events. In this minireview, we present two alternative approaches to the coarse-grained (CG) modeling of dynamic properties of protein systems. We discuss two CG representations of polypeptide chains used for Monte Carlo dynamics simulations of protein local dynamics and conformational transitions, and highly simplified structure-based elastic network models of protein flexibility. In contrast to classical all-atom molecular dynamics, the modeling strategies discussed here allow the quite accurate modeling of much larger systems and longer-time dynamic phenomena. We briefly describe the main features of these models and outline some of their applications, including modeling of near-native structure fluctuations, sampling of large regions of the protein conformational space, or possible support for the structure prediction of large proteins and their complexes.
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Kouza M, Banerji A, Kolinski A, Buhimschi I, Kloczkowski A. Role of Resultant Dipole Moment in Mechanical Dissociation of Biological Complexes. Molecules 2018; 23:molecules23081995. [PMID: 30103417 PMCID: PMC6222447 DOI: 10.3390/molecules23081995] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 08/07/2018] [Accepted: 08/08/2018] [Indexed: 12/25/2022] Open
Abstract
Protein-peptide interactions play essential roles in many cellular processes and their structural characterization is the major focus of current experimental and theoretical research. Two decades ago, it was proposed to employ the steered molecular dynamics (SMD) to assess the strength of protein-peptide interactions. The idea behind using SMD simulations is that the mechanical stability can be used as a promising and an efficient alternative to computationally highly demanding estimation of binding affinity. However, mechanical stability defined as a peak in force-extension profile depends on the choice of the pulling direction. Here we propose an uncommon choice of the pulling direction along resultant dipole moment (RDM) vector, which has not been explored in SMD simulations so far. Using explicit solvent all-atom MD simulations, we apply SMD technique to probe mechanical resistance of ligand-receptor system pulled along two different vectors. A novel pulling direction—when ligand unbinds along the RDM vector—results in stronger forces compared to commonly used ligand unbinding along center of masses vector. Our observation that RDM is one of the factors influencing the mechanical stability of protein-peptide complex can be used to improve the ranking of binding affinities by using mechanical stability as an effective scoring function.
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Affiliation(s)
- Maksim Kouza
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
- Battelle Center for Mathematical Medicine, Nationwide Children’s Hospital, Columbus, OH 43215, USA;
- Correspondence: ; Tel.: +48-22-55-26-364
| | - Anirban Banerji
- Battelle Center for Mathematical Medicine, Nationwide Children’s Hospital, Columbus, OH 43215, USA;
| | - Andrzej Kolinski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
| | - Irina Buhimschi
- Center for Perinatal Research, Research Institute at Nationwide Children’s Hospital, Columbus, OH 43215, USA;
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43215, USA
| | - Andrzej Kloczkowski
- Battelle Center for Mathematical Medicine, Nationwide Children’s Hospital, Columbus, OH 43215, USA;
- Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43215, USA
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Kouza M, Co NT, Li MS, Kmiecik S, Kolinski A, Kloczkowski A, Buhimschi IA. Kinetics and mechanical stability of the fibril state control fibril formation time of polypeptide chains: A computational study. J Chem Phys 2018; 148:215106. [PMID: 29884031 DOI: 10.1063/1.5028575] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Fibril formation resulting from protein misfolding and aggregation is a hallmark of several neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Despite much progress in the understanding of the protein aggregation process, the factors governing fibril formation rates and fibril stability have not been fully understood. Using lattice models, we have shown that the fibril formation time is controlled by the kinetic stability of the fibril state but not by its energy. Having performed all-atom explicit solvent molecular dynamics simulations with the GROMOS43a1 force field for full-length amyloid beta peptides Aβ40 and Aβ42 and truncated peptides, we demonstrated that kinetic stability can be accessed via mechanical stability in such a way that the higher the mechanical stability or the kinetic stability, the faster the fibril formation. This result opens up a new way for predicting fibril formation rates based on mechanical stability that may be easily estimated by steered molecular dynamics.
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Affiliation(s)
- Maksim Kouza
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Nguyen Truong Co
- Institute of Physics, Polish Academy of Sciences, Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Mai Suan Li
- Institute of Physics, Polish Academy of Sciences, Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Sebastian Kmiecik
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Andrzej Kolinski
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Andrzej Kloczkowski
- Battelle Center for Mathematical Medicine, The Research Nationwide Children's Hospital, 575 Children's Crossroad, Columbus, Ohio 43215, USA
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Plata CA, Scholl ZN, Marszalek PE, Prados A. Relevance of the Speed and Direction of Pulling in Simple Modular Proteins. J Chem Theory Comput 2018; 14:2910-2918. [DOI: 10.1021/acs.jctc.8b00347] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Carlos A. Plata
- Física Teórica, Universidad de Sevilla, Apdo. de Correos 1065, Sevilla 41080, Spain
| | - Zackary N. Scholl
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Piotr E. Marszalek
- Department of Mechanical Engineering and Materials Science, Duke University, Durham 27708, North Carolina, United States
| | - Antonio Prados
- Física Teórica, Universidad de Sevilla, Apdo. de Correos 1065, Sevilla 41080, Spain
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Habibi M, Plotkin SS, Rottler J. Soft Vibrational Modes Predict Breaking Events during Force-Induced Protein Unfolding. Biophys J 2018; 114:562-569. [PMID: 29414701 PMCID: PMC5985024 DOI: 10.1016/j.bpj.2017.11.3781] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/04/2017] [Accepted: 11/27/2017] [Indexed: 01/03/2023] Open
Abstract
We investigate the correlation between soft vibrational modes and unfolding events in simulated force spectroscopy of proteins. Unfolding trajectories are obtained from molecular dynamics simulations of a Gō model of a monomer of a mutant of superoxide dismutase 1 protein containing all heavy atoms in the protein, and a normal mode analysis is performed based on the anisotropic network model. We show that a softness map constructed from the superposition of the amplitudes of localized soft modes correlates with unfolding events at different stages of the unfolding process. Soft residues are up to eight times more likely to undergo disruption of native structure than the average amino acid. The memory of the softness map is retained for extensions of up to several nanometers, but decorrelates more rapidly during force drops.
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Affiliation(s)
- Mona Habibi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
| | - Steven S Plotkin
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada.
| | - Jörg Rottler
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada; Quantum Matter Institute, University of British Columbia, Vancouver, Canada
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Kouza M, Lan PD, Gabovich AM, Kolinski A, Li MS. Switch from thermal to force-driven pathways of protein refolding. J Chem Phys 2017; 146:135101. [DOI: 10.1063/1.4979201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Habibi M, Rottler J, Plotkin SS. As Simple As Possible, but Not Simpler: Exploring the Fidelity of Coarse-Grained Protein Models for Simulated Force Spectroscopy. PLoS Comput Biol 2016; 12:e1005211. [PMID: 27898663 PMCID: PMC5127490 DOI: 10.1371/journal.pcbi.1005211] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/14/2016] [Indexed: 01/18/2023] Open
Abstract
Mechanical unfolding of a single domain of loop-truncated superoxide dismutase protein has been simulated via force spectroscopy techniques with both all-atom (AA) models and several coarse-grained models having different levels of resolution: A Gō model containing all heavy atoms in the protein (HA-Gō), the associative memory, water mediated, structure and energy model (AWSEM) which has 3 interaction sites per amino acid, and a Gō model containing only one interaction site per amino acid at the Cα position (Cα-Gō). To systematically compare results across models, the scales of time, energy, and force had to be suitably renormalized in each model. Surprisingly, the HA-Gō model gives the softest protein, exhibiting much smaller force peaks than all other models after the above renormalization. Clustering to render a structural taxonomy as the protein unfolds showed that the AA, HA-Gō, and Cα-Gō models exhibit a single pathway for early unfolding, which eventually bifurcates repeatedly to multiple branches only after the protein is about half-unfolded. The AWSEM model shows a single dominant unfolding pathway over the whole range of unfolding, in contrast to all other models. TM alignment, clustering analysis, and native contact maps show that the AWSEM pathway has however the most structural similarity to the AA model at high nativeness, but the least structural similarity to the AA model at low nativeness. In comparison to the AA model, the sequence of native contact breakage is best predicted by the HA-Gō model. All models consistently predict a similar unfolding mechanism for early force-induced unfolding events, but diverge in their predictions for late stage unfolding events when the protein is more significantly disordered.
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Affiliation(s)
- Mona Habibi
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jörg Rottler
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Steven S. Plotkin
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
- Genome Sciences and Technology Program, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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11
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Connecting thermal and mechanical protein (un)folding landscapes. Biophys J 2016; 107:2950-2961. [PMID: 25517160 DOI: 10.1016/j.bpj.2014.10.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/08/2014] [Accepted: 10/15/2014] [Indexed: 11/22/2022] Open
Abstract
Molecular dynamics simulations supplement single-molecule pulling experiments by providing the possibility of examining the full free energy landscape using many coordinates. Here, we use an all-atom structure-based model to study the force and temperature dependence of the unfolding of the protein filamin by applying force at both termini. The unfolding time-force relation τ(F) indicates that the force-induced unfolding behavior of filamin can be characterized into three regimes: barrier-limited low- and intermediate-force regimes, and a barrierless high-force regime. Slope changes of τ(F) separate the three regimes. We show that the behavior of τ(F) can be understood from a two-dimensional free energy landscape projected onto the extension X and the fraction of native contacts Q. In the low-force regime, the unfolding rate is roughly force-independent due to the small (even negative) separation in X between the native ensemble and transition state ensemble (TSE). In the intermediate-force regime, force sufficiently separates the TSE from the native ensemble such that τ(F) roughly follows an exponential relation. This regime is typically explored by pulling experiments. While X may fail to resolve the TSE due to overlap with the unfolded ensemble just below the folding temperature, the overlap is minimal at lower temperatures where experiments are likely to be conducted. The TSE becomes increasingly structured with force, whereas the average order of structural events during unfolding remains roughly unchanged. The high-force regime is characterized by barrierless unfolding, and the unfolding time approaches a limit of ∼10 μs for the highest forces we studied. Finally, a combination of X and Q is shown to be a good reaction coordinate for almost the entire force range.
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