1
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Rangubpit W, Sungted S, Wong-Ekkabut J, Distaffen HE, Nilsson BL, Dias CL. Pore Formation by Amyloid-like Peptides: Effects of the Nonpolar-Polar Sequence Pattern. ACS Chem Neurosci 2024; 15:3354-3362. [PMID: 39172951 PMCID: PMC11443323 DOI: 10.1021/acschemneuro.4c00333] [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: 08/24/2024] Open
Abstract
One of the mechanisms accounting for the toxicity of amyloid peptides in diseases like Alzheimer's and Parkinson's is the formation of pores on the plasma membrane of neurons. Here, we perform unbiased all-atom simulations of the full membrane damaging pathway, which includes adsorption, aggregation, and perforation of the lipid bilayer accounting for pore-like structures. Simulations are performed using four peptides made with the same amino acids. Differences in the nonpolar-polar sequence pattern of these peptides prompt them to adsorb into the membrane with the extended conformations oriented either parallel [peptide labeled F1, Ac-(FKFE)2-NH2], perpendicular (F4, Ac-FFFFKKEE-NH2), or with an intermediate orientation (F2, Ac-FFKKFFEE-NH2, and F3, Ac-FFFKFEKE-NH2) in regard to the membrane surface. At the water-lipid interface, only F1 fully self-assembles into β-sheets, and F2 peptides partially fold into an α-helical structure. The β-sheets of F1 emerge as electrostatic interactions attract neighboring peptides to intermediate distances where nonpolar side chains can interact within the dry core of the bilayer. This complex interplay between electrostatic and nonpolar interactions is not observed for the other peptides. Although β-sheets of F1 peptides are mostly parallel to the membrane, some of their edges penetrate deep inside the bilayer, dragging water molecules with them. This precedes pore formation, which starts with the flow of two water layers through the membrane that expand into a stable cylindrical pore delimited by polar faces of β-sheets spanning both leaflets of the bilayer.
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Affiliation(s)
- Warin Rangubpit
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
| | - Siwaporn Sungted
- Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Computational Biomodelling Laboratory for Agricultural Science and Technology (CBLAST), Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Jirasak Wong-Ekkabut
- Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
- Computational Biomodelling Laboratory for Agricultural Science and Technology (CBLAST), Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Hannah E Distaffen
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
| | - Bradley L Nilsson
- Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, United States
- Materials Science Program, University of Rochester, Rochester, New York 14627-0166, United States
| | - Cristiano L Dias
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
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2
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Luo H, Ma Y, Bi J, Li Z, Wang Y, Su Z, Gerstweiler L, Ren Y, Zhang S. Experimental and molecular dynamics simulation studies on the physical properties of three HBc-VLP derivatives as nanoparticle protein vaccine candidates. Vaccine 2024; 42:125992. [PMID: 38811268 DOI: 10.1016/j.vaccine.2024.05.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/19/2024] [Accepted: 05/20/2024] [Indexed: 05/31/2024]
Abstract
Self-assembling virus-like particles (VLPs) are promising platforms for vaccine development. However, the unpredictability of the physical properties, such as self-assembly capability, hydrophobicity, and overall stability in engineered protein particles fused with antigens, presents substantial challenges in their downstream processing. We envision that these challenges can be addressed by combining more precise computer-aided molecular dynamics (MD) simulations with experimental studies on the modified products, with more to-date forcefield descriptions and larger models closely resembling real assemblies, realized by rapid advancement in computing technology. In this study, three chimeric designs based on the hepatitis B core (HBc) protein as model vaccine candidates were constructed to study and compare the influence of inserted epitopes as well as insertion strategy on HBc modifications. Large partial VLP models containing 17 chains for the HBc chimeric model vaccines were constructed based on the wild-type (wt) HBc assembly template. The findings from our simulation analysis have demonstrated good consistency with experimental results, pertaining to the surface hydrophobicity and overall stability of the chimeric vaccine candidates. Furthermore, the different impact of foreign antigen insertions on the HBc scaffold was investigated through simulations. It was found that separately inserting two epitopes into the HBc platform at the N-terminal and the major immunogenic regions (MIR) yields better results compared to a serial insertion at MIR in terms of protein structural stability. This study substantiates that an MD-guided design approach can facilitate vaccine development and improve its manufacturing efficiency by predicting products with extreme surface hydrophobicity or structural instability.
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Affiliation(s)
- Hong Luo
- School of Chemical Engineering, Faculty of Science, Engineering and Technology, University of Adelaide, Adelaide 5005, Australia; State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery (CAS), Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; Institute of Pharmaceutical and Food Engineering, Shanxi University of Chinese Medicine, Jinzhong 030619, PR China
| | - Yanyan Ma
- State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery (CAS), Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Jingxiu Bi
- School of Chemical Engineering, Faculty of Science, Engineering and Technology, University of Adelaide, Adelaide 5005, Australia
| | - Zhengjun Li
- State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery (CAS), Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Yingli Wang
- Institute of Pharmaceutical and Food Engineering, Shanxi University of Chinese Medicine, Jinzhong 030619, PR China
| | - Zhiguo Su
- State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery (CAS), Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Lukas Gerstweiler
- School of Chemical Engineering, Faculty of Science, Engineering and Technology, University of Adelaide, Adelaide 5005, Australia.
| | - Ying Ren
- State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Songping Zhang
- State Key Laboratory of Biochemical Engineering, Key Laboratory of Biopharmaceutical Preparation and Delivery (CAS), Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
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3
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Diessner E, Thomas LJ, Butts CT. Production of Distinct Fibrillar, Oligomeric, and Other Aggregation States from Network Models of Multibody Interaction. J Chem Theory Comput 2024; 20. [PMID: 39259851 PMCID: PMC11448054 DOI: 10.1021/acs.jctc.4c00916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2024] [Revised: 08/28/2024] [Accepted: 08/29/2024] [Indexed: 09/13/2024]
Abstract
Protein aggregation can produce a wide range of states, ranging from fibrillar structures and oligomers to unstructured and semistructured gel phases. Recent work has shown that many of these states can be recapitulated by relatively simple, topological models specified in terms of multibody interaction energies, providing a direct connection between aggregate intermolecular forces and aggregation products. Here, we examine a low-dimensional network Hamiltonian model (NHM) based on four basic multibody interactions found in any aggregate system. We characterize the phase behavior of this NHM family, showing that fibrils arise from a balance between elongation-inducing and contact-inhibiting forces. Complex oligomers (including annular oligomers resembling those thought to be toxic species in Alzheimer's disease) also form distinct phases in this regime, controlled in part by closure-inducing forces. We show that phase structure is largely independent of system size, and provide evidence of a rich structure of minor oligomeric phases that can arise from appropriate conditions. We characterize the phase behavior of this NHM family, demonstrating the range of ordered and disordered aggregation states possible with this set of interactions. As we show, fibrils arise from a balance between elongation-inducing and contact-inhibiting forces, existing in a regime bounded by gel-like and disaggregated phases; complex oligomers (including annular oligomers resembling those thought to be toxic species in Alzheimer's disease) also form distinct phases in this regime, controlled in part by closure-inducing forces. We show that phase structure is largely independent of system size, allowing generalization to macroscopic systems, and provide evidence of a rich structure of minor oligomeric phases that can arise from appropriate conditions.
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Affiliation(s)
- Elizabeth
M. Diessner
- Department
of Chemistry, University of California, Irvine, California 92697, United States
| | - Loring J. Thomas
- Department
of Sociology, University of California, Irvine, California 92697, United States
| | - Carter T. Butts
- Department
of Sociology, University of California, Irvine, California 92697, United States
- Departments
of Statistics, Computer Science, and EECS, University of California, Irvine, California 92697, United States
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4
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Hribar-Lee B, Lukšič M. Biophysical Principles Emerging from Experiments on Protein-Protein Association and Aggregation. Annu Rev Biophys 2024; 53:1-18. [PMID: 37906740 DOI: 10.1146/annurev-biophys-030722-111729] [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: 11/02/2023]
Abstract
Protein-protein association and aggregation are fundamental processes that play critical roles in various biological phenomena, from cellular signaling to disease progression. Understanding the underlying biophysical principles governing these processes is crucial for elucidating their mechanisms and developing strategies for therapeutic intervention. In this review, we provide an overview of recent experimental studies focused on protein-protein association and aggregation. We explore the key biophysical factors that influence these processes, including protein structure, conformational dynamics, and intermolecular interactions. We discuss the effects of environmental conditions such as temperature, pH and related buffer-specific effects, and ionic strength and related ion-specific effects on protein aggregation. The effects of polymer crowders and sugars are also addressed. We list the techniques used to study aggregation. We analyze emerging trends and challenges in the field, including the development of computational models and the integration of multidisciplinary approaches for a comprehensive understanding of protein-protein association and aggregation.
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Affiliation(s)
- Barbara Hribar-Lee
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia;
| | - Miha Lukšič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia;
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5
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Ding X, Xu C, Zheng B, Yu H, Zheng P. Molecular Mechanism of Interaction between DNA Aptamer and Receptor-Binding Domain of Severe Acute Respiratory Syndrome Coronavirus 2 Variants Revealed by Steered Molecular Dynamics Simulations. Molecules 2024; 29:2215. [PMID: 38792076 PMCID: PMC11124494 DOI: 10.3390/molecules29102215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
The ongoing SARS-CoV-2 pandemic has underscored the urgent need for versatile and rapidly deployable antiviral strategies. While vaccines have been pivotal in controlling the spread of the virus, the emergence of new variants continues to pose significant challenges to global health. Here, our study focuses on a novel approach to antiviral therapy using DNA aptamers, short oligonucleotides with high specificity and affinity for their targets, as potential inhibitors against the spike protein of SARS-CoV-2 variants Omicron and JN.1. Our research utilizes steered molecular dynamics (SMD) simulations to elucidate the binding mechanisms of a specifically designed DNA aptamer, AM032-4, to the receptor-binding domain (RBD) of the aforementioned variants. The simulations reveal detailed molecular insights into the aptamer-RBD interaction, demonstrating the aptamer's potential to maintain effective binding in the face of rapid viral evolution. Our work not only demonstrates the dynamic interaction between aptamer-RBD for possible antiviral therapy but also introduces a computational method to study aptamer-protein interactions.
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Affiliation(s)
- Xuan Ding
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210093, China
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Chao Xu
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Bin Zheng
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Hanyang Yu
- Department of Biomedical Engineering, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
| | - Peng Zheng
- School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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6
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Mao CM, Sampath J, Pfaendtner J. Molecular Driving Forces in the Self-Association of Silaffin Peptide R5 from MD Simulations. Chembiochem 2024:e202300788. [PMID: 38485668 DOI: 10.1002/cbic.202300788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/13/2024] [Indexed: 05/15/2024]
Abstract
The 19-residue silaffin-R5 peptide has been widely studied for its ability to precipitate uniform SiO2 particles through mild temperature and pH pathways, in the absence of any organic solvents. There is consensus that post-translational modification (PTM) of side chains has a large impact on the biomineralization process. Thus, it is imperative to understand the precise mechanisms that dictate the formation of SiO2 from R5 peptide, including the effects of PTM on peptide aggregation and peptide-surface adsorption. In this work, we use molecular dynamics (MD) simulations to study the aggregation of R5 dimer with multiple PTMs, with the presence of different ions in solution. Since this system has strong interactions with deep metastable states, we use parallel bias metadynamics with partitioned families to efficiently sample the different states of the system. We find that peptide aggregation is a prerequisite for biomineralization. We observe that the electrostatic interactions are essential in the R5 dimer aggregation; for wild type R5 that only has positively charged residues, phosphate ions HPO4 2- in the solution form a bridge between two peptides and are essential for peptide aggregation.
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Affiliation(s)
- Coco M Mao
- Department of Materials Science and Engineering, University of Washington, Seattle WA, 98195
| | - Janani Sampath
- Department of Chemical Engineering, University of Florida, Gainesville, FL, 32611
| | - Jim Pfaendtner
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695
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7
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Thapa S, Clark F, Schneebeli ST, Li J. Multiscale Simulations to Discover Self-Assembled Oligopeptides: A Benchmarking Study. J Chem Theory Comput 2024; 20:375-384. [PMID: 38013425 PMCID: PMC11070933 DOI: 10.1021/acs.jctc.3c00699] [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: 11/29/2023]
Abstract
Peptide self-assembly is critical for biomedical and material discovery and production. While it is costly to experimentally test every possible peptide design, computational assessment provides an affordable solution to evaluate many designs and prioritize synthesis and characterization. Following a theoretical investigation, we present a systematic analysis of all-atom and coarse-grained simulations to predict peptide self-assembly. Benchmarking studies of two model dipeptides allow us to assess the impacts of intrinsic properties (such as amino acids and terminal modifications) and external environment (such as salinity) on the simulated aggregation. Further examination of 20 oligopeptides containing two to five amino acids shows good agreement among our theory, simulations, and prior experimental observations. The success rate of our prediction is 90%. Therefore, our theory, simulation, and analysis can be useful to identify peptide designs that can self-assemble and predict the potential nanostructures. These findings lay the ground for future virtual screening of peptide-assembled nanostructures and computer-aided biologics design.
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Affiliation(s)
- Subhadra Thapa
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Finley Clark
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
| | - Severin. T. Schneebeli
- Department of Industrial and Physical Pharmacy and Department of Chemistry, Purdue University, West Lafayette, IN 47907
| | - Jianing Li
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907
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8
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Vlachy V, Kalyuzhnyi YV, Hribar-Lee B, Dill KA. Protein Association in Solution: Statistical Mechanical Modeling. Biomolecules 2023; 13:1703. [PMID: 38136574 PMCID: PMC10742237 DOI: 10.3390/biom13121703] [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: 10/25/2023] [Revised: 11/16/2023] [Accepted: 11/20/2023] [Indexed: 12/24/2023] Open
Abstract
Protein molecules associate in solution, often in clusters beyond pairwise, leading to liquid phase separations and high viscosities. It is often impractical to study these multi-protein systems by atomistic computer simulations, particularly in multi-component solvents. Instead, their forces and states can be studied by liquid state statistical mechanics. However, past such approaches, such as the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, were limited to modeling proteins as spheres, and contained no microscopic structure-property relations. Recently, this limitation has been partly overcome by bringing the powerful Wertheim theory of associating molecules to bear on protein association equilibria. Here, we review these developments.
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Affiliation(s)
- Vojko Vlachy
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | | | - Barbara Hribar-Lee
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Ken A. Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, New York, NY 11794, USA;
- Department of Chemistry, Physics and Astronomy, Stony Brook University, New York, NY 11790, USA
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9
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Abstract
The formation of amyloid fibrils is a complex phenomenon that remains poorly understood at the atomic scale. Herein, we perform extended unbiased all-atom simulations in explicit solvent of a short amphipathic peptide to shed light on the three mechanisms accounting for fibril formation, namely, nucleation via primary and secondary mechanisms, and fibril growth. We find that primary nucleation takes place via the formation of an intermediate state made of two laminated β-sheets oriented perpendicular to each other. The amyloid fibril spine subsequently emerges from the rotation of these β-sheets to account for peptides that are parallel to each other and perpendicular to the main axis of the fibril. Growth of this spine, in turn, takes place via a dock-and-lock mechanism. We find that peptides dock onto the fibril tip either from bulk solution or after diffusing on the fibril surface. The latter docking pathway contributes significantly to populate the fibril tip with peptides. We also find that side chain interactions drive the motion of peptides in the lock phase during growth, enabling them to adopt the structure imposed by the fibril tip with atomic fidelity. Conversely, the docked peptide becomes trapped in a local free energy minimum when docked-conformations are sampled randomly. Our simulations also highlight the role played by nonpolar fibril surface patches in catalyzing and orienting the formation of small cross-β structures. More broadly, our simulations provide important new insights into the pathways and interactions accounting for primary and secondary nucleation as well as the growth of amyloid fibrils.
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Affiliation(s)
- Sharareh Jalali
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
| | - Ruoyao Zhang
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Mikko P Haataja
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Princeton Materials Institute, Princeton University, Princeton, New Jersey 08544, United States
| | - Cristiano L Dias
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
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10
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Drajkowska A, Molski A. Aggregation and partitioning of amyloid peptide fragments in the presence of a lipid bilayer: A coarse grained molecular dynamics study. Biophys Chem 2023; 300:107051. [PMID: 37329644 DOI: 10.1016/j.bpc.2023.107051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/19/2023]
Abstract
Amyloidogenicity and toxicity of amyloid peptides have been linked to the peptide aggregation and interactions with lipid bilayers. In this work we used the coarse grained MARTINI model to study the aggregation and partitioning of amyloid peptide fragments Aβ(1-28) and Aβ(25-35) in the presence of a dipalmitoylphosphatidylcholine bilayer. We explored the peptide aggregation starting from three initial spatial arrangements where free monomers were placed in solution outside the membrane, at the membrane-solution interface, or in the membrane. We found that Aβ(1-28) and Aβ(25-35) interact with the bilayer quite differently. The Aβ(1-28) fragments show strong peptide-peptide and peptide-lipid interactions leading to irreversible aggregation where the aggregates stay confined to their initial spatial location. The Aβ(25-35) fragments show weaker peptide-peptide and peptide-lipid interaction leading to reversible aggregation and accumulation at the membrane-solution interface irrespective of their initial spatial arrangement. Those findings can be explained in terms of the shape of the potential of mean force for the single-peptide translocation across the membrane.
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Affiliation(s)
- Aleksandra Drajkowska
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, ul. Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
| | - Andrzej Molski
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, ul. Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
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11
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Cheung DL. Aggregation of an Amyloidogenic Peptide on Gold Surfaces. Biomolecules 2023; 13:1261. [PMID: 37627326 PMCID: PMC10452923 DOI: 10.3390/biom13081261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/03/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Solid surfaces have been shown to affect the aggregation and assembly of many biomolecular systems. One important example is the formation of protein fibrils, which can occur on a range of biological and synthetic surfaces. The rate of fibrillation depends on both the protein structure and the surface chemistry, with the different molecular and oligomer structures adopted by proteins on surfaces likely to be crucial. In this paper, the aggregation of the model amyloidogenic peptide, Aβ(16-22), corresponding to a hydrophobic segment of the amyloid beta protein on a gold surface is studied using molecular dynamics simulation. Previous simulations of this peptide on gold surfaces have shown that it adopts conformations on surfaces that are quite different from those in bulk solution. These simulations show that this then leads to significant differences in the oligomer structures formed in solution and on gold surfaces. In particular, oligomers formed on the surface are low in beta-strands so are unlike the structures formed in bulk solution. When oligomers formed in solution adsorb onto gold surfaces they can then restructure themselves. This can then help explain the inhibition of Aβ(16-22) fibrillation by gold surfaces and nanoparticles seen experimentally.
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Affiliation(s)
- David L Cheung
- School of Biological and Chemical Sciences, University of Galway, H91 TK33 Galway, Ireland
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12
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Szała-Mendyk B, Drajkowska A, Molski A. Modified Smoluchowski Rate Equations for Aggregation and Fragmentation in Finite Systems. J Phys Chem B 2023. [PMID: 37369009 DOI: 10.1021/acs.jpcb.3c02884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Protein self-assembly into supramolecular structures is important for cell biology. Theoretical methods employed to investigate protein aggregation and analogous processes include molecular dynamics simulations, stochastic models, and deterministic rate equations based on the mass-action law. In molecular dynamics simulations, the computation cost limits the system size, simulation length, and number of simulation repeats. Therefore, it is of practical interest to develop new methods for the kinetic analysis of simulations. In this work we consider the Smoluchowski rate equations modified to account for reversible aggregation in finite systems. We present several examples and argue that the modified Smoluchowski equations combined with Monte Carlo simulations of the corresponding master equation provide an effective tool for developing kinetic models of peptide aggregation in molecular dynamics simulations.
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Affiliation(s)
- Beata Szała-Mendyk
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
| | - Aleksandra Drajkowska
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
| | - Andrzej Molski
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
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13
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Tammara V, Das A. Governing dynamics and preferential binding of the AXH domain influence the aggregation pathway of Ataxin-1. Proteins 2023; 91:380-394. [PMID: 36208132 DOI: 10.1002/prot.26436] [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: 03/15/2022] [Revised: 08/30/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022]
Abstract
The present state of understanding the mechanism of Spinocerebellar Ataxia-1, a fatal neurodegenerative disease linked to the protein Ataxin-1 (ATXN1), is baffled by a set of self-contradictory, and hence, inconclusive observations. This fallacy poses a bottleneck to the effective designing of curable drugs as the field is currently missing the specific druggable site. To understand the fundamentals of pathogenesis, we tried to decipher the intricacies of the extremely complicated landscape by targeting the relevant species that supposedly dictate the structure-function paradigm. The atomic-level description and characterization of the dynamism of the systems reveal the existence of structural polymorphism in all the leading stakeholders of the overall system. The very existence of conformational heterogeneity in every species creates numerous possible combinations of favorable interactions because of the variability in segmental cross-talks and hence claims its role in the choice of routes between functional activity and dysfunctional disease-causing aggregation. Despite this emergent configurational diversity, there is a common mode of operative intermolecular forces that dictates the extent of stability of all the multimeric complexes due to the localized population of a specific type of residue. The present research proposes a dynamic switch mechanism between aggregability and functional activity, based on the logical interpretation of the estimated variables, which is practically dictated by the effective concentration of the interacting species involved in the cell.
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Affiliation(s)
- Vaishnavi Tammara
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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14
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Li Q, Wen C, Yang J, Zhou X, Zhu Y, Zheng J, Cheng G, Bai J, Xu T, Ji J, Jiang S, Zhang L, Zhang P. Zwitterionic Biomaterials. Chem Rev 2022; 122:17073-17154. [PMID: 36201481 DOI: 10.1021/acs.chemrev.2c00344] [Citation(s) in RCA: 130] [Impact Index Per Article: 65.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The term "zwitterionic polymers" refers to polymers that bear a pair of oppositely charged groups in their repeating units. When these oppositely charged groups are equally distributed at the molecular level, the molecules exhibit an overall neutral charge with a strong hydration effect via ionic solvation. The strong hydration effect constitutes the foundation of a series of exceptional properties of zwitterionic materials, including resistance to protein adsorption, lubrication at interfaces, promotion of protein stabilities, antifreezing in solutions, etc. As a result, zwitterionic materials have drawn great attention in biomedical and engineering applications in recent years. In this review, we give a comprehensive and panoramic overview of zwitterionic materials, covering the fundamentals of hydration and nonfouling behaviors, different types of zwitterionic surfaces and polymers, and their biomedical applications.
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Affiliation(s)
- Qingsi Li
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Chiyu Wen
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Jing Yang
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Xianchi Zhou
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Yingnan Zhu
- Institute of Drug Discovery and Development, School of Pharmaceutical Sciences, Center for Drug Safety Evaluation and Research, Zhengzhou University, Zhengzhou 450001, China
| | - Jie Zheng
- Department of Chemical, Biomolecular, and Corrosion Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Gang Cheng
- Department of Chemical Engineering, The University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Jie Bai
- College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China
| | - Tong Xu
- College of Chemical Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051, China
| | - Jian Ji
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Shaoyi Jiang
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Lei Zhang
- Department of Biochemical Engineering, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China
| | - Peng Zhang
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, China
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15
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Wu K, Sun W, Li D, Diao J, Xiu P. Inhibition of Amyloid Nucleation by Steric Hindrance. J Phys Chem B 2022; 126:10045-10054. [PMID: 36417323 DOI: 10.1021/acs.jpcb.2c06330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Despite recent experiments and simulations suggesting that small-molecule inhibitors and some post-translational modifications (e.g., glycosylation and ubiquitination) can suppress the pathogenic aggregation of proteins due to steric hindrance, the effect of steric hindrance on amyloid formation has not been systematically studied. Based on Monte Carlo simulations using a coarse-grained model for amyloidogenic proteins and a hard sphere acting as steric hindrance, we investigated how steric hindrance on proteins could affect amyloid formation, particularly two steps of primary nucleation, namely, oligomerization and conformational conversion into a β-sheet-enriched nucleus. We found that steric spheres played an inhibitory role in oligomerization with the effect proportional to the sphere radius RS, which we attributed to the decline in the nonspecific attractions between proteins. During the second step, small steric spheres facilitated the conformational conversion of proteins while large ones suppressed the conversion. The overall steric effect on amyloid nucleation was inhibitory regardless of RS. As RS increased, oligomeric assemblies changed from amorphous into sheet-like, structurally ordered species, reminiscent of the structure of amyloid fibrils. The oligomers with large RS were off-pathway with their ordered structures induced by the competition between steric hindrance and nonspecific attractions of soluble proteins. Interestingly, the equimolar mixture of proteins with and without steric hindrance amplified the sterically inhibitory effect by increasing the energy barrier of protein's conformational conversion. The physical mechanisms and biological implications of the above results are discussed. Our findings improve the current understanding of how nature regulates protein aggregation and amyloid formation by steric hindrance.
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Affiliation(s)
- Kai Wu
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China.,Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States of America
| | - Wuxuepeng Sun
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Dechang Li
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States of America
| | - Peng Xiu
- Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, People's Republic of China
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16
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Adhikary R, Das A. Atomistic Pictures of Self-Assembled Helical Peptide Nanofibers. J Phys Chem B 2022; 126:9476-9492. [PMID: 36350248 DOI: 10.1021/acs.jpcb.2c04484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Spontaneous self-assembly of peptides has been at the forefront of supramolecular chemistry and materials science research over the last two decades. Despite the wealth of information on the morphology of the assembled objects, atomic resolution details of molecular arrangements inside them are largely unknown. In this paper, we investigated non-covalent assemblies of zwitterionic l-phenylalanine tripeptides in water using all-atom explicit-solvent molecular dynamics computer simulations. Our studies produced atomistic pictures of spontaneously assembled nanofibers composed of hundreds of peptide molecules. The dimensions of the nanofibers varied from 10 to 18 nm, with irregular helical twists along the long axes. Previously published experimental data, acquired under similar conditions, provided direct validation of the fibrous morphology and indirect support for the non-trivial helicity observed in our simulations. Quantitative analyses of peptide-water and peptide-peptide interactions revealed heterogeneous local environments of molecules across the nanometer length scales. The combination of electrostatic, hydrogen bonding, van der Waals, and hydrophobic interactions, adopted by a single molecule, was dependent on its relative position inside the fiber. Despite the presence of three hydrophobic phenyl groups, very few molecules were found to be completely shielded from the surrounding water, indicating a subtle role of the hydrophobic effect. Limited conformational flexibility of the tripeptide, along with bare electrostatic interactions, appeared to play a crucial role in the emergence of fibrous morphology of the nanostructures. Our analyses led us to formulate plausible qualitative explanations of the assembly behavior in terms of thermodynamic driving forces and kinetic considerations. We established a clear relationship between details of chemical interactions operating within few molecules and characteristics of the self-assembled states at much longer length scales.
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Affiliation(s)
- Rumela Adhikary
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
| | - Avisek Das
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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17
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Szała-Mendyk B, Molski A. Side Chain Geometry Determines the Fibrillation Propensity of a Minimal Two-Beads-per-Residue Peptide Model. J Phys Chem B 2022; 126:5772-5780. [PMID: 35917439 PMCID: PMC9376954 DOI: 10.1021/acs.jpcb.2c03502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The molecular mechanism of fibrillation is an important
issue for
understanding peptide aggregation. In our previous work, we demonstrated
that the interchain attraction and intrachain bending stiffness control
the aggregation kinetics and transient aggregate morphologies of a
one-bead-per-residue implicit solvent peptide model. However, that
model did not lead to fibrillation. In this work, we study the molecular
origin of fibril formation using a two-beads-per-residue model, where
one bead represents the backbone residue atoms and the other the side
chain atoms. We show that the side chain geometry determines the fibrillation
propensity that is further modulated by the modified terminal beads.
This allows us to bring out the effects of side chain geometry and
terminal capping on the fibrillation propensity. Our model does not
assume a secondary structure and is, perhaps, the simplest bead-based
chain model leading to fibrillation.
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Affiliation(s)
- Beata Szała-Mendyk
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
| | - Andrzej Molski
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland
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18
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Bhagavatula H, Sarkar A, Santra B, Das A. Scan-Find-Scan-Model: Discrete Site-Targeted Suppressor Design Strategy for Amyloid-β. ACS Chem Neurosci 2022; 13:2191-2208. [PMID: 35767676 DOI: 10.1021/acschemneuro.2c00272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease is undoubtedly the most well-studied neurodegenerative disease. Consequently, the amyloid-β (Aβ) protein ranks at the top in terms of getting attention from the scientific community for structural property-based characterization. Even after decades of extensive research, there is existing volatility in terms of understanding and hence the effective tackling procedures against the disease that arises due to the lack of knowledge of both specific target- and site-specific drugs. Here, we develop a multidimensional approach based on the characterization of the common static-dynamic-thermodynamic trait of the monomeric protein, which efficiently identifies a small target sequence that contains an inherent tendency to misfold and consequently aggregate. The robustness of the identification of the target sequence comes with an abundance of a priori knowledge about the length and sequence of the target and hence guides toward effective designing of the target-specific drug with a very low probability of bottleneck and failure. Based on the target sequence information, we further identified a specific mutant that showed the maximum potential to act as a destabilizer of the monomeric protein as well as enormous success as an aggregation suppressor. We eventually tested the drug efficacy by estimating the extent of modulation of binding affinity existing within the fibrillar form of the Aβ protein due to a single-point mutation and hence provided a proof of concept of the entire protocol.
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Affiliation(s)
- Hasathi Bhagavatula
- Department of Biotechnology, Progressive Education Society's Modern College of Arts Science and Commerce, Shivajinagar, Pune 411005, India
| | - Archishman Sarkar
- School of Applied and Interdisciplinary Sciences, Indian Association for the Cultivation of Science, 2A & 2B, Raja Subodh Chandra Mallick Road, Kolkata, West Bengal 700032, India
| | - Binit Santra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kalyanpur, Kanpur, Uttar Pradesh 208016, India
| | - Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra 411008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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19
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Chen Q, Zhang J, Zhang Y, Kaplan DL, Wang Q. Protein-amylose/amylopectin molecular interactions during high-moisture extruded texturization toward plant-based meat substitutes applications. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107559] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Sakae Y, Kawasaki T, Okamoto Y. Distribution and Structure Analysis of Fibril-Forming Peptides Focusing on Concentration Dependency. ACS OMEGA 2022; 7:10012-10021. [PMID: 35382341 PMCID: PMC8975544 DOI: 10.1021/acsomega.1c04960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
We focus on the concentration dependency of fibril-forming peptides, which have the potential of aggregation by themselves. In this study, we performed replica-exchange molecular dynamics simulations of Lys-Phe-Phe-Glu (KFFE) fragments, which are known to form fibrils in experiments under different concentration environments. The analysis by static structure factors suggested that the density fluctuation of the KFFE fragments becomes large as the concentration increases. It was also found that the number of β-structures and oligomers also increases under a high concentration environment. Hence, a high concentration environment of fibril-forming peptides is likely to cause protein aggregation.
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Affiliation(s)
- Yoshitake Sakae
- Research
Organization for Information Science and Technology, Tokyo 105-0013, Japan
- Department
of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Takeshi Kawasaki
- Department
of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
| | - Yuko Okamoto
- Department
of Physics, Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
- Information
Technology Center, Nagoya University, Nagoya, Aichi 464-8601, Japan
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21
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Blanco MA. Computational models for studying physical instabilities in high concentration biotherapeutic formulations. MAbs 2022; 14:2044744. [PMID: 35282775 PMCID: PMC8928847 DOI: 10.1080/19420862.2022.2044744] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Computational prediction of the behavior of concentrated protein solutions is particularly advantageous in early development stages of biotherapeutics when material availability is limited and a large set of formulation conditions needs to be explored. This review provides an overview of the different computational paradigms that have been successfully used in modeling undesirable physical behaviors of protein solutions with a particular emphasis on high-concentration drug formulations. This includes models ranging from all-atom simulations, coarse-grained representations to macro-scale mathematical descriptions used to study physical instability phenomena of protein solutions such as aggregation, elevated viscosity, and phase separation. These models are compared and summarized in the context of the physical processes and their underlying assumptions and limitations. A detailed analysis is also given for identifying protein interaction processes that are explicitly or implicitly considered in the different modeling approaches and particularly their relations to various formulation parameters. Lastly, many of the shortcomings of existing computational models are discussed, providing perspectives and possible directions toward an efficient computational framework for designing effective protein formulations.
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Affiliation(s)
- Marco A. Blanco
- Materials and Biophysical Characterization, Analytical R & D, Merck & Co., Inc, Kenilworth, NJ USA
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22
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Das A. Systematic Search for a Predictor for the Clinical Observables of Alzheimer's Disease. J Phys Chem B 2021; 125:12177-12186. [PMID: 34723517 DOI: 10.1021/acs.jpcb.1c06725] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
One of the prevailing life-threatening incurable neurodegenerative diseases that are presently endangering human society as a whole, and hence, baffling the entire spectrum of the scientific and pharmaceutical world, is Alzheimer's disease (AD). AD is a manifestation of self-assembly of both wild-type (sporadic) and mutated (familial) forms of the amyloid-β peptide, a proteolytic product of the amyloid precursor protein, where the self-assembly results in the genesis of pathogenic fibrillar aggregates. Currently prevailing diagnostic and hence therapeutic challenges originate from the unavailability of a specific predictor for clinical observables. The continuous emergence of novel pathogenic mutants with unpredictable phenotypes adds immensely to the nonspecific nature of the problem. The current research reports a simple physical parameter, the binding affinity of a protofilament to its protofibril, which predicts the clinical observables of familial AD with astounding accuracy and more importantly, without any adjustable parameters.
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Affiliation(s)
- Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra 411 008, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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23
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Aggregation and structure of amyloid β-protein. Neurochem Int 2021; 151:105208. [PMID: 34655726 DOI: 10.1016/j.neuint.2021.105208] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/07/2021] [Accepted: 10/10/2021] [Indexed: 01/21/2023]
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder and is characterized by major pathological hallmarks in the brain, including plaques composed of amyloid β-protein (Aβ) and neurofibrillary tangles of tau protein. Genetic studies, biochemical data, and animal models have suggested that Aβ is a critical species in the pathogenesis of AD. Aβ molecules aggregate to form oligomers, protofibrils (PFs), and mature fibrils. Because of their instability and structural heterogeneity, the misfolding and aggregation of Aβ is a highly complex process, leading to a variety of aggregates with different structures and morphologies. However, the elucidation of Aβ molecules is essential because they are believed to play an important role in AD pathogenesis. Recent combination studies using nuclear magnetic resonance (NMR) and cryo-electron microscopy (cryo-EM) have primarily revealed more detailed information about their aggregation process, including fibril extension and secondary nucleation, and the structural polymorphism of the fibrils under a variety of some conditions, including the actual brain. This review attempts to summarize the existing information on the major properties of the structure and aggregation of Aβ.
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24
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Sepehri A, Nepal B, Lazaridis T. Distinct Modes of Action of IAPP Oligomers on Membranes. J Chem Inf Model 2021; 61:4645-4655. [PMID: 34499498 DOI: 10.1021/acs.jcim.1c00767] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Islet amyloid polypeptide (IAPP, also known as amylin) is a peptide hormone that is co-secreted with insulin by pancreatic β-cells and forms amyloid aggregates in type II diabetes. Various lines of evidence indicate that oligomers of this peptide may induce toxicity by disrupting or forming pores in cell membranes, but the structure of these pores is unknown. Here, we create models of pores for both helical and β-structured peptides using implicit membrane modeling and test their stability using multimicrosecond all-atom simulations. We find that the helical peptides behave similarly to antimicrobial peptides; they remain stably inserted in a highly tilted or partially unfolded configuration creating a narrow water channel. Parallel helix orientation creates a somewhat larger pore. An octameric β barrel of parallel β-hairpins is highly stable in the membrane, whereas the corresponding barrel made of antiparallel hairpins is not. We propose that certain experiments probe the helical pore state while others probe the β-structured pore state; this provides a possible explanation for lack of correlation that is sometimes observed between in vivo toxicity and in vitro liposome permeabilization experiments.
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Affiliation(s)
- Aliasghar Sepehri
- Department of Chemistry, City College of New York, New York, New York 10031, United States
| | - Binod Nepal
- Department of Chemistry, City College of New York, New York, New York 10031, United States
| | - Themis Lazaridis
- Department of Chemistry, City College of New York, New York, New York 10031, United States.,Graduate Programs in Chemistry, Biochemistry, and Physics, The Graduate Center, City University of New York, New York, New York, New York 10016, United States
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25
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Szała-Mendyk B, Molski A. Diverse Aggregation Kinetics Predicted by a Coarse-Grained Peptide Model. J Phys Chem B 2021; 125:7587-7597. [PMID: 34251838 PMCID: PMC8389928 DOI: 10.1021/acs.jpcb.1c00290] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
![]()
Protein and peptide
aggregation is a ubiquitous phenomenon with
implications in medicine, pharmaceutical industry, and materials science.
An important issue in peptide aggregation is the molecular mechanism
of aggregate nucleation and growth. In many experimental studies,
sigmoidal kinetics curves show a clear lag phase ascribed to nucleation;
however, experimental studies also show downhill kinetics curves,
where the monomers decay continuously and no lag phase can be seen.
In this work, we study peptide aggregation kinetics using a coarse-grained
implicit solvent model introduced in our previous work. Our simulations
explore the hypothesis that the interplay between interchain attraction
and intrachain bending stiffness controls the aggregation kinetics
and transient aggregate morphologies. Indeed, our model reproduces
the aggregation modes seen in experiment: no observed aggregation,
nucleated aggregation, and rapid downhill aggregation. We find that
the interaction strength is the primary parameter determining the
aggregation mode, whereas the stiffness is a secondary parameter modulating
the transient morphologies and aggregation rates: more attractive
and stiff chains aggregate more rapidly and the transient morphologies
are more ordered. We also explore the effects of the initial monomer
concentration and the chain length. As the concentration decreases,
the aggregation mode shifts from downhill to nucleated and no-aggregation.
This concentration effect is in line with an experimental observation
that the transition between downhill and nucleated kinetics is concentration-dependent.
We find that longer peptides can aggregate at conditions where short
peptides do not aggregate at all. It supports an experimental observation
that the elongation of a homopeptide, e.g., polyglutamine, can increase
the aggregation propensity.
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Affiliation(s)
- Beata Szała-Mendyk
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614 Poznań, Poland
| | - Andrzej Molski
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Umultowska 89b, 61-614 Poznań, Poland
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26
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Nguyen PH, Ramamoorthy A, Sahoo BR, Zheng J, Faller P, Straub JE, Dominguez L, Shea JE, Dokholyan NV, De Simone A, Ma B, Nussinov R, Najafi S, Ngo ST, Loquet A, Chiricotto M, Ganguly P, McCarty J, Li MS, Hall C, Wang Y, Miller Y, Melchionna S, Habenstein B, Timr S, Chen J, Hnath B, Strodel B, Kayed R, Lesné S, Wei G, Sterpone F, Doig AJ, Derreumaux P. Amyloid Oligomers: A Joint Experimental/Computational Perspective on Alzheimer's Disease, Parkinson's Disease, Type II Diabetes, and Amyotrophic Lateral Sclerosis. Chem Rev 2021; 121:2545-2647. [PMID: 33543942 PMCID: PMC8836097 DOI: 10.1021/acs.chemrev.0c01122] [Citation(s) in RCA: 386] [Impact Index Per Article: 128.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein misfolding and aggregation is observed in many amyloidogenic diseases affecting either the central nervous system or a variety of peripheral tissues. Structural and dynamic characterization of all species along the pathways from monomers to fibrils is challenging by experimental and computational means because they involve intrinsically disordered proteins in most diseases. Yet understanding how amyloid species become toxic is the challenge in developing a treatment for these diseases. Here we review what computer, in vitro, in vivo, and pharmacological experiments tell us about the accumulation and deposition of the oligomers of the (Aβ, tau), α-synuclein, IAPP, and superoxide dismutase 1 proteins, which have been the mainstream concept underlying Alzheimer's disease (AD), Parkinson's disease (PD), type II diabetes (T2D), and amyotrophic lateral sclerosis (ALS) research, respectively, for many years.
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Affiliation(s)
- Phuong H Nguyen
- CNRS, UPR9080, Université de Paris, Laboratory of Theoretical Biochemistry, IBPC, Fondation Edmond de Rothschild, PSL Research University, Paris 75005, France
| | - Ayyalusamy Ramamoorthy
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Bikash R Sahoo
- Biophysics and Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Jie Zheng
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Peter Faller
- Institut de Chimie, UMR 7177, CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - John E Straub
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
| | - Laura Dominguez
- Facultad de Química, Departamento de Fisicoquímica, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, and Department of Physics, University of California, Santa Barbara, California 93106, United States
| | - Nikolay V Dokholyan
- Department of Pharmacology and Biochemistry & Molecular Biology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, United States
- Department of Chemistry, and Biomedical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Alfonso De Simone
- Department of Life Sciences, Imperial College London, London SW7 2AZ, U.K
- Molecular Biology, University of Naples Federico II, Naples 80138, Italy
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, United States
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, United States
- Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Saeed Najafi
- Department of Chemistry and Biochemistry, and Department of Physics, University of California, Santa Barbara, California 93106, United States
| | - Son Tung Ngo
- Laboratory of Theoretical and Computational Biophysics & Faculty of Applied Sciences, Ton Duc Thang University, 33000 Ho Chi Minh City, Vietnam
| | - Antoine Loquet
- Institute of Chemistry & Biology of Membranes & Nanoobjects, (UMR5248 CBMN), CNRS, Université Bordeaux, Institut Européen de Chimie et Biologie, 33600 Pessac, France
| | - Mara Chiricotto
- Department of Chemical Engineering and Analytical Science, University of Manchester, Manchester M13 9PL, U.K
| | - Pritam Ganguly
- Department of Chemistry and Biochemistry, and Department of Physics, University of California, Santa Barbara, California 93106, United States
| | - James McCarty
- Chemistry Department, Western Washington University, Bellingham, Washington 98225, United States
| | - Mai Suan Li
- Institute for Computational Science and Technology, SBI Building, Quang Trung Software City, Tan Chanh Hiep Ward, District 12, Ho Chi Minh City 700000, Vietnam
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland
| | - Carol Hall
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, United States
| | - Yiming Wang
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, United States
| | - Yifat Miller
- Department of Chemistry and The Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Be'er Sheva 84105, Israel
| | | | - Birgit Habenstein
- Institute of Chemistry & Biology of Membranes & Nanoobjects, (UMR5248 CBMN), CNRS, Université Bordeaux, Institut Européen de Chimie et Biologie, 33600 Pessac, France
| | - Stepan Timr
- CNRS, UPR9080, Université de Paris, Laboratory of Theoretical Biochemistry, IBPC, Fondation Edmond de Rothschild, PSL Research University, Paris 75005, France
| | - Jiaxing Chen
- Department of Pharmacology and Biochemistry & Molecular Biology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Brianna Hnath
- Department of Pharmacology and Biochemistry & Molecular Biology, Penn State University College of Medicine, Hershey, Pennsylvania 17033, United States
| | - Birgit Strodel
- Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative Diseases, and Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas 77555, United States
| | - Sylvain Lesné
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Science, Multiscale Research Institute of Complex Systems, Fudan University, Shanghai 200438, China
| | - Fabio Sterpone
- CNRS, UPR9080, Université de Paris, Laboratory of Theoretical Biochemistry, IBPC, Fondation Edmond de Rothschild, PSL Research University, Paris 75005, France
| | - Andrew J Doig
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PT, U.K
| | - Philippe Derreumaux
- CNRS, UPR9080, Université de Paris, Laboratory of Theoretical Biochemistry, IBPC, Fondation Edmond de Rothschild, PSL Research University, Paris 75005, France
- Laboratory of Theoretical Chemistry, Ton Duc Thang University, 33000 Ho Chi Minh City, Vietnam
- Faculty of Pharmacy, Ton Duc Thang University, 33000 Ho Chi Minh City, Vietnam
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27
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Prabakaran R, Rawat P, Thangakani AM, Kumar S, Gromiha MM. Protein aggregation: in silico algorithms and applications. Biophys Rev 2021; 13:71-89. [PMID: 33747245 PMCID: PMC7930180 DOI: 10.1007/s12551-021-00778-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/01/2021] [Indexed: 01/08/2023] Open
Abstract
Protein aggregation is a topic of immense interest to the scientific community due to its role in several neurodegenerative diseases/disorders and industrial importance. Several in silico techniques, tools, and algorithms have been developed to predict aggregation in proteins and understand the aggregation mechanisms. This review attempts to provide an essence of the vast developments in in silico approaches, resources available, and future perspectives. It reviews aggregation-related databases, mechanistic models (aggregation-prone region and aggregation propensity prediction), kinetic models (aggregation rate prediction), and molecular dynamics studies related to aggregation. With a multitude of prediction models related to aggregation already available to the scientific community, the field of protein aggregation is rapidly maturing to tackle new applications.
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Affiliation(s)
- R. Prabakaran
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamil Nadu India
| | - Puneet Rawat
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamil Nadu India
| | - A. Mary Thangakani
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamil Nadu India
| | - Sandeep Kumar
- Biotherapeutics Discovery, Boehringer Ingelheim Pharmaceutical Inc., Ridgefield, CT USA
| | - M. Michael Gromiha
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, Tamil Nadu India
- School of Computing, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa Japan
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28
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Brudar S, Gujt J, Spohr E, Hribar-Lee B. Studying the mechanism of phase separation in aqueous solutions of globular proteins via molecular dynamics computer simulations. Phys Chem Chem Phys 2021; 23:415-424. [PMID: 33319872 PMCID: PMC8210815 DOI: 10.1039/d0cp05160h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Proteins are the most abundant biomacromolecules in living cells, where they perform vital roles in virtually every biological process. To maintain their function, proteins need to remain in a stable (native) state. Inter- and intramolecular interactions in aqueous protein solutions govern the fate of proteins, as they can provoke their unfolding or association into aggregates. The initial steps of protein aggregation are difficult to capture experimentally, therefore we used molecular dynamics simulations in this study. We investigated the initial phase of aggregation of two different lysozymes, hen egg-white (HEWL) and T4 WT* lysozyme and also human lens γ-D crystallin by using atomistic simulations. We monitored the phase stability of their aqueous solutions by calculating time-dependent density fluctuations. We found that all proteins remained in their compact form despite aggregation. With an extensive analysis of intermolecular residue-residue interactions we discovered that arginine is of paramount importance in the initial stage of aggregation of HEWL and γ-D crystallin, meanwhile lysine was found to be the most involved amino acid in forming initial contacts between T4 WT* molecules.
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Affiliation(s)
- Sandi Brudar
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI-1000 Ljubljana, Slovenia.
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29
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Cingolani M, Mummolo L, Lugli F, Zaffagnini M, Genovese D. Protein aggregation detection with fluorescent macromolecular and nanostructured probes: challenges and opportunities. NEW J CHEM 2021. [DOI: 10.1039/d1nj01606g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nanoprobes based on various nanomaterials, polymers or AIEgens are overcoming previous limitations for diagnosis and therapy of early-stage protein aggregation.
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Affiliation(s)
- Matteo Cingolani
- Dipartimento di Chimica “Giacomo Ciamician”
- Università di Bologna
- 40126 Bologna
- Italy
| | - Liviana Mummolo
- Dipartimento di Chimica “Giacomo Ciamician”
- Università di Bologna
- 40126 Bologna
- Italy
| | - Francesca Lugli
- Dipartimento di Chimica “Giacomo Ciamician”
- Università di Bologna
- 40126 Bologna
- Italy
| | - Mirko Zaffagnini
- Dipartimento di Farmacia e Biotecnologia
- Università di Bologna
- 40126 Bologna
- Italy
| | - Damiano Genovese
- Dipartimento di Chimica “Giacomo Ciamician”
- Università di Bologna
- 40126 Bologna
- Italy
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30
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Assessing the role of osmolytes on the conformational harmony of islet amyloid polypeptide. Int J Biol Macromol 2020; 164:2569-2582. [DOI: 10.1016/j.ijbiomac.2020.08.104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 08/05/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023]
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31
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Temperature dependent aggregation mechanism and pathway of lysozyme: By all atom and coarse grained molecular dynamics simulation. J Mol Graph Model 2020; 103:107816. [PMID: 33291026 DOI: 10.1016/j.jmgm.2020.107816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 11/18/2020] [Accepted: 11/18/2020] [Indexed: 11/21/2022]
Abstract
Aggregation of protein causes various diseases including Alzheimer's disease, Parkinson's disease, and type II diabetes. It was found that aggregation of protein depends on many factors like temperature, pH, salt type, salt concentration, ionic strength, protein concentration, co solutes. Here we have tried to capture the aggregation mechanism and pathway of hen egg white lysozyme using molecular dynamics simulations at two different temperatures; 300 K and 340 K. Along with the all atom simulations to get the atomistic details of aggregation mechanism, we have used coarse grained simulation with MARTINI force field to monitor the aggregation for longer duration. Our results suggest that due to the aggregation, changes in the conformation of lysozyme are more at 340 K than at 300 K. The change in the conformation of the lysozyme at 300 K is mainly due to aggregation where at 340 K change in conformation of lysozyme is due to both aggregation and temperature. Also, a more compact aggregated system is formed at 340 K.
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32
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Szała-Mendyk B, Molski A. Clustering and Fibril Formation during GNNQQNY Aggregation: A Molecular Dynamics Study. Biomolecules 2020; 10:biom10101362. [PMID: 32987720 PMCID: PMC7598727 DOI: 10.3390/biom10101362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/02/2022] Open
Abstract
The precise kinetic pathways of peptide clustering and fibril formation are not fully understood. Here we study the initial clustering kinetics and transient cluster morphologies during aggregation of the heptapeptide fragment GNNQQNY from the yeast prion protein Sup35. We use a mid-resolution coarse-grained molecular dynamics model of Bereau and Deserno to explore the aggregation pathways from the initial random distribution of free monomers to the formation of large clusters. By increasing the system size to 72 peptides we could follow directly the molecular events leading to the formation of stable fibril-like structures. To quantify those structures we developed a new cluster helicity parameter. We found that the formation of fibril-like structures is a cooperative processes that requires a critical number of monomers, M⋆≈25, in a cluster. The terminal tyrosine residue is the structural determinant in the formation of helical fibril-like structures. This work supports and quantifies the two-step aggregation model where the initially formed amorphous clusters grow and, when they are large enough, rearrange into mature twisted structures. However, in addition to the nucleated fibrillation, growing aggregates undergo further internal reorganization, which leads to more compact structures of large aggregates.
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33
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Charest N, Tro M, Bowers MT, Shea JE. Latent Models of Molecular Dynamics Data: Automatic Order Parameter Generation for Peptide Fibrillization. J Phys Chem B 2020; 124:8012-8022. [PMID: 32790375 DOI: 10.1021/acs.jpcb.0c05763] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Variational autoencoders are artificial neural networks with the capability to reduce highly dimensional sets of data to smaller dimensional, latent representations. In this work, these models are applied to molecular dynamics simulations of the self-assembly of coarse-grained peptides to obtain a singled-valued order parameter for amyloid aggregation. This automatically learned order parameter is constructed by time-averaging the latent parametrizations of internal coordinate representations and compared to the nematic order parameter which is commonly used to study ordering of similar systems in literature. It is found that the latent space value provides more tailored insight into the aggregation mechanism's details, correctly identifying fibril formation in instances where the nematic order parameter fails to do so. A means is provided by which the latent space value can be analyzed so that the major contributing internal coordinates are identified, allowing for a direct interpretation of the latent space order parameter in terms of the behavior of the system. The latent model is found to be an effective and convenient way of representing the data from the dynamic ensemble and provides a means of reducing the dimensionality of a system whose scale exceeds molecular systems so-far considered with similar tools. This bypasses a need for researcher speculation on what elements of a system best contribute to summarizing major transitions and suggests latent models are effective and insightful when applied to large systems with a diversity of complex behaviors.
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Affiliation(s)
- Nathaniel Charest
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106-9510, United States
| | - Michael Tro
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106-9510, United States
| | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106-9510, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106-9510, United States
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34
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Szała B, Molski A. Chiral structure fluctuations predicted by a coarse-grained model of peptide aggregation. SOFT MATTER 2020; 16:5071-5080. [PMID: 32453328 DOI: 10.1039/d0sm00090f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This work reports on the chiral structure fluctuations of peptide clusters at the early stages of aggregation in a coarse-grained peptide model. Our model reproduces a variety of aggregate structures, from disordered to crystal-like, that are observed experimentally. Unexpectedly, our molecular dynamics simulations showed that the small peptide cluster undergoes chiral structure fluctuations although the underlying implicit solvent model does not assume the chirality of peptides. The chiral fluctuations are quantified through a cluster twist parameter. A simple model is presented where the twist parameter undergoes a stochastic diffusion on a 1D potential surface. The shape of the potential surface changes with the cluster size. The model shows semi-quantitative agreement with the simulations. We hypothesize that the chiral fluctuations at the early stages of peptide aggregation can contribute to the selection of the final fibril structures.
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Affiliation(s)
- Beata Szała
- Adam Mickiewicz University in Poznań, Faculty of Chemistry, Umultowska 89b, 61-614 Poznań, Poland.
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35
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Amyloid assembly is dominated by misregistered kinetic traps on an unbiased energy landscape. Proc Natl Acad Sci U S A 2020; 117:10322-10328. [PMID: 32345723 DOI: 10.1073/pnas.1911153117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Atomistic description of protein fibril formation has been elusive due to the complexity and long time scales of the conformational search. Here, we develop a multiscale approach combining numerous atomistic simulations in explicit solvent to construct Markov State Models (MSMs) of fibril growth. The search for the in-register fully bound fibril state is modeled as a random walk on a rugged two-dimensional energy landscape defined by β-sheet alignment and hydrogen-bonding states, whereas transitions involving states without hydrogen bonds are derived from kinetic clustering. The reversible association/dissociation of an incoming peptide and overall growth kinetics are then computed from MSM simulations. This approach is applied to derive a parameter-free, comprehensive description of fibril elongation of Aβ16-22 and how it is modulated by phenylalanine-to-cyclohexylalanine (CHA) mutations. The trajectories show an aggregation mechanism in which the peptide spends most of its time trapped in misregistered β-sheet states connected by weakly bound states twith short lifetimes. Our results recapitulate the experimental observation that mutants CHA19 and CHA1920 accelerate fibril elongation but have a relatively minor effect on the critical concentration for fibril growth. Importantly, the kinetic consequences of mutations arise from cumulative effects of perturbing the network of productive and nonproductive pathways of fibril growth. This is consistent with the expectation that nonfunctional states will not have evolved efficient folding pathways and, therefore, will require a random search of configuration space. This study highlights the importance of describing the complete energy landscape when studying the elongation mechanism and kinetics of protein fibrils.
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36
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Lam YPY, Wootton CA, Hands-Portman I, Wei J, Chiu CKC, Romero-Canelon I, Lermyte F, Barrow MP, O'Connor PB. Determination of the Aggregate Binding Site of Amyloid Protofibrils Using Electron Capture Dissociation Tandem Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:267-276. [PMID: 31922736 DOI: 10.1021/jasms.9b00053] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Amyloid fibril formation is a hallmark in a range of human diseases. Analysis of the molecular details of amyloid aggregation, however, is limited by the difficulties in solubilizing, separating, and identifying the aggregated biomolecules. Additional labeling or protein modification is required in many current analytical techniques in order to provide molecular details of amyloid protein aggregation, but these modifications may result in protein structure disruption. Herein, ultrahigh resolution mass spectrometry (MS) with electron capture dissociation tandem MS (ECD MS/MS) has been applied to monitor the formation of early oligomers of human islet amyloid polypeptide (hIAPP), which aggregate rapidly in the pancreas of type II diabetes (T2D) patients. ECD MS/MS results show the aggregation region of the early oligomers is at the Ser-28/Ser-29 residue of a hIAPP unit and at the Asn-35 residue of another hIAPP unit near the C-terminus in the gas phase. These data contribute to the understanding of the binding site between hIAPP units which may help for specific target region therapeutic development in the future. Furthermore, MS has also been applied to quantify the amount of soluble amyloid protein remaining in the incubated solutions, which can be used to estimate the aggregation rate of amyloid protein during incubation (28 days). These data are further correlated with the results obtained using fluorescence spectroscopy and transmission electron microscopy (TEM) to generate a general overview of amyloid protein aggregation. The methods demonstrated in this article not only explore the aggregation site of hIAPP down to an amino acid residue level, but are also applicable to many amyloid protein aggregation studies.
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Affiliation(s)
- Yuko P Y Lam
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Christopher A Wootton
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Ian Hands-Portman
- Department of Life Sciences, Gibbet Hill Campus , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Juan Wei
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Cookson K C Chiu
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - I Romero-Canelon
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
- School of Pharmacy , University of Birmingham , Edgbaston , Birmingham B15 2TT , United Kingdom
| | - Frederik Lermyte
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Mark P Barrow
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Peter B O'Connor
- Department of Chemistry, Gibbet Hill Road , University of Warwick , Coventry CV4 7AL , United Kingdom
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37
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Theoretical and computational advances in protein misfolding. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 118:1-31. [PMID: 31928722 DOI: 10.1016/bs.apcsb.2019.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
Misfolded proteins escape the cellular quality control mechanism and fail to fold properly or remain correctly folded leading to a loss in their functional specificity. Thus misfolding of proteins cause a large number of very different diseases ranging from errors in metabolism to various types of complex neurodegenerative diseases. A theoretical and computational perspective of protein misfolding is presented with a special emphasis on its salient features, mechanism and consequences. These insights quantitatively analyze different determinants of misfolding, that may be applied to design disease specific molecular targets.
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38
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Dasari S, Mallik BS. Conformational dynamics of amyloid-β (16–22) peptide in aqueous ionic liquids. RSC Adv 2020; 10:33248-33260. [PMID: 35515066 PMCID: PMC9056671 DOI: 10.1039/d0ra06609e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 09/01/2020] [Indexed: 12/04/2022] Open
Abstract
Molecular dynamics simulations of amyloid-β (16–22) peptide dimer in water as well as at two different experimentally studied concentrations of hydrated ionic liquids (ILs), ethylammonium mesylate (EAM), ethylammonium nitrate (EAN), and triethylammonium mesylate (TEAM), were carried out employing an umbrella sampling method. We used the average Ψ angle of the peptide backbone as the reaction coordinate to observe the conformational changes of a peptide dimer. Secondary structural element values were calculated for the peptide dimer along the reaction coordinate to see the transition of the peptide dimer between β-sheet and α-helix conformations. We observe the β-sheet conformation as the global minimum on the free energy surfaces in both EAM and EAN ILs at both the concentrations and at a low concentration of TEAM. However, we observe α-helix conformation as the global minimum at a high concentration of TEAM. Our results are in good correlation with the experimental findings. We calculated the average number of intramolecular and intermolecular hydrogen bonds of α-helix and β-sheet conformations in all solutions, and they are in correlation with the secondary structure element values. To understand the peptide–IL interactions, atom–atom radial distribution functions of cation, anion, and water around amide oxygen and hydrogen atoms were calculated. The solvent-accessible surface area of the peptide dimer was calculated to understand the exposure of the peptide towards the solvent during conformational changes. Finally, van der Waals (vdW) and Coulomb interaction energies were calculated between peptide–cation, peptide–anion, and peptide–water to understand the stability of conformations in different concentrations. We find that the TEA cation has more vdW interaction energy compared to Coulomb interaction energy with peptide in 70% (w/w) TEAM, which mimics a membrane-like environment to induce α-helix conformation rather than β-sheet conformation. Molecular dynamics simulations of amyloid-β (16–22) peptide dimer at two different experimentally studied concentrations of hydrated ethylammonium mesylate, ethylammonium nitrate, and triethylammonium mesylate were carried out employing an umbrella sampling method.![]()
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Affiliation(s)
- Sathish Dasari
- Department of Chemistry
- Indian Institute of Technology Hyderabad
- Sangareddy-502285
- India
| | - Bhabani S. Mallik
- Department of Chemistry
- Indian Institute of Technology Hyderabad
- Sangareddy-502285
- India
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39
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Kumari A, Sharma R, Shrivastava N, Somvanshi P, Grover A. Bleomycin modulates amyloid aggregation in β-amyloid and hIAPP. RSC Adv 2020; 10:25929-25946. [PMID: 35518630 PMCID: PMC9055351 DOI: 10.1039/d0ra04949b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 06/29/2020] [Indexed: 12/06/2022] Open
Abstract
Aberrant misfolding and amyloid aggregation, which result in amyloid fibrils, are frequent and critical pathological incidents in various neurodegenerative disorders. Multiple drugs or inhibitors have been investigated to avert amyloid aggregation in individual peptides, exhibiting sequence-dependent inhibition mechanisms. Establishing or inventing inhibitors capable of preventing amyloid aggregation in a wide variety of amyloid peptides is quite a daunting task. Bleomycin (BLM), a complex glycopeptide, has been widely used as an antibiotic and antitumor drug due to its ability to inhibit DNA metabolism, and as an antineoplastic, especially for solid tumors. In this study, we investigated the dual inhibitory effects of BLM on Aβ aggregation, associated with Alzheimer's disease and hIAPP, which is linked to type 2 diabetes, using both computational and experimental techniques. Combined results from drug repurposing and replica exchange molecular dynamics simulations demonstrate that BLM binds to the β-sheet region considered a hotspot for amyloid fibrils of Aβ and hIAPP. BLM was also found to be involved in β-sheet destabilization and, ultimately, in its reduction. Further, experimental validation through in vitro amyloid aggregation assays was obtained wherein the fibrillar load was decreased for the BLM-treated Aβ and hIAPP peptides in comparison to controls. For the first time, this study shows that BLM is a dual inhibitor of Aβ and hIAPP amyloid aggregation. In the future, the conformational optimization and processing of BLM may help develop various efficient sequence-dependent inhibitors against amyloid aggregation in various amyloid peptides. Bleomycin acts as a dual inhibitor against both amyloid β and human islet amyloid polypeptide by binding to the β-sheet grooves considered as the amyloids hotspot.![]()
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Affiliation(s)
- Anchala Kumari
- Department of Biotechnology
- Teri School of Advanced Studies
- New Delhi
- India
- School of Biotechnology
| | - Ritika Sharma
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
| | | | - Pallavi Somvanshi
- Department of Biotechnology
- Teri School of Advanced Studies
- New Delhi
- India
| | - Abhinav Grover
- School of Biotechnology
- Jawaharlal Nehru University
- New Delhi
- India
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40
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Crowet JM, Sinnaeve D, Fehér K, Laurin Y, Deleu M, Martins JC, Lins L. Molecular Model for the Self-Assembly of the Cyclic Lipodepsipeptide Pseudodesmin A. J Phys Chem B 2019; 123:8916-8922. [PMID: 31558021 DOI: 10.1021/acs.jpcb.9b08035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Self-assembly of peptides into supramolecular structures represents an active field of research with potential applications ranging from material science to medicine. Their study typically involves the application of a large toolbox of spectroscopic and imaging techniques. However, quite often, the structural aspects remain underexposed. Besides, molecular modeling of the self-assembly process is usually difficult to handle, since a vast conformational space has to be sampled. Here, we have used an approach that combines short molecular dynamics simulations for peptide dimerization and NMR restraints to build a model of the supramolecular structure from the dimeric units. Experimental NMR data notably provide crucial information about the conformation of the monomeric units, the supramolecular assembly dimensions, and the orientation of the individual peptides within the assembly. This in silico/in vitro mixed approach enables us to define accurate atomistic models of supramolecular structures of the bacterial cyclic lipodepsipeptide pseudodesmin A.
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Affiliation(s)
- Jean-Marc Crowet
- Laboratory of Molecular Biophysics at Interfaces, TERRA Research Center, Gembloux Agro-Bio Tech , University of Liège , Passage des déportés 2 , B-5030 Gembloux , Belgium
| | - Davy Sinnaeve
- CNRS-Unité de Glycobiologie structurale et fonctionnelle (UGSF) UMR 8576 , 50, Avenue de Halley, Campus CNRS de la Haute Borne , 59658 Villeneuve d'Ascq , France
| | - Krisztina Fehér
- Heidelberg Institute for Theoretical Studies , Schloss-Wolfsbrunnenweg 35 , 69118 Heidelberg , Germany
| | - Yoann Laurin
- Laboratory of Molecular Biophysics at Interfaces, TERRA Research Center, Gembloux Agro-Bio Tech , University of Liège , Passage des déportés 2 , B-5030 Gembloux , Belgium
| | - Magali Deleu
- Laboratory of Molecular Biophysics at Interfaces, TERRA Research Center, Gembloux Agro-Bio Tech , University of Liège , Passage des déportés 2 , B-5030 Gembloux , Belgium
| | - José C Martins
- NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry , Ghent University , Krijgslaan 281 S4 , B-9000 Gent , Belgium
| | - Laurence Lins
- Laboratory of Molecular Biophysics at Interfaces, TERRA Research Center, Gembloux Agro-Bio Tech , University of Liège , Passage des déportés 2 , B-5030 Gembloux , Belgium
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41
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Sanyal T, Mittal J, Shell MS. A hybrid, bottom-up, structurally accurate, Go¯-like coarse-grained protein model. J Chem Phys 2019; 151:044111. [PMID: 31370551 PMCID: PMC6663515 DOI: 10.1063/1.5108761] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 06/24/2019] [Indexed: 12/21/2022] Open
Abstract
Coarse-grained (CG) protein models in the structural biology literature have improved over the years from being simple tools to understand general folding and aggregation driving forces to capturing detailed structures achieved by actual folding sequences. Here, we ask whether such models can be developed systematically from recent advances in bottom-up coarse-graining methods without relying on bioinformatic data (e.g., protein data bank statistics). We use relative entropy coarse-graining to develop a hybrid CG but Go¯-like CG peptide model, hypothesizing that the landscape of proteinlike folds is encoded by the backbone interactions, while the sidechain interactions define which of these structures globally minimizes the free energy in a unique native fold. To construct a model capable of capturing varied secondary structures, we use a new extended ensemble relative entropy method to coarse-grain based on multiple reference atomistic simulations of short polypeptides with varied α and β character. Subsequently, we assess the CG model as a putative protein backbone forcefield by combining it with sidechain interactions based on native contacts but not incorporating native distances explicitly, unlike standard Go¯ models. We test the model's ability to fold a range of proteins and find that it achieves high accuracy (∼2 Å root mean square deviation resolution for both short sequences and large globular proteins), suggesting the strong role that backbone conformational preferences play in defining the fold landscape. This model can be systematically extended to non-natural amino acids and nonprotein polymers and sets the stage for extensions to non-Go¯ models with sequence-specific sidechain interactions.
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Affiliation(s)
- Tanmoy Sanyal
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Jeetain Mittal
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, USA
| | - M. Scott Shell
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA
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42
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Ilie IM, Caflisch A. Simulation Studies of Amyloidogenic Polypeptides and Their Aggregates. Chem Rev 2019; 119:6956-6993. [DOI: 10.1021/acs.chemrev.8b00731] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Ioana M. Ilie
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich CH-8057, Switzerland
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43
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Chiricotto M, Melchionna S, Derreumaux P, Sterpone F. Multiscale Aggregation of the Amyloid Aβ 16-22 Peptide: From Disordered Coagulation and Lateral Branching to Amorphous Prefibrils. J Phys Chem Lett 2019; 10:1594-1599. [PMID: 30892042 DOI: 10.1021/acs.jpclett.9b00423] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work we investigate the multiscale dynamics of the aggregation process of an amyloid peptide, Aβ16-22. By performing massive coarse-grained simulations at the quasi-atomistic resolution and including hydrodynamic effects, we followed the formation and growth of a large elongated aggregate and its slow structuring. The elongation proceeds via a two-step nucleation mechanism with disordered aggregates formed initially and subsequently fusing to elongate the amorphous prefibril. A variety of coagulation events coexist, including lateral growth. The latter mechanism, sustained by long-range hydrodynamics correlations, actually can create a large branched structure spanning a few tens of nanometers. Our findings confirm the experimental hypothesis of a critical contribution of lateral growth to the amyloid aggregation kinetics and the capability of our model to sample critical structures like prefibril hosting annular pores.
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Affiliation(s)
- Mara Chiricotto
- Laboratoire de Biochimie Théorique, IBPC, CNRS UPR9080 , Univ. Paris Diderot, Sorbonne Paris Cité , 13 rue Pierre et Marie Curie , 75005 Paris , France
| | - Simone Melchionna
- ISC-CNR, Dipartimento di Fisica , Universita Sapienza , P.le A. Moro 5 , 00185 Rome , Italy
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, IBPC, CNRS UPR9080 , Univ. Paris Diderot, Sorbonne Paris Cité , 13 rue Pierre et Marie Curie , 75005 Paris , France
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, IBPC, CNRS UPR9080 , Univ. Paris Diderot, Sorbonne Paris Cité , 13 rue Pierre et Marie Curie , 75005 Paris , France
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44
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Zhao X, Liao C, Ma YT, Ferrell JB, Schneebeli ST, Li J. Top-down Multiscale Approach To Simulate Peptide Self-Assembly from Monomers. J Chem Theory Comput 2019; 15:1514-1522. [PMID: 30677300 DOI: 10.1021/acs.jctc.8b01025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Modeling peptide assembly from monomers on large time and length scales is often intractable at the atomistic resolution. To address this challenge, we present a new approach which integrates coarse-grained (CG), mixed-resolution, and all-atom (AA) modeling in a single simulation. We simulate the initial encounter stage with the CG model, while the further assembly and reorganization stages are simulated with the mixed-resolution and AA models. We have implemented this top-down approach with new tools to automate model transformations and to monitor oligomer formations. Further, a theory was developed to estimate the optimal simulation length for each stage using a model peptide, melittin. The assembly level, the oligomer distribution, and the secondary structures of melittin simulated by the optimal protocol show good agreement with prior experiments and AA simulations. Finally, our approach and theory have been successfully validated with three amyloid peptides (β-amyloid 16-22, GNNQQNY fragment from the yeast prion protein SUP35, and α-synuclein fibril 35-55), which highlight the synergy from modeling at multiple resolutions. This work not only serves as proof of concept for multiresolution simulation studies but also presents practical guidelines for further self-assembly simulations at more physically and chemically relevant scales.
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Affiliation(s)
- Xiaochuan Zhao
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Chenyi Liao
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Yong-Tao Ma
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Jonathon B Ferrell
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Severin T Schneebeli
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
| | - Jianing Li
- Department of Chemistry , The University of Vermont , Burlington , Vermont 05405 , United States
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Van Liefferinge F, Krammer EM, Sengupta D, Prévost M. Lipid composition and salt concentration as regulatory factors of the anion selectivity of VDAC studied by coarse-grained molecular dynamics simulations. Chem Phys Lipids 2018; 220:66-76. [PMID: 30448398 DOI: 10.1016/j.chemphyslip.2018.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 12/27/2022]
Abstract
The voltage-dependent anion channel (VDAC) is a mitochondrial outer membrane protein whose fundamental function is to facilitate and regulate the flow of metabolites between the cytosol and the mitochondrial intermembrane space. Using coarse-grained molecular dynamics simulations, we investigated the dependence of VDAC selectivity towards small inorganic anions on two factors: the ionic strength and the lipid composition. In agreement with experimental data we found that VDAC becomes less anion selective with increasing salt concentration due to the screening of a few basic residues that point into the pore lumen. The molecular dynamics simulations provide insight into the regulation mechanism of VDAC selectivity by the composition in the lipid membrane and suggest that the ion distribution is differently modulated by POPE compared to the POPC bilayer. This occurs through the more persistent interactions of acidic residues located at both rims of the β-barrel with head groups of POPE which in turn impact the electrostatic potential and thereby the selectivity of the pore. This mechanism occurs not only in POPE single component membranes but also in a mixed POPE/POPC bilayer by an enrichment of POPE over POPC lipids on the surface of VDAC. Thus we show here that computationally-inexpensive coarse-grained simulations are able to capture, in a semi-quantitative way, essential features of VDAC anion selectivity and could pave the way toward a molecular level understanding of metabolite transport in natural membranes.
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Affiliation(s)
- F Van Liefferinge
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - E-M Krammer
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - D Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411 008, India
| | - M Prévost
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium.
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Chakraborty M, Xu C, White AD. Encoding and selecting coarse-grain mapping operators with hierarchical graphs. J Chem Phys 2018; 149:134106. [PMID: 30292213 DOI: 10.1063/1.5040114] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Coarse-grained (CG) molecular dynamics (MD) can simulate systems inaccessible to fine-grained (FG) MD simulations. A CG simulation decreases the degrees of freedom by mapping atoms from an FG representation into agglomerate CG particles. The FG to CG mapping is not unique. Research into systematic selection of these mappings is challenging due to their combinatorial growth with respect to the number of atoms in a molecule. Here we present a method of reducing the total count of mappings by imposing molecular topology and symmetry constraints. The count reduction is illustrated by considering all mappings for nearly 50 000 molecules. The resulting number of mapping operators is still large, so we introduce a novel hierarchical graphical approach which encodes multiple CG mapping operators. The encoding method is demonstrated for methanol and a 14-mer peptide. With the test cases, we show how the encoding can be used for automated selection of reasonable CG mapping operators.
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Affiliation(s)
- Maghesree Chakraborty
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Chenliang Xu
- Department of Computer Science, University of Rochester, Rochester, New York 14627, USA
| | - Andrew D White
- Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, USA
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Zidar M, Kuzman D, Ravnik M. Characterisation of protein aggregation with the Smoluchowski coagulation approach for use in biopharmaceuticals. SOFT MATTER 2018; 14:6001-6012. [PMID: 29972188 DOI: 10.1039/c8sm00919h] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Protein aggregation is a field of increasing importance in the biopharmaceutical industry. Aggregated particles decrease the effectiveness of the drug and are associated with other risks, such as increased immunogenicity. This article explores the possibility of using the Smoluchowski coagulation equation and similar models in the prediction of aggregate-particle formation. Three different monoclonal antibodies, exhibiting different aggregation pathways, are analysed. Experimental data are complemented with aggregation dynamics calculated by a coagulation model. Different processes are implemented in the coagulation equation approach, needed to cover the actual phenomena observed in the aggregation of biopharmaceuticals, such as the initial conformational change of the native monomer and reversibility of smaller oligomers. When describing the formation of larger particles, the effect of different aggregation kernel parameters on the corresponding particle size distribution is studied. A significant impact of the aggregate fractal nature on overall particle size distribution is also analysed. More generally, this work is aimed to establish a mesoscopic phenomenological approach for characterisation of protein aggregation phenomena in the context of biopharmaceuticals, capable of covering various aggregate size scales from nanometres to micrometres and reach large time-scales, up to years, as needed for drug development.
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Affiliation(s)
- Mitja Zidar
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia.
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Ren B, Liu Y, Zhang Y, Cai Y, Gong X, Chang Y, Xu L, Zheng J. Genistein: A Dual Inhibitor of Both Amyloid β and Human Islet Amylin Peptides. ACS Chem Neurosci 2018; 9:1215-1224. [PMID: 29432676 DOI: 10.1021/acschemneuro.8b00039] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Abnormal misfolding and aggregation of amyloid peptides into amyloid fibrils are common and critical pathological events in many neurodegenerative diseases. Most inhibitors or drugs have been developed to prevent amyloid aggregation of a specific peptide, showing sequence-dependent inhibition mechanisms. It is more challenging to develop or discover inhibitors capable of preventing the aggregation of two or more different amyloid peptides. Genistein, a major phytoestrogen in soybean, has been widely used as an anti-inflammation and cerebrovascular drug due to its antioxidation and antiacetylcholinesterase effects. Herein, we examine the inhibitory effects of genistein on the aggregation of amyloid-β (Aβ, associated with Alzheimer's disease) and human islet amylin (hIAPP, associated with type 2 diabetes) and Aβ- and hIAPP-induced neurotoxicity using a combination of experimental and computational approaches. Collective experimental results from thioflavin T (ThT), atomic force microscopy (AFM), and circular dichroism (CD) demonstrate that genistein shows strong inhibition ability to prevent the conformational transition of both Aβ and hIAPP monomers to β-sheet structures, thus reducing final amyloid fibrillization from Aβ and hIAPP monomer aggregation by 40-63%. Further 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and large unilamellar vesicle (LUV) assays show that genistein helps to increase cell viability, decrease cell apoptosis, and reduce cell membrane leakage, where the cell protection effect of genistein is likely correlated with its reduced membrane leakage. Comparative molecular dynamics (MD) simulations reveal that genistein prefers to bind the β-sheet groove, a common structural motif of amyloid fibrils, of both Aβ and hIAPP oligomers to interfere with their self-aggregation. This work for the first time demonstrates genistein as a dual inhibitor of Aβ and hIAPP aggregation. Further structural optimization and refinement of genistein may generate a series of effective sequence-independent inhibitors against the aggregation and toxicity of different amyloid peptides.
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Affiliation(s)
- Baiping Ren
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, P. R. China
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Yonglan Liu
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Yanxian Zhang
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Yongqing Cai
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Xiong Gong
- Department of Polymer Engineering, College of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li, Taoyuan 320, Taiwan
| | - Lijian Xu
- Hunan Key Laboratory of Biomedical Nanomaterials and Devices, College of Life Science and Chemistry, Hunan University of Technology, Zhuzhou 412007, P. R. China
| | - Jie Zheng
- Department of Chemical & Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States
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Ilie IM, Nayar D, den Otter WK, van der Vegt NFA, Briels WJ. Intrinsic Conformational Preferences and Interactions in α-Synuclein Fibrils: Insights from Molecular Dynamics Simulations. J Chem Theory Comput 2018; 14:3298-3310. [PMID: 29715424 DOI: 10.1021/acs.jctc.8b00183] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Amyloid formation by the intrinsically disordered α-synuclein protein is the hallmark of Parkinson's disease. We present atomistic Molecular Dynamics simulations of the core of α-synuclein using enhanced sampling techniques to describe the conformational and binding free energy landscapes of fragments implicated in fibril stabilization. The theoretical framework is derived to combine the free energy profiles of the fragments into the reaction free energy of a protein binding to a fibril. Our study shows that individual fragments in solution have a propensity toward attaining non-β conformations, indicating that in a fibril β-strands are stabilized by interactions with other strands. We show that most dimers of hydrogen-bonded fragments are unstable in solution, while hydrogen bonding stabilizes the collective binding of five fragments to the end of a fibril. Hydrophobic effects make further contributions to the stability of fibrils. This study is the first of its kind where structural and binding preferences of the five major fragments of the hydrophobic core of α-synuclein have been investigated. This approach improves sampling of intrinsically disordered proteins, provides information on the binding mechanism between the core sequences of α-synuclein, and enables the parametrization of coarse grained models.
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Affiliation(s)
- Ioana M Ilie
- Computational Chemical Physics, Faculty of Science and Technology , University of Twente , 7500 AE Enschede , the Netherlands.,MESA+ Institute for Nanotechnology , 7500 AE Enschede , the Netherlands.,Department of Biochemistry , University of Zürich , 8057 Zürich , Switzerland
| | - Divya Nayar
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Center of Smart Interfaces , Technische Universität Darmstadt , 64287 Darmstadt , Germany
| | - Wouter K den Otter
- Computational Chemical Physics, Faculty of Science and Technology , University of Twente , 7500 AE Enschede , the Netherlands.,MESA+ Institute for Nanotechnology , 7500 AE Enschede , the Netherlands.,Multi Scale Mechanics, Faculty of Engineering Technology , University of Twente , 7500 AE Enschede , the Netherlands
| | - Nico F A van der Vegt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Center of Smart Interfaces , Technische Universität Darmstadt , 64287 Darmstadt , Germany
| | - Wim J Briels
- Computational Chemical Physics, Faculty of Science and Technology , University of Twente , 7500 AE Enschede , the Netherlands.,Forschungszentrum Jülich , ICS-3 , D-52428 Jülich , Germany
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50
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Amyloid growth and membrane damage: Current themes and emerging perspectives from theory and experiments on Aβ and hIAPP. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1625-1638. [PMID: 29501606 DOI: 10.1016/j.bbamem.2018.02.022] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 02/21/2018] [Accepted: 02/21/2018] [Indexed: 12/15/2022]
Abstract
Alzheimer's Disease (AD) and Type 2 diabetes mellitus (T2DM) are two incurable diseases both hallmarked by an abnormal deposition of the amyloidogenic peptides Aβ and Islet Amyloid Polypeptide (IAPP) in affected tissues. Epidemiological data demonstrate that patients suffering from diabetes are at high risk of developing AD, thus making the search for factors common to the two pathologies of special interest for the design of new therapies. Accumulating evidence suggests that the toxic properties of both Aβ or IAPP are ascribable to their ability to damage the cell membrane. However, the molecular details describing Aβ or IAPP interaction with membranes are poorly understood. This review focuses on biophysical and in silico studies addressing these topics. Effects of calcium, cholesterol and membrane lipid composition in driving aberrant Aβ or IAPP interaction with the membrane will be specifically considered. The cross correlation of all these factors appears to be a key issue not only to shed light in the countless and often controversial reports relative to this area but also to gain valuable insights into the central events leading to membrane damage caused by amyloidogenic peptides. This article is part of a Special Issue entitled: Protein Aggregation and Misfolding at the Cell Membrane Interface edited by Ayyalusamy Ramamoorthy.
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