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Khan MT, Ali A, Wei X, Nadeem T, Muhammad S, Al-Sehemi AG, Wei D. Inhibitory effect of thymoquinone from Nigella sativa against SARS-CoV-2 main protease. An in-silico study. BRAZ J BIOL 2024; 84:e250667. [DOI: 10.1590/1519-6984.25066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 01/24/2022] [Indexed: 11/21/2022] Open
Abstract
Abstract Nigella sativa is known for the safety profile, containing a wealth of useful antiviral compounds. The main protease (Mpro, 3CLpro) of severe acute respiratory syndrome 2 (SARS-CoV-2) is being considered as one of the most attractive viral target, processing the polyproteins during viral pathogenesis and replication. In the current investigation we analyzed the potency of active component, thymoquinone (TQ) of Nigella sativa against SARS-CoV-2 Mpro. The structures of TQ and Mpro was retrieved from PubChem (CID10281) and Protein Data Bank (PDB ID 6MO3) respectively. The Mpro and TQ were docked and the complex was subjected to molecular dynamic (MD) simulations for a period 50ns. Protein folding effect was analyzed using radius of gyration (Rg) while stability and flexibility was measured, using root means square deviations (RMSD) and root means square fluctuation (RMSF) respectively. The simulation results shows that TQ is exhibiting good binding activity against SARS-CoV-2 Mpro, interacting many residues, present in the active site (His41, Cys145) and also the Glu166, facilitating the pocket shape. Further, experimental approaches are needed to validate the role of TQ against virus infection. The TQ is interfering with pocket maintaining residues as well as active site of virus Mpro which may be used as a potential inhibitor against SARS-CoV-2 for better management of COVID-19.
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Affiliation(s)
| | - A. Ali
- Shanghai Jiao Tong University, China
| | - X. Wei
- Shanghai Jiao Tong University, China
| | | | | | | | - Dongqing Wei
- Shanghai Jiao Tong University, China; Peng Cheng Laboratory, China
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2
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Mohanty S, Bhadane R, Kumar S. Bioinformatics insights into CENP-T and CENP-W protein-protein interaction disruptive amino acid substitution in the CENP-T-W complex. J Cell Biochem 2023; 124:1870-1885. [PMID: 37943107 DOI: 10.1002/jcb.30495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 11/10/2023]
Abstract
Kinetochores are multi-protein assemblies present at the centromere of the human chromosome and play a crucial role in cellular mitosis. The CENP-T and CENP-W chains form a heterodimer, which is an integral part of the inner kinetochore, interacting with the linker DNA on one side and the outer kinetochore on the other. Additionally, the CENP-T-W dimer interacts with other regulatory proteins involved in forming inner kinetochores. The specific roles of different amino acids in the CENP-W at the protein-protein interaction (PPI) interface during the CENP-T-W dimer formation remain incompletely understood. Since cell division goes awry in diseases like cancer, this CENP-T-W partnership is a potential target for new drugs that could restore healthy cell division. We employed molecular docking, binding free energy calculations, and molecular dynamics (MD) simulations to investigate the disruptive effects of amino acids substitutions in the CENP-W chain on CENP-T-W dimer formation. By conducting a molecular docking study and analysing hydrogen bonding interactions, we identified key residues in CENP-W (ASN-46, ARG-53, LEU-83, SER-86, ARG-87, and GLY-88) for further investigation. Through site-directed mutagenesis and subsequent binding free energy calculations, we refined the selection of mutant. We chose four mutants (N46K, R53K, L83K, and R87E) of CENP-W to assess their comparative potential in forming CENP-T-W dimer. Our analysis from 250 ns long revealed that the substitution of LEU83 and ARG53 residues in CENP-W with the LYS significantly disrupts the formation of CENP-T-W dimer. In conclusion, LEU83 and ARG53 play a critical role in CENP-T and CENP-W dimerization which is ultimately required for cellular mitosis. Our findings not only deepen our understanding of cell division but also hint at exciting drug-target possibilities.
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Affiliation(s)
- Suryakanta Mohanty
- Molecular Signaling & Drug Discovery Laboratory, Department of Biochemistry, Central University of Punjab, Guddha, Bathinda, India
| | - Rajendra Bhadane
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Turku, Finland
| | - Shashank Kumar
- Molecular Signaling & Drug Discovery Laboratory, Department of Biochemistry, Central University of Punjab, Guddha, Bathinda, India
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3
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El-Arabey AA, Abdalla M, Rashad Abd-Allah A, Marenga H, Modafer Y, Aloufi AS. Molecular dynamic and bioinformatic studies of metformin-induced ACE2 phosphorylation in the presence of different SARS-CoV-2 S protein mutations. Saudi J Biol Sci 2023; 30:103699. [PMID: 37292255 PMCID: PMC10238124 DOI: 10.1016/j.sjbs.2023.103699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/17/2023] [Accepted: 05/24/2023] [Indexed: 06/10/2023] Open
Abstract
The SARS-CoV-2 infection activates host kinases and causes high phosphorylation in both the host and the virus. There were around 70 phosphorylation sites found in SARS-CoV-2 viral proteins. Besides, almost 15,000 host phosphorylation sites were found in SARS-CoV-2-infected cells. COVID-19 is thought to enter cells via the well-known receptor Angiotensin-Converting Enzyme 2 (ACE2) and the serine protease TMPRSS2. Substantially, the COVID-19 infection doesn't induce phosphorylation of the ACE2 receptor at Serin-680(s680). Metformin's numerous pleiotropic properties and extensive use in medicine including COVID-19, have inspired experts to call it the "aspirin of the twenty-first century". Metformin's impact on COVID-19 has been verified in clinical investigations via ACE2 receptor phosphorylation at s680. In the infection of COVID-19, sodium-dependent transporters including the major neutral amino acid (B0AT1) is regulated by ACE2. The structure of B0AT1 complexing with the COVID-19 receptor ACE2 enabled significant progress in the creation of mRNA vaccines. We aimed to study the impact of the interaction of the phosphorylation form of ACE2-s680 with wild-type (WT) and different mutations of SARS-CoV-2 infection such as delta, omicron, and gamma (γ) on their entrance of host cells as well as the regulation of B0AT1by the SARS-CoV-2 receptor ACE2. Interestingly, compared to WT SARS-CoV-2, ACE2 receptor phosphorylation at s680 produces conformational alterations in all types of SARS-CoV-2. Furthermore, our results showed for the first time that this phosphorylation significantly influences ACE2 sites K625, K676, and R678, which are key mediators for ACE2-B0AT1 complex.
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Affiliation(s)
- Amr Ahmed El-Arabey
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo 11751, Egypt
| | - Mohnad Abdalla
- Pediatric Research Institute, Children’s Hospital Affiliated to Shandong University, Jinan 250022, China
| | - Adel Rashad Abd-Allah
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo 11751, Egypt
| | - Hanin.S. Marenga
- Department of Pharmaceutical chemistry, College of pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Yosra Modafer
- Department of Biology, Faculty of Science, Jazan university, Jazan 45142, Saudi Arabia
| | - Abeer S. Aloufi
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
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4
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Mollica L, Giachin G. Recognition Mechanisms between a Nanobody and Disordered Epitopes of the Human Prion Protein: An Integrative Molecular Dynamics Study. J Chem Inf Model 2022; 63:531-545. [PMID: 36580661 PMCID: PMC9875307 DOI: 10.1021/acs.jcim.2c01062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Immunotherapy using antibodies to target the aggregation of flexible proteins holds promise for therapeutic interventions in neurodegenerative diseases caused by protein misfolding. Prions or PrPSc, the causal agents of transmissible spongiform encephalopathies (TSE), represent a model target for immunotherapies as TSE are prototypical protein misfolding diseases. The X-ray crystal structure of the wild-type (WT) human prion protein (HuPrP) bound to a camelid antibody fragment, denoted as Nanobody 484 (Nb484), has been previously solved. Nb484 was found to inhibit prion aggregation in vitro through a unique mechanism of structural stabilization of two disordered epitopes, that is, the palindromic motif (residues 113-120) and the β2-α2 loop region (residues 164-185). The study of the structural basis for antibody recognition of flexible proteins requires appropriate sampling techniques for the identification of conformational states occurring in disordered epitopes. To elucidate the Nb484-HuPrP recognition mechanisms, here we applied molecular dynamics (MD) simulations complemented with available NMR and X-ray crystallography data collected on the WT HuPrP to describe the conformational spaces occurring on HuPrP prior to Nb484 binding. We observe the experimentally determined binding competent conformations within the ensembles of pre-existing conformational states in solution before binding. We also described the Nb484 recognition mechanisms in two HuPrP carrying a polymorphism (E219K) and a TSE-causing mutation (V210I). Our hybrid approaches allow the identification of dynamic conformational landscapes existing on HuPrP and highly characterized by molecular disorder to identify physiologically relevant and druggable transitions.
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Affiliation(s)
- Luca Mollica
- Department
of Medical Biotechnology and Translational Medicine, University of Milan, Segrate, 20090 Milan, Italy,
| | - Gabriele Giachin
- Department
of Chemical Sciences (DiSC), University
of Padua, 35131 Padova, Italy,
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5
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Al-Wahaibi LH, Abdalla M, Mary YS, Mary YS, Costa RA, Rana M, El-Emam AA, Hassan HM, Al-Shaalan NH. Spectroscopic, Solvation Effects and MD Simulation of an Adamantane-Carbohydrazide Derivative, a Potential Antiviral Agent. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2022.2039233] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Lamya H. Al-Wahaibi
- Department of Chemistry, College of Sciences, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Mohnad Abdalla
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, P.R. China
| | | | | | - Renyer Alves Costa
- Department of Chemistry, Federal University of Amazonas (DQ-UFAM), Manaus, Brazil
| | - Meenakshi Rana
- Department of Physics, School of Sciences, Uttarakhand Open University, Haldwani, India
| | - Ali A. El-Emam
- Department of Medicinal Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Hanan M. Hassan
- Department of Pharmacology and Biochemistry, Faculty of Pharmacy, Delta University for Science and Technology, International Costal Road, Gamasa City, Mansoura, Egypt
| | - Nora H. Al-Shaalan
- Department of Chemistry, College of Sciences, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
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6
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Abdalla M, Eltayb WA, El-Arabey AA, Singh K, Jiang X. Molecular dynamic study of SARS-CoV-2 with various S protein mutations and their effect on thermodynamic properties. Comput Biol Med 2021; 141:105025. [PMID: 34772510 PMCID: PMC8576119 DOI: 10.1016/j.compbiomed.2021.105025] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 11/30/2022]
Abstract
Studying the structure of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein is important to understand the infection process. The S protein is necessary in completing the virus life cycle and is responsible for the appearance of new variants and drug and vaccine resistance. Understanding the structure and dynamics of biological macromolecules is essential for understanding how they function. In this work, we investigated the effects of mutations on S protein stability and solubility through molecular dynamic (MD) simulation in a 100 ns (ns) period. We screened four variants in addition to the wild type (WT). Results show that changes on MD simulation parameters of S protein indicate fluctuations and changes in the conformation, especially in the area between 300 and 600 amino acids (aa). This provides us an image of how the virus protein can reshape itself to adapt to any changes that occur in human angiotensin-converting enzyme 2 or drugs that can target the protein region. Our results also show that the Brazil variant has high fluctuations and unstable folding at some stages compared with other variants.
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Affiliation(s)
- Mohnad Abdalla
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, 44 Cultural West Road, Shandong Province, 250012, PR China.
| | - Wafa Ali Eltayb
- Biotechnology Department, Faculty of Science and Technology, Shendi University, Shendi, Nher Anile, Sudan
| | - Amr Ahmed El-Arabey
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
| | - Kamal Singh
- Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Xinyi Jiang
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, 44 Cultural West Road, Shandong Province, 250012, PR China.
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7
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Sharma B, Dill KA. MELD-accelerated molecular dynamics help determine amyloid fibril structures. Commun Biol 2021; 4:942. [PMID: 34354239 PMCID: PMC8342454 DOI: 10.1038/s42003-021-02461-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
It is challenging to determine the structures of protein fibrils such as amyloids. In principle, Molecular Dynamics (MD) modeling can aid experiments, but normal MD has been impractical for these large multi-molecules. Here, we show that MELD accelerated MD (MELD x MD) can give amyloid structures from limited data. Five long-chain fibril structures are accurately predicted from NMR and Solid State NMR (SSNMR) data. Ten short-chain fibril structures are accurately predicted from more limited restraints information derived from the knowledge of strand directions. Although the present study only tests against structure predictions - which are the most detailed form of validation currently available - the main promise of this physical approach is ultimately in going beyond structures to also give mechanical properties, conformational ensembles, and relative stabilities.
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Affiliation(s)
- Bhanita Sharma
- grid.36425.360000 0001 2216 9681Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY USA
| | - Ken A. Dill
- grid.36425.360000 0001 2216 9681Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY USA ,grid.36425.360000 0001 2216 9681Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY USA ,grid.36425.360000 0001 2216 9681Departments of Chemistry and Physics, Stony Brook University, Stony Brook, NY USA
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8
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Mou K, Abdalla M, Wei DQ, Khan MT, Lodhi MS, Darwish DB, Sharaf M, Tu X. Emerging mutations in envelope protein of SARS-CoV-2 and their effect on thermodynamic properties. INFORMATICS IN MEDICINE UNLOCKED 2021; 25:100675. [PMID: 34337139 PMCID: PMC8314890 DOI: 10.1016/j.imu.2021.100675] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/11/2021] [Accepted: 07/19/2021] [Indexed: 12/23/2022] Open
Abstract
Structural proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are potential drug targets due to their role in the virus life cycle. The envelope (E) protein is one of the structural proteins; plays a critical role in virulency. However, the emergence of mutations oftenly leads to drug resistance and may also play a vital role in virus stabilization and evolution. In this study, we aimed to identify mutations in E proteins that affect the protein stability. About 0.3 million complete whole genome sequences were analyzed to screen mutations in E protein. All these mutations were subjected to stability prediction using the DynaMut server. The most common mutations that were detected at the C-terminal domain, Ser68Phe, Pro71Ser, and Leu73Phe, were examined through molecular dynamics (MD) simulations for a 100ns period. The sequence analysis shows the existence of 259 mutations in E protein. Interestingly, 16 of them were detected in the DFLV amino acid (aa) motif (aa72-aa75) that binds the host PALS1 protein. The results of root mean square deviation, fluctuations, radius of gyration, and free energy landscape show that Ser68Phe, Pro71Ser, and Leu73Phe are exhibiting a more stabilizing effect. However, a more comprehensive experimental study may be required to see the effect on virus pathogenicity. Potential antiviral drugs, and vaccines may be developed used after screening the genomic variations for better management of SARS-CoV-2 infections.
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Affiliation(s)
- Kejie Mou
- Department of Neurosurgery, Bishan Hospital of Chongqing, Chongqing, China
| | - Mohnad Abdalla
- Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, 44 Cultural West Road, Shandong Province, 250012, PR China
| | - Dong Qing Wei
- State Key Laboratory of Microbial Metabolism, Shanghai-Islamabad-Belgrade Joint Innovation Center on Antibacterial Resistances, Joint International Research Laboratory of Metabolic & Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, PR China
- Peng Cheng Laboratory, Vanke Cloud City Phase I Building 8, Xili Street, Nashan District, Shenzhen, Guangdong, 518055, PR China
| | - Muhammad Tahir Khan
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, KM Defence Road, Lahore, Pakistan, 58810
| | - Madeeha Shahzad Lodhi
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, KM Defence Road, Lahore, Pakistan, 58810
| | - Doaa B Darwish
- Department of Biology, Faculty of Science, University of Tabuk, 71491, Saudi Arabia
| | - Mohamed Sharaf
- Department of Biochemistry and Molecular Biology, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, PR China
- Department of Biochemistry, Faculty of Agriculture, AL-Azhar University, Nasr City, Cairo, 11751, Egypt
| | - Xudong Tu
- Chongqing Medical and Pharmaceutical College, Chongqing, China
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Kaur A, Goyal D, Goyal B. An α-helix mimetic oligopyridylamide, ADH-31, modulates Aβ 42 monomer aggregation and destabilizes protofibril structures: insights from molecular dynamics simulations. Phys Chem Chem Phys 2020; 22:28055-28073. [PMID: 33289734 DOI: 10.1039/d0cp04672h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD), an epidemic growing worldwide due to no effective medical aid available in the market, is a neurological disorder. AD is known to be directly associated with the toxicity of amyloid-β (Aβ) aggregates. In search of potent inhibitors of Aβ aggregation, Hamilton and co-workers reported an α-helix mimetic, ADH-31, which acts as a powerful antagonist of Aβ42 aggregation. To identify the key interactions between protein-ligand complexes and to gain insights into the inhibitory mechanism of ADH-31 against Aβ42 aggregation, molecular dynamics (MD) simulations were performed in the present study. The MD simulations highlighted that ADH-31 showed distinct binding capabilities with residues spanning from the N-terminal to the central hydrophobic core (CHC) region of Aβ42 and restricted the conformational transition of the helix-rich structure of Aβ42 into another form of secondary structures (coil/turn/β-sheet). Hydrophobic contacts, hydrogen bonding and π-π interaction contribute to the strong binding between ADH-31 and Aβ42 monomer. The Dictionary of Secondary Structure of Proteins (DSSP) analysis highlighted that the probability of helical content increases from 38.5% to 50.2% and the turn content reduces from 14.7% to 6.2% with almost complete loss of the β-sheet structure (4.5% to 0%) in the Aβ42 monomer + ADH-31 complex. The per-residue binding free energy analysis demonstrated that Arg5, Tyr10, His14, Gln15, Lys16, Val18, Phe19 and Lys28 residues of Aβ42 are responsible for the favourable binding free energy in Aβ42 monomer + ADH-31 complex, which is consistent with the 2D HSQC NMR of the Aβ42 monomer that depicted a change in the chemical shift of residues spanning from Glu11 to Phe20 in the presence of ADH-31. The MD simulations highlighted the prevention of sampling of amyloidogenic β-strand conformations in Aβ42 trimer in the presence of ADH-31 as well as the ability of ADH-31 to destabilize Aβ42 trimer and protofibril structures. The lower binding affinity between Aβ42 trimer chains in the presence of ADH-31 highlights the destabilization of the Aβ42 trimer structure. Overall, MD results highlighted that ADH-31 inhibited Aβ42 aggregation by constraining Aβ peptides into helical conformation and destabilized Aβ42 trimer as well as protofibril structures. The present study provides a theoretical insight into the atomic level details of the inhibitory mechanism of ADH-31 against Aβ42 aggregation as well as protofibril destabilization and could be implemented in the structure-based drug design of potent therapeutic agents for AD.
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Affiliation(s)
- Anupamjeet Kaur
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India.
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10
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Saini R, Shuaib S, Goyal D, Goyal B. Impact of Mutations on the Conformational Transition from α-Helix to β-Sheet Structures in Arctic-Type Aβ 40: Insights from Molecular Dynamics Simulations. ACS OMEGA 2020; 5:23219-23228. [PMID: 32954172 PMCID: PMC7495726 DOI: 10.1021/acsomega.0c02983] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 08/13/2020] [Indexed: 05/13/2023]
Abstract
The amyloid-β (Aβ) protein aggregation into toxic oligomers and fibrils has been recognized as a key player in the pathogenesis of Alzheimer's disease. Recent experiments reported that a double alanine mutation (L17A/F19A) in the central hydrophobic core (CHC) region of [G22]Aβ40 (familial Arctic mutation) diminished the self-assembly propensity of [G22]Aβ40. However, the molecular mechanism behind the decreased aggregation tendency of [A17/A19/G22]Aβ40 is not well understood. Herein, we carried out molecular dynamics simulations to elucidate the structure and dynamics of [G22]Aβ40 and [A17/A19/G22]Aβ40. The results for the secondary structure analysis reveal a significantly increased amount of the helical content in the CHC and C-terminal region of [A17/A19/G22]Aβ40 as compared to [G22]Aβ40. The bending free-energy analysis of D23-K28 salt bridge suggests that the double alanine mutation in the CHC region of [G22]Aβ40 has the potential to reduce the fibril formation rate by 0.57 times of [G22]Aβ40. Unlike [G22]Aβ40, [A17/A19/G22]Aβ40 largely sampled helical conformation, as determined by the minimum energy conformations extracted from the free-energy landscape. The present study provided atomic level details into the experimentally observed diminished aggregation tendency of [A17/A19/G22]Aβ40 as compared to [G22]Aβ40.
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Affiliation(s)
- Rajneet
Kaur Saini
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Suniba Shuaib
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Deepti Goyal
- Department
of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab, India
| | - Bhupesh Goyal
- School
of Chemistry & Biochemistry, Thapar
Institute of Engineering & Technology, Patiala 147004, Punjab, India
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11
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Narang SS, Shuaib S, Goyal D, Goyal B. In silico-guided identification of potential inhibitors against β2m aggregation in dialysis-related amyloidosis. J Biomol Struct Dyn 2019; 38:3927-3941. [DOI: 10.1080/07391102.2019.1668852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Simranjeet Singh Narang
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, India
| | - Suniba Shuaib
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, India
| | - Deepti Goyal
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab, India
| | - Bhupesh Goyal
- School of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, Patiala, Punjab, India
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12
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Saini RK, Shuaib S, Goyal D, Goyal B. Molecular insights into the effect L17A/F19A double mutation on the structure and dynamics of Aβ
40
: A molecular dynamics simulation study. J Cell Biochem 2018; 119:8949-8961. [DOI: 10.1002/jcb.27149] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 05/18/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Rajneet Kaur Saini
- Department of Chemistry, Faculty of Basic and Applied Sciences Sri Guru Granth Sahib World University Fatehgarh Sahib India
| | - Suniba Shuaib
- Department of Chemistry, Faculty of Basic and Applied Sciences Sri Guru Granth Sahib World University Fatehgarh Sahib India
| | - Deepti Goyal
- Department of Chemistry, Faculty of Basic and Applied Sciences Sri Guru Granth Sahib World University Fatehgarh Sahib India
| | - Bhupesh Goyal
- School of Chemistry & Biochemistry Thapar Institute of Engineering & Technology Patiala India
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13
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Melvin RL, Xiao J, Berenhaut KS, Godwin RC, Salsbury FR. Using correlated motions to determine sufficient sampling times for molecular dynamics. Phys Rev E 2018; 98:023307. [PMID: 30253618 PMCID: PMC6325644 DOI: 10.1103/physreve.98.023307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Indexed: 06/08/2023]
Abstract
Here we present a time-dependent correlation method that provides insight into how long a system takes to grow into its equal-time (Pearson) correlation. We also show a usage of an extant time-lagged correlation method that indicates the time for parts of a system to become decorrelated, relative to equal-time correlation. Given a completed simulation (or set of simulations), these tools estimate (i) how long of a simulation of the same system would be sufficient to observe the same correlated motions, (ii) if patterns of observed correlated motions indicate events beyond the timescale of the simulation, and (iii) how long of a simulation is needed to observe these longer timescale events. We view this method as a decision-support tool that will aid researchers in determining necessary sampling times. In principle, this tool is extendable to any multidimensional time series data with a notion of correlated fluctuations; however, here we limit our discussion to data from molecular-dynamics simulations.
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Affiliation(s)
- Ryan L. Melvin
- Department of Physics and Department of Mathematics and Statistics, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, North Carolina 27109, USA
| | - Jiajie Xiao
- Department of Physics and Department of Computer Science, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, North Carolina 27109, USA
| | - Kenneth S. Berenhaut
- Department of Mathematics and Statistics, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, North Carolina 27109, USA
| | - Ryan C. Godwin
- Department of Physics, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, North Carolina 27109, USA
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Liu Y, Qu K, Hai Y, Li X, Zhao L, Zhao C. SNP mutations occurring in thyroid hormone receptor influenced individual susceptibility to triiodothyronine: Molecular dynamics and site-directed mutagenesis approaches. J Cell Biochem 2017; 119:2604-2616. [PMID: 29024007 DOI: 10.1002/jcb.26425] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 10/03/2017] [Indexed: 12/11/2022]
Abstract
The increasing evidences have suggested that expression of single nucleotide polymorphisms (SNP) coded thyroid hormone receptors (THR) generally are associated with individual susceptibility to chemicals. In the present research, multiple molecular dynamics simulations on four SNP mutants (G332R, T337Δ, G345R, and G347E) were performed to investigate the structural and dynamical altering, which could lead to a binding capability variation to triiodothyronine (T3). It proved the structures of two SNP mutants (G345R and T337Δ) occurring in the THR proteins had experienced conformational change to a great extend, which also led to a significant decreasing in binding ability with T3. In addition, two mutates (G345R and G347E) and wild type THR proteins were expressed and purified based on site-directed mutagenesis technology to test their binding abilities with T3 by fluorescence experiments. The fluorescence quenching efficiencies of two mutates displayed that the conjugation with T3 decreased with a significant rate in G345R system and a little rate in G347E system compared with its wild type. It was consistent with the molecular dynamic research that the SNP mutations did change structures of THR protein, and thereby decreased the binding behavior of T3 at different extent. The overall molecular-level look at the protein structure may provide the structural basis to explain how one amino acid change can create a ripple effect on the protein structures and eventually affect the binding affinity of the ligands, which maybe the first stage to understand how SNP mutation results in individual difference in susceptibility to variant chemicals.
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Affiliation(s)
- Yaquan Liu
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Kaili Qu
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Ying Hai
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Xin Li
- College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, China
| | - Lei Zhao
- Key Laboratory of Chemistry and Quality for Traditional Chinese Medicines of the University of Gansu Province, Gansu University of Chinese Medicines, Lanzhou, China
| | - Chunyan Zhao
- School of Pharmacy, Lanzhou University, Lanzhou, China
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15
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Narang SS, Shuaib S, Goyal D, Goyal B. Assessing the effect of D59P mutation in the DE loop region in amyloid aggregation propensity of β2‐microglobulin: A molecular dynamics simulation study. J Cell Biochem 2017; 119:782-792. [DOI: 10.1002/jcb.26241] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Simranjeet S. Narang
- Department of Chemistry School of Basic and Applied Sciences Sri Guru Granth Sahib World University Punjab India
| | - Suniba Shuaib
- Department of Chemistry School of Basic and Applied Sciences Sri Guru Granth Sahib World University Punjab India
| | - Deepti Goyal
- Department of Chemistry School of Basic and Applied Sciences Sri Guru Granth Sahib World University Punjab India
| | - Bhupesh Goyal
- Department of Chemistry School of Basic and Applied Sciences Sri Guru Granth Sahib World University Punjab India
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16
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Srivastava A, Balaji PV. Molecular events during the early stages of aggregation of GNNQQNY: An all atom MD simulation study of randomly dispersed peptides. J Struct Biol 2015; 192:376-391. [DOI: 10.1016/j.jsb.2015.09.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/26/2015] [Accepted: 09/30/2015] [Indexed: 12/11/2022]
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17
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Pouplana R, Campanera JM. Energetic contributions of residues to the formation of early amyloid-β oligomers. Phys Chem Chem Phys 2014; 17:2823-37. [PMID: 25503571 DOI: 10.1039/c4cp04544k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Low-weight amyloid-β (Aβ) oligomers formed at early stages of oligomerization rather than fibril assemblies seem to be the toxic components that drive neurodegeneration in Alzheimer's disease. Unfortunately, detailed knowledge of the structure of these early oligomers at the residue level is not yet available. In this study, we performed all-atom explicit solvent molecular dynamics simulations to examine the oligomerization process of Aβ10-35 monomers when forming dimers, trimers, tetramers and octamers, with four independent simulations of a total simulated time of 3 μs for each oligomer system. The decomposition of the stability free energy by MM-GBSA methodology allowed us to unravel the network of energetic interactions that stabilize such oligomers. The contribution of the intermonomeric van der Waals term is the most significant energy feature of the oligomerization process, consistent with the so-called hydrophobic effect. Furthermore, the decomposition of the stability free energy into residues and residue-pairwise terms revealed that it is mainly apolar interactions between the three specific hydrophobic fragments 31-35 (C-terminal region), 17-20 (central hydrophobic core) and 12-14 (N-terminal region) that are responsible for such a favourable effect. The conformation in which the hydrophobic cthr-chc interaction is oriented perpendicularly is particularly important. We propose three other model substructures that favour the oligomerization process and can thus be considered as molecular targets for future inhibitors. Understanding Aβ oligomerization at the residue level could lead to more efficient design of inhibitors of this process.
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Affiliation(s)
- R Pouplana
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII, s/n, Diagonal Sud, 08028, Barcelona, Catalonia, Spain.
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18
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Berhanu WM, Hansmann UHE. Stability of amyloid oligomers. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2014; 96:113-41. [PMID: 25443956 DOI: 10.1016/bs.apcsb.2014.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Molecular simulations are now commonly used to complement experimental techniques in investigating amyloids and their role in human diseases. In this chapter, we will summarize techniques and approaches often used in amyloid simulations and will present recent success stories. Our examples will be focused on lessons learned from molecular dynamics simulations in aqueous environments that start from preformed aggregates. These studies explore the limitations that arise from the choice of force field, the role of mutations in the growth of amyloid aggregates, segmental polymorphism, and the importance of cross-seeding. Furthermore, they give evidence for potential toxicity mechanisms. We finally discuss the role of molecular simulations in the search for aggregation inhibitors.
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Affiliation(s)
- Workalemahu M Berhanu
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Ulrich H E Hansmann
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, USA.
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Srivastava A, Balaji PV. Interplay of sequence, topology and termini charge in determining the stability of the aggregates of GNNQQNY mutants: a molecular dynamics study. PLoS One 2014; 9:e96660. [PMID: 24817093 PMCID: PMC4015988 DOI: 10.1371/journal.pone.0096660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 04/11/2014] [Indexed: 01/16/2023] Open
Abstract
This study explores the stabilities of single sheet parallel systems of three sequence variants of 1GNNQQNY7, N2D, N2S and N6D, with variations in aggregate size (5–8) and termini charge (charged or neutral). The aggregates were simulated at 300 and 330 K. These mutations decrease amyloid formation in the yeast prion protein Sup35. The present study finds that these mutations cause instability even in the peptide context. The protonation status of termini is found to be a key determinant of stabilities; other determinants are sequence, position of mutation and aggregate size. All systems with charged termini are unstable, whereas both stable and unstable systems are found when the termini are neutral. When termini are charged, the largest stable aggregate for the N2S and N6D systems has 3 to 4 peptides whereas N2D mutation supports oligomers of larger size (5-and 6-mers) as well. Mutation at 2nd position (N2S and N2D) results in fewer H-bonds at the mutated as well as neighboring (Gly1/Gln4) positions. However, no such effect is found if mutation is at 6th position (N6D). The effect of Asn→Asp mutation depends on the position and termini charge: it is more destabilizing at the 2nd position than at the 6th in case of neutral termini, however, the opposite is true in case of charged termini. Appearance of twist in stable systems and in smaller aggregates formed in unstable systems suggests that twist is integral to amyloid arrangement. Disorder, dissociation or rearrangement of peptides, disintegration or collapse of aggregates and formation of amorphous aggregates observed in these simulations are likely to occur during the early stages of aggregation also. The smaller aggregates formed due to such events have a variety of arrangements of peptides. This suggests polymorphic nature of oligomers and presence of a heterogeneous mixture of oligomers during early stages of aggregation.
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Affiliation(s)
- Alka Srivastava
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Petety V. Balaji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
- * E-mail:
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20
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Berhanu WM, Hansmann UHE. Inter-species cross-seeding: stability and assembly of rat-human amylin aggregates. PLoS One 2014; 9:e97051. [PMID: 24810618 PMCID: PMC4014569 DOI: 10.1371/journal.pone.0097051] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 03/28/2014] [Indexed: 12/14/2022] Open
Abstract
Diseases such as type 2 diabetes, Alzheimer's and Parkinson's share as common feature the accumulation of mis-folded disease-specific protein aggregates into fibrillar structures, or plaques. These fibrils may either be toxic by themselves, or act as reservoirs for smaller cytotoxic oligomers. This suggests to investigate molecules as potential therapeutics that either reduce fibril formation or increase fibril stability. One example is rat amylin, which can inhibit aggregation of human amylin, a hallmark of type 2 diabetes. In the present paper, we use molecular dynamics to compare the stability of various preformed aggregates, built out of either human amylin, rat amylin, or mixtures of both. We considered two types of fibril-like oligomers: a single-layer in-register conformation, and a double-layer conformation in which the first U-shaped layer consists of rat amylin and the second layer of human amylin. Our results explain the weak amyloid-inhibiting properties of rat amylin and suggest that membrane leakage due to pore formation is responsible for the toxicity of rat amylin observed in a recent experiment. Together, our results put in question the use of rat amylin or the similar FDA approved drug pramlintide as an inhibitor of human amylin aggregation. They also point to mixed human-rat amylin fibril-like oligomers as possible model-systems for studies of amyloid formation that involve cross-species transmission.
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Affiliation(s)
- Workalemahu M. Berhanu
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Ulrich H. E. Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
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21
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The characterization and comparison of amyloidogenic segments and non-amyloidogenic segments shed light on amyloid formation. Biochem Biophys Res Commun 2014; 447:255-62. [DOI: 10.1016/j.bbrc.2014.03.115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 11/30/2022]
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22
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LU YAN, XI WENHUI, WEI GUANGHONG. STRUCTURAL INSIGHT INTO THE POLYMORPHISM OF NNQNTF PROTOFIBRIL: IMPORTANCE OF INTERFACIAL WATER, POLAR AND AROMATIC RESIDUES. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613410125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Polymorphism is widely observed in amyloid fibrils associated with many neurodegenerative diseases. Recent experimental study reported that fibrils formed by the segment NNQNTF of elk prion protein exhibited facial polymorphism with the two β-sheets either in back-to-back (BB) or in face-to-face (FF) packing arrangement. In the BB packing, the side chains of N2, N4 and F6 are interdigitated to form steric zipper, while in the FF packing, the side chains of N1, Q3 and T5 form the interdigitated interface. In this study, we investigate the water-mediated assembly of two preformed β-sheets and the physical interactions that stabilize the two different fibrils using all-atom molecular dynamics (MD) simulations. Multiple MD simulations have been carried out by starting from FF or BB packing of two β-sheets according to the facial polymorphism revealed by X-ray microcrystallography. For both packing patterns, we observe that the assembly of β-sheets is mediated by water molecules in the interface between β-sheets, leading to a long-lived protofibrils with wet interface prior to the formation of dry amyloid fibrils. Detailed structural analysis shows that besides the side chain steric zipper interactions, intra-sheet hydrogen bonding and aromatic stacking interactions play an important role on the stabilization of the protofibril with BB packing, while the intra-sheet and inter-sheet hydrogen bonding interactions are crucial for the formation of BB protofibril. These findings provide insights into the mechanism that lead to the facial polymorphism of NNQNTF fibrils.
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Affiliation(s)
- YAN LU
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences, (Ministry of Education) and Department of Physics, Fudan University, 220 Handan Road, Shanghai, 200433, P. R. China
| | - WENHUI XI
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences, (Ministry of Education) and Department of Physics, Fudan University, 220 Handan Road, Shanghai, 200433, P. R. China
| | - GUANGHONG WEI
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences, (Ministry of Education) and Department of Physics, Fudan University, 220 Handan Road, Shanghai, 200433, P. R. China
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23
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Berhanu WM, Yaşar F, Hansmann UHE. In silico cross seeding of Aβ and amylin fibril-like oligomers. ACS Chem Neurosci 2013; 4:1488-500. [PMID: 24007594 DOI: 10.1021/cn400141x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Recent epidemiological data have shown that patients suffering from Type 2 Diabetes Mellitus have an increased risk to develop Alzheimer's disease and vice versa. A possible explanation is the cross-sequence interaction between Aβ and amylin. Because the resulting amyloid oligomers are difficult to probe in experiments, we investigate stability and conformational changes of Aβ-amylin heteroassemblies through molecular dynamics simulations. We find that Aβ is a good template for the growth of amylin and vice versa. We see water molecules permeate the β-strand-turn-β-strand motif pore of the oligomers, supporting a commonly accepted mechanism for toxicity of β-rich amyloid oligomers. Aiming for a better understanding of the physical mechanisms of cross-seeding and cell toxicity of amylin and Aβ aggregates, our simulations also allow us to identify targets for the rational design of inhibitors against toxic fibril-like oligomers of Aβ and amylin oligomers.
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Affiliation(s)
- Workalemahu M. Berhanu
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Fatih Yaşar
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Ulrich H. E. Hansmann
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma 73019, United States
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24
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Berhanu WM, Hansmann UHE. The stability of cylindrin β-barrel amyloid oligomer models-a molecular dynamics study. Proteins 2013; 81:1542-55. [PMID: 23606599 DOI: 10.1002/prot.24302] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Revised: 03/21/2013] [Accepted: 04/01/2013] [Indexed: 11/10/2022]
Abstract
Small-soluble amyloid oligomers are believed to play a significant role in the pathology of amyloid diseases. Recently, the atomic structure of a toxic oligomer formed by an 11 residue and its tandem repeat was found to have an out-off register antiparallel β-strands in the shape of a β-barrel. In the present article we investigate the effect of mutations in the hydrophobic cores on the structure and dynamic of the β-barrels using all atom multiple molecular dynamics simulations with an explicit solvent. Extending previous experiments with molecular dynamics simulations we systematically test how stability and formation of cylindrin depends on the interplay between hydrophobicity and steric effects of the core residues. We find that strong hydrophobic interactions between geometrically fitting residues keep the strands (both in register and out-off-register interface) in close proximity, which in turn stabilizes the side-chain and main-chain hydrogen bonds, and the salt bridges on the outer surface along the weak out-of-register interface. Our simulations also indicate presence of water molecules in the hydrophobic interior of the cylindrin β-barrel.Proteins 2013.
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Affiliation(s)
- Workalemahu M Berhanu
- Department of Chemistry & Biochemistry, University of Oklahoma, Norman, Oklahoma, 73019
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25
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Han C, Fang S, Cao H, Lu Y, Ma Y, Wei D, Xie X, Liu X, Li X, Fei D, Zhao C. Molecular interaction of PCB153 to human serum albumin: insights from spectroscopic and molecular modeling studies. JOURNAL OF HAZARDOUS MATERIALS 2013; 248-249:313-321. [PMID: 23416474 DOI: 10.1016/j.jhazmat.2012.12.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 12/11/2012] [Accepted: 12/30/2012] [Indexed: 06/01/2023]
Abstract
Polychlorinated biphenyls (PCBs) possessed much potential hazard to environment because of its chemical stability and biological toxicity. Here, we identified the binding mode of a representative compound, PCB153, to human serum albumin (HSA) using fluorescence and molecular dynamics simulation methods. The fluorescence study showed that the intrinsic fluorescence of HSA was quenched by addition of PCB153 through a static quenching mechanism. The thermodynamic analysis proved the binding behavior was mainly governed by hydrophobic force. Furthermore, as evidenced by site marker displacement experiments using two probe compounds, it revealed that PCB153 acted exactly on subdomain IIIA (site II) of HSA. On the other hand, the molecular dynamics studies as well as free energy calculations made another important contribution to understand the conformational changes of HSA and the stability of HSA-PCB153 system. Molecular docking revealed PCB153 can bind in a large hydrophobic activity of subdomain IIIA by the hydrophobic interaction and hydrogen bond interactions between chlorine atoms and residue ASN391. The present work provided reasonable models helping us further understand the transporting, distribution and toxicity effect of PCBs when it spread into human blood serum.
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Affiliation(s)
- Chao Han
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China
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26
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Nishiyama K. Local fluctuation control of papain by changing a highly fluctuating residue. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.10.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Berhanu WM, Hansmann UHE. Side-chain hydrophobicity and the stability of Aβ₁₆₋₂₂ aggregates. Protein Sci 2012; 21:1837-48. [PMID: 23015407 PMCID: PMC3575914 DOI: 10.1002/pro.2164] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/06/2012] [Accepted: 09/14/2012] [Indexed: 11/05/2022]
Abstract
Recent mutagenesis studies using the hydrophobic segment of Aβ suggest that aromatic π-stacking interactions may not be critical for fibril formation. We have tested this conjecture by probing the effect of Leu, Ile, and Ala mutation of the aromatic Phe residues at positions 19 and 20, on the double-layer hexametric chains of Aβ fragment Aβ₁₆₋₂₂ using explicit solvent all-atom molecular dynamics. As these simulations rely on the accuracy of the utilized force fields, we first evaluated the dynamic and stability dependence on various force fields of small amyloid aggregates. These initial investigations led us to choose AMBER99SB-ILDN as force field in multiple long molecular dynamics simulations of 100 ns that probe the stability of the wild-type and mutants oligomers. Single-point and double-point mutants confirm that size and hydrophobicity are key for the aggregation and stability of the hydrophobic core region (Aβ₁₆₋₂₂). This suggests as a venue for designing Aβ aggregation inhibitors the substitution of residues (especially, Phe 19 and 20) in the hydrophobic region (Aβ₁₆₋₂₂) with natural and non-natural amino acids of similar size and hydrophobicity.
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Affiliation(s)
- Workalemahu M Berhanu
- Department of Chemistry and Biochemistry, University of OklahomaNorman, Oklahoma 73019
| | - Ulrich H E Hansmann
- Department of Chemistry and Biochemistry, University of OklahomaNorman, Oklahoma 73019
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28
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Liu FF, Liu Z, Bai S, Dong XY, Sun Y. Exploring the inter-molecular interactions in amyloid-β protofibril with molecular dynamics simulations and molecular mechanics Poisson-Boltzmann surface area free energy calculations. J Chem Phys 2012; 136:145101. [PMID: 22502547 DOI: 10.1063/1.3702195] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Aggregation of amyloid-β (Aβ) peptides correlates with the pathology of Alzheimer's disease. However, the inter-molecular interactions between Aβ protofibril remain elusive. Herein, molecular mechanics Poisson-Boltzmann surface area analysis based on all-atom molecular dynamics simulations was performed to study the inter-molecular interactions in Aβ(17-42) protofibril. It is found that the nonpolar interactions are the important forces to stabilize the Aβ(17-42) protofibril, while electrostatic interactions play a minor role. Through free energy decomposition, 18 residues of the Aβ(17-42) are identified to provide interaction energy lower than -2.5 kcal/mol. The nonpolar interactions are mainly provided by the main chain of the peptide and the side chains of nine hydrophobic residues (Leu17, Phe19, Phe20, Leu32, Leu34, Met35, Val36, Val40, and Ile41). However, the electrostatic interactions are mainly supplied by the main chains of six hydrophobic residues (Phe19, Phe20, Val24, Met35, Val36, and Val40) and the side chains of the charged residues (Glu22, Asp23, and Lys28). In the electrostatic interactions, the overwhelming majority of hydrogen bonds involve the main chains of Aβ as well as the guanidinium group of the charged side chain of Lys28. The work has thus elucidated the molecular mechanism of the inter-molecular interactions between Aβ monomers in Aβ(17-42) protofibril, and the findings are considered critical for exploring effective agents for the inhibition of Aβ aggregation.
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Affiliation(s)
- Fu-Feng Liu
- Department of Biochemical Engineering and Key Laboratory of Systems Bioengineering of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
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29
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Wise-Scira O, Xu L, Kitahara T, Perry G, Coskuner O. Amyloid-β peptide structure in aqueous solution varies with fragment size. J Chem Phys 2012; 135:205101. [PMID: 22128957 DOI: 10.1063/1.3662490] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Various fragment sizes of the amyloid-β (Aβ) peptide have been utilized to mimic the properties of the full-length Aβ peptide in solution. Among these smaller fragments, Aβ16 and Aβ28 have been investigated extensively. In this work, we report the structural and thermodynamic properties of the Aβ16, Aβ28, and Aβ42 peptides in an aqueous solution environment. We performed replica exchange molecular dynamics simulations along with thermodynamic calculations for investigating the conformational free energies, secondary and tertiary structures of the Aβ16, Aβ28, and Aβ42 peptides. The results show that the thermodynamic properties vary from each other for these peptides. Furthermore, the secondary structures in the Asp1-Lys16 and Asp1-Lys28 regions of Aβ42 cannot be completely captured by the Aβ16 and Aβ28 fragments. For example, the β-sheet structures in the N-terminal region of Aβ16 and Aβ28 are either not present or the abundance is significantly decreased in Aβ42. The α-helix and β-sheet abundances in Aβ28 and Aβ42 show trends--to some extent--with the potential of mean forces but no such trend could be obtained for Aβ16. Interestingly, Arg5 forms salt bridges with large abundances in all three peptides. The formation of a salt bridge between Asp23-Lys28 is more preferred over the Glu22-Lys28 salt bridge in Aβ28 but this trend is vice versa for Aβ42. This study shows that the Asp1-Lys16 and Asp1-Lys28 regions of the full length Aβ42 peptide cannot be completely mimicked by studying the Aβ16 and Aβ28 peptides.
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Affiliation(s)
- Olivia Wise-Scira
- The University of Texas at San Antonio, Department of Chemistry, One UTSA Circle, San Antonio, Texas 78249, USA
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30
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Berhanu WM, Hansmann UHE. Structure and dynamics of amyloid-β segmental polymorphisms. PLoS One 2012; 7:e41479. [PMID: 22911797 PMCID: PMC3404032 DOI: 10.1371/journal.pone.0041479] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/21/2012] [Indexed: 11/23/2022] Open
Abstract
It is believed that amyloid-beta (Aβ) aggregates play a role in the pathogenesis of Alzheimer's disease. Aβ molecules form β-sheet structures with multiple interaction sites. This polymorphism gives rise to differences in morphology, physico-chemical property and level of cellular toxicity. We have investigated the conformational stability of various segmental polymorphisms using molecular dynamics simulations and find that the segmental polymorphic models of Aβ retain a U-shaped architecture. Our results demonstrate the importance of inter-sheet side chain-side chain contacts, hydrophobic contacts among the strands (β1 and β2) and of salt bridges in stabilizing the aggregates. Residues in β-sheet regions have smaller fluctuation while those at the edge and loop region are more mobile. The inter-peptide salt bridges between Asp23 and Lys28 are strong compared to intra-chain salt bridge and there is an exchange of the inter-chain salt-bridge with intra-chain salt bridge. As our results suggest that Aβ exists under physiological conditions as an ensemble of distinct segmental polymorphs, it may be necessary to account in the development of therapeutics for Alzheimer's disease the differences in structural stability and aggregation behavior of the various Aβ polymorphic forms.
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Affiliation(s)
- Workalemahu M. Berhanu
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
| | - Ulrich H. E. Hansmann
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, United States of America
- * E-mail:
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31
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Berhanu WM, Masunov AE. Alternative packing modes leading to amyloid polymorphism in five fragments studied with molecular dynamics. Biopolymers 2011; 98:131-44. [PMID: 22020870 DOI: 10.1002/bip.21731] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/13/2011] [Accepted: 10/14/2011] [Indexed: 12/13/2022]
Abstract
Amyloid aggregates have been implicated in the pathogenesis of diseases such as type 2 diabetes, Alzheimer's, Parkinson's, and prion disease. Recently determined microcrystal structures of several short peptide segments derived from fibril-forming proteins revealed coexistence of alternative aggregation modes (amyloid polymorphism) formed by the same segment. This polymorphism may help in understanding the influence of the side chain packing on the amyloid stability. Here we use molecular dynamics (MD) simulation to analyze the stability of five pairs of polar and nonpolar polymorphic oligomers. MD simulation shows polymorphs with steric zipper interface containing large polar and/or aromatic side chains (GNNQQNY, and NNQNTF) are more stable than steric zipper interfaces made of small or hydrophobic residues (SSTNGVG, VQIVYK, and MVGGVV). Several geometric analyses revealed that larger sheet to sheet interface of the dry steric zipper through polar Q/N rich side chains holds the sheets together. Mutant simulations (Q/N→G) show substitutions with glycine disrupt the steric zipper, leading to unstable oligomers. Stability of Q/N rich oligomers was found to result from the large average number of hydrogen bonds. The molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) method reports the nonpolar component of free energy to be favorable, while electrostatic solvation is unfavorable for β-sheet association. Knowledge of structural properties of these fibrils might be useful for developing therapeutic agents against amyloidoses as well as for developing biomaterials. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 131-144, 2012.
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