1
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Ruttenberg SM, Nowick JS. A turn for the worse: Aβ β-hairpins in Alzheimer's disease. Bioorg Med Chem 2024; 105:117715. [PMID: 38615460 DOI: 10.1016/j.bmc.2024.117715] [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: 02/15/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/16/2024]
Abstract
Amyloid-β (Aβ) oligomers are a cause of neurodegeneration in Alzheimer's disease (AD). These soluble aggregates of the Aβ peptide have proven difficult to study due to their inherent metastability and heterogeneity. Strategies to isolate and stabilize homogenous Aβ oligomer populations have emerged such as mutations, covalent cross-linking, and protein fusions. These strategies along with molecular dynamics simulations have provided a variety of proposed structures of Aβ oligomers, many of which consist of molecules of Aβ in β-hairpin conformations. β-Hairpins are intramolecular antiparallel β-sheets composed of two β-strands connected by a loop or turn. Three decades of research suggests that Aβ peptides form several different β-hairpin conformations, some of which are building blocks of toxic Aβ oligomers. The insights from these studies are currently being used to design anti-Aβ antibodies and vaccines to treat AD. Research suggests that antibody therapies designed to target oligomeric Aβ may be more successful at treating AD than antibodies designed to target linear epitopes of Aβ or fibrillar Aβ. Aβ β-hairpins are good epitopes to use in antibody development to selectively target oligomeric Aβ. This review summarizes the research on β-hairpins in Aβ peptides and discusses the relevance of this conformation in AD pathogenesis and drug development.
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Affiliation(s)
- Sarah M Ruttenberg
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, United States
| | - James S Nowick
- Department of Chemistry, University of California, Irvine, Irvine, CA 92697-2025, United States.
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2
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Rahman A, Saikia B, Gogoi CR, Baruah A. Advances in the understanding of protein misfolding and aggregation through molecular dynamics simulation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 175:31-48. [PMID: 36044970 DOI: 10.1016/j.pbiomolbio.2022.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
Aberrant protein folding known as protein misfolding is counted as one of the striking factors of neurodegenerative diseases. The extensive range of pathologies caused by protein misfolding, aggregation and subsequent accumulation are mainly classified into either gain of function diseases or loss of function diseases. In order to seek for novel strategies for treatment and diagnosis of neurodegenerative diseases, insights into the mechanism of misfolding and aggregation is essential. A comprehensive knowledge on the factors influencing misfolding and aggregation is required as well. An extensive experimental study on protein aggregation is somewhat challenging due to the insoluble and noncrystalline nature of amyloid fibrils. Thus there has been a growing use of computational approaches including Monte Carlo simulation, docking simulation, molecular dynamics simulation in the study of protein misfolding and aggregation. The review presents a discussion on molecular dynamics simulation alone as to how it has emerged as a promising tool in the understanding of protein misfolding and aggregation in general, detailing upon three different aspects considering four misfold prone proteins in particular. It is noticeable that all four proteins considered in this review i.e prion, superoxide dismutase1, huntingtin and amyloid β are linked to chronic neurodegenerative diseases with debilitating effects. Initially the review elaborates on the factors influencing the misfolding and aggregation. Next, it addresses our current understanding of the amyloid structures and the associated aggregation mechanisms, finally, summarizing the contribution of this computational tool in the search for therapeutic strategies against the respective protein-deposition diseases.
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Affiliation(s)
- Aziza Rahman
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Bondeepa Saikia
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Chimi Rekha Gogoi
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India
| | - Anupaul Baruah
- Department of Chemistry, Dibrugarh University, Dibrugarh, 786004, Assam, India.
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3
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Yasar F, Ray AJ, Hansmann UHE. Resolution exchange with tunneling for enhanced sampling of protein landscapes. Phys Rev E 2022; 106:015302. [PMID: 35974556 PMCID: PMC9389597 DOI: 10.1103/physreve.106.015302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
Simulations of protein folding and protein association happen on timescales that are orders of magnitude larger than what can typically be covered in all-atom molecular dynamics simulations. Use of low-resolution models alleviates this problem but may reduce the accuracy of the simulations. We introduce a replica-exchange-based multiscale sampling technique that combines the faster sampling in coarse-grained simulations with the potentially higher accuracy of all-atom simulations. After testing the efficiency of our Resolution Exchange with Tunneling (ResET) in simulations of the Trp-cage protein, an often used model to evaluate sampling techniques in protein simulations, we use our approach to compare the landscape of wild-type and A2T mutant Aβ_{1-42} peptides. Our results suggest a mechanism by that the mutation of a small hydrophobic alanine (A) into a bulky polar threonine (T) may interfere with the self-assembly of Aβ fibrils.
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Affiliation(s)
- Fatih Yasar
- Dept. of Chemistry & Biochemistry, University of Oklahoma, Norman, OK 73019, USA
| | - Alan J. Ray
- Dept. of Chemistry & Biochemistry, University of Oklahoma, Norman, OK 73019, USA
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4
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Yuan M, Tang X, Han W. Anatomy and Formation Mechanisms of Early Amyloid-β Oligomers with Lateral Branching: Graph Network Analysis on Large-Scale Simulations. Chem Sci 2022; 13:2649-2660. [PMID: 35356670 PMCID: PMC8890322 DOI: 10.1039/d1sc06337e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 02/08/2022] [Indexed: 11/29/2022] Open
Abstract
Oligomeric amyloid-β aggregates (AβOs) effectively trigger Alzheimer's disease-related toxicity, generating great interest in understanding their structures and formation mechanisms. However, AβOs are heterogeneous and transient, making their structure and formation difficult to study. Here, we performed graph network analysis of tens of microsecond massive simulations of early amyloid-β (Aβ) aggregations at near-atomic resolution to characterize AβO structures with sizes up to 20-mers. We found that AβOs exhibit highly curvilinear, irregular shapes with occasional lateral branches, consistent with recent cryo-electron tomography experiments. We also found that Aβ40 oligomers were more likely to develop branches than Aβ42 oligomers, explaining an experimental observation that only Aβ40 was trapped in network-like aggregates and exhibited slower fibrillization kinetics. Moreover, AβO architecture dissection revealed that their curvilinear appearance is related to the local packing geometries of neighboring peptides and that Aβ40's greater branching ability originates from specific C-terminal interactions at branching interfaces. Finally, we demonstrate that whether Aβ oligomerization causes oligomers to elongate or to branch depends on the sizes and shapes of colliding aggregates. Collectively, this study provides bottom-up structural information for understanding early Aβ aggregation and AβO toxicity. Graph network analysis on large-scale simulations uncovers the differential branching behaviours of large Aβ40 and Aβ42 oligomers.![]()
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Affiliation(s)
- Miao Yuan
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School Shenzhen 518055 China
| | - Xuan Tang
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School Shenzhen 518055 China
| | - Wei Han
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School Shenzhen 518055 China
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5
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Bhattacharya S, Xu L, Thompson D. Characterization of Amyloidogenic Peptide Aggregability in Helical Subspace. Methods Mol Biol 2022; 2340:401-448. [PMID: 35167084 DOI: 10.1007/978-1-0716-1546-1_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Prototypical amyloidogenic peptides amyloid-β (Aβ) and α-synuclein (αS) can undergo helix-helix associations via partially folded helical conformers, which may influence pathological progression to Alzheimer's (AD) and Parkinson's disease (PD), respectively. At the other extreme, stable folded helical conformers have been reported to resist self-assembly and amyloid formation. Experimental characterisation of such disparities in aggregation profiles due to subtle differences in peptide stabilities is precluded by the conformational heterogeneity of helical subspace. The diverse physical models used in molecular simulations allow sampling distinct regions of the phase space and are extensive in capturing the ensemble of rich helical subspace. Robust and powerful computational predictive methods utilizing network theory and free energy mapping can model the origin of helical population shifts in amyloidogenic peptides, which highlight their inherent aggregability. In this chapter, we discuss computational models, methods, design rules, and strategies to identify the driving force behind helical self-assembly and the molecular origin of aggregation resistance in helical intermediates of Aβ42 and αS. By extensive multiscale mapping of intrapeptide interactions, we show that the computational models can capture features that are otherwise imperceptible to experiments. Our models predict that targeting terminal residues may allow modulation and control of initial pathogenic aggregability of amyloidogenic peptides.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
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6
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Limegrover CS, LeVine H, Izzo NJ, Yurko R, Mozzoni K, Rehak C, Sadlek K, Safferstein H, Catalano SM. Alzheimer's protection effect of A673T mutation may be driven by lower Aβ oligomer binding affinity. J Neurochem 2021; 157:1316-1330. [PMID: 33025581 PMCID: PMC8246829 DOI: 10.1111/jnc.15212] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 12/16/2022]
Abstract
Several mutations conferring protection against Alzheimer's disease (AD) have been described, none as profound as the A673T mutation, where carriers are four times less likely to get AD compared to noncarriers. This mutation results in reduced amyloid beta (Aβ) protein production in vitro and lower lifetime Aβ concentration in carriers. Better understanding of the protective mechanisms of the mutation may provide important insights into AD pathophysiology and identify productive therapeutic intervention strategies for disease modification. Aβ(1-42) protein forms oligomers that bind saturably to a single receptor site on neuronal synapses, initiating the downstream toxicities observed in AD. Decreased formation, toxicity, or stability of soluble Aβ oligomers, or reduction of synaptic binding of these oligomers, may combine with overall lower Aβ concentration to underlie A673T's disease protecting mechanism. To investigate these possibilities, we compared the formation rate of soluble oligomers made from Icelandic A673T mutant and wild type (wt) Aβ(1-42) synthetic protein, the amount and intensity of oligomer bound to mature primary rat hippocampal/cortical neuronal synapses, and the potency of bound oligomers to impact trafficking rate in neurons in vitro using a physiologically relevant oligomer preparation method. At equal protein concentrations, mutant protein forms approximately 50% or fewer oligomers of high molecular weight (>50 kDa) compared to wt protein. Mutant oligomers are twice as potent at altering the cellular vesicle trafficking rate as wt at equivalent concentrations, however, mutant oligomers have a >4-fold lower binding affinity to synaptic receptors (Kd = 1,950 vs. 442 nM). The net effect of these differences is a lower overall toxicity at a given concentration. This study demonstrates for the first time that mutant A673T Aβ oligomers prepared with this method have fundamentally different assembly characteristics and biological impact from wt protein and indicates that its disease protecting mechanism may result primarily from the mutant protein's much lower binding affinity to synaptic receptors. This suggests that therapeutics that effectively reduce oligomer binding to synapses in the brain may be beneficial in AD.
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Affiliation(s)
| | - Harry LeVine
- Sanders‐Brown Center on AgingUniversity of KentuckyLexingtonKYUSA
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7
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Wells C, Brennan S, Keon M, Ooi L. The role of amyloid oligomers in neurodegenerative pathologies. Int J Biol Macromol 2021; 181:582-604. [PMID: 33766600 DOI: 10.1016/j.ijbiomac.2021.03.113] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 02/18/2021] [Accepted: 03/19/2021] [Indexed: 11/25/2022]
Abstract
Many neurodegenerative diseases are rooted in the activities of amyloid-like proteins which possess conformations that spread to healthy proteins. These include Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS). While their clinical manifestations vary, their protein-level mechanisms are remarkably similar. Aberrant monomeric proteins undergo conformational shifts, facilitating aggregation and formation of solid fibrils. However, there is growing evidence that intermediate oligomeric stages are key drivers of neuronal toxicity. Analysis of protein dynamics is complicated by the fact that nucleation and growth of amyloid-like proteins is not a linear pathway. Feedback within this pathway results in exponential acceleration of aggregation, but activities exerted by oligomers and fibrils can alter cellular interactions and the cellular environment as a whole. The resulting cascade of effects likely contributes to the late onset and accelerating progression of amyloid-like protein disorders and the widespread effects they have on the body. In this review we explore the amyloid-like proteins associated with AD, PD, HD and ALS, as well as the common mechanisms of amyloid-like protein nucleation and aggregation. From this, we identify core elements of pathological progression which have been targeted for therapies, and which may become future therapeutic targets.
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Affiliation(s)
- Cameron Wells
- GenieUs Genomics, Sydney, NSW 2010, Australia; University of New South Wales, Sydney, NSW 2052, Australia
| | | | - Matt Keon
- GenieUs Genomics, Sydney, NSW 2010, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; School of Chemistry and Molecular Bioscience, and Molecular Horizons, University of Wollongong, Wollongong, NSW 2522, Australia; GenieUs Genomics, Sydney, NSW 2010, Australia
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8
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Mahmoudinobar F, Nilsson BL, Dias CL. Effects of Ions and Small Compounds on the Structure of Aβ 42 Monomers. J Phys Chem B 2021; 125:1085-1097. [PMID: 33481611 DOI: 10.1021/acs.jpcb.0c09617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Aggregation of amyloid-β (Aβ) proteins in the brain is a hallmark of Alzheimer's disease. This phenomenon can be promoted or inhibited by adding small molecules to the solution where Aβ is embedded. These molecules affect the ensemble of conformations sampled by Aβ monomers even before aggregation starts. Here, we perform extensive all-atom replica exchange molecular dynamics (REMD) simulations to provide a comparative study of the ensemble of conformations sampled by Aβ42 monomers in solutions that promote (i.e., aqueous solution containing NaCl) and inhibit (i.e., aqueous solutions containing scyllo-inositol or 4-aminophenol) aggregation. Simulations performed in pure water are used as our reference. We find that secondary-structure content is only affected in an antagonistic manner by promoters and inhibitors at the C-terminus and the central hydrophilic core. Moreover, the end of the C-terminus binds more favorably to the central hydrophobic core region of Aβ42 in NaCl adopting a type of strand-loop-strand structure that is disfavored by inhibitors. Nonpolar residues that form the dry core of larger aggregates of Aβ42 (e.g., PDB ID 2BEG) are found at close proximity in these strand-loop-strand structures, suggesting that their formation could play an important role in initiating nucleation. In the presence of inhibitors, the C-terminus binds the central hydrophilic core with a higher probability than in our reference simulation. This sensitivity of the C-terminus, which is affected in an antagonistic manner by inhibitors and promoters, provides evidence for its critical role in accounting for aggregation.
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Affiliation(s)
- Farbod Mahmoudinobar
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
| | - Bradley L Nilsson
- Department of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - Cristiano L Dias
- Department of Physics, New Jersey Institute of Technology, Newark, New Jersey 07102-1982, United States
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9
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Mitochondria and Neurodegenerative Diseases. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11474-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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10
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Aggarwal L, Biswas P. Effect of Alzheimer’s Disease Causative and Protective Mutations on the Hydration Environment of Amyloid-β. J Phys Chem B 2020; 124:2311-2322. [DOI: 10.1021/acs.jpcb.9b10425] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Leena Aggarwal
- Department of Chemistry, University of Delhi, Delhi 110007, India
| | - Parbati Biswas
- Department of Chemistry, University of Delhi, Delhi 110007, India
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11
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Pilkington AW, Schupp J, Nyman M, Valentine SJ, Smith DM, Legleiter J. Acetylation of Aβ 40 Alters Aggregation in the Presence and Absence of Lipid Membranes. ACS Chem Neurosci 2020; 11:146-161. [PMID: 31834770 DOI: 10.1021/acschemneuro.9b00483] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A hallmark of Alzheimer's disease (AD) is the formation of senile plaques comprised of the β-amyloid (Aβ) peptide. Aβ fibrillization is a complex nucleation-dependent process involving a variety of metastable intermediate aggregates and features the formation of inter- and intramolecular salt bridges involving lysine residues, K16 and K28. Cationic lysine residues also mediate protein-lipid interactions via association with anionic lipid headgroups. As several toxic mechanisms attributed to Aβ involve membrane interactions, the impact of acetylation on Aβ40 aggregation in the presence and absence of membranes was determined. Using chemical acetylation, varying mixtures of acetylated and nonacetylated Aβ40 were produced. With increasing acetylation, fibril and oligomer formation decreased, eventually completely arresting fibrillization. In the presence of total brain lipid extract (TBLE) vesicles, acetylation reduced the interaction of Aβ40 with membranes; however, fibrils still formed at near complete levels of acetylation. Additionally, the combination of TBLE and acetylated Aβ promoted annular aggregates. Finally, toxicity associated with Aβ40 was reduced with increasing acetylation in a cell culture assay. These results suggest that in the absence of membranes that the cationic character of lysine plays a major role in fibril formation. However, acetylation promotes unique aggregation pathways in the presence of lipid membranes.
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Affiliation(s)
- Albert W. Pilkington
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Jane Schupp
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Morgan Nyman
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J. Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - David M. Smith
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box
9303, Morgantown, West Virginia 26505, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box
9303, Morgantown, West Virginia 26505, United States
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12
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Bhattacharya S, Xu L, Thompson D. Molecular Simulations Reveal Terminal Group Mediated Stabilization of Helical Conformers in Both Amyloid-β42 and α-Synuclein. ACS Chem Neurosci 2019; 10:2830-2842. [PMID: 30917651 DOI: 10.1021/acschemneuro.9b00053] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The presence of partially structured helices in natively unfolded amyloid-β42 (Aβ42) and α-synuclein (αS) has been shown to accelerate fibrillation in the onset of Alzheimer's and Parkinson's disease, respectively. At the other extreme, folded stable helical conformers have also been reported to resist amyloid formation. Recent studies indicate that amyloidogenic aggregation can be impeded using small molecules that stabilize the α-helical monomers and switch off the neurotoxic pathway. We predict a common intrapeptide route to stabilization based on the plasticity of helical conformations of Aβ42 and αS as assessed through extensive atomistic molecular dynamics (MD) computer simulations (∼36 μs) across ten distinct protein force field and water model combinations. Computed free energies and interaction maps (not obtainable from experiments alone) show that flexible terminal groups (N-terminus of Aβ42 and C-terminus of αS) show a tendency to stabilize folded helical conformations in both peptides via primary hydrophobic interactions with central hydrophobic domains, and secondary salt bridges with other domains. These interactions confer aggregation resistance by decreasing the population of partially structured helices and are absent in control simulations of complete unfolding. Computed helical stability is also significantly reduced in terminal-deleted variants. The models suggest new strategies to tackle neurodegeneration by rationally re-engineering terminal groups to optimize their predicted ability to deactivate helical monomers.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
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13
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Arya S, Singh AK, Bhasne K, Dogra P, Datta A, Das P, Mukhopadhyay S. Femtosecond Hydration Map of Intrinsically Disordered α-Synuclein. Biophys J 2019; 114:2540-2551. [PMID: 29874605 DOI: 10.1016/j.bpj.2018.04.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 10/14/2022] Open
Abstract
Protein hydration water plays a fundamentally important role in protein folding, binding, assembly, and function. Little is known about the hydration water in intrinsically disordered proteins that challenge the conventional sequence-structure-function paradigm. Here, by combining experiments and simulations, we show the existence of dynamical heterogeneity of hydration water in an intrinsically disordered presynaptic protein, namely α-synuclein, implicated in Parkinson's disease. We took advantage of nonoccurrence of cysteine in the sequence and incorporated a number of cysteine residues at the N-terminal segment, the central amyloidogenic nonamyloid-β component (NAC) domain, and the C-terminal end of α-synuclein. We then labeled these cysteine variants using environment-sensitive thiol-active fluorophore and monitored the solvation dynamics using femtosecond time-resolved fluorescence. The site-specific femtosecond time-resolved experiments allowed us to construct the hydration map of α-synuclein. Our results show the presence of three dynamically distinct types of water: bulk, hydration, and confined water. The amyloidogenic NAC domain contains dynamically restrained water molecules that are strikingly different from the water molecules present in the other two domains. Atomistic molecular dynamics simulations revealed longer residence times for water molecules near the NAC domain and supported our experimental observations. Additionally, our simulations allowed us to decipher the molecular origin of the dynamical heterogeneity of water in α-synuclein. These simulations captured the quasi-bound water molecules within the NAC domain originating from a complex interplay between the local chain compaction and the sequence composition. Our findings from this synergistic experimental simulation approach suggest longer trapping of interfacial water molecules near the amyloidogenic hotspot that triggers the pathological conversion into amyloids via chain sequestration, chain desolvation, and entropic liberation of ordered water molecules.
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Affiliation(s)
- Shruti Arya
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Avinash K Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Karishma Bhasne
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Priyanka Dogra
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India
| | - Anindya Datta
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, India.
| | - Payel Das
- Data Science Department, IBM Thomas J. Watson Research Center, Yorktown Heights, New York.
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India; Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, Punjab, India.
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14
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Leri M, Natalello A, Bruzzone E, Stefani M, Bucciantini M. Oleuropein aglycone and hydroxytyrosol interfere differently with toxic Aβ 1-42 aggregation. Food Chem Toxicol 2019; 129:1-12. [PMID: 30995514 DOI: 10.1016/j.fct.2019.04.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 12/18/2022]
Abstract
Oleuropein aglycone (OleA), the most abundant polyphenol in extra virgin olive oil (EVOO), and Hydroxythyrosol (HT), the OleA main metabolite, have attracted our interest due to their multitarget effects, including the interference with amyloid aggregation path. However, the mechanistic details of their anti-amyloid effect are not known yet. We report here a broad biophysical approach and cell biology techniques that enabled us to characterize the different molecular mechanisms by which OleA and HT modulate the Aβ1-42 fibrillation, a main histopathological feature of Alzheimer's disease (AD). In particular, OleA prevents the growth of toxic Aβ1-42 oligomers and blocks their successive growth into mature fibrils following its interaction with the peptide N-terminus, while HT speeds up harmless fibril formation. Our data demonstrate that, by stabilizing oligomers and fibrils, both polyphenols reduce their seeding activity and aggregate/membrane interaction on human neuroblastoma SH-SY5Y cells. These findings highlight the great potential of EVOO polyphenols and offer the possibility to validate and to optimize their use for possible AD prevention and therapy.
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Affiliation(s)
- Manuela Leri
- Department of Biomedical, Experimental and Clinical Sciences 'Mario Serio', University of Florence, Viale Morgagni 50 - 50134, Florence, Italy; Department of Neuroscience, Psychology, Area of Medicine and Health of the Child of the University of Florence, Viale Pieraccini, 6 - 50139 Florence, Italy.
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Piazza della Scienza 2, 20126, Milano, Italy.
| | - Elena Bruzzone
- Department of Biomedical, Experimental and Clinical Sciences 'Mario Serio', University of Florence, Viale Morgagni 50 - 50134, Florence, Italy.
| | - Massimo Stefani
- Department of Biomedical, Experimental and Clinical Sciences 'Mario Serio', University of Florence, Viale Morgagni 50 - 50134, Florence, Italy; Interuniversity Center for the Study of Neurodegenerative Diseases (CIMN), Florence, Italy.
| | - Monica Bucciantini
- Department of Biomedical, Experimental and Clinical Sciences 'Mario Serio', University of Florence, Viale Morgagni 50 - 50134, Florence, Italy; Interuniversity Center for the Study of Neurodegenerative Diseases (CIMN), Florence, Italy.
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15
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Recent Advances in Computational Protocols Addressing Intrinsically Disordered Proteins. Biomolecules 2019; 9:biom9040146. [PMID: 30979035 PMCID: PMC6523529 DOI: 10.3390/biom9040146] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 01/09/2023] Open
Abstract
Intrinsically disordered proteins (IDP) are abundant in the human genome and have recently emerged as major therapeutic targets for various diseases. Unlike traditional proteins that adopt a definitive structure, IDPs in free solution are disordered and exist as an ensemble of conformations. This enables the IDPs to signal through multiple signaling pathways and serve as scaffolds for multi-protein complexes. The challenge in studying IDPs experimentally stems from their disordered nature. Nuclear magnetic resonance (NMR), circular dichroism, small angle X-ray scattering, and single molecule Förster resonance energy transfer (FRET) can give the local structural information and overall dimension of IDPs, but seldom provide a unified picture of the whole protein. To understand the conformational dynamics of IDPs and how their structural ensembles recognize multiple binding partners and small molecule inhibitors, knowledge-based and physics-based sampling techniques are utilized in-silico, guided by experimental structural data. However, efficient sampling of the IDP conformational ensemble requires traversing the numerous degrees of freedom in the IDP energy landscape, as well as force-fields that accurately model the protein and solvent interactions. In this review, we have provided an overview of the current state of computational methods for studying IDP structure and dynamics and discussed the major challenges faced in this field.
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16
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Liu Z, Jiang F, Wu YD. Significantly different contact patterns between Aβ40 and Aβ42 monomers involving the N-terminal region. Chem Biol Drug Des 2018; 94:1615-1625. [PMID: 30381893 DOI: 10.1111/cbdd.13431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 09/28/2018] [Accepted: 10/10/2018] [Indexed: 01/03/2023]
Abstract
Aβ42 peptide, with two additional residues at C-terminus, aggregates much faster than Aβ40. We performed equilibrium replica-exchange molecular dynamics simulations of their monomers using our residue-specific force field. Simulated 3 JHNH α -coupling constants agree excellently with experimental data. Aβ40 and Aβ42 have very similar local conformational features, with considerable β-strand structures in the segments: A2-H6 (A), L17-A21 (B), A30-V36 (C) of both peptides and V39-I41 (D) of Aβ42. Both peptides have abundant A-B and B-C contacts, but Aβ40 has much more contacts between A and C than Aβ42, which may retard its aggregation. Only Aβ42 has considerable A-B-C-D topology. Decreased probability of A-C contact in Aβ42 relates to the competition from C-D contact. Increased A-C contact probability may also explain the slower aggregation of A2T and A2V mutants of Aβ42.
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Affiliation(s)
- Ziye Liu
- Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Fan Jiang
- Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Yun-Dong Wu
- Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen, China.,College of Chemistry and Molecular Engineering, Peking University, Beijing, China
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17
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Atrián-Blasco E, Gonzalez P, Santoro A, Alies B, Faller P, Hureau C. Cu and Zn coordination to amyloid peptides: From fascinating chemistry to debated pathological relevance. Coord Chem Rev 2018; 375:38-55. [PMID: 30262932 DOI: 10.1016/j.ccr.2018.04.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Several diseases share misfolding of different peptides and proteins as a key feature for their development. This is the case of important neurodegenerative diseases such as Alzheimer's and Parkinson's diseases and type II diabetes mellitus. Even more, metal ions such as copper and zinc might play an important role upon interaction with amyloidogenic peptides and proteins, which could impact their aggregation and toxicity abilities. In this review, the different coordination modes proposed for copper and zinc with amyloid-β, α-synuclein and IAPP will be reviewed as well as their impact on the aggregation, and ROS production in the case of copper. In addition, a special focus will be given to the mutations that affect metal binding and lead to familial cases of the diseases. Different modifications of the peptides that have been observed in vivo and could be relevant for the coordination of metal ions are also described.
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Affiliation(s)
- Elena Atrián-Blasco
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
| | - Paulina Gonzalez
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Alice Santoro
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Bruno Alies
- Université de Bordeaux, ChemBioPharm INSERM U1212 CNRS UMR 5320, Bordeaux, France
| | - Peter Faller
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, 4 rue B. Pascal, 67081 Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
| | - Christelle Hureau
- CNRS, LCC (Laboratoire de Chimie de Coordination), 205 route de Narbonne, BP 44099 31077 Toulouse Cedex 4, France
- University of Toulouse, UPS, INPT, 31077 Toulouse Cedex 4, France
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18
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Sharma B, Ranganathan SV, Belfort G. Weaker N-Terminal Interactions for the Protective over the Causative Aβ Peptide Dimer Mutants. ACS Chem Neurosci 2018; 9:1247-1253. [PMID: 29465978 DOI: 10.1021/acschemneuro.7b00412] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Knowing that abeta amyloid peptide (Aβ42) dimers are the smallest and most abundant neurotoxic oligomers for Alzheimer's disease (AD), we used molecular simulations with advanced sampling methods (replica-exchange) to characterize and compare interactions between the N-termini (residues 1-16) of wild type (WT-WT) and five mutant dimers under constrained and unconstrained conditions. The number of contacts and distances between the N-termini, and contact maps of their conformational landscape illustrate substantial differences for a single residue change. The N-terminal contacts are significantly diminished for the dimers containing the monomers that protect against (WT-A2T) as compared with those that predispose toward (A2V-A2V) AD and for the control WT-WT dimers. The reduced number of N-terminal contacts not only occurs at or near the second residue mutations but also is distributed through to the 10th residue. These findings provide added support to the accumulating evidence for the "N-terminal hypothesis of AD" and offer an alternate mechanism for the cause of protection from the A2T mutant.
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Affiliation(s)
- Bhanushee Sharma
- Howard P Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
| | - Srivathsan V. Ranganathan
- The RNA Institute, University at Albany, State University of New York, Albany, New York 12222, United States
| | - Georges Belfort
- Howard P Isermann Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
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19
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Nguyen PH, del Castillo-Frias MP, Berthoumieux O, Faller P, Doig AJ, Derreumaux P. Amyloid-β/Drug Interactions from Computer Simulations and Cell-Based Assays. J Alzheimers Dis 2018; 64:S659-S672. [DOI: 10.3233/jad-179902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Phuong H. Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, Paris, France
| | - Maria P. del Castillo-Frias
- Manchester Institute of Biotechnology and Department of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, UK
| | - Olivia Berthoumieux
- CNRS, LCC (Laboratoire de Chimie de Coordination), Toulouse Cedex 4, France et Université de Toulouse, UPS, INPT, Toulouse Cedex 4, France
| | - Peter Faller
- Biometals and Biology Chemistry, Institut de Chimie (CNRS UMR7177), Université de Strasbourg, Strasbourg, France
| | - Andrew J. Doig
- Manchester Institute of Biotechnology and Department of Chemistry, Faculty of Science and Engineering, The University of Manchester, Manchester, UK
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, Paris, France
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20
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Das P, Matysiak S, Mittal J. Looking at the Disordered Proteins through the Computational Microscope. ACS CENTRAL SCIENCE 2018; 4:534-542. [PMID: 29805999 PMCID: PMC5968442 DOI: 10.1021/acscentsci.7b00626] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Indexed: 05/04/2023]
Abstract
Intrinsically disordered proteins (IDPs) have attracted wide interest over the past decade due to their surprising prevalence in the proteome and versatile roles in cell physiology and pathology. A large selection of IDPs has been identified as potential targets for therapeutic intervention. Characterizing the structure-function relationship of disordered proteins is therefore an essential but daunting task, as these proteins can adapt transient structure, necessitating a new paradigm for connecting structural disorder to function. Molecular simulation has emerged as a natural complement to experiments for atomic-level characterizations and mechanistic investigations of this intriguing class of proteins. The diverse range of length and time scales involved in IDP function requires performing simulations at multiple levels of resolution. In this Outlook, we focus on summarizing available simulation methods, along with a few interesting example applications. We also provide an outlook on how these simulation methods can be further improved in order to provide a more accurate description of IDP structure, binding, and assembly.
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Affiliation(s)
- Payel Das
- IBM Thomas J.
Watson Research Center, Yorktown Heights, New York 10598, United States
- E-mail:
| | - Silvina Matysiak
- Fischell
Department of Bioengineering, University
of Maryland, College Park, Maryland 20742, United States
| | - Jeetain Mittal
- Department
of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
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21
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Coskuner-Weber O, Uversky VN. Insights into the Molecular Mechanisms of Alzheimer's and Parkinson's Diseases with Molecular Simulations: Understanding the Roles of Artificial and Pathological Missense Mutations in Intrinsically Disordered Proteins Related to Pathology. Int J Mol Sci 2018; 19:E336. [PMID: 29364151 PMCID: PMC5855558 DOI: 10.3390/ijms19020336] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 01/14/2018] [Accepted: 01/16/2018] [Indexed: 12/18/2022] Open
Abstract
Amyloid-β and α-synuclein are intrinsically disordered proteins (IDPs), which are at the center of Alzheimer's and Parkinson's disease pathologies, respectively. These IDPs are extremely flexible and do not adopt stable structures. Furthermore, both amyloid-β and α-synuclein can form toxic oligomers, amyloid fibrils and other type of aggregates in Alzheimer's and Parkinson's diseases. Experimentalists face challenges in investigating the structures and thermodynamic properties of these IDPs in their monomeric and oligomeric forms due to the rapid conformational changes, fast aggregation processes and strong solvent effects. Classical molecular dynamics simulations complement experiments and provide structural information at the atomic level with dynamics without facing the same experimental limitations. Artificial missense mutations are employed experimentally and computationally for providing insights into the structure-function relationships of amyloid-β and α-synuclein in relation to the pathologies of Alzheimer's and Parkinson's diseases. Furthermore, there are several natural genetic variations that play a role in the pathogenesis of familial cases of Alzheimer's and Parkinson's diseases, which are related to specific genetic defects inherited in dominant or recessive patterns. The present review summarizes the current understanding of monomeric and oligomeric forms of amyloid-β and α-synuclein, as well as the impacts of artificial and pathological missense mutations on the structural ensembles of these IDPs using molecular dynamics simulations. We also emphasize the recent investigations on residual secondary structure formation in dynamic conformational ensembles of amyloid-β and α-synuclein, such as β-structure linked to the oligomerization and fibrillation mechanisms related to the pathologies of Alzheimer's and Parkinson's diseases. This information represents an important foundation for the successful and efficient drug design studies.
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Affiliation(s)
- Orkid Coskuner-Weber
- Türkisch-Deutsche Universität, Theoretical and Computational Biophysics Group, Molecular Biotechnology, Sahinkaya Caddesi, No. 86, Beykoz, Istanbul 34820, Turkey.
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA.
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.
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22
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Liu X, Shi D, Zhou S, Liu H, Liu H, Yao X. Molecular dynamics simulations and novel drug discovery. Expert Opin Drug Discov 2017; 13:23-37. [DOI: 10.1080/17460441.2018.1403419] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Xuewei Liu
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | - Danfeng Shi
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
| | | | - Hongli Liu
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Huanxiang Liu
- School of Pharmacy, Lanzhou University, Lanzhou, China
| | - Xiaojun Yao
- State Key Laboratory of Applied Organic Chemistry and Department of Chemistry, Lanzhou University, Lanzhou, China
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23
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Weber OC, Uversky VN. How accurate are your simulations? Effects of confined aqueous volume and AMBER FF99SB and CHARMM22/CMAP force field parameters on structural ensembles of intrinsically disordered proteins: Amyloid-β 42 in water. INTRINSICALLY DISORDERED PROTEINS 2017; 5:e1377813. [PMID: 30250773 DOI: 10.1080/21690707.2017.1377813] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 12/14/2022]
Abstract
Amyloid-β42 (Aβ42) is an intrinsically disordered peptide intimately related to the pathogenesis of several neurodegenerative diseases. Molecular dynamics (MD) simulations are extensively utilized in the characterization of the structures and conformational dynamics of intrinsically disordered proteins (IDPs) including Aβ42, with AMBER and CHARMM parameters being commonly used in these studies. Recently, comparison of the effects of force field parameters on the Aβ42 structures has started to gain significant attention. In this study, the structures of Aβ42 are simulated using AMBER FF99SB and CHARMM22/CMAP parameters via replica exchange MD simulations utilizing a widely used clustering algorithm. These analyses show that the structural properties (extent and positioning of the elements of secondary and tertiary structure), radius of gyration values, number and position of salt bridges are extremely dependent on the chosen force field parameters notably with the usage of clustering algorithms. For example, predicted secondary structure elements, which are of the great importance for better understanding of the molecular mechanisms of neurodegenerative diseases, deviate enormously in models generated using currently available force field parameters for proteins. Based on the derived models, chemical shift values are calculated and compared to the experimentally determined data. This comparison revealed that although both force field parameters yield results in agreement with experiments, the obtained structural properties were rather different using a clustering algorithm. In other words, these results show that the predicted structures depend heavily on the force field parameters. Importantly, since none of the force field parameters currently utilized in MD studies were developed specifically taking into account the disordered nature of IDPs, these findings clearly indicate that new force field parameters have to be developed for IDPs considering their rapid flexibility and dynamics with high amplitude. Furthermore, molecular simulations of IDPs are typically conducted using one water volume. We show that the confined aqueous volume impacts the predicted structural properties of Aβ42 in water. Although up to date, confined aqueous volume effects have been ignored in the MD simulations of IDPs in water, our data indicate that these effects have to be taken into account in predicting the structural and thermodynamic properties of disordered proteins in solution.
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Affiliation(s)
- Orkid Coskuner Weber
- Department of Chemistry and Neurosciences Institute, The University of Texas at San Antonio, San Antonio, TX, USA.,Institut für Physikalische Chemie, Universität zu Köln, Köln, Germany.,Molecular Biotechnology Division, Turkisch-Deutsche Universität, Istanbul Turkey
| | - Vladimir N Uversky
- Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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24
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Chakraborty S, Das P. Emergence of Alternative Structures in Amyloid Beta 1-42 Monomeric Landscape by N-terminal Hexapeptide Amyloid Inhibitors. Sci Rep 2017; 7:9941. [PMID: 28855598 PMCID: PMC5577341 DOI: 10.1038/s41598-017-10212-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/04/2017] [Indexed: 02/01/2023] Open
Abstract
Alzheimer’s disease (AD) is characterized by deposition of amyloid beta (Aβ) peptides into senile plaques in the brain. While most familial mutations are associated with early-onset AD, recent studies report the AD-protective nature of two genetic human Aβ variants, i.e. A2T and A2V, in the heterozygous state. The mixture of A2V Aβ1-6 (Aβ6) hexapeptide and WT Aβ1–42 (Αβ42) is also found neuroprotective. Motivated by these findings, in this study we investigate the effects of WT, A2V, and A2T Aβ6 hexapeptide binding on the monomeric WT Aβ42 landscape. For this purpose, we have performed extensive atomistic Replica Exchange Molecular Dynamics simulations, elucidating preferential binding of Aβ42 with the A2V and A2T hexapeptides compared to WT Aβ6. A notable reorganization of the Aβ42 landscape is revealed due to hexapeptide association, as manifested by lowering of transient interactions between the central and C-terminal hydrophobic patches. Concurrently, Aβ6-bound Aβ42 monomer exhibits alternative structural features that are strongly dependent on the hexapeptide sequence. For example, a central helix is more frequently populated within the A2T-bound monomer, while A2V-bound Aβ42 is often enhanced in overall disorder. Taken together, the present simulations offer novel molecular insights onto the effect of the N-terminal hexapeptide binding on the Aβ42 monomer structure, which might help in explaining their reported amyloid inhibition properties.
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Affiliation(s)
| | - Payel Das
- IBM Thomas J. Watson Research Center, Yorktown Heights, NY, 10598, USA.
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25
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Gimeno A, Santos LM, Alemi M, Rivas J, Blasi D, Cotrina EY, Llop J, Valencia G, Cardoso I, Quintana J, Arsequell G, Jiménez-Barbero J. Insights on the Interaction between Transthyretin and Aβ in Solution. A Saturation Transfer Difference (STD) NMR Analysis of the Role of Iododiflunisal. J Med Chem 2017; 60:5749-5758. [DOI: 10.1021/acs.jmedchem.7b00428] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ana Gimeno
- CIC bioGUNE, Bizkaia Technology
Park, Building 801A, 48170 Derio, Spain
| | - Luis M. Santos
- IBMC—Instituto de Biologia Celular e Molecular, Campo Alegre 823, 4150 Porto, Portugal
- i3S—Instituto
de Investigação e Inovação em Saúde, Universidade do Porto, Alfredo Allen, 4200-135 Porto, Portugal
| | - Mobina Alemi
- IBMC—Instituto de Biologia Celular e Molecular, Campo Alegre 823, 4150 Porto, Portugal
- i3S—Instituto
de Investigação e Inovação em Saúde, Universidade do Porto, Alfredo Allen, 4200-135 Porto, Portugal
- Faculdade
de Medicina, Universidade do Porto, Alameda Prof. Hernani Monteiro, 4200-319 Porto, Portugal
| | - Josep Rivas
- Plataforma
Drug
Discovery, Parc Científic de Barcelona (PCB), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Daniel Blasi
- Plataforma
Drug
Discovery, Parc Científic de Barcelona (PCB), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Ellen Y. Cotrina
- Institut de Química
Avançada de Catalunya (I.Q.A.C.-C.S.I.C.), 08034 Barcelona, Spain
| | - Jordi Llop
- Radiochemistry
and Nuclear Imaging Group, CIC biomaGUNE, Paseo Miramon 182, 20009 Donostia-San Sebastian, Spain
| | - Gregorio Valencia
- Institut de Química
Avançada de Catalunya (I.Q.A.C.-C.S.I.C.), 08034 Barcelona, Spain
| | - Isabel Cardoso
- IBMC—Instituto de Biologia Celular e Molecular, Campo Alegre 823, 4150 Porto, Portugal
- i3S—Instituto
de Investigação e Inovação em Saúde, Universidade do Porto, Alfredo Allen, 4200-135 Porto, Portugal
| | - Jordi Quintana
- Plataforma
Drug
Discovery, Parc Científic de Barcelona (PCB), Baldiri Reixac 10, 08028 Barcelona, Spain
| | - Gemma Arsequell
- Institut de Química
Avançada de Catalunya (I.Q.A.C.-C.S.I.C.), 08034 Barcelona, Spain
| | - Jesús Jiménez-Barbero
- CIC bioGUNE, Bizkaia Technology
Park, Building 801A, 48170 Derio, Spain
- Ikerbasque, Basque Foundation for Science, Maria Diaz de Haro 13, 48009 Bilbao, Spain
- Departament
of Organic Chemistry II, Faculty of Science and Technology, University of the Basque Country, 48940 Leioa, Bizkaia, Spain
- Plataforma
Drug
Discovery, Parc Científic de Barcelona (PCB), Baldiri Reixac 10, 08028 Barcelona, Spain
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26
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Man VH, Nguyen PH, Derreumaux P. High-Resolution Structures of the Amyloid-β 1-42 Dimers from the Comparison of Four Atomistic Force Fields. J Phys Chem B 2017; 121:5977-5987. [PMID: 28538095 DOI: 10.1021/acs.jpcb.7b04689] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The dimer of the amyloid-β peptide Aβ of 42 residues is the smallest toxic species in Alzheimer's disease, but its equilibrium structures are unknown. Here we determined the equilibrium ensembles generated by the four atomistic OPLS-AA, CHARMM22*, AMBER99sb-ildn, and AMBERsb14 force fields with the TIP3P water model. On the basis of 144 μs replica exchange molecular dynamics simulations (with 750 ns per replica), we find that the four force fields lead to random coil ensembles with calculated cross-collision sections, hydrodynamics properties, and small-angle X-ray scattering profiles independent of the force field. There are, however, marked differences in secondary structure, with the AMBERsb14 and CHARMM22* ensembles overestimating the CD-derived helix content, and the OPLS-AA and AMBER99sb-ildn secondary structure contents in agreement with CD data. Also the intramolecular beta-hairpin content spanning residues 17-21 and 30-36 varies between 1.5% and 13%. Overall, there are significant differences in tertiary and quaternary conformations among all force fields, and the key finding, irrespective of the force field, is that the dimer is stabilized by nonspecific interactions, explaining therefore its possible transient binding to multiple cellular partners and, in part, its toxicity.
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Affiliation(s)
- Viet Hoang Man
- Department of Physics, North Carolina State University , Raleigh, North Carolina 27695-8202, United States
| | - Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot , Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot , Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
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27
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Pathogenic Aβ A2V versus protective Aβ A2T mutation: Early stage aggregation and membrane interaction. Biophys Chem 2017; 229:11-18. [PMID: 28502484 DOI: 10.1016/j.bpc.2017.05.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 05/05/2017] [Accepted: 05/05/2017] [Indexed: 11/20/2022]
Abstract
We investigated the effects of punctual A-to-V and A-to-T mutations in the amyloid precursor protein APP, corresponding to position 2 of Aβ1-42. Those mutations had opposite effects on the onset and progression of Alzheimer disease, the former inducing early AD pathology and the latter protecting against the onset of the disease. We applied Static and Dynamic Light Scattering and Circular Dichroism, to study the different mutants in the early stages of the aggregation process, essential for the disease. Comparative results showed that the aggregation pathways differ in the kinetics and extent of the process, in the size of the aggregates and in the evolution of the secondary structure, resulting in fibrils of different morphology, as seen by AFM. Mutated peptides had comparable toxic effects on N2a cells. Moreover, as assessed by X-ray scattering, all of them displayed disordering effects on the internal structure of mixed phospholipids-gangliosides model membranes.
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28
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Dammers C, Reiss K, Gremer L, Lecher J, Ziehm T, Stoldt M, Schwarten M, Willbold D. Pyroglutamate-Modified Amyloid-β(3-42) Shows α-Helical Intermediates before Amyloid Formation. Biophys J 2017; 112:1621-1633. [PMID: 28445753 PMCID: PMC5406372 DOI: 10.1016/j.bpj.2017.03.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/02/2017] [Accepted: 03/08/2017] [Indexed: 01/15/2023] Open
Abstract
Pyroglutamate-modified amyloid-β (pEAβ) has been described as a relevant Aβ species in Alzheimer's-disease-affected brains, with pEAβ (3-42) as a dominant isoform. Aβ (1-40) and Aβ (1-42) have been well characterized under various solution conditions, including aqueous solutions containing trifluoroethanol (TFE). To characterize structural properties of pEAβ (3-42) possibly underlying its drastically increased aggregation propensity compared to Aβ (1-42), we started our studies in various TFE-water mixtures and found striking differences between the two Aβ species. Soluble pEAβ (3-42) has an increased tendency to form β-sheet-rich structures compared to Aβ (1-42), as indicated by circular dichroism spectroscopy data. Kinetic assays monitored by thioflavin-T show drastically accelerated aggregation leading to large fibrils visualized by electron microscopy of pEAβ (3-42) in contrast to Aβ (1-42). NMR spectroscopy was performed for backbone and side-chain chemical-shift assignments of monomeric pEAβ (3-42) in 40% TFE solution. Although the difference between pEAβ (3-42) and Aβ (1-42) is purely N-terminal, it has a significant impact on the chemical environment of >20% of the total amino acid residues, as revealed by their NMR chemical-shift differences. Freshly dissolved pEAβ (3-42) contains two α-helical regions connected by a flexible linker, whereas the N-terminus remains unstructured. We found that these α-helices act as a transient intermediate to β-sheet and fibril formation of pEAβ (3-42).
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Affiliation(s)
- Christina Dammers
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany
| | - Kerstin Reiss
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany
| | - Lothar Gremer
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Justin Lecher
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Tamar Ziehm
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany
| | - Matthias Stoldt
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Melanie Schwarten
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany
| | - Dieter Willbold
- Institute of Complex Systems (ICS-6) Structural Biochemistry, Forschungszentrum Jülich, Jülich, Germany; Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
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29
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Lin TW, Chang CF, Chang YJ, Liao YH, Yu HM, Chen YR. Alzheimer's amyloid-β A2T variant and its N-terminal peptides inhibit amyloid-β fibrillization and rescue the induced cytotoxicity. PLoS One 2017; 12:e0174561. [PMID: 28362827 PMCID: PMC5376091 DOI: 10.1371/journal.pone.0174561] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 03/11/2017] [Indexed: 01/21/2023] Open
Abstract
Alzheimer’s disease (AD) is the most common dementia affecting tens of million people worldwide. The primary neuropathological hallmark in AD is amyloid plaques composed of amyloid-β peptide (Aβ). Several familial mutations found in Aβ sequence result in early onset of AD. Previous studies showed that the mutations located at N-terminus of Aβ, such as the English (H6R) and Tottori (D7N) mutations, promote fibril formation and increase cytotoxicity. However, A2T mutant located at the very N-terminus of Aβ shows low-prevalence incidence of AD, whereas, another mutant A2V causes early onset of AD. To understand the molecular mechanism of the distinct effect and develop new potential therapeutic strategy, here, we examined the effect of full-length and N-terminal A2V/T variants to wild type (WT) Aβ40 by fibrillization assays and NMR studies. We found that full-length and N-terminal A2V accelerated WT fibrillization and induced large chemical shifts on the N-terminus of WT Aβ, whereas, full-length and N-terminal A2T retarded the fibrillization. We further examined the inhibition effect of various N-terminal fragments (NTFs) of A2T to WT Aβ. The A2T NTFs ranging from residue 1 to residue 7 to 10, but not 1 to 6 or shorter, are capable to retard WT Aβ fibrillization and rescue cytotoxicity. The results suggest that in the presence of full-length or specific N-terminal A2T can retard Aβ aggregation and the A2T NTFs can mitigate its toxicity. Our results provide a novel targeting site for future therapeutic development of AD.
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Affiliation(s)
- Tien-Wei Lin
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Chi-Fon Chang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yu-Jen Chang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yi-Hung Liao
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Hui-Ming Yu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yun-Ru Chen
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
- * E-mail:
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30
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Man VH, Nguyen PH, Derreumaux P. Conformational Ensembles of the Wild-Type and S8C Aβ1-42 Dimers. J Phys Chem B 2017; 121:2434-2442. [PMID: 28245647 PMCID: PMC5944329 DOI: 10.1021/acs.jpcb.7b00267] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We characterized the dimer of the amyloid-β wild-type (WT) peptide, Aβ, of 42 residues and its disulfide-bond-locked double mutant (S8C) by replica exchange molecular dynamics simulations. Aβ dimers are known to be the smallest toxic species in Alzheimer's disease, and the S8C mutant has been shown experimentally to form an exclusive homogeneous and neurotoxic dimer. Our 50 μs all-atom simulations reveal similar secondary structures and collision cross-sections but very different intramolecular and intermolecular conformations upon double S8C mutation. Both dimers are very dynamic with hundreds of free-energy minima that differ from the U-shape and S-shape conformations of the peptides in the fibrils. The only common structural feature, shared by both species with a probability of 4% in WT and 12% in S8C-S8C, is a three-stranded β-sheet spanning the 17-23, 29-36, and 39-41 residues, which does not exist in the Aβ40 WT dimers.
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Affiliation(s)
- Viet Hoang Man
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, United States
| | - Phuong H. Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Paris Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
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31
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Das P, Chacko AR, Belfort G. Alzheimer's Protective Cross-Interaction between Wild-Type and A2T Variants Alters Aβ 42 Dimer Structure. ACS Chem Neurosci 2017; 8:606-618. [PMID: 28292185 DOI: 10.1021/acschemneuro.6b00357] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Whole genome sequencing has recently revealed the protective effect of a single A2T mutation in heterozygous carriers against Alzheimer's disease (AD) and age-related cognitive decline. The impact of the protective cross-interaction between the wild-type (WT) and A2T variants on the dimer structure is therefore of high interest, as the Aβ dimers are the smallest known neurotoxic species. Toward this goal, extensive atomistic replica exchange molecular dynamics simulations of the solvated WT homo- and A2T hetero- Aβ1-42 dimers have been performed, resulting into a total of 51 μs of sampling for each system. Weakening of a set of transient, intrachain contacts formed between the central and C-terminal hydrophobic residues is observed in the heterodimeric system. The majority of the heterodimers with reduced interaction between central and C-terminal regions lack any significant secondary structure and display a weak interchain interface. Interestingly, the A2T N-terminus, particularly residue F4, is frequently engaged in tertiary and quaternary interactions with central and C-terminal hydrophobic residues in those distinct structures, leading to hydrophobic burial. This atypical involvement of the N-terminus within A2T heterodimer revealed in our simulations implies possible interference on Aβ42 aggregation and toxic oligomer formation, which is consistent with experiments. In conclusion, the present study provides detailed structural insights onto A2T Aβ42 heterodimer, which might provide molecular insights onto the AD protective effect of the A2T mutation in the heterozygous state.
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Affiliation(s)
- Payel Das
- IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Anita R. Chacko
- IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Georges Belfort
- Howard
P. Isermann Department of Chemical and Biological Engineering, and
Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
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32
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Abstract
Although the amyloid (abeta peptide, Aβ) hypothesis is 25 years old, is the dominant model of Alzheimer's disease (AD) pathogenesis, and guides the development of potential treatments, it is still controversial. One possible reason is a lack of a mechanistic path from the cleavage products of the amyloid precursor protein (APP) such as soluble Aβ monomer and soluble molecular fragments to the deleterious effects on synaptic form and function. From a review of the recent literature and our own published work including aggregation kinetics and structural morphology, Aβ clearance, molecular simulations, long-term potentiation measurements with inhibition binding, and the binding of a commercial monoclonal antibody, aducanumab, we hypothesize that the N-terminal domains of neurotoxic Aβ oligomers are implicated in causing the disease.
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Affiliation(s)
- Brian Murray
- Howard P. Isermann Department of Chemical and Biological Engineering and the Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
| | - Bhanushee Sharma
- Howard P. Isermann Department of Chemical and Biological Engineering and the Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
| | - Georges Belfort
- Howard P. Isermann Department of Chemical and Biological Engineering and the Center for Biotechnology & Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180-3590, United States
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33
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Carballo‐Pacheco M, Strodel B. Comparison of force fields for Alzheimer's A β42: A case study for intrinsically disordered proteins. Protein Sci 2017; 26:174-185. [PMID: 27727496 PMCID: PMC5275744 DOI: 10.1002/pro.3064] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 10/02/2016] [Accepted: 10/09/2016] [Indexed: 01/06/2023]
Abstract
Intrinsically disordered proteins are essential for biological processes such as cell signalling, but are also associated to devastating diseases including Alzheimer's disease, Parkinson's disease or type II diabetes. Because of their lack of a stable three-dimensional structure, molecular dynamics simulations are often used to obtain atomistic details that cannot be observed experimentally. The applicability of molecular dynamics simulations depends on the accuracy of the force field chosen to represent the underlying free energy surface of the system. Here, we use replica exchange molecular dynamics simulations to test five modern force fields, OPLS, AMBER99SB, AMBER99SB*ILDN, AMBER99SBILDN-NMR and CHARMM22*, in their ability to model Aβ42 , an intrinsically disordered peptide associated with Alzheimer's disease, and compare our results to nuclear magnetic resonance (NMR) experimental data. We observe that all force fields except AMBER99SBILDN-NMR successfully reproduce local NMR observables, with CHARMM22* being slightly better than the other force fields.
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Affiliation(s)
- Martín Carballo‐Pacheco
- Institute of Complex Systems, Structural Biochemistry (ICS‐6), Forschungszentrum Jülich GmbHJülich52425Germany
- AICES Graduate School, RWTH Aachen UniversitySchinkelstraße 2Aachen52062Germany
| | - Birgit Strodel
- Institute of Complex Systems, Structural Biochemistry (ICS‐6), Forschungszentrum Jülich GmbHJülich52425Germany
- Institute of Theoretical and Computational Chemistry, Heinrich Heine University DüsseldorfUniversitätstraße 1Düsseldorf40225Germany
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34
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Hawking ZL. Alzheimer's disease: the role of mitochondrial dysfunction and potential new therapies. ACTA ACUST UNITED AC 2016. [DOI: 10.1093/biohorizons/hzw014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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35
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Nguyen PH, Sterpone F, Pouplana R, Derreumaux P, Campanera JM. Dimerization Mechanism of Alzheimer Aβ 40 Peptides: The High Content of Intrapeptide-Stabilized Conformations in A2V and A2T Heterozygous Dimers Retards Amyloid Fibril Formation. J Phys Chem B 2016; 120:12111-12126. [PMID: 27933940 DOI: 10.1021/acs.jpcb.6b10722] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amyloid beta (Aβ) oligomerization is associated with the origin and progression of Alzheimer's disease (AD). While the A2V mutation enhances aggregation kinetics and toxicity, mixtures of wild-type (WT) and A2V, and also WT and A2T, peptides retard fibril formation and protect against AD. In this study, we simulate the equilibrium ensemble of WT:A2T Aβ40 dimer by means of extensive atomistic replica exchange molecular dynamics and compare our results with previous equivalent simulations of A2V:A2V, WT:WT, and WT:A2V Aβ40 dimers for a total time scale of nearly 0.1 ms. Qualitative comparison of the resulting thermodynamic properties, such as the relative binding free energies, with the reported experimental kinetic and thermodynamic data affords us important insight into the conversion from slow-pathway to fast-pathway dimer conformations. The crucial reaction coordinate or driving force of such transformation turns out to be related to hydrophobic interpeptide interactions. Analysis of the equilibrium ensembles shows that the fast-pathway conformations contain interpeptide out-of-register antiparallel β-sheet structures at short interpeptide distances. In contrast, the slow-pathway conformations are formed by the association of peptides at large interpeptide distances and high intrapeptide compactness, such as conformations containing intramolecular three-stranded β-sheets which sharply distinguish fast (A2V:A2V and WT:WT) and slow (WT:A2T and WT:A2V) amyloid-forming sequences. Also, this analysis leads us to predict that a molecule stabilizing the intramolecular three-stranded β-sheet or inhibiting the formation of an interpeptide β-sheet spanning residues 17-20 and 31-37 would further reduce fibril formation and probably the cytotoxicity of Aβ species.
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Affiliation(s)
- Phuong H Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité , 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité , 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Ramon Pouplana
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona , 08028 Barcelona, Catalonia, Spain
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS, IBPC, Université Paris Diderot, Sorbonne Paris Cité , 13 Rue Pierre et Marie Curie, 75005 Paris, France.,IUF (Institut Universitaire de France) , 103 Boulevard Michel, 75005 Paris, France
| | - Josep M Campanera
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona , 08028 Barcelona, Catalonia, Spain
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36
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Exploring the aggregation free energy landscape of the amyloid-β protein (1-40). Proc Natl Acad Sci U S A 2016; 113:11835-11840. [PMID: 27698130 DOI: 10.1073/pnas.1612362113] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A predictive coarse-grained protein force field [associative memory, water-mediated, structure, and energy model for molecular dynamics (AWSEM)-MD] is used to study the energy landscapes and relative stabilities of amyloid-β protein (1-40) in the monomer and all of its oligomeric forms up to an octamer. We find that an isolated monomer is mainly disordered with a short α-helix formed at the central hydrophobic core region (L17-D23). A less stable hairpin structure, however, becomes increasingly more stable in oligomers, where hydrogen bonds can form between neighboring monomers. We explore the structure and stability of both prefibrillar oligomers that consist of mainly antiparallel β-sheets and fibrillar oligomers with only parallel β-sheets. Prefibrillar oligomers are polymorphic but typically take on a cylindrin-like shape composed of mostly antiparallel β-strands. At the concentration of the simulation, the aggregation free energy landscape is nearly downhill. We use umbrella sampling along a structural progress coordinate for interconversion between prefibrillar and fibrillar forms to identify a conversion pathway between these forms. The fibrillar oligomer only becomes favored over its prefibrillar counterpart in the pentamer where an interconversion bottleneck appears. The structural characterization of the pathway along with statistical mechanical perturbation theory allow us to evaluate the effects of concentration on the free energy landscape of aggregation as well as the effects of the Dutch and Arctic mutations associated with early onset of Alzheimer's disease.
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37
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Chiricotto M, Tran TT, Nguyen PH, Melchionna S, Sterpone F, Derreumaux P. Coarse-grained and All-atom Simulations towards the Early and Late Steps of Amyloid Fibril Formation. Isr J Chem 2016. [DOI: 10.1002/ijch.201600048] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Mara Chiricotto
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Thanh Thuy Tran
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Phuong H. Nguyen
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Simone Melchionna
- Istituto Sistemi Complessi; Consiglio Nazionale delle Ricerche; P. le A. Moro 2 00185 Rome Italy
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, UPR 9080 CNRS; Université Paris Diderot, Sorbonne Paris Cité, IBPC; 13 Rue Pierre et Marie Curie 75005 Paris France
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38
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Nguyen PH, Sterpone F, Campanera JM, Nasica-Labouze J, Derreumaux P. Impact of the A2V Mutation on the Heterozygous and Homozygous Aβ1-40 Dimer Structures from Atomistic Simulations. ACS Chem Neurosci 2016; 7:823-32. [PMID: 27007027 DOI: 10.1021/acschemneuro.6b00053] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The A2V mutation was reported to protect from Alzheimer's disease in its heterozygous form and cause an early Alzheimer's disease type dementia in its homozygous form. Experiments showed that the aggregation rate follows the order A2V > WT (wild-type) > A2V-WT. To understand the impact of this mutation, we carried out replica exchange molecular dynamics simulations of Aβ1-40 WT-A2V and A2V-A2V dimers and compared to the WT dimer. Our atomistic simulations reveal that the mean secondary structure remains constant, but there are substantial differences in the intramolecular and intermolecular conformations upon single and double A2V mutation. Upon single mutation, the intrinsic disorder is reduced, the intermolecular potential energies are reduced, the population of intramolecular three-stranded β-sheets is increased, and the number of all α dimer topologies is decreased. Taken together, these results offer an explanation for the reduced aggregation rate of the Aβ1-40 A2V-WT peptides and the protective effect of A2V in heterozygotes.
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Affiliation(s)
- Phuong H. Nguyen
- Laboratoire de
Biochimie Théorique, UPR 9080 CNRS, Université Paris
Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Fabio Sterpone
- Laboratoire de
Biochimie Théorique, UPR 9080 CNRS, Université Paris
Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Josep M. Campanera
- Departament
de Fisicoquimica, Facultat de Farmacia, Universitat de Barcelona, 08028 Barcelona, Catalonia, Spain
| | - Jessica Nasica-Labouze
- Laboratoire de
Biochimie Théorique, UPR 9080 CNRS, Université Paris
Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Derreumaux
- Laboratoire de
Biochimie Théorique, UPR 9080 CNRS, Université Paris
Diderot, Sorbonne Paris Cité, IBPC, 13 Rue Pierre et Marie Curie, 75005 Paris, France
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39
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Murray B, Sorci M, Rosenthal J, Lippens J, Isaacson D, Das P, Fabris D, Li S, Belfort G. A2T and A2V Aβ peptides exhibit different aggregation kinetics, primary nucleation, morphology, structure, and LTP inhibition. Proteins 2016; 84:488-500. [PMID: 26799157 DOI: 10.1002/prot.24995] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/23/2015] [Accepted: 01/11/2016] [Indexed: 01/03/2023]
Abstract
The histopathological hallmark of Alzheimer's disease (AD) is the aggregation and accumulation of the amyloid beta peptide (Aβ) into misfolded oligomers and fibrils. Here we examine the biophysical properties of a protective Aβ variant against AD, A2T, and a causative mutation, A2T, along with the wild type (WT) peptide. The main finding here is that the A2V native monomer is more stable than both A2T and WT, and this manifests itself in different biophysical behaviors: the kinetics of aggregation, the initial monomer conversion to an aggregation prone state (primary nucleation), the abundances of oligomers, and extended conformations. Aggregation reaction modeling of the conversion kinetics from native monomers to fibrils predicts the enhanced stability of the A2V monomer, while ion mobility spectrometry-mass spectrometry measures this directly confirming earlier predictions. Additionally, unique morphologies of the A2T aggregates are observed using atomic force microscopy, providing a basis for the reduction in long term potentiation inhibition of hippocampal cells for A2T compared with A2V and the wild type (WT) peptide. The stability difference of the A2V monomer and the difference in aggregate morphology for A2T (both compared with WT) are offered as alternate explanations for their pathological effects.
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Affiliation(s)
- Brian Murray
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Mirco Sorci
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Joseph Rosenthal
- Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Jennifer Lippens
- Department of Chemistry, University at Albany, State University of New York, Albany, New York, 12222
| | - David Isaacson
- Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Payel Das
- Soft Matter Theory and Simulations Group, Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York, 10598
| | - Daniele Fabris
- Department of Chemistry, University at Albany, State University of New York, Albany, New York, 12222
| | - Shaomin Li
- Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, 02115
| | - Georges Belfort
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
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40
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Baram M, Atsmon-Raz Y, Ma B, Nussinov R, Miller Y. Amylin-Aβ oligomers at atomic resolution using molecular dynamics simulations: a link between Type 2 diabetes and Alzheimer's disease. Phys Chem Chem Phys 2016; 18:2330-8. [PMID: 26349542 PMCID: PMC4720542 DOI: 10.1039/c5cp03338a] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Clinical studies have identified Type 2 diabetes (T2D) as a risk factor of Alzheimer's disease (AD). One of the potential mechanisms that link T2D and AD is the loss of cells associated with degenerative changes. Amylin1-37 aggregates (the pathological species in T2D) were found to be co-localized with those of Aβ1-42 (the pathological species in AD) to form the Amylin1-37-Aβ1-42 plaques, promoting aggregation and thus contributing to the etiology of AD. However, the mechanisms by which Amylin1-37 co-aggregates with Aβ1-42 are still elusive. This work presents the interactions between Amylin1-37 oligomers and Aβ1-42 oligomers at atomic resolution applying extensive molecular dynamics simulations for relatively large ensemble of cross-seeding Amylin1-37-Aβ1-42 oligomers. The main conclusions of this study are first, Aβ1-42 oligomers prefer to interact with Amylin1-37 oligomers to form single layer conformations (in-register interactions) rather than double layer conformations; and second, in some double layer conformations of the cross-seeding Amylin1-37-Aβ1-42 oligomers, the Amylin1-37 oligomers destabilize the Aβ1-42 oligomers and thus inhibit Aβ1-42 aggregation, while in other double layer conformations, the Amylin1-37 oligomers stabilize Aβ1-42 oligomers and thus promote Aβ1-42 aggregation.
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Affiliation(s)
- Michal Baram
- Department of Chemistry, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel.
| | - Yoav Atsmon-Raz
- Department of Chemistry, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel.
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA.
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA. and Sackler Inst. of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yifat Miller
- Department of Chemistry, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beér-Sheva 84105, Israel.
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41
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Xu L, Nussinov R, Ma B. Allosteric stabilization of the amyloid-β peptide hairpin by the fluctuating N-terminal. Chem Commun (Camb) 2016; 52:1733-6. [PMID: 26666686 PMCID: PMC4720562 DOI: 10.1039/c5cc08107f] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Immobilized ions modulate nearby hydrophobic interactions and influence molecular recognition and self-assembly. We simulated disulfide bond-locked double mutants (L17C/L34C) and observed allosteric modulation of the peptide's intra-molecular interactions by the N-terminal tail. We revealed that the non-contacting charged N-terminal residues help the transfer of entropy to the surrounding solvation shell and stabilizing β-hairpin.
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Affiliation(s)
- Liang Xu
- School of Chemistry, Dalian University of Technology, Dalian, China
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA
- Sackler Inst. of Molecular Medicine Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA
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42
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Rosenman DJ, Wang C, García AE. Characterization of Aβ Monomers through the Convergence of Ensemble Properties among Simulations with Multiple Force Fields. J Phys Chem B 2015; 120:259-77. [PMID: 26562747 DOI: 10.1021/acs.jpcb.5b09379] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloid β (Aβ) monomers represent a base state in the pathways of aggregation that result in the fibrils and oligomers implicated in the pathogenesis of Alzheimer's disease (AD). The structural properties of these intrinsically disordered peptides remain unclear despite extensive experimental and computational investigations. Further, there are mutations within Aβ that change the way the peptide aggregates and are known to cause familial AD (FAD). Here, we analyze the ensembles of different isoforms (Aβ42 and Aβ40) and mutants (E22Δ, D23N, E22K, E22G, and A2T in Aβ40) of Aβ generated with all-atom replica exchange molecular dynamics (REMD) simulations on the μs/replica time scale. These were run using three different force field/water model combinations: OPLS-AA/L and TIP3P ("OPLS"), AMBER99sb-ILDN and TIP4P-Ew ("ILDN"), as well as CHARMM22* and TIP3SP ("CHARMM"). Despite fundamental changes in simulation parameters, we find that the resulting ensembles demonstrate a strong convergence in structural properties. In particular, antiparallel contacts between L17-A21 and A30-L34 are prevalent in ensembles of Aβ40, directly forming β sheets in the OPLS and ILDN combinations. A21-A30 commonly forms an interceding region that rarely interacts with the rest of the peptide. Further, Aβ42 contributes new β hairpin motifs involving V40-I41 in both OPLS and ILDN. However, the structural flexibility of the central region and the electrostatic interactions that characterize it are notably different between the different conditions. Further, for OPLS, each of the FAD mutations disrupts central bend character and increases the polymorphism of antiparallel contacts across the central region. However, the studied mutations in the ILDN set primarily encourage more global contacts involving the N-terminus and the central region, and promote the formation of new β topologies that may seed different aggregates involved in disease phenotypes. These differences aside, the large degree of agreement between simulation sets across multiple force fields provides a generalizable characterization of Aβ that is also consistent with experimental data and models.
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Affiliation(s)
- David J Rosenman
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States
| | - Chunyu Wang
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Graduate Program in Biochemistry and Biophysics, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States
| | - Angel E García
- Department of Biology, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute , 110 Eighth Street, Troy, New York 12180, United States.,Center for Non Linear Studies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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43
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Zheng X, Liu D, Roychaudhuri R, Teplow DB, Bowers MT. Amyloid β-Protein Assembly: Differential Effects of the Protective A2T Mutation and Recessive A2V Familial Alzheimer's Disease Mutation. ACS Chem Neurosci 2015; 6:1732-40. [PMID: 26244608 DOI: 10.1021/acschemneuro.5b00171] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Oligomeric states of the amyloid β-protein (Aβ) appear to be causally related to Alzheimer's disease (AD). Recently, two familial mutations in the amyloid precursor protein gene have been described, both resulting in amino acid substitutions at Ala2 (A2) within Aβ. An A2V mutation causes autosomal recessive early onset AD. Interestingly, heterozygotes enjoy some protection against development of the disease. An A2T substitution protects against AD and age-related cognitive decline in non-AD patients. Here, we use ion mobility-mass spectrometry (IM-MS) to examine the effects of these mutations on Aβ assembly. These studies reveal different assembly pathways for early oligomer formation for each peptide. A2T Aβ42 formed dimers, tetramers, and hexamers, but dodecamer formation was inhibited. In contrast, no significant effects on Aβ40 assembly were observed. A2V Aβ42 also formed dimers, tetramers, and hexamers, but it did not form dodecamers. However, A2V Aβ42 formed trimers, unlike A2T or wild-type (wt) Aβ42. In addition, the A2V substitution caused Aβ40 to oligomerize similar to that of wt Aβ42, as evidenced by the formation of dimers, tetramers, hexamers, and dodecamers. In contrast, wt Aβ40 formed only dimers and tetramers. These results provide a basis for understanding how these two mutations lead to, or protect against, AD. They also suggest that the Aβ N-terminus, in addition to the oft discussed central hydrophobic cluster and C-terminus, can play a key role in controlling disease susceptibility.
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Affiliation(s)
- Xueyun Zheng
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Deyu Liu
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
| | - Robin Roychaudhuri
- Department of Neurology, David Geffen School
of Medicine, Molecular Biology Institute and Brain Research Institute, University of California Los Angeles, Los Angeles, California 90095, United States
| | - David B. Teplow
- Department of Neurology, David Geffen School
of Medicine, Molecular Biology Institute and Brain Research Institute, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Michael T. Bowers
- Department
of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States
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44
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Carballo-Pacheco M, Ismail AE, Strodel B. Oligomer Formation of Toxic and Functional Amyloid Peptides Studied with Atomistic Simulations. J Phys Chem B 2015; 119:9696-705. [PMID: 26130191 DOI: 10.1021/acs.jpcb.5b04822] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Amyloids are associated with diseases, including Alzheimer's, as well as functional roles such as storage of peptide hormones. It is still unclear what differences exist between aberrant and functional amyloids. However, it is known that soluble oligomers formed during amyloid aggregation are more toxic than the final fibrils. Here, we perform molecular dynamics simulations to study the aggregation of the amyloid-β peptide Aβ25-35, associated with Alzheimer's disease, and two functional amyloid-forming tachykinin peptides: kassinin and neuromedin K. Although the three peptides have similar primary sequences, tachykinin peptides, in contrast to Aβ25-35, form nontoxic amyloids. Our simulations reveal that the charge of the C-terminus is essential to controlling the aggregation process. In particular, when the kassinin C-terminus is not amidated, the aggregation kinetics decreases considerably. In addition, we observe that the monomeric peptides in extended conformations aggregate faster than those in collapsed hairpin-like conformations.
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Affiliation(s)
- Martín Carballo-Pacheco
- †AICES Graduate School and Aachener Verfahrenstechnik: Molecular Simulations and Transformations, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany.,‡Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Ahmed E Ismail
- †AICES Graduate School and Aachener Verfahrenstechnik: Molecular Simulations and Transformations, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany
| | - Birgit Strodel
- ‡Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.,¶Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf, Universitätstraße 1, 40225 Düsseldorf, Germany
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45
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Zhang T, Nguyen PH, Nasica-Labouze J, Mu Y, Derreumaux P. Folding Atomistic Proteins in Explicit Solvent Using Simulated Tempering. J Phys Chem B 2015; 119:6941-51. [PMID: 25985144 DOI: 10.1021/acs.jpcb.5b03381] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Following a previous report on a coarse-grained protein model in implicit solvent, we applied simulated tempering (ST) with on-the-fly Helmholtz free energy (weight factors) determination to the folding or aggregation of seven proteins with the CHARMM, OPLS, and AMBER protein, and the SPC and TIP3P water force fields. For efficiency and reliability, we also performed replica exchange molecular dynamics (REMD) simulations on the alanine di- and deca-peptide, and the dimer of the Aβ16-22 Alzheimer's fragment, and used experimental data and previous simulation results on the chignolin, beta3s, Trp-cage, and WW domain peptides of 10-37 amino acids. The sampling with ST is found to be more efficient than with REMD for a much lower CPU cost. Starting from unfolded or extended conformations, the WW domain and the Trp-cage peptide fold to their NMR structures with a backbone RMSD of 2.0 and 1 Å. Remarkably, the ST simulation explores transient non-native topologies for Trp-cage that have been rarely discussed by other simulations. Our ST simulations also show that the CHARMM22* force field has limitations in describing accurately the beta3s peptide. Taken together, these results open the door to the study of the configurations of single proteins, protein aggregates, and any molecular systems at atomic details in explicit solvent using a single normal CPU. They also demonstrate that our ST scheme can be used with any force field ranging from quantum mechanics to coarse-grain and atomistic.
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Affiliation(s)
- Tong Zhang
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,‡School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Phuong H Nguyen
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Jessica Nasica-Labouze
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,§International School of Advanced Studies (SISSA), Via Bonomea, 265, 34126 Trieste, Italy
| | - Yuguang Mu
- ‡School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Philippe Derreumaux
- †Laboratoire de Biochimie Théorique, UPR 9080 CNRS, Université Denis Diderot, Sorbonne Paris Cité, IBPC, 13 rue Pierre et Marie Curie, 75005 Paris, France.,∥Institut Universitaire de France, 103 Boulevard Saint-Michel, 75005 Paris, France
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