1
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Prasad AK, Samajdar R, Panwar AS, Martin LL. Origin of Secondary Structure Transitions and Peptide Self-Assembly Propensity in Trifluoroethanol-Water Mixtures. J Phys Chem B 2024; 128:7736-7749. [PMID: 39088441 DOI: 10.1021/acs.jpcb.4c02594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
Membrane-peptide interactions are key to the formation of helical intermediates in the early stages of amyloidogenesis. Aqueous solutions of 2,2,2-trifluoroethanol (TFE) provide a membrane-mimetic environment capable of promoting and stabilizing local peptide interactions. Uperin 3.5 (U3.5), a 17-residue and amidated antimicrobial peptide, is unstructured in water but self-assembles into fibrils in the presence of salt. Secondary structure transitions linked to U3.5 self-assembly were investigated in TFE/water mixtures, in both the absence and presence of salt, to assess the role of membrane-peptide interactions on peptide self-assembly and amyloid formation. A 5-to-7-fold increase in fibril yield of U3.5 was observed at low TFE concentrations (10% TFE/water v/v) compared with physiological buffer but only in the presence of salt. No aggregation was observed in salt-free TFE/water mixtures. Circular dichroism spectra showed that partial helical structures, initially stabilized by TFE, transitioned to β-sheet-rich aggregates in a saline buffer. Molecular dynamics simulations confirmed that TFE and salt act synergistically to enhance peptide-peptide interactions, resulting in β-sheet-rich U3.5 oligomers at low TFE concentrations. Specifically, TFE stabilized amphipathic, helical intermediates, leading to increased peptide-peptide attraction through hydrophobic interactions. The presence of salt further enhanced the peptide-peptide interactions by screening positively charged residues. Thus, the study revealed the role of a membrane mimic in stabilizing helical intermediates on the pathway to amyloid formation in the antimicrobial U3.5 peptide.
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Affiliation(s)
- Anup Kumar Prasad
- IITB-Monash Research Academy, Indian Institute of Technology Bombay, Mumbai 400076, India
- Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
- School of Chemistry, Monash University, Clayton 3800, VIC, Australia
| | - Rajarshi Samajdar
- Department of Chemical Engineering, Institute of Chemical Technology, Mumbai 400019, India
| | - Ajay Singh Panwar
- Department of Metallurgical Engineering & Materials Science, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Lisandra L Martin
- School of Chemistry, Monash University, Clayton 3800, VIC, Australia
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2
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Xu Z, Zhang J, Tang J, Gong Y, Zou Y, Zhang Q. Dissecting the effect of ALS mutation S375G on the conformational properties and aggregation dynamics of TDP-43 370-375 fragment. Biophys Chem 2024; 310:107230. [PMID: 38615537 DOI: 10.1016/j.bpc.2024.107230] [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: 01/15/2024] [Revised: 03/19/2024] [Accepted: 03/28/2024] [Indexed: 04/16/2024]
Abstract
The aggregation of transactive response deoxyribonucleic acid (DNA) binding protein of 43 kDa (TDP-43) into ubiquitin-positive inclusions is closely associated with amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration, and chronic traumatic encephalopathy. The 370-375 fragment of TDP-43 (370GNNSYS375, TDP-43370-375), the amyloidogenic hexapeptides, can be prone to forming pathogenic amyloid fibrils with the characteristic of steric zippers. Previous experiments reported the ALS-associated mutation, serine 375 substituted by glycine (S375G) is linked to early onset disease and protein aggregation of TDP-43. Based on this, it is necessary to explore the underlying molecular mechanisms. By utilizing all-atom molecular dynamics (MD) simulations of 102 μs in total, we investigated the impact of S375G mutation on the conformational ensembles and oligomerization dynamics of TDP-43370-375 peptides. Our replica exchange MD simulations show that S375G mutation could promote the unstructured conformation formation and induce peptides to form a loose packed oligomer, thus inhibiting the aggregation of TDP-43370-375. Further analyses suggest that S375G mutation displays a reduction effect on the number of total hydrogen bonds and contacts among TDP-43370-375 peptides. Hydrogen bonding and polar interactions among TDP-43370-375 peptides, as well as Y374-Y374 π-π stacking interaction, are attenuated by S375G mutation. Additional microsecond MD simulations demonstrate that S375G mutation could prohibit the conformational conversion to β-structure-rich aggregates and possess an inhibitory effect on the oligomerization dynamics of TDP-43370-375. This study offers for the first time of molecular insights into the S375G mutation affecting the aggregation of TDP-43370-375 at the atomic level, and may open new avenues in the development of future site-specific mutation therapeutics.
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Affiliation(s)
- Zhengdong Xu
- Department of Physical Education, Shanghai University of Engineering Science, 333 Long Teng Road, Shanghai 201620, People's Republic of China
| | - Jianxin Zhang
- Department of Physical Education, Shanghai University of Engineering Science, 333 Long Teng Road, Shanghai 201620, People's Republic of China
| | - Jiaxing Tang
- College of Physical Education, Shanghai University of Sport, 399 Chang Hai Road, Shanghai 200438, People's Republic of China
| | - Yehong Gong
- General Education Center, Westlake University, 600 Dunyu Road, Hangzhou 310030, People's Republic of China
| | - Yu Zou
- Department Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310007, Zhejiang, People's Republic of China.
| | - Qingwen Zhang
- College of Physical Education, Shanghai University of Sport, 399 Chang Hai Road, Shanghai 200438, People's Republic of China.
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3
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Dutta A, Sepehri A, Lazaridis T. Putative Pore Structures of Amyloid β 25-35 in Lipid Bilayers. Biochemistry 2023; 62:2549-2558. [PMID: 37582191 DOI: 10.1021/acs.biochem.3c00323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
The amyloid β peptide aggregates to form extracellular plaques in the brains of Alzheimer's disease patients. Certain of its fragments have been found to have similar properties to those of the full-length peptide. The best-studied of these is 25-35, which aggregates into fibrils, is toxic to neurons, and forms ion channels in synthetic lipid bilayers. Here, we investigate possible pore-forming structures of oligomers of this peptide in a POPC/POPG membrane. We consider octameric and decameric β-barrels of different topology, strand orientation, and shear, evaluate their stability in an implicit membrane model, and subject the best models to multimicrosecond all-atom molecular dynamics simulations. We find two decameric structures that are kinetically stable in membranes on this time scale: an imperfectly closed antiparallel β-barrel with K28 in the pore lumen and a short parallel β-barrel with K28 toward the membrane interface. Both structures exhibit dehydrated gaps in the pore lumen, which are larger for the antiparallel barrel. Based on these results, the experimental cation selectivity, the dependence of ion channel activity on voltage direction, and certain mutation data, the parallel model seems more compatible with experimental data.
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Affiliation(s)
- Ankita Dutta
- Department of Chemistry, City College of New York/CUNY, 160 Convent Avenue, New York, New York 10031, United States
- Graduate Program in Biochemistry, The Graduate Center, City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Aliasghar Sepehri
- Department of Chemistry, City College of New York/CUNY, 160 Convent Avenue, New York, New York 10031, United States
| | - Themis Lazaridis
- Department of Chemistry, City College of New York/CUNY, 160 Convent Avenue, New York, New York 10031, United States
- Graduate Programs in Chemistry, Biochemistry, and Physics The Graduate Center, City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
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4
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Tan Y, Chen Y, Liu X, Tang Y, Lao Z, Wei G. Dissecting how ALS-associated D290V mutation enhances pathogenic aggregation of hnRNPA2 286-291 peptides: Dynamics and conformational ensembles. Int J Biol Macromol 2023; 241:124659. [PMID: 37119915 DOI: 10.1016/j.ijbiomac.2023.124659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/22/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023]
Abstract
The aggregation of RNA binding proteins, including hnRNPA1/2, TDP-43 and FUS, is heavily implicated in causing or increasing disease risk for a series of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). A recent experimental study demonstrated that an ALS-related D290V mutation in the low complexity domain (LCD) of hnRNPA2 can enhance the aggregation propensity of wild type (WT) hnRNPA2286-291 peptide. However, the underlying molecular mechanisms remain elusive. Herein, we investigated effects of D290V mutation on aggregation dynamics of hnRNPA2286-291 peptide and the conformational ensemble of hnRNPA2286-291 oligomers by performing all-atom molecular dynamic and replica-exchange molecular dynamic simulations. Our simulations demonstrate that D290V mutation greatly reduces the dynamics of hnRNPA2286-291 peptide and that D290V oligomers possess higher compactness and β-sheet content than WT, indicative of mutation-enhanced aggregation capability. Specifically, D290V mutation strengthens inter-peptide hydrophobic, main-chain hydrogen bonding and side-chain aromatic stacking interactions. Those interactions collectively lead to the enhancement of aggregation capability of hnRNPA2286-291 peptides. Overall, our study provides insights into the dynamics and thermodynamic mechanisms underlying D290V-induced disease-causing aggregation of hnRNPA2286-291, which could contribute to better understanding of the transitions from reversible condensates to irreversible pathogenic aggregates of hnRNPA2 LCD in ALS-related diseases.
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Affiliation(s)
- Yuan Tan
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Yujie Chen
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Xianshi Liu
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Yiming Tang
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Zenghui Lao
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Guanghong Wei
- Department of Physics, Fudan University, Shanghai 200438, People's Republic of China; State Key Laboratory of Surface Physics, Fudan University, Shanghai 200438, People's Republic of China; Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China.
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5
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Liu X, Li X, Qiao Q, Li F, Wei G. ALS-Linked A315T and A315E Mutations Enhance β-Barrel Formation of the TDP-43 307-319 Hexamer: A REST2 Simulation Study. ACS Chem Neurosci 2023; 14:1310-1320. [PMID: 36888995 DOI: 10.1021/acschemneuro.3c00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023] Open
Abstract
Pathogenic mutations of transactivation response element DNA-binding protein 43 (TDP-43) are closely linked with amyotrophic lateral sclerosis (ALS). It was recently reported that two ALS-linked familial mutants A315T and A315E of TDP-43307-319 peptides can self-assemble into oligomers including tetramers, hexamers, and octamers, among which hexamers were suggested to form the β-barrel structure. However, due to the transient nature of oligomers, their conformational properties and the atomic mechanisms underlying the β-barrel formation remain largely elusive. Herein, we investigated the hexameric conformational distributions of the wild-type (WT) TDP-43307-319 fragment and its A315T and A315E mutants by performing all-atom explicit-solvent replica exchange with solute tempering 2 simulations. Our simulations reveal that each peptide can self-assemble into diverse conformations including ordered β-barrels, bilayer β-sheets and/or monolayer β-sheets, and disordered complexes. A315T and A315E mutants display higher propensity to form β-barrel structures than the WT, which provides atomic explanation for their enhanced neurotoxicity reported previously. Detailed interaction analysis shows that A315T and A315E mutations increase inter-molecular interactions. Also, the β-barrel structures formed by the three different peptides are stabilized by distinct inter-peptide side-chain hydrogen bonding, hydrophobic, and aromatic stacking interactions. This study demonstrates the enhanced β-barrel formation of the TDP-43307-319 hexamer by the pathogenic A315T and A315E mutations and reveals the underlying molecular determinants, which may be helpful for in-depth understanding of the ALS-mutation-induced neurotoxicity of TDP-43 protein.
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Affiliation(s)
- Xianshi Liu
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Qin Qiao
- Digital Medical Research Center, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.,Shanghai Key Laboratory of Medical Image Computing and Computer Assisted Intervention, Shanghai 200032, China
| | - Fangying Li
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, People's Republic of China
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Chowdhury UD, Malayil I, Bhargava BL. Understanding the screening effect of aqueous DES on the IDPs: A molecular dynamics simulation study using amyloid β 42 monomer. J Mol Graph Model 2023; 119:108398. [PMID: 36542916 DOI: 10.1016/j.jmgm.2022.108398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/16/2022] [Accepted: 12/12/2022] [Indexed: 12/16/2022]
Abstract
Deep eutectic solvents (DESs) have emerged as the promising replacement to the ionic liquids in solvent engineering for bio-compatibility. We aim to understand the effect of aqueous deep eutectic solvents on the conformation of intrinsically disordered proteins (IDPs). In this context, we have studied the effect on amyloid beta (Aβ42) monomer in the hydrated DES composed of tetrabutylammonium chloride and ethylene glycol in a 3:1 ratio using all-atom molecular dynamics simulations. DES is found to effectively screen the interaction of four zones of the amyloid beta monomer with water. Water molecules and the DES constituents modulate the local protein-solvent interactions, in the solvation shell of the protein. In addition, the aqueous DES medium conserves the secondary structure of the Aβ42 monomer by increasing the intramolecular hydrogen bonding and D23-K28 salt-bridge interactions when compared to the pure water medium. The current study provides insights into the impact of DES in stabilizing an IDP, at molecular level. We envisage the hindered aggregation of the amyloid beta structures in DES medium over the pure water medium due to the screening of hydrophobic intramolecular interactions.
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Affiliation(s)
- Unmesh D Chowdhury
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, an OCC of Homi Bhabha National Institute, P.O. Jatni, Khurda, Odisha 752050, India
| | - Insha Malayil
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, an OCC of Homi Bhabha National Institute, P.O. Jatni, Khurda, Odisha 752050, India
| | - B L Bhargava
- School of Chemical Sciences, National Institute of Science Education & Research-Bhubaneswar, an OCC of Homi Bhabha National Institute, P.O. Jatni, Khurda, Odisha 752050, India.
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7
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Canet G, Zussy C, Hernandez C, Maurice T, Desrumaux C, Givalois L. The pathomimetic oAβ25–35 model of Alzheimer's disease: Potential for screening of new therapeutic agents. Pharmacol Ther 2023; 245:108398. [PMID: 37001735 DOI: 10.1016/j.pharmthera.2023.108398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly, currently affecting more than 40 million people worldwide. The two main histopathological hallmarks of AD were identified in the 1980s: senile plaques (composed of aggregated amyloid-β (Aβ) peptides) and neurofibrillary tangles (composed of hyperphosphorylated tau protein). In the human brain, both Aβ and tau show aggregation into soluble and insoluble oligomers. Soluble oligomers of Aβ include their most predominant forms - Aβ1-40 and Aβ1-42 - as well as shorter peptides such as Aβ25-35 or Aβ25-35/40. Most animal models of AD have been developed using transgenesis, based on identified human mutations. However, these familial forms of AD represent less than 1% of AD cases. In this context, the idea emerged in the 1990s to directly inject the Aβ25-35 fragment into the rodent brain to develop an acute model of AD that could mimic the disease's sporadic forms (99% of all cases). This review aims to: (1) summarize the biological activity of Aβ25-35, focusing on its impact on the main structural and functional alterations observed in AD (cognitive deficits, APP misprocessing, tau system dysfunction, neuroinflammation, oxidative stress, cholinergic and glutamatergic alterations, HPA axis dysregulation, synaptic deficits and cell death); and (2) confirm the interest of this pathomimetic model in AD research, as it has helped identify and characterize many molecules (marketed, in clinical development, and in preclinical testing), and to the development of alternative approaches for AD prevention and therapy. Today, the Aβ25-35 model appears as a first-intent choice model to rapidly screen the symptomatic or neuroprotective potencies of new compounds, chemical series, or innovative therapeutic strategies.
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Role of amyloid beta (25-35) neurotoxicity in the ferroptosis and necroptosis as modalities of regulated cell death in Alzheimer's disease. Neurotoxicology 2023; 94:71-86. [PMID: 36347329 DOI: 10.1016/j.neuro.2022.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 10/26/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022]
Abstract
Neuronal cell death as a prominent pathological feature contributes to cognitive decline and memory loss in Alzheimer's disease. We investigated the role of two forms of cell death pathways, ferroptosis and necroptosis, and their interactions following entorhinal cortex (EC) amyloidopathy. The Aβ25-35 was bilaterally injected into the rat's EC, and Morris Water Maze was applied to determine spatial performance one week after Aβ injection. For evaluation of ferroptosis and necroptosis involvement in Aβ induced pathology, ferroptosis inhibitor, Ferrostatin (Fer-1), and necroptosis inhibitor, Necrostatin (Nec-1), were injected into the EC during training days of behavioral test. Our behavioral and histological assessment showed spatial learning and memory impairment, along with neuropathology changes such as cell survival and intracellular Aβ deposits in response to EC amyloidopathy, which were ameliorated by treatment with Fer-1 or Nec-1. The expression of ferroptosis key factors GPX4 and SLC7A11 were decreased and the level of TfR was increased following Aβ toxicity. Also, Necroptosis pathway related factors RIP1, RIP3, and MLKL were modulated by Aβ neurotoxicity. However, application of Fer-1 or Nec-1 could inhibit the hippocampal ferroptosis and necroptosis pathways due to EC amyloidopathy. Our data also demonstrated that Aβ-induced necroptosis suppressed by Fer-1, although Nec-1 had no effect on ferroptosis, indicating that ferroptosis pathway is upstream of necroptosis process in the Aβ neurotoxicity. Moreover, Aβ induced hippocampal mGLUR5 overexpression and reduced level of STIM1/2 recovered by Fer-1 or Nec-1. According to our findings ferroptosis and necroptosis pathways are involved in Aβ neurotoxicity through modulation of mGLUR5 and STIM1/2 signaling.
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9
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Alraawi Z, Banerjee N, Mohanty S, Kumar TKS. Amyloidogenesis: What Do We Know So Far? Int J Mol Sci 2022; 23:ijms232213970. [PMID: 36430450 PMCID: PMC9695042 DOI: 10.3390/ijms232213970] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/01/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022] Open
Abstract
The study of protein aggregation, and amyloidosis in particular, has gained considerable interest in recent times. Several neurodegenerative diseases, such as Alzheimer's (AD) and Parkinson's (PD) show a characteristic buildup of proteinaceous aggregates in several organs, especially the brain. Despite the enormous upsurge in research articles in this arena, it would not be incorrect to say that we still lack a crystal-clear idea surrounding these notorious aggregates. In this review, we attempt to present a holistic picture on protein aggregation and amyloids in particular. Using a chronological order of discoveries, we present the case of amyloids right from the onset of their discovery, various biophysical techniques, including analysis of the structure, the mechanisms and kinetics of the formation of amyloids. We have discussed important questions on whether aggregation and amyloidosis are restricted to a subset of specific proteins or more broadly influenced by the biophysiochemical and cellular environment. The therapeutic strategies and the significant failure rate of drugs in clinical trials pertaining to these neurodegenerative diseases have been also discussed at length. At a time when the COVID-19 pandemic has hit the globe hard, the review also discusses the plausibility of the far-reaching consequences posed by the virus, such as triggering early onset of amyloidosis. Finally, the application(s) of amyloids as useful biomaterials has also been discussed briefly in this review.
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Affiliation(s)
- Zeina Alraawi
- Department of Chemistry and Biochemistry, Fulbright College of Art and Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Nayan Banerjee
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Srujana Mohanty
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata 741246, India
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10
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Dinic J, Schnorenberg MR, Tirrell MV. Sequence-Controlled Secondary Structures and Stimuli Responsiveness of Bioinspired Polyampholytes. Biomacromolecules 2022; 23:3798-3809. [PMID: 35969881 DOI: 10.1021/acs.biomac.2c00666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A comprehensive study focusing on the influence of the sequence charge pattern on the secondary structure preferences of annealed polyampholytes and their responsiveness to external stimuli is presented. Two sequences are designed composed entirely of ionizable amino acids (charge fraction, f = 1) and an equal number of positive and negative charges (f+ = f- = 0.5) with distinct charge patterns consisting of lysine and glutamic acid monomers. The study reveals that the sequence charge pattern has a significant influence on the secondary structure preferences of polyampholytes at physiological pH. Furthermore, it shows that external stimuli such as pH, ionic strength, and solvent dielectric constant can be used to modulate the secondary structure of the two studied sequences. The observed secondary structure transformations for the two sequences are also substantially different from those determined for uniformly charged homo-polypeptides under matching conditions.
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Affiliation(s)
- Jelena Dinic
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Mathew R Schnorenberg
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew V Tirrell
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
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11
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Figueira AJ, Moreira GG, Saavedra J, Cardoso I, Gomes CM. Tetramerization of the S100B Chaperone Spawns a Ca 2+ Independent Regulatory Surface that Enhances Anti-aggregation Activity and Client Specificity. J Mol Biol 2022; 434:167791. [PMID: 35970403 DOI: 10.1016/j.jmb.2022.167791] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 10/15/2022]
Abstract
Alzheimer's disease (AD) hallmarks include the aggregation of amyloid-β (Aβ), tau and neuroinflammation promoted by several alarmins. Among these is S100B, a small astrocytic homodimeric protein, upregulated in AD, whose multiple biological activities depend on localization, concentration, and assembly state. S100B was reported to inhibit the aggregation and toxicity of Aβ42 and tau similarly to a holdase-type chaperone. This activity is dependent of Ca2+-binding, which triggers the exposure of a regulatory binding cleft at the S100B dimer interface with which amyloidogenic clients dynamically interact. Although the dimer prevails, a significant portion of secreted S100B in the human brain occurs as higher order multimers, whose protective functions remain uncharacterized and which we here investigate. Resorting to ThT-monitored aggregation kinetics, we determined that unlike the dimer, tetrameric S100B inhibits Aβ42 aggregation at sub/equimolar ratios, an effect that persists in the absence of Ca2+ binding. Structural analysis revealed that S100B tetramerization spawns a novel extended cleft accommodating an aggregation-prone surface that mediates interactions with monomeric Aβ client via hydrophobic interactions, as corroborated by Bis-ANS fluorescence and docking analysis. Correspondingly, at high ionic strength that reduces solvation and favours hydrophobic contacts, the inhibition of Aβ42 aggregation by tetrameric S100B is 3-fold increased. Interestingly, this extended Ca2+-independent surface favours Aβ42 as substrate, as tau K18 aggregation is not inhibited by the apo tetramer. Overall, results illustrate a mechanism through which oligomerization of the S100B chaperone fine-tunes anti-aggregation activity and client specificity, highlighting the potential functional relevance of S100B multimers in the regulation of AD proteotoxicity.
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Affiliation(s)
- António J Figueira
- BioISI - Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal. https://twitter.com/Antonio27902425
| | - Guilherme G Moreira
- BioISI - Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal. https://twitter.com/GuilhermeGilMo1
| | - Joana Saavedra
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal
| | - Isabel Cardoso
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Portugal
| | - Cláudio M Gomes
- BioISI - Instituto de Biosistemas e Ciências Integrativas, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal.
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12
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Liu X, Ganguly P, Jin Y, Jhatro MJ, Shea JE, Buratto SK, Bowers MT. Tachykinin Neuropeptides and Amyloid β (25-35) Assembly: Friend or Foe? J Am Chem Soc 2022; 144:14614-14626. [PMID: 35917596 DOI: 10.1021/jacs.2c03845] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amyloid β (Aβ) protein is responsible for Alzheimer's disease, and one of its important fragments, Aβ(25-35), is found in the brain and has been shown to be neurotoxic. Tachykinin neuropeptides, including Neuromedin K (NK), Kassinin, and Substance P, have been reported to reduce Aβ(25-35)'s toxicity in cells even though they share similar primary structures with Aβ(25-35). Here, we seek to understand the molecular mechanisms of how these peptides interact with Aβ(25-35) and to shed light on why some peptides with similar primary structures are toxic and others nontoxic. We use both experimental and computational methods, including ion mobility mass spectrometry and enhanced-sampling replica-exchange molecular dynamics simulations, to study the aggregation pathways of Aβ(25-35), NK, Kassinin, Substance P, and mixtures of the latter three with Aβ(25-35). NK and Substance P were observed to remove the higher-order oligomers (i.e., hexamers and dodecamers) of Aβ(25-35), which are related to its toxicity, although Substance P did so more slowly. In contrast, Kassinin was found to promote the formation of these higher-order oligomers. This result conflicts with what is expected and is elaborated on in the text. We also observe that even though they have significant structural homology with Aβ(25-35), NK, Kassinin, and Substance P do not form hexamers with a β-sheet structure like Aβ(25-35). The hexamer structure of Aβ(25-35) has been identified as a cylindrin, and this structure has been strongly correlated to toxic species. The reasons why the three tachykinin peptides behave so differently when mixed with Aβ(25-35) are discussed.
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Affiliation(s)
- Xikun Liu
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Pritam Ganguly
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Yingying Jin
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Michael J Jhatro
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Joan-Emma Shea
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Steven K Buratto
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Michael T Bowers
- Department of Chemistry & Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
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13
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Pal T, Paul R, Paul S. Phenylpropanoids on the Inhibition of β-Amyloid Aggregation and the Movement of These Molecules through the POPC Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7775-7790. [PMID: 35687701 DOI: 10.1021/acs.langmuir.2c00827] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Alzheimer's disease (AD), caused by Aβ aggregation, is a major concern in medical research. It is a neurodegenerative disorder, leading to a loss of cognitive abilities, which is still claiming the lives of many people all over the world. This poses a challenge before the scientific community to discover effective drugs which can prevent such toxic aggregation. Recent experimental findings suggest the potency of two naturally-occurring phenylpropanoids, Schizotenuin A (SCH) and Lycopic Acid B (LAB) which can effectively combat the deleterious effects of Aβ aggregation, although nothing is known about their mechanism of inhibition. In this work, we deal with an extensive computational study on the inhibitory effects of these inhibitors by using an all-atom molecular dynamics simulation to interpret the underlying mechanism of their inhibitory processes. A series of investigations is carried out while studying the various structural and conformational changes of the peptide chains in the absence and presence of inhibitors. To investigate the details of the interactions between the peptide residues and inhibitors, nonbonding energy calculations, the radial distribution function, the coordination number of water and inhibitor molecules around the peptide residues, and hydrogen-bonding interactions are calculated. The potential of mean force (PMF) is calculated to estimate aggregate formation from their free-energy profiles. It is seen that the hydrophobic core of the KLVFFAE undergoes aggregation and that these inhibitors show great promise in preventing the onset of AD in the future by preventing Aβ aggregation. Also, the translocation studies on these inhibitors through a model POPC lipid bilayer shed light on their permeation properties and biocompatibility.
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Affiliation(s)
- Triasha Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Rabindranath Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
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14
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Liu X, Lao Z, Li X, Dong X, Wei G. ALS-associated A315E and A315pT variants exhibit distinct mechanisms in inducing irreversible aggregation of TDP-43 312-317 peptides. Phys Chem Chem Phys 2022; 24:16263-16273. [PMID: 35758309 DOI: 10.1039/d2cp01625g] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is intensively associated with insoluble aggregates formed by transactivation response element DNA-binding protein 43 (TDP-43) in the cytoplasm of neuron cells. A recent experimental study reported that two ALS-linked familial variants, A315E and A315pT (pT, phosphorylated threonine), can induce irreversible aggregation of the TDP-43 312NFGAFS317 segment (TDP-43312-317). However, the underlying molecular mechanism remains largely elusive. Here, we investigated the early aggregation process of the wild type (WT) 312NFGAFS317 segment and its A315E and A315pT variants by performing multiple microsecond all-atom molecular dynamics simulations. Our simulations show that the two variants display lower fluidity than WT, consistent with their decreased labilities observed in previous denaturation assay experiments. Despite each of the two variants carrying one negative charge, unexpectedly, we find that both A315E mutation and A315pT phosphorylation enhance intermolecular interactions and result in the formation of more compact oligomers. Compared to WT, A315E oligomers possess low β-sheet content but a compact hydrophobic core, while A315pT oligomers have high β-sheet content and large β-sheets. Side chain hydrogen-bonding and hydrophobic interactions as well as N312-E315 salt bridges contribute most to the increased aggregation propensity of the A315E mutant. By contrast, main chain and side chain hydrogen-bonding interactions, side chain hydrophobic and aromatic interactions, are crucial to the enhanced aggregation capability of the A315pT variant. These results indicate that glutamate mutation and phosphorylation at position 315 induce the irreversible aggregation of TDP-43312-317 peptides through differential mechanisms, which remind us that we should be careful in the investigation of the phosphorylation effect on protein aggregation by using phosphomimetic substitutions. This study provides mechanistic insights into the A315E/A315pT-induced irreversible aggregation of TDP-43312-317, which may be helpful for the in-depth understanding of ALS-mutation/phosphorylation-associated liquid-to-solid phase transition of TDP-43 protein aggregates.
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Affiliation(s)
- Xianshi Liu
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, P. R. China.
| | - Zenghui Lao
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, P. R. China.
| | - Xuhua Li
- MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Xuewei Dong
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, P. R. China.
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Key Laboratory for Computational Physical Sciences (Ministry of Education), Fudan University, Shanghai 200438, P. R. China.
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15
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Abstract
Experimental studies of amyloids encounter many challenges. There are many methods available for studying proteins, which can be applied to amyloids: from basic staining techniques, allowing visualization of fibers, to complex methods, e.g., AFM-IR used to their detailed biochemical and structural characterization in nanoscale. Which method is appropriate depends on the goal of an experiment: verification of aggregational properties of a peptide, distinguishing oligomers from mature fibers, or kinetic studies. Insolubility, rapid aggregation, and the need of using a high-purity peptide may be a limiting factor in studies involving amyloids. Moreover, the results obtained by various experimental methods often differ significantly, which may lead to misclassification of amyloid peptides. Due to ambiguity of experimental results, laborious and time-consuming analysis, bioinformatical methods become more widely used for amyloids.
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Affiliation(s)
| | - Natalia Szulc
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wrocław, Poland
| | - Monika Szefczyk
- Department of Bioorganic Chemistry, Wroclaw University of Science and Technology, Wrocław, Poland
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16
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Sanchez Ramirez DO, Cruz-Maya I, Vineis C, Guarino V, Tonetti C, Varesano A. Wool Keratin-Based Nanofibres-In Vitro Validation. Bioengineering (Basel) 2021; 8:224. [PMID: 34940377 PMCID: PMC8698655 DOI: 10.3390/bioengineering8120224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 11/17/2022] Open
Abstract
Protein-based nanofibres are commonly used in the biomedical field to support cell growth. For this study, the cell viability of wool keratin-based nanofibres was tested. Membranes were obtained by electrospinning using formic acid, hexafluoroisopropanol, and water as solvents. For aqueous solutions, polyethylene oxide blended with keratin was employed, and their use to support in vitro cell interactions was also validated. Morphological characterization and secondary structure quantification were carried out by SEM and FTIR analyses. Although formic acid produced the best nanofibres from a morphological point of view, the results showed a better response to cell proliferation after 14 days in the case of fibres from hexafluoroisopropanol solution. Polyethylene oxide in keratin nanofibres was demonstrated, over time, to influence in vitro cell interactions, modifying membranes-wettability and reducing the contact between keratin chains and water molecules, respectively.
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Affiliation(s)
- Diego Omar Sanchez Ramirez
- National Research Council-Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing (CNR-STIIMA), Corso Giuseppe Pella 16, 13900 Biella, Italy; (C.V.); (C.T.); (A.V.)
| | - Iriczalli Cruz-Maya
- National Research Council-Institute for Polymers, Composites and Biomaterials (CNR-IPCB), Mostra d’Oltremare, Pad. 20, V.le J.F. Kennedy 54, 80125 Napoli, Italy;
| | - Claudia Vineis
- National Research Council-Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing (CNR-STIIMA), Corso Giuseppe Pella 16, 13900 Biella, Italy; (C.V.); (C.T.); (A.V.)
| | - Vincenzo Guarino
- National Research Council-Institute for Polymers, Composites and Biomaterials (CNR-IPCB), Mostra d’Oltremare, Pad. 20, V.le J.F. Kennedy 54, 80125 Napoli, Italy;
| | - Cinzia Tonetti
- National Research Council-Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing (CNR-STIIMA), Corso Giuseppe Pella 16, 13900 Biella, Italy; (C.V.); (C.T.); (A.V.)
| | - Alessio Varesano
- National Research Council-Institute of Intelligent Industrial Technologies and Systems for Advanced Manufacturing (CNR-STIIMA), Corso Giuseppe Pella 16, 13900 Biella, Italy; (C.V.); (C.T.); (A.V.)
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17
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You DG, Lee HR, Kim HK, Lee GY, Yoo YD. A Novel Peptide Derived from the Transmembrane Domain of Romo1 Is a Promising Candidate for Sepsis Treatment and Multidrug-Resistant Bacteria. Int J Mol Sci 2021; 22:ijms22158243. [PMID: 34361008 PMCID: PMC8348110 DOI: 10.3390/ijms22158243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 02/03/2023] Open
Abstract
The emergence of multidrug-resistant (MDR) bacteria through the abuse and long-term use of antibiotics is a serious health problem worldwide. Therefore, novel antimicrobial agents that can cure an infection from MDR bacteria, especially gram-negative bacteria, are urgently needed. Antimicrobial peptides, part of the innate immunity system, have been studied to find bactericidal agents potent against MDR bacteria. However, they have many problems, such as restrained systemic activity and cytotoxicity. In a previous study, we suggested that the K58–R78 domain of Romo1, a mitochondrial protein encoded by the nucleus, was a promising treatment candidate for sepsis caused by MDR bacteria. Here, we performed sequence optimization to enhance the antimicrobial activity of this peptide and named it as AMPR-22 (antimicrobial peptide derived from Romo1). It showed broad-spectrum antimicrobial activity against 17 sepsis-causing bacteria, including MDR strains, by inducing membrane permeabilization. Moreover, treatment with AMPR-22 enabled a remarkable survival rate in mice injected with MDR bacteria in a murine model of sepsis. Based on these results, we suggest that AMPR-22 could be prescribed as a first-line therapy (prior to bacterial identification) for patients diagnosed with sepsis.
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Affiliation(s)
- Deok-Gyun You
- Laboratory of Molecular Cell Biology, Graduate School of Medicines, Korea University College of Medicine, Korea University, Seoul 02841, Korea; (D.-G.Y.); (H.-R.L.); (G.-Y.L.)
| | - Hye-Ra Lee
- Laboratory of Molecular Cell Biology, Graduate School of Medicines, Korea University College of Medicine, Korea University, Seoul 02841, Korea; (D.-G.Y.); (H.-R.L.); (G.-Y.L.)
| | - Hong-Kyu Kim
- Department of Surgery, Seoul National University College of Medicine, Seoul 03080, Korea;
| | - Gi-Young Lee
- Laboratory of Molecular Cell Biology, Graduate School of Medicines, Korea University College of Medicine, Korea University, Seoul 02841, Korea; (D.-G.Y.); (H.-R.L.); (G.-Y.L.)
| | - Young-Do Yoo
- Laboratory of Molecular Cell Biology, Graduate School of Medicines, Korea University College of Medicine, Korea University, Seoul 02841, Korea; (D.-G.Y.); (H.-R.L.); (G.-Y.L.)
- Correspondence:
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18
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Li X, Lao Z, Zou Y, Dong X, Li L, Wei G. Mechanistic Insights into the Co-Aggregation of Aβ and hIAPP: An All-Atom Molecular Dynamic Study. J Phys Chem B 2021; 125:2050-2060. [PMID: 33616398 DOI: 10.1021/acs.jpcb.0c11132] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Patients with Alzheimer's disease (AD) have a high risk of developing Type II diabetes (T2D). The co-aggregation of the two disease-related proteins, Aβ and hIAPP, has been proposed as a potential molecular mechanism. However, the detailed Aβ-hIAPP interactions and structural characteristics of co-aggregates are mostly unknown at atomic level. Here, we explore the conformational ensembles of the Aβ-hIAPP heterodimer and Aβ or hIAPP homodimer by performing all-atom explicit-solvent replica exchange molecular dynamic simulations. Our simulations show that the interaction propensity of Aβ-hIAPP in the heterodimer is comparable with that of Aβ-Aβ/hIAPP-hIAPP in the homodimer. Similar hot spot residues of Aβ/hIAPP in the homodimer and heterodimer are identified, indicating that both Aβ and hIAPP have similar molecular recognition sites for self-aggregation and co-aggregation. Aβ in the heterodimer possesses three high β-sheet probability regions: the N-terminal region E3-H6, the central hydrophobic core region K16-E22, and the C-terminal hydrophobic region I31-A41, which is highly similar to Aβ in the homodimer. More importantly, in the heterodimer, the regions E3-H6, F19-E22, and I31-M35 of Aβ and the amyloid core region N20-T30 of hIAPP display higher β-sheet probability than they do in homodimer, implying their crucial roles in the formation of β-sheet-rich co-aggregates. Our study sheds light on the co-aggregation of Aβ and hIAPP at an atomic level, which will be helpful for an in-depth understanding of the molecular mechanism for epidemiological correlation of AD and T2D.
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Affiliation(s)
- Xuhua Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China.,MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zenghui Lao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Yu Zou
- Department of Sport and Exercise Science, College of Education, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310007 Zhejiang, China
| | - Xuewei Dong
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Le Li
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
| | - Guanghong Wei
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 2005 Songhu Road, Shanghai 200438, China
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19
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Yamauchi M, Okumura H. Dimerization of α-Synuclein Fragments Studied by Isothermal-Isobaric Replica-Permutation Molecular Dynamics Simulation. J Chem Inf Model 2021; 61:1307-1321. [PMID: 33625841 DOI: 10.1021/acs.jcim.0c01056] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aggregates and fibrils of intrinsically disordered α-synuclein are associated with Parkinson's disease. Within a non-amyloid β component (NAC) spanning from the 61st to the 95th residue of α-synuclein, an 11-residue segment called NACore (68GAVVTGVTAVA78) is an essential region for both fibril formation and cytotoxicity. Although NACore peptides alone are known to form aggregates and amyloid fibrils, the mechanisms of aggregation and fibrillation remain unknown. This study investigated the dimerization process of NACore peptides as the initial stage of the aggregation and fibrillation processes. We performed an isothermal-isobaric replica-permutation molecular dynamics simulation, which is one of the efficient sampling methods, for the two NACore peptides in explicit water over 96 μs. The simulation succeeded in sampling a variety of dimer structures. An analysis of secondary structure revealed that most of the NACore dimers form intermolecular β-bridges. In particular, more antiparallel β-bridges were observed than parallel β-bridges. We also found that intramolecular secondary structures such as α-helix and antiparallel β-bridge are stabilized in the pre-dimer state. However, we identified that the intermolecular β-bridges tend to form directly between residues with no specific structure rather than via the intramolecular β-bridges. This is because the NACore peptides still have a low propensity to form the intramolecular secondary structures even though they are stabilized in the pre-dimer state.
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Affiliation(s)
- Masataka Yamauchi
- Department of Structural Molecular Science, The Graduate University for Advanced Studies(SOKENDAI), Okazaki, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Institute for Molecular Science (IMS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Hisashi Okumura
- Department of Structural Molecular Science, The Graduate University for Advanced Studies(SOKENDAI), Okazaki, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan.,Institute for Molecular Science (IMS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
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20
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Amyloid Beta Peptides and Th1 Cytokines Modulate Human Brain Vascular Smooth Muscle Tonic Contractile Capacity In Vitro: Relevance to Alzheimer's Disease? PATHOPHYSIOLOGY 2021; 28:64-75. [PMID: 35366270 PMCID: PMC8830442 DOI: 10.3390/pathophysiology28010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/04/2021] [Accepted: 02/09/2021] [Indexed: 11/17/2022] Open
Abstract
Alzheimer's Disease (AD) is a neurodegenerative condition characterized both by the presence of tau protein neurofibrillary tangles and amyloid beta (Aβ) containing extracellular "plaques". The cleavage of amyloid precursor protein (APP) yields several Aβ peptides. Although Aβ toxicity to neurons has been described extensively, its effects on other components of the neurovasculature such as vascular smooth muscle cells have been less well characterized. AD is now also recognized as a neurovascular disease characterized by cerebral microbleeds and disturbances in autoregulation. AD is also a neuroinflammatory condition in which several proinflammatory cytokines are elevated and may contribute to the intensification of AD severity. Cerebral autoregulation (the mechanism by which brain blood flow is maintained despite changes in perfusion pressure) is extremely tightly controlled in the brain and shows disturbances in AD. The failure of autoregulation in AD may make the brain susceptible to cerebral microbleeds through a reduced capacity to limit blood flow when pressure is increased. Conversely, reduced vasodilation during low flow might could also exacerbate tissue hypoxia. Currently, whether and how Aβ peptides and inflammatory cytokines depress brain smooth muscle cell tonic contraction is not known, but could reveal important targets in the preservation of autoregulation which is disturbed in AD. We used a collagen gel contractility assay to evaluate the influence of Aβ25-35, Aβ1-40 and Aβ1-42 peptides and inflammatory cytokines on the tonic contractility of human brain vascular smooth muscle cells (HBVSMC) as an in vitro model of cerebral autoregulation. We found that 5 and 10 μM Aβ1-42 significantly depressed HBVSM contractility, while Aβ1-40 5-20 μM had no effect on contractility. Conversely, Aβ25-35 (1-50 μM) increased contractility. Interestingly, the inflammatory cytokines TNF-α (20 ng/mL), IL-1β (20 ng/mL) and IFN-γ (1000 U/mL) also depressed HBVSM tonic contractility alone and in combination. These data suggest that both the inflammatory milieu in AD as well as the abundance of Aβ peptides may promote autoregulatory failure and increase brain susceptibility to dysregulated perfusion and microbleeds which are an important and devastating characteristic of AD.
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21
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Yao Y, Tang Y, Wei G. Epigallocatechin Gallate Destabilizes α-Synuclein Fibril by Disrupting the E46-K80 Salt-Bridge and Inter-protofibril Interface. ACS Chem Neurosci 2020; 11:4351-4361. [PMID: 33186020 DOI: 10.1021/acschemneuro.0c00598] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The accumulation and deposition of fibrillar aggregates of α-synuclein (α-syn) into Lewy bodies are the major hallmarks of Parkinson's disease (PD) for which there is no cure yet. Disrupting preformed α-syn fibrils is considered one of the rational therapeutic strategies to combat PD. Experimental studies reported that epigallocatechin gallate (EGCG), a polyphenol extracted from green tea, can disrupt α-syn fibrils into benign amorphous aggregates. However, the molecular mechanism of action is poorly understood. Herein, we performed molecular dynamics simulations on a newly released Greek-key-like α-syn fibril with or without EGCG to investigate the influence of EGCG on α-syn fibril. Our simulations show that EGCG disrupts the local β-sheet structure, E46-K80 salt-bridge crucial for the stabilization of the Greek-key-like structure, and hydrophobic interactions stabilizing the inter-protofibril interface and destabilizes the global structure of the α-syn fibril. Interaction analyses reveal that hydrophobic and hydrogen-bonding interactions between EGCG and α-syn fibrils play important roles in the destabilization of the fibril. We find that the disruption of the E46-K80 salt-bridge closely correlates with the formation of hydrogen-bonds (H-bonds) between EGCG and E46/K80. Our results provide mechanistic insights into the disruption modes of α-syn fibril by EGCG, which may pave the way for designing drug candidates targeting α-syn fibrillization to treat PD.
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Affiliation(s)
- Yifei Yao
- Department of Physics, State Key Laboratory of Surface Physics, and Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200438, People’s Republic of China
| | - Yiming Tang
- Department of Physics, State Key Laboratory of Surface Physics, and Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200438, People’s Republic of China
| | - Guanghong Wei
- Department of Physics, State Key Laboratory of Surface Physics, and Collaborative Innovation Center of Advanced Microstructures (Nanjing), Fudan University, Shanghai 200438, People’s Republic of China
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22
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Thapak P, Khare P, Bishnoi M, Sharma SS. Neuroprotective Effect of 2-Aminoethoxydiphenyl Borate (2-APB) in Amyloid β-Induced Memory Dysfunction: A Mechanistic Study. Cell Mol Neurobiol 2020; 42:1211-1223. [PMID: 33219878 DOI: 10.1007/s10571-020-01012-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 11/13/2020] [Indexed: 02/08/2023]
Abstract
β-Amyloid (Aβ) peptide is a characteristic feature of Alzheimer's disease (AD) and accumulation of Aβ is associated with loss of synaptic plasticity and neuronal cell death. Aggregation of Aβ initiates numerous molecular signalling pathways leading to oxidative stress, mitochondrial dysfunction as well as an imbalance of calcium ion influx homeostasis. Recently, it has been shown that transient receptor potential melastatin 2 (TRPM2), a non-selective calcium-permeable cation channel has been postulated to play a vital role in the neuronal death, indicating the potential of TRPM2 inhibition in CNS disease. In this study, neuroprotective potential of 2-aminoethoxydiphenyl borate (2-APB), a broad-spectrum calcium channels blocker was investigated in Aβ-induced memory deficits in rats. In addition, effect of 2-APB on TRPM2 channels gene and protein expressions and also on calcium and memory related proteins was investigated in the hippocampus. Intracerebroventricular (I.C.V.) administration of Aβ (Aβ25-35, 10 μg) markedly induced cognitive impairment and upregulation of mRNA and protein expression of TRPM2 in the hippocampus. In addition, AChE activity was also increased in the cortex of the Aβ administered animals. Three-week treatment with 2-APB led to the down-regulation of TRPM2 mRNA and protein expression in the hippocampus and also improved the cognitive functions which was evident from the behavioral parameters. Moreover, 2-APB treatment also increased the calcium and memory associated proteins namely p-CaMKII, p-GSK-3β, p-CREB and PSD-95 in the hippocampus and reduced the mRNA level of calcium buffering proteins and calcineurin A (PPP3CA) in the hippocampus. Furthermore, 2-APB treatment significantly reduced the AChE activity in the cortex. Thus, our findings suggest the neuroprotective effect of 2-APB in Aβ-induced cognitive impairment.
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Affiliation(s)
- Pavan Thapak
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India
| | - Pragyanshu Khare
- National Agri-Food Biotechnology Institute (NABI), S.A.S. Nagar, Mohali, Punjab, India
| | - Mahendra Bishnoi
- National Agri-Food Biotechnology Institute (NABI), S.A.S. Nagar, Mohali, Punjab, India
| | - Shyam Sunder Sharma
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), S.A.S. Nagar, Mohali, Punjab, 160062, India.
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23
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Arya S, Ganguly P, Arsiccio A, Claud SL, Trapp B, Schonfeld GE, Liu X, Lazar Cantrell K, Shea JE, Bowers MT. Terminal Capping of an Amyloidogenic Tau Fragment Modulates Its Fibrillation Propensity. J Phys Chem B 2020; 124:8772-8783. [PMID: 32816481 DOI: 10.1021/acs.jpcb.0c05768] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Aberrant protein folding leading to the formation of characteristic cross-β-sheet-rich amyloid structures is well known for its association with a variety of debilitating human diseases. Often, depending upon amino acid composition, only a small segment of a large protein participates in amyloid formation and is in fact capable of self-assembling into amyloid, independent of the rest of the protein. Therefore, such peptide fragments serve as useful model systems for understanding the process of amyloid formation. An important factor that has often been overlooked while using peptides to mimic full-length protein is the charge on the termini of these peptides. Here, we show the influence of terminal charges on the aggregation of an amyloidogenic peptide from microtubule-associated protein Tau, implicated in Alzheimer's disease and tauopathies. We found that modification of terminal charges by capping the peptide at one or both of the termini drastically modulates the fibrillation of the hexapeptide sequence paired helical filament 6 (PHF6) from repeat 3 of Tau, both with and without heparin. Without heparin, the PHF6 peptide capped at both termini and PHF6 capped only at the N-terminus self-assembled to form amyloid fibrils. With heparin, all capping variants of PHF6, except for PHF6 with both termini free, formed typical amyloid fibrils. However, the rate and extent of aggregation both with and without heparin as well as the morphology of aggregates were found to be highly dependent on the terminal charges. Our molecular dynamics simulations on PHF6 capping variants corroborated our experiments and provided critical insights into the mechanism of PHF6 self-assembly. Overall, our results emphasize the importance of terminal modifications in fibrillation of small peptide fragments and provide significant insights into the aggregation of a small Tau fragment, which is considered essential for Tau filament assembly.
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Affiliation(s)
- Shruti Arya
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Pritam Ganguly
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Andrea Arsiccio
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Sarah L Claud
- Department of Chemistry, Westmont College, Santa Barbara, California 93108, United States
| | - Benjamin Trapp
- Neon Therapeutics, Cambridge, Massachusetts 02139, United States
| | - Grace E Schonfeld
- Department of Chemistry, Westmont College, Santa Barbara, California 93108, United States
| | - Xikun Liu
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Kristi Lazar Cantrell
- Department of Chemistry, Westmont College, Santa Barbara, California 93108, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Michael T Bowers
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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Bibič L, Stokes L. Revisiting the Idea That Amyloid-β Peptide Acts as an Agonist for P2X7. Front Mol Neurosci 2020; 13:166. [PMID: 33071753 PMCID: PMC7530339 DOI: 10.3389/fnmol.2020.00166] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 08/11/2020] [Indexed: 01/24/2023] Open
Abstract
The P2X7 receptor (P2X7) is a cell surface ligand-gated ion channel, activated by its physiological nucleotide agonist ATP and a synthetic analog (BzATP). However, it has also been suggested that there may be structurally unrelated, non-nucleotide agonists such as the amyloidogenic β peptide. Here we aimed to reassess the effect of amyloid β peptides in various in vitro cell models, namely HEK293 overexpressing human P2X7, the microglial BV-2 cell line, and BV-2 cells lacking P2X7. We measured YO-PRO-1 dye uptake in response to full-length amyloid β peptide (1-42) or the shorter amyloid β peptide (25-35) and there was a concentration-dependent increase in YO-PRO-1 dye uptake in HEK-hP2X7 cells. However, these amyloid β peptide-induced increases in YO-PRO-1 dye uptake were also identical in non-transfected HEK-293 cells. We could observe small transient increases in [Ca2+] i induced by amyloid β peptides in BV-2 cells, however these were identical in BV-2 cells lacking P2X7. Furthermore, our metabolic viability and LDH release experiments suggest no significant change in viability or cell membrane damage in HEK-hP2X7 cells. In the BV-2 cells we found that high concentrations of amyloid β peptides (1-42) and (25-35) could reduce cell viability by up to 35% but this was also seen in BV-2 cells lacking P2X7. We found no evidence of LDH release by amyloid β peptides. In summary, we found no evidence that amyloid β peptides act as agonists of P2X7 in our in vitro models. Our study raises the possibility that amyloid β peptides simply mimic features of P2X7 activation.
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Affiliation(s)
- Lučka Bibič
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
| | - Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich, United Kingdom
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Rudajev V, Novotny J. The Role of Lipid Environment in Ganglioside GM1-Induced Amyloid β Aggregation. MEMBRANES 2020; 10:membranes10090226. [PMID: 32916822 PMCID: PMC7558528 DOI: 10.3390/membranes10090226] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/04/2020] [Accepted: 09/07/2020] [Indexed: 01/14/2023]
Abstract
Ganglioside GM1 is the most common brain ganglioside enriched in plasma membrane regions known as lipid rafts or membrane microdomains. GM1 participates in many modulatory and communication functions associated with the development, differentiation, and protection of neuronal tissue. It has, however, been demonstrated that GM1 plays a negative role in the pathophysiology of Alzheimer's disease (AD). The two features of AD are the formation of intracellular neurofibrillary bodies and the accumulation of extracellular amyloid β (Aβ). Aβ is a peptide characterized by intrinsic conformational flexibility. Depending on its partners, Aβ can adopt different spatial arrangements. GM1 has been shown to induce specific changes in the spatial organization of Aβ, which lead to enhanced peptide accumulation and deleterious effect especially on neuronal membranes containing clusters of this ganglioside. Changes in GM1 levels and distribution during the development of AD may contribute to the aggravation of the disease.
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López-Gambero AJ, Sanjuan C, Serrano-Castro PJ, Suárez J, Rodríguez de Fonseca F. The Biomedical Uses of Inositols: A Nutraceutical Approach to Metabolic Dysfunction in Aging and Neurodegenerative Diseases. Biomedicines 2020; 8:biomedicines8090295. [PMID: 32825356 PMCID: PMC7554709 DOI: 10.3390/biomedicines8090295] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/05/2023] Open
Abstract
Inositols are sugar-like compounds that are widely distributed in nature and are a part of membrane molecules, participating as second messengers in several cell-signaling processes. Isolation and characterization of inositol phosphoglycans containing myo- or d-chiro-inositol have been milestones for understanding the physiological regulation of insulin signaling. Other functions of inositols have been derived from the existence of multiple stereoisomers, which may confer antioxidant properties. In the brain, fluctuation of inositols in extracellular and intracellular compartments regulates neuronal and glial activity. Myo-inositol imbalance is observed in psychiatric diseases and its use shows efficacy for treatment of depression, anxiety, and compulsive disorders. Epi- and scyllo-inositol isomers are capable of stabilizing non-toxic forms of β-amyloid proteins, which are characteristic of Alzheimer’s disease and cognitive dementia in Down’s syndrome, both associated with brain insulin resistance. However, uncertainties of the intrinsic mechanisms of inositols regarding their biology are still unsolved. This work presents a critical review of inositol actions on insulin signaling, oxidative stress, and endothelial dysfunction, and its potential for either preventing or delaying cognitive impairment in aging and neurodegenerative diseases. The biomedical uses of inositols may represent a paradigm in the industrial approach perspective, which has generated growing interest for two decades, accompanied by clinical trials for Alzheimer’s disease.
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Affiliation(s)
- Antonio J. López-Gambero
- Departamento de Biología Celular, Genética y Fisiología, Campus de Teatinos s/n, Universidad de Málaga, Andalucia Tech, 29071 Málaga, Spain;
- UGC Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario Regional de Málaga, 29010 Málaga, Spain
| | | | - Pedro Jesús Serrano-Castro
- UGC Neurología, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario Regional de Málaga, 29010 Málaga, Spain;
| | - Juan Suárez
- UGC Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario Regional de Málaga, 29010 Málaga, Spain
- Correspondence: (J.S.); (F.R.d.F.); Tel.: +34-952614012 (J.S.)
| | - Fernando Rodríguez de Fonseca
- UGC Salud Mental, Instituto de Investigación Biomédica de Málaga (IBIMA), Hospital Universitario Regional de Málaga, 29010 Málaga, Spain
- Correspondence: (J.S.); (F.R.d.F.); Tel.: +34-952614012 (J.S.)
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27
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Boopathi S, Dinh Quoc Huy P, Gonzalez W, Theodorakis PE, Li MS. Zinc binding promotes greater hydrophobicity inAlzheimer's Aβ42peptide than copper binding: Molecular dynamics and solvation thermodynamics studies. Proteins 2020; 88:1285-1302. [DOI: 10.1002/prot.25901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Subramanian Boopathi
- Centro de Bioinformática y Simulación Molecular (CBSM), Facultad de IngenieríaUniversidad de Talca Talca Chile
| | | | - Wendy Gonzalez
- Centro de Bioinformática y Simulación Molecular (CBSM), Facultad de IngenieríaUniversidad de Talca Talca Chile
- Millennium Nucleus of Ion Channels‐Associated Diseases (MiNICAD)Universidad de Talca Talca Chile
| | | | - Mai Suan Li
- Institute of PhysicsPolish Academy of Sciences Warsaw Poland
- Institute for Computational Science and Technology, Quang Trung Software City Tan Chanh Hiep Ward Ho Chi Minh City Vietnam
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28
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Karkisaval AG, Rostagno A, Azimov R, Ban DK, Ghiso J, Kagan BL, Lal R. Ion channel formation by N-terminally truncated Aβ (4-42): relevance for the pathogenesis of Alzheimer's disease. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 29:102235. [PMID: 32531337 DOI: 10.1016/j.nano.2020.102235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 11/17/2022]
Abstract
Aβ deposition is a pathological hallmark of Alzheimer's disease (AD). Besides the full-length amyloid forming peptides (Aβ1-40 and Aβ1-42), biochemical analyses of brain deposits have identified a variety of N- and C-terminally truncated Aβ variants in sporadic and familial AD patients. However, their relevance for AD pathogenesis remains largely understudied. We demonstrate that Aβ4-42 exhibits a high tendency to form β-sheet structures leading to fast self-aggregation and formation of oligomeric assemblies. Atomic force microscopy and electrophysiological studies reveal that Aβ4-42 forms highly stable ion channels in lipid membranes. These channels that are blocked by monoclonal antibodies specifically recognizing the N-terminus of Aβ4-42. An Aβ variant with a double truncation at phenylalanine-4 and leucine 34, (Aβ4-34), exhibits unstable channel formation capability. Taken together the results presented herein highlight the potential benefit of C-terminal proteolytic cleavage and further support an important pathogenic role for N-truncated Aβ species in AD pathophysiology.
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Affiliation(s)
- Abhijith G Karkisaval
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA
| | - Agueda Rostagno
- Department of Pathology, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA
| | - Rustam Azimov
- Department of Psychiatry, Geffen School of Medicine, University of California, Los Angeles, California 90095, USA; Semel Neuropsychiatric for Neuroscience & Human Behavior, University of California, Los Angeles, California 90095, United States
| | - Deependra K Ban
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA
| | - Jorge Ghiso
- Department of Pathology, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA; Department of Psychiatry, New York University Grossman School of Medicine, 550 First Avenue, New York, NY, 10016, USA.
| | - Bruce L Kagan
- Department of Psychiatry, Geffen School of Medicine, University of California, Los Angeles, California 90095, USA; Semel Neuropsychiatric for Neuroscience & Human Behavior, University of California, Los Angeles, California 90095, United States.
| | - Ratnesh Lal
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, California, 92092, USA; Department of Bioengineering, University of California San Diego, La Jolla, California, 92092, USA; Materials Science and Engineering, University of California San Diego, La Jolla, California, 92092, USA.
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29
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Porter KN, Sarkar SN, Dakhlallah DA, Vannoy ME, Quintana DD, Simpkins JW. Medroxyprogesterone Acetate Impairs Amyloid Beta Degradation in a Matrix Metalloproteinase-9 Dependent Manner. Front Aging Neurosci 2020; 12:92. [PMID: 32317959 PMCID: PMC7155169 DOI: 10.3389/fnagi.2020.00092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/18/2020] [Indexed: 12/25/2022] Open
Abstract
Despite the extensive use of hormonal methods as either contraception or menopausal hormone therapy (HT), there is very little known about the potential effects of these compounds on the cellular processes of the brain. Medroxyprogesterone Acetate (MPA) is a progestogen used globally in the hormonal contraceptive, Depo Provera, by women in their reproductive prime and is a major compound found in HT formulations used by menopausal women. MPA promotes changes in the circulating levels of matrix metalloproteinases (MMPs), such as MMP-9, in the endometrium, yet limited literature studying the effects of MPA on neurons and astroglia cells has been conducted. Additionally, the dysregulation of MMPs has been implicated in the pathology of Alzheimer's disease (AD), where inhibiting the secretion of MMP-9 from astroglia reduces the proteolytic degradation of amyloid-beta. Thus, we hypothesize that exposure to MPA disrupts proteolytic degradation of amyloid-beta through the downregulation of MMP-9 expression and subsequent secretion. To assess the effect of progestins on MMP-9 and amyloid-beta, in vitro, C6 rat glial cells were exposed to MPA for 48 h and then the enzymatic, secretory, and amyloid-beta degrading capacity of MMP-9 was assessed from the conditioned culture medium. We found that MPA treatment inhibited transcription of MMP-9, which resulted in a subsequent decrease in the production and secretion of MMP-9 protein, in part through the glucocorticoid receptor. Additionally, we investigated the consequences of amyloid beta-degrading activity and found that MPA treatment decreased proteolytic degradation of amyloid-beta. Our results suggest MPA suppresses amyloid-beta degradation in an MMP-9-dependent manner, in vitro, and potentially compromises the clearance of amyloid-beta in vivo.
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Affiliation(s)
- Keyana N. Porter
- Department of Pharmaceutical and Pharmacological Sciences, West Virginia University School of Pharmacy, Morgantown, WV, United States
| | - Saumyendra N. Sarkar
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, United States
| | - Duaa A. Dakhlallah
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, United States
| | - Mya E. Vannoy
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, WV, United States
| | - Dominic D. Quintana
- Department of Neuroscience, Center for Basic and Translational Stroke Research, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, United States
| | - James W. Simpkins
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, United States
- Department of Neuroscience, Center for Basic and Translational Stroke Research, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV, United States
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30
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Penke B, Szűcs M, Bogár F. Oligomerization and Conformational Change Turn Monomeric β-Amyloid and Tau Proteins Toxic: Their Role in Alzheimer's Pathogenesis. Molecules 2020; 25:molecules25071659. [PMID: 32260279 PMCID: PMC7180792 DOI: 10.3390/molecules25071659] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/29/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
The structural polymorphism and the physiological and pathophysiological roles of two important proteins, β-amyloid (Aβ) and tau, that play a key role in Alzheimer's disease (AD) are reviewed. Recent results demonstrate that monomeric Aβ has important physiological functions. Toxic oligomeric Aβ assemblies (AβOs) may play a decisive role in AD pathogenesis. The polymorph fibrillar Aβ (fAβ) form has a very ordered cross-β structure and is assumed to be non-toxic. Tau monomers also have several important physiological actions; however, their oligomerization leads to toxic oligomers (TauOs). Further polymerization results in probably non-toxic fibrillar structures, among others neurofibrillary tangles (NFTs). Their structure was determined by cryo-electron microscopy at atomic level. Both AβOs and TauOs may initiate neurodegenerative processes, and their interactions and crosstalk determine the pathophysiological changes in AD. TauOs (perhaps also AβO) have prionoid character, and they may be responsible for cell-to-cell spreading of the disease. Both extra- and intracellular AβOs and TauOs (and not the previously hypothesized amyloid plaques and NFTs) may represent the novel targets of AD drug research.
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Affiliation(s)
- Botond Penke
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (M.S.); (F.B.)
- Correspondence:
| | - Mária Szűcs
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (M.S.); (F.B.)
| | - Ferenc Bogár
- Department of Medical Chemistry, University of Szeged, H-6720 Szeged, Hungary; (M.S.); (F.B.)
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, H-6720 Szeged, Hungary
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31
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Ermilova I, Lyubartsev AP. Modelling of interactions between Aβ(25-35) peptide and phospholipid bilayers: effects of cholesterol and lipid saturation. RSC Adv 2020; 10:3902-3915. [PMID: 35492630 PMCID: PMC9048594 DOI: 10.1039/c9ra06424a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/14/2019] [Indexed: 11/25/2022] Open
Abstract
Aggregation of amyloid beta (Aβ) peptides in neuronal membranes is a known promoter of Alzheimer’s disease. To gain insight into the molecular details of Aβ peptide aggregation and its effect on model neuronal membranes, we carried out molecular dynamics simulations of the Aβ(25–35) fragment of the amyloid precursor protein in phospholipid bilayers composed of either fully saturated or highly unsaturated lipids, in the presence or absence of cholesterol. It was found that the peptide does not penetrate through any of the considered membranes, but can reside in the headgroup region and upper part of the lipid tails showing a clear preference to a polyunsaturated cholesterol-free membrane. Due to the ordering and condensing effect upon addition of cholesterol, membranes become more rigid facilitating peptide aggregation on the surface. Except for the case of the cholesterol-free saturated lipid bilayer, the peptides have a small effect on the membrane structure and ordering. It was also found that the most “active” amino-acid for peptide–lipid and peptide–cholesterol interaction is methionine-35, followed by asparagine-27 and serine-26, which form hydrogen bonds between peptides and polar atoms of lipid headgroups. These amino acids are also primarily responsible for peptide aggregation. This work will be relevant for designing strategies to develop drugs to combat Alzheimer’s disease. Molecular dynamics simulations of Aβ(25–35) peptides in phospholipid bilayers are carried out to investigate the effect of polyunsaturated lipids and cholesterol on aggregation of the peptides. ![]()
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Affiliation(s)
- Inna Ermilova
- Department of Materials and Environmental Chemistry, Stockholm University Stockholm Sweden +46 8161193
| | - Alexander P Lyubartsev
- Department of Materials and Environmental Chemistry, Stockholm University Stockholm Sweden +46 8161193
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32
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Yang Y, Liu Y, Ning L, Wang L, Mu Y, Li W. Binding Process and Free Energy Characteristics of Cellulose Chain into the Catalytic Domain of Cellobiohydrolase TrCel7A. J Phys Chem B 2019; 123:8853-8860. [PMID: 31557037 DOI: 10.1021/acs.jpcb.9b05023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
It was observed in experiments that the catalytic domain (CD) of Trichoderma reesei Cel7A (TrCel7A) hydrolyzes crystalline cellulose in a processive manner, but the underlying binding mechanism is still unknown. Here, through replica-exchange molecular dynamics simulations, we find that the loading and sucking-in process of the cellulose chain into CD is entropy-driven and enthalpy-unfavorable, which firmly relate to the desolvation of the binding channel of CD. During the loading process, hydrophobic interactions play a dominant role because several aromatic residues have been identified to guide the cellulose chain processing. At the active site, a transition from enthalpy- to entropy-driven is detected for the driving force. Such a finding reveals the indispensability of the catalytic reaction of the glycosidic bond to provide the energy to drive the movements of the cellulose chain. Our study reveals the interaction pictures between the cellulose chain and TrCel7A at the atomic level, which helps better understand the catalytic mechanism of TrCel7A.
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Affiliation(s)
- Yanmei Yang
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education , Shandong Normal University , Jinan 250014 , China
| | | | - Lulu Ning
- School of Biological Sciences , Nanyang Technological University , 637551 Singapore
| | | | - Yuguang Mu
- School of Biological Sciences , Nanyang Technological University , 637551 Singapore
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Seong SH, Paudel P, Jung HA, Choi JS. Identifying Phlorofucofuroeckol-A as a Dual Inhibitor of Amyloid-β 25-35 Self-Aggregation and Insulin Glycation: Elucidation of the Molecular Mechanism of Action. Mar Drugs 2019; 17:E600. [PMID: 31652867 PMCID: PMC6891666 DOI: 10.3390/md17110600] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 10/19/2019] [Accepted: 10/20/2019] [Indexed: 02/07/2023] Open
Abstract
Both amyloid-β (Aβ) and insulin are amyloidogenic peptides, and they play a critical role in Alzheimer's disease (AD) and type-2 diabetes (T2D). Misfolded or aggregated Aβ and glycated insulin are commonly found in AD and T2D patients, respectively, and exhibit neurotoxicity and oxidative stress. The present study examined the anti-Aβ25-35 aggregation and anti-insulin glycation activities of five phlorotannins isolated from Ecklonia stolonifera. Thioflavin-T assay results suggest that eckol, dioxinodehydroeckol, dieckol, and phlorofucofuroeckol-A (PFFA) significantly inhibit Aβ25-35 self-assembly. Molecular docking and dynamic simulation analyses confirmed that these phlorotannins have a strong potential to interact with Aβ25-35 peptides and interrupt their self-assembly and conformational transformation, thereby inhibiting Aβ25-35 aggregation. In addition, PFFA dose-dependently inhibited d-ribose and d-glucose induced non-enzymatic insulin glycation. To understand the molecular mechanism for insulin glycation and its inhibition, we predicted the binding site of PFFA in insulin via computational analysis. Interestingly, PFFA strongly interacted with the Phe1 in insulin chain-B, and this interaction could block d-glucose access to the glycation site of insulin. Taken together, our novel findings suggest that phlorofucofuroeckol-A could be a new scaffold for AD treatment by inhibiting the formation of β-sheet rich structures in Aβ25-35 and advanced glycation end-products (AGEs) in insulin.
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Affiliation(s)
- Su Hui Seong
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
| | - Pradeep Paudel
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
| | - Hyun Ah Jung
- Department of Food Science and Human Nutrition, Jeonbuk National University, Jeonju 54896, Korea.
| | - Jae Sue Choi
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
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Choi H, Lee W, Lee G, Yoon DS, Na S. The Formation Mechanism of Segmented Ring-Shaped Aβ Oligomers and Protofibrils. ACS Chem Neurosci 2019; 10:3830-3838. [PMID: 31313912 DOI: 10.1021/acschemneuro.9b00324] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A clear understanding of amyloid formation with diverse morphologies is critical to overcoming the fatal disease amyloidosis. Studies have revealed that monomer concentration is a crucial factor for determining amyloid morphologies, such as protofibrils, annular, or spherical oligomers. However, gaining a complete understanding of the mechanism of formation of the various amyloid morphologies has been limited by the lack of experimental devices and insufficient knowledge. In this study, we demonstrate that the monomer concentration is an essential factor in determining the morphology of beta-amyloid (Aβ) oligomers or protofibrils. By computational and experimental approaches, we investigated the strategies for structural stabilization of amyloid protein, the morphological changes, and amyloid aggregation. In particular, we found unprecedented conformations, e.g., single bent oligomers and segmented ring-shaped protofibrils, the formation of which was explained by the computational analysis. Our findings provide insight into the structural features of amyloid molecules formed at low concentrations of monomer, which will help determine the clinical targets (in therapy) to effectively inhibit amyloid formation in the early stages of the amyloid growth phase.
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Affiliation(s)
| | - Wonseok Lee
- Department of Control and Instrumentation Engineering , Korea University , Sejong 30019 , Republic of Korea
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35
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Penke B, Bogár F, Paragi G, Gera J, Fülöp L. Key Peptides and Proteins in Alzheimer's Disease. Curr Protein Pept Sci 2019; 20:577-599. [PMID: 30605056 DOI: 10.2174/1389203720666190103123434] [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] [Received: 10/16/2018] [Revised: 12/03/2018] [Accepted: 12/27/2018] [Indexed: 02/02/2023]
Abstract
Alzheimer's Disease (AD) is a form of progressive dementia involving cognitive impairment, loss of learning and memory. Different proteins (such as amyloid precursor protein (APP), β- amyloid (Aβ) and tau protein) play a key role in the initiation and progression of AD. We review the role of the most important proteins and peptides in AD pathogenesis. The structure, biosynthesis and physiological role of APP are shortly summarized. The details of trafficking and processing of APP to Aβ, the cytosolic intracellular Aβ domain (AICD) and small soluble proteins are shown, together with other amyloid-forming proteins such as tau and α-synuclein (α-syn). Hypothetic physiological functions of Aβ are summarized. The mechanism of conformational change, the formation and the role of neurotoxic amyloid oligomeric (oAβ) are shown. The fibril formation process and the co-existence of different steric structures (U-shaped and S-shaped) of Aβ monomers in mature fibrils are demonstrated. We summarize the known pathogenic and non-pathogenic mutations and show the toxic interactions of Aβ species after binding to cellular receptors. Tau phosphorylation, fibrillation, the molecular structure of tau filaments and their toxic effect on microtubules are shown. Development of Aβ and tau imaging in AD brain and CSF as well as blood biomarkers is shortly summarized. The most probable pathomechanisms of AD including the toxic effects of oAβ and tau; the three (biochemical, cellular and clinical) phases of AD are shown. Finally, the last section summarizes the present state of Aβ- and tau-directed therapies and future directions of AD research and drug development.
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Affiliation(s)
- Botond Penke
- Department of Medical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Dom square 8, Szeged, H-6720, Hungary
| | - Ferenc Bogár
- Department of Medical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Dom square 8, Szeged, H-6720, Hungary.,MTA-SZTE Biomimetic Systems Research Group, University of Szeged, H-6720 Szeged, Dom square 8, Hungary
| | - Gábor Paragi
- MTA-SZTE Biomimetic Systems Research Group, University of Szeged, H-6720 Szeged, Dom square 8, Hungary.,Institute of Physics, University of Pécs, H-7624 Pecs, Ifjusag utja 6, Hungary
| | - János Gera
- Department of Medical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Dom square 8, Szeged, H-6720, Hungary
| | - Lívia Fülöp
- Department of Medical Chemistry, Interdisciplinary Excellence Centre, University of Szeged, Dom square 8, Szeged, H-6720, Hungary
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36
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Liu F, Ma Z, Sang J, Lu F. Edaravone inhibits the conformational transition of amyloid-β42: insights from molecular dynamics simulations. J Biomol Struct Dyn 2019; 38:2377-2388. [PMID: 31234720 DOI: 10.1080/07391102.2019.1632225] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Previous work has shown that edaravone inhibits fibrillogenesis of amyloid-β protein (Aβ). However, the detailed mechanism by which edaravone inhibits the conformational transition of the Aβ42 monomer is not known at the molecular level. Here, explicit-solvent molecular dynamics (MD) simulations were coupled with molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method to address the issue. MD simulations confirmed that edaravone inhibits the conformational transition of the Aβ42 monomer in a dose-dependent manner. It was found that the direct interactions between edaravone and Aβ42 are responsible for its inhibiting effects. The analysis of binding free energy using the MM-PBSA method demonstrated that the nonpolar interactions provide favourable contributions (about -71.7 kcal/mol). Conversely, the polar interactions are unfavourable for the binding process. A total of 14 residues were identified as greatly contributing to the binding free energy between edaravone and the Aβ42 monomer. In addition, the intra-peptide hydrophobic interactions were weakened and the salt bridge D23-K28 was interrupted by edaravone. Therefore, the conformational transition was inhibited. Our studies provide molecular-level insights into how edaravone molecules inhibit the conformational transition of the Aβ42 monomer, which may be useful for designing amyloid inhibitors.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Fufeng Liu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin, PR China.,Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, PR China
| | - Zheng Ma
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, PR China
| | - Jingcheng Sang
- College of Biotechnology, Tianjin University of Science & Technology, Tianjin, PR China
| | - Fuping Lu
- Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin, PR China.,Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin, PR China.,College of Biotechnology, Tianjin University of Science & Technology, Tianjin, PR China
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37
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Ray S, Holden S, Martin LL, Panwar AS. Mechanistic insight into the early stages of amyloid formation using an anuran peptide. Pept Sci (Hoboken) 2019. [DOI: 10.1002/pep2.24120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Sourav Ray
- IITB‐Monash Research AcademyIndian Institute of Technology Bombay Powai Mumbai India
- School of ChemistryMonash University Clayton Victoria Australia
- Department of Metallurgical Engineering and Materials ScienceIndian Institute of Technology Bombay Powai Mumbai India
| | | | | | - Ajay Singh Panwar
- Department of Metallurgical Engineering and Materials ScienceIndian Institute of Technology Bombay Powai Mumbai India
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38
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Roy P, Ghosh B, Chatterjee P, Sengupta N. Cosolvent Impurities in SWCNT Nanochannel Confinement: Length Dependence of Water Dynamics Investigated with Atomistic Simulations. J Chem Inf Model 2019; 59:2026-2034. [PMID: 30908024 DOI: 10.1021/acs.jcim.8b00889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The advent of nanotechnology has seen a growing interest in the nature of fluid flow and transport under nanoconfinement. The present study leverages fully atomistic molecular dynamics (MD) simulations to study the effect of nanochannel length and intrusion of molecules of the organic solvent, hexafluoro-2-propanol (HFIP), on the dynamical characteristics of water within it. Favorable interactions of HFIP with the nanochannels comprised of single-walled carbon nanotubes traps them over time scales greater than 100 ns, and confinement confers small but distinguishable spatial redistribution between neighboring HFIP pairs. Water molecules within the nanochannels show clear signatures of dynamical slowdown relative to bulk water even for pure systems. The presence of HFIP causes further rotational and translational slowdown in waters when the nanochannel dimension falls below a critical length of 30 Å. The enhanced slowdown in the presence of HFIP is quantified from characteristic relaxation parameters and diffusion coefficients in the absence and presence of HFIP. It is finally seen that the net flow of water between the ends of the nanochannel shows a decreasing dependence with nanochannel length only when the number of HFIP molecules is small. These results lend insights into devising ways of modulating solvent properties within nanochannels with cosolvent impurities.
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Affiliation(s)
- Priti Roy
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
| | - Brataraj Ghosh
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
| | - Prathit Chatterjee
- Advanced Polymer Lab in association with Polymer Research Centre , IISER Kolkata, ADO ADDITIVES MFG PVT. LTD. , 201/A, Nadibhag 2nd Lane , Madhyamgram, Kolkata 700 128 , India
| | - Neelanjana Sengupta
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India.,Centre for Advanced Functional Materials (CAFM) , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
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39
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Recent Advances by In Silico and In Vitro Studies of Amyloid-β 1-42 Fibril Depicted a S-Shape Conformation. Int J Mol Sci 2018; 19:ijms19082415. [PMID: 30115846 PMCID: PMC6121414 DOI: 10.3390/ijms19082415] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 12/19/2022] Open
Abstract
The amyloid-β 1-42 (Aβ1-42) peptide is produced by proteolytic cleavage of the amyloid precursor protein (APP) by sequential reactions that are catalyzed by γ and β secretases. Aβ1-42, together with the Tau protein are two principal hallmarks of Alzheimer's disease (AD) that are related to disease genesis and progression. Aβ1-42 possesses a higher aggregation propensity, and it is able to form fibrils via nucleated fibril formation. To date, there are compounds available that prevent Aβ1-42 aggregation, but none have been successful in clinical trials, possibly because the Aβ1-42 structure and aggregation mechanisms are not thoroughly understood. New molecules have been designed, employing knowledge of the Aβ1-42 structure and are based on preventing or breaking the ionic interactions that have been proposed for formation of the Aβ1-42 fibril U-shaped structure. Recently, a new Aβ1-42 fibril S-shaped structure was reported that, together with its aggregation and catalytic properties, could be helpful in the design of new inhibitor molecules. Therefore, in silico and in vitro methods have been employed to analyze the Aβ1-42 fibril S-shaped structure and its aggregation to obtain more accurate Aβ1-42 oligomerization data for the design and evaluation of new molecules that can prevent the fibrillation process.
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40
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Visentin C, Navarro S, Grasso G, Regonesi ME, Deriu MA, Tortora P, Ventura S. Protein Environment: A Crucial Triggering Factor in Josephin Domain Aggregation: The Role of 2,2,2-Trifluoroethanol. Int J Mol Sci 2018; 19:ijms19082151. [PMID: 30042316 PMCID: PMC6121581 DOI: 10.3390/ijms19082151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022] Open
Abstract
The protein ataxin-3 contains a polyglutamine stretch that triggers amyloid aggregation when it is expanded beyond a critical threshold. This results in the onset of the spinocerebellar ataxia type 3. The protein consists of the globular N-terminal Josephin domain and a disordered C-terminal tail where the polyglutamine stretch is located. Expanded ataxin-3 aggregates via a two-stage mechanism: first, Josephin domain self-association, then polyQ fibrillation. This highlights the intrinsic amyloidogenic potential of Josephin domain. Therefore, much effort has been put into investigating its aggregation mechanism(s). A key issue regards the conformational requirements for triggering amyloid aggregation, as it is believed that, generally, misfolding should precede aggregation. Here, we have assayed the effect of 2,2,2-trifluoroethanol, a co-solvent capable of stabilizing secondary structures, especially α-helices. By combining biophysical methods and molecular dynamics, we demonstrated that both secondary and tertiary JD structures are virtually unchanged in the presence of up to 5% 2,2,2-trifluoroethanol. Despite the preservation of JD structure, 1% of 2,2,2-trifluoroethanol suffices to exacerbate the intrinsic aggregation propensity of this domain, by slightly decreasing its conformational stability. These results indicate that in the case of JD, conformational fluctuations might suffice to promote a transition towards an aggregated state without the need for extensive unfolding, and highlights the important role played by the environment on the aggregation of this globular domain.
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Affiliation(s)
- Cristina Visentin
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Susanna Navarro
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Gianvito Grasso
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Maria Elena Regonesi
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Marco Agostino Deriu
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Paolo Tortora
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
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41
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Choi H, Yoon T, Na S. Length-Dependent Manifestation of Vibration Modes Regulates a Specific Intermediate Morphology of Aβ17-42 in Different Environments. Chemphyschem 2018; 19:1643-1654. [PMID: 29575445 DOI: 10.1002/cphc.201800010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Indexed: 12/25/2022]
Abstract
Various cytotoxic mechanisms for neurodegenerative disease are induced by specific conformations of Aβ intermediates. The efforts to understand the diverse intermediate forms of amyloid oligomers have been focused on understanding the aggregation mechanism of specific morphologies for Aβ intermediates. However, these are still not easy tasks to be accomplished because the diverse conformations of Aβ intermediates can be altered during the aggregation process, even though the same Aβ monomers are present. Thus, efforts to reveal the conformational change mechanism could be a fundamental process to understand the formation of diverse Aβ intermediate conformations. Here, we evaluate the conformational characteristics of Aβ17-42 fibrillar oligomers in different environments according to the length. We observed that Aβ fibrillar oligomers optimize their inherent hydrogen bonds and configurational entropy to stabilize their structure according to the simulation time and their length increase. In addition, we revealed the role of the expressed vibration mode shape in the fibrillar oligomers' elongation and deformation processes. Our results suggest that limitations in amyloid oligomer growth and transformations of their morphologies can be regulated and controlled by modifying the vibration features.
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Affiliation(s)
- Hyunsung Choi
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Taeyoung Yoon
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
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42
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Smith AK, Klimov DK. Binding of Cytotoxic Aβ25–35 Peptide to the Dimyristoylphosphatidylcholine Lipid Bilayer. J Chem Inf Model 2018; 58:1053-1065. [DOI: 10.1021/acs.jcim.8b00045] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Amy K. Smith
- School of Systems Biology, George Mason University, Manassas, Virginia 20110, United States
| | - Dmitri K. Klimov
- School of Systems Biology, George Mason University, Manassas, Virginia 20110, United States
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43
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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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44
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Capping effects on polymorphic Aβ 16-21 amyloids depend on their size: A molecular dynamics simulation study. Biophys Chem 2017; 232:1-11. [PMID: 29046256 DOI: 10.1016/j.bpc.2017.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 11/24/2022]
Abstract
Understanding Aβ amyloid oligomers associated with neuro-degenerative diseases is needed due to their toxic characteristics and mediation of amyloid fibril growth. Depending on various physiological circumstances such as ionic strength, metal ion, and point-residue mutation, oligomeric amyloids exhibit polymorphic behavior and structural stabilities, i.e. showing different conformation and stabilities. Specifically, experimental and computational researchers have found that the capping modulates the physical and chemical properties of amyloids by preserving electrostatic energy interactions, which is one of the dominant factors for amyloid stability. Still, there is no detailed knowledge for the polymorphic amyloids with reflecting the terminal capping effects. In the present study, we investigated the role of terminal capping (i.e. N-terminal acetylation and C-terminal amidation) on polymorphic Aβ16-21 amyloid oligomer and protofibrils via molecular dynamics (MD) simulations. We found that the capping effects have differently altered the conformation of polymorphic antiparallel-homo and -hetero Aβ16-21 amyloid oligomer, but not Aβ16-21 amyloid protofibrils. However, regardless of polymorphic composition of the amyloids, the capping induces the thermodynamic instabilities of Aβ16-21 amyloid oligomers, but does not show any distinct affect on Aβ16-21 amyloid protofibrils. Specifically, among the molecular mechanic factors, electrostatic energy dominantly contributes the thermodynamic stability of the Aβ16-21 amyloids. We hope that our computation study about the role of the capping effects on the polymorphic amyloids will facilitate additional efforts to enhance degradation of amyloids and to design a selective drug in the future.
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45
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Wang B, Pilkington EH, Sun Y, Davis TP, Ke PC, Ding F. Modulating protein amyloid aggregation with nanomaterials. ENVIRONMENTAL SCIENCE. NANO 2017; 4:1772-1783. [PMID: 29230295 PMCID: PMC5722024 DOI: 10.1039/c7en00436b] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Direct exposure or intake of nanopaticles (NPs) to the human body can invoke a series of biological responses, some of which are deleterious, and as such the role of NPs in vivo requires thorough examination. Over the past decade, it has been established that biomolecules such as proteins can bind NPs to form a 'corona', where the structures and dynamics of NP-associated proteins can assign new functionality, systemic distribution and toxicity. However, the behavior and fate of NPs in biological systems are still far from being fully understood. Growing evidence has shown that some natural or artificial NPs could either up- or down-regulate protein amyloid aggregation, which is associated with neurodegenerative diseases like Alzheimer's and Parkinson's diseases, as well as metabolic diseases such as type 2 diabetes. These effects can be either indirect (e.g., through a crowding effect) or direct, depending on the NP composition, size, shape and surface chemistry. However, efforts to design anti-amyloid NPs for biomedical applications have been largely hindered by insufficient understanding of the complex processes, even though proof-of-concept experiments have been conducted. Therefore, exploring the general mechanisms of NP-meditated protein aggregation marks an emerging field in bio-nano research and a new stage of handling nanotechnology that not only aids in elucidating the origin of nanotoxicity, but also provides a foundation for engineering de novo anti-amyloid nanomedicines. In this review, we summarize research on NP-mediated protein amyloid aggregation, with the goal of contributing to sustained nanotechnology and safe nanomedicine against amyloid diseases.
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Affiliation(s)
- Bo Wang
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
| | - Emily H Pilkington
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade Parkville, VIC 3052, Australia
| | - Yunxiang Sun
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
| | - Thomas P Davis
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade Parkville, VIC 3052, Australia
- Department of Chemistry, University of Warwick, Gibbet Hill, Coventry, CV4 7AL, UK
| | - Pu Chun Ke
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade Parkville, VIC 3052, Australia
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC, USA
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46
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Zhang T, Tian Y, Li Z, Liu S, Hu X, Yang Z, Ling X, Liu S, Zhang J. Molecular Dynamics Study to Investigate the Dimeric Structure of the Full-Length α-Synuclein in Aqueous Solution. J Chem Inf Model 2017; 57:2281-2293. [DOI: 10.1021/acs.jcim.7b00210] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Tingting Zhang
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Yuanxin Tian
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Zhonghuang Li
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Siming Liu
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Xiang Hu
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Zichao Yang
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Xiaotong Ling
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Shuwen Liu
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
| | - Jiajie Zhang
- Guangdong Provincial Key Laboratory of
New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, 510515, PR China
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47
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Use-dependent inhibition of glycine-activated chloride current in rat neurons by β-amyloid peptide pretreated with hexafluoroisopropanol. Neuroreport 2017; 28:579-583. [PMID: 28489663 DOI: 10.1097/wnr.0000000000000801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Hexafluoroisopropanol (HFIP) is a nonpolar organic solvent that is often used to prepare β-amyloid peptide (Aβ) samples. In this work, we compare the effects of two different species derived from synthetic Aβ1-42 and prepared without HFIP (Aβ) or using HFIP (Aβ/HFIP) on the glycine-activated chloride current (IGly). The experiments were conducted on the pyramidal neurons isolated from CA3 region of rat hippocampus. Transmembrane currents were recorded using a conventional patch-clamp technique in the whole-cell configuration. The IGly was induced by a step application of the agonist for 600 ms through glass capillary. Aβ or Aβ/HFIP was coapplied with glycine. The effects of the two species of the peptide have similar and distinctive features. Both substances caused a reduction in the peak amplitude and an acceleration of desensitization of the IGly. At the same time, the effect of Aβ/HFIP was found to develop and recover more slowly and required several repeated applications for its saturation (use dependence). The effect of Aβ/HFIP was voltage independent and equally pronounced at negative and positive membrane potentials. First, our results confirm that HFIP pretreatment may influence the properties of Aβ. Second, new information on the glycine receptor ability to interact with drugs in use-dependent mode was obtained.
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48
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Jong K, Grisanti L, Hassanali A. Hydrogen Bond Networks and Hydrophobic Effects in the Amyloid β30–35 Chain in Water: A Molecular Dynamics Study. J Chem Inf Model 2017; 57:1548-1562. [DOI: 10.1021/acs.jcim.7b00085] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- KwangHyok Jong
- Condensed
Matter and Statistical Physics, International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
- SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Bonomea 265, Trieste 34136, Italy
- Department
of Physics, Kim II Sung University, RyongNam Dong, TaeSong District, Pyongyang, D.P.R., Korea
| | - Luca Grisanti
- Condensed
Matter and Statistical Physics, International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
- SISSA-Scuola Internazionale Superiore di Studi Avanzati, via Bonomea 265, Trieste 34136, Italy
| | - Ali Hassanali
- Condensed
Matter and Statistical Physics, International Centre for Theoretical Physics, Strada Costiera 11, Trieste 34151, Italy
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49
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Choi H, Chang HJ, Lee M, Na S. Characterizing Structural Stability of Amyloid Motif Fibrils Mediated by Water Molecules. Chemphyschem 2017; 18:817-827. [PMID: 28160391 DOI: 10.1002/cphc.201601327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/12/2017] [Indexed: 11/12/2022]
Abstract
In biological systems, structural confinements of amyloid fibrils can be mediated by the role of water molecules. However, the underlying effect of the dynamic behavior of water molecules on structural stabilities of amyloid fibrils is still unclear. By performing molecular dynamics simulations, we investigate the dynamic features and the effect of interior water molecules on conformations and mechanical characteristics of various amyloid fibrils. We find that a specific mechanism induced by the dynamic properties of interior water molecules can affect diffusion of water molecules inside amyloid fibrils, inducing their different structural stabilities. The conformation of amyloid fibrils induced by interior water molecules show the fibrils' different mechanical features. We elucidate the role of confined and movable interior water molecules in structural stabilities of various amyloid fibrils. Our results offer insights not only in further understanding of mechanical features of amyloids as mediated by water molecules, but also in the fine-tuning of the functional abilities of amyloid fibrils for applications.
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Affiliation(s)
- Hyunsung Choi
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Hyun Joon Chang
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Myeongsang Lee
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Sungsoo Na
- Department of Mechanical Engineering, Korea University, Seoul, 02841, Republic of Korea
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Abdul Ghani NS, Karjiban RA, Basri M, Faujan NH, Lim WZ. Unveiling Amyloid-β1–42 Interaction with Zinc in Water and Mixed Hexafluoroisopropanol Solution in Alzheimer’s Disease. Int J Pept Res Ther 2017. [DOI: 10.1007/s10989-016-9570-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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