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Kaur G, Mankoo OK, Kaur A, Goyal D, Goyal B. Insights into the baicalein-induced destabilization of LS-shaped Aβ 42 protofibrils using computer simulations. Phys Chem Chem Phys 2024; 26:16674-16686. [PMID: 38809059 DOI: 10.1039/d3cp06006c] [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: 05/30/2024]
Abstract
Amyloid-β (Aβ) peptides aggregate spontaneously into various aggregating species comprising oligomers, protofibrils, and mature fibrils in Alzheimer's disease (AD). Disrupting β-sheet rich neurotoxic smaller soluble Aβ42 oligomers formed at early stages is considered a potent strategy to interfere with AD pathology. Previous experiments have demonstrated the inhibition of the early stages of Aβ aggregation by baicalein; however, the molecular mechanism behind inhibition remains largely unknown. Thus, in this work, molecular dynamics (MD) simulations have been employed to illuminate the molecular mechanism of baicalein-induced destabilization of preformed Aβ42 protofibrils. Baicalein binds to chain A of the Aβ42 protofibril through hydrogen bonds, π-π interactions, and hydrophobic contacts with the central hydrophobic core (CHC) residues of the Aβ42 protofibril. The binding of baicalein to the CHC region of the Aβ42 protofibril resulted in the elongation of the kink angle and disruption of K28-A42 salt bridges, which resulted in the distortion of the protofibril structure. Importantly, the β-sheet content was notably reduced in Aβ42 protofibrils upon incorporation of baicalein with a concomitant increase in the coil content, which is consistent with ThT fluorescence and AFM images depicting disaggregation of pre-existing Aβ42 fibrils on the incorporation of baicalein. Remarkably, the interchain binding affinity in Aβ42 protofibrils was notably reduced in the presence of baicalein leading to distortion in the overall structure, which agrees with the structural stability analyses and conformational snapshots. This work sheds light on the molecular mechanism of baicalein in disrupting the Aβ42 protofibril structure, which will be beneficial to the design of therapeutic candidates against disrupting β-sheet rich neurotoxic Aβ42 oligomers in AD.
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Affiliation(s)
- Gagandeep Kaur
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Opinder Kaur Mankoo
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Anupamjeet Kaur
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Deepti Goyal
- Department of Chemistry, DAV College, Sector 10, Chandigarh-160011, India.
| | - Bhupesh Goyal
- Department of Chemistry & Biochemistry, Thapar Institute of Engineering & Technology, Patiala-147004, Punjab, India.
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Uttarkar A, Rao V, Bhat D, Niranjan V. Disaggregation of amyloid-beta fibrils via natural metabolites using long timescale replica exchange molecular dynamics simulation studies. J Mol Model 2024; 30:61. [PMID: 38321243 DOI: 10.1007/s00894-024-05860-0] [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: 09/05/2023] [Accepted: 01/30/2024] [Indexed: 02/08/2024]
Abstract
CONTEXT Amyloid fibrils are self-assembled fibrous protein aggregates that are associated with several presently incurable diseases such as Alzheimer's. disease that is characterized by the accumulation of amyloid fibrils in the brain, which leads to the formation of plaques and the death of brain cells. Disaggregation of amyloid fibrils is considered a promising approach to cure Alzheimer's disease. The mechanism of amyloid fibril formation is complex and not fully understood, making it difficult to develop drugs that can target the process. Diacetonamine and cystathionine are potential lead compounds to induce disaggregation of amyloid fibrils. METHODS In the current research, we have used long timescale molecular simulation studies and replica exchange molecular dynamics (REMD) for 1000 ns (1 μs) to examine the mechanisms by which natural metabolites can disaggregate amyloid-beta fibrils. Molecular docking was carried out using Glide and with prior protein minimization and ligand preparation. We focused on a screening a database of natural metabolites, as potential candidates for disaggregating amyloid fibrils. We used Desmond with OPLS 3e as a force field. MM-GBSA calculations were performed. Blood-brain barrier permeability, SASA, and radius of gyration parameters were calculated.
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Affiliation(s)
- Akshay Uttarkar
- Department of Biotechnology, R V College of Engineering, Mysuru Road, Kengeri, Bangalore, 560059, affiliated to Visvesvaraya Technological University, Belagavi, 590018, India
| | - Vibha Rao
- Department of Biotechnology, R V College of Engineering, Mysuru Road, Kengeri, Bangalore, 560059, affiliated to Visvesvaraya Technological University, Belagavi, 590018, India
| | - Dhrithi Bhat
- Department of Biotechnology, R V College of Engineering, Mysuru Road, Kengeri, Bangalore, 560059, affiliated to Visvesvaraya Technological University, Belagavi, 590018, India
| | - Vidya Niranjan
- Department of Biotechnology, R V College of Engineering, Mysuru Road, Kengeri, Bangalore, 560059, affiliated to Visvesvaraya Technological University, Belagavi, 590018, India.
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Huang F, Fan X, Wang Y, Zou Y, Lian J, Wang C, Ding F, Sun Y. Computational insights into the cross-talk between medin and Aβ: implications for age-related vascular risk factors in Alzheimer's disease. Brief Bioinform 2024; 25:bbad526. [PMID: 38271485 PMCID: PMC10810335 DOI: 10.1093/bib/bbad526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/07/2023] [Accepted: 12/18/2023] [Indexed: 01/27/2024] Open
Abstract
The aggregation of medin forming aortic medial amyloid is linked to arterial wall degeneration and cerebrovascular dysfunction. Elevated levels of arteriolar medin are correlated with an increased presence of vascular amyloid-β (Aβ) aggregates, a hallmark of Alzheimer's disease (AD) and vascular dementia. The cross-interaction between medin and Aβ results in the formation of heterologous fibrils through co-aggregation and cross-seeding processes both in vitro and in vivo. However, a comprehensive molecular understanding of the cross-interaction between medin and Aβ-two intrinsically disordered proteins-is critically lacking. Here, we employed atomistic discrete molecular dynamics simulations to systematically investigate the self-association, co-aggregation and also the phenomenon of cross-seeding between these two proteins. Our results demonstrated that both Aβ and medin were aggregation prone and their mixture tended to form β-sheet-rich hetero-aggregates. The formation of Aβ-medin hetero-aggregates did not hinder Aβ and medin from recruiting additional Aβ and medin peptides to grow into larger β-sheet-rich aggregates. The β-barrel oligomer intermediates observed in the self-aggregations of Aβ and medin were also present during their co-aggregation. In cross-seeding simulations, preformed Aβ fibrils could recruit isolated medin monomers to form elongated β-sheets. Overall, our comprehensive simulations suggested that the cross-interaction between Aβ and medin may contribute to their pathological aggregation, given the inherent amyloidogenic tendencies of both medin and Aβ. Targeting medin, therefore, could offer a novel therapeutic approach to preserving brain function during aging and AD by improving vascular health.
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Affiliation(s)
- Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Ningbo 315211, China
| | - Xinjie Fan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Ying Wang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Jiangfang Lian
- Ningbo Institute of Innovation for Combined Medicine and Engineering, Lihuili Hospital Affiliated to Ningbo University, Ningbo University, Ningbo 315211, China
| | - Chuang Wang
- School of Medicine, Ningbo University, Ningbo 315211, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
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Yan J, Wang Y, Fan X, Zou Y, Ding F, Huang F, Sun Y. Deciphering the influence of Y12L and N17H substitutions on the conformation and oligomerization of human calcitonin. SOFT MATTER 2024; 20:693-703. [PMID: 38164981 PMCID: PMC10845004 DOI: 10.1039/d3sm01332d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The abnormal aggregation of human calcitonin (hCT) hormone peptides impairs their physiological function, leading to harmful immune responses and cytotoxicity, which limits their clinical utility. Interestingly, a representative hCT analog incorporating Y12L and N17H substitutions (DM-hCT) has shown reduced aggregation tendencies while maintaining bioactivity. But the molecular mechanism of Y12L and N17H substitutions on the conformational dynamics of hCT remains unclear. Here, we systematically investigated the folding and self-assembly dynamics of hCT and DM-hCT using atomistic discrete molecular dynamics (DMD) simulations. Our findings revealed that hCT monomers predominantly adopted unstructured conformations with dynamic helices. Oligomerization of hCT resulted in the formation of β-sheet-rich aggregates and β-barrel intermediates. The Y12L and N17H substitutions enhanced helical conformations and suppressed β-sheet formation in both monomers and oligomers. These substitutions stabilized the dynamic helices and disrupted aromatic interactions responsible for β-sheet formation at residue 12. Notably, DM-hCT assemblies still exhibited β-sheets in phenylalanine-rich and C-terminal hydrophobic regions, suggesting that future optimizations should focus on these areas. Our simulations provide insights into the molecular mechanisms underlying hCT aggregation and the amyloid-resistant effects of Y12L and N17H substitutions. These findings have valuable implications for the development of clinical hCT analogs.
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Affiliation(s)
- Jiajia Yan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China.
| | - Ying Wang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Xinjie Fan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
| | - Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China.
| | - Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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Okumura H. Perspective for Molecular Dynamics Simulation Studies of Amyloid-β Aggregates. J Phys Chem B 2023; 127:10931-10940. [PMID: 38109338 DOI: 10.1021/acs.jpcb.3c06051] [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: 12/20/2023]
Abstract
The cause of Alzheimer's disease is related to aggregates such as oligomers and amyloid fibrils consisting of amyloid-β (Aβ) peptides. Molecular dynamics (MD) simulation studies have been conducted to understand the molecular mechanism of the formation and disruption of Aβ aggregates. In this Perspective, the MD simulation studies are classified into four categories, focusing on the target systems: aggregation of Aβ peptides in bulk solution, Aβ aggregation at the interface, aggregation inhibitor against Aβ peptides, and nonequilibrium MD simulation of Aβ aggregates. MD simulation studies in these categories are first reviewed. Future perspectives in each category are then presented. Finally, the overall perspective is presented on how MD simulations of Aβ aggregates can be utilized for developing Alzheimer's disease treatment.
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Affiliation(s)
- Hisashi Okumura
- Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Institute for Molecular Science, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Graduate Institute for Advanced Studies, SOKENDAI, Okazaki, Aichi 444-8787, Japan
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Huang F, Liu Y, Wang Y, Xu J, Lian J, Zou Y, Wang C, Ding F, Sun Y. Co-aggregation of α-synuclein with amyloid-β stabilizes β-sheet-rich oligomers and enhances the formation of β-barrels. Phys Chem Chem Phys 2023; 25:31604-31614. [PMID: 37964757 DOI: 10.1039/d3cp04138g] [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: 11/16/2023]
Abstract
Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative diseases with markedly different pathological features of β-amyloid (Aβ) plaques and α-synuclein (αS) Lewy bodies (LBs), respectively. However, clinical overlaps in symptoms and pathologies between AD and PD are commonly observed caused by the cross-interaction between Aβ and αS. To uncover the molecular mechanisms behind their overlapping symptoms and pathologies, we computationally investigated the impact of αS on an Aβ monomer and dimerization using atomistic discrete molecular dynamics simulations (DMD). Our results revealed that αS could directly interact with Aβ monomers and dimers, thus forming β-sheet-rich oligomers, including potentially toxic β-barrel intermediates. The binding hotspot involved the second half of the N-terminal domain and NAC region in αS, along with residues 10-21 and 31-42 in Aβ. In their hetero-complex, the binding hotspot primarily assumed a β-sheet core buried inside, which was dynamically shielded by the highly charged, amyloid-resistant C-terminus of αS. Because the amyloid prion region was the same as the binding hotspot being buried, their fibrillization may be delayed, causing the toxic oligomers to increase. This study sheds light on the intricate relationship between Aβ and αS and provides insights into the overlapping pathology of AD and PD.
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Affiliation(s)
- Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China
| | - Yuying Liu
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Ying Wang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
| | - Jia Xu
- School of Medicine, Ningbo University, Ningbo 315211, China.
| | - Jiangfang Lian
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Chuang Wang
- School of Medicine, Ningbo University, Ningbo 315211, China.
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
| | - Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China.
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA.
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Huang F, Fan X, Wang Y, Wang C, Zou Y, Lian J, Ding F, Sun Y. Unveiling Medin Folding and Dimerization Dynamics and Conformations via Atomistic Discrete Molecular Dynamics Simulations. J Chem Inf Model 2023; 63:6376-6385. [PMID: 37782573 PMCID: PMC10752383 DOI: 10.1021/acs.jcim.3c01267] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Medin is a principal component of localized amyloid found in the vasculature of individuals over 50 years old. Its amyloid aggregation has been linked to endothelial dysfunction and vascular inflammation, contributing to the pathogenesis of various vascular diseases. Despite its significance, the structures of the medin monomer, oligomer, and fibril remain elusive, and the dynamic processes of medin aggregation are not fully understood. In this study, we comprehensively investigated the medin folding and dimerization dynamics and conformations using atomistic discrete molecular dynamics simulations. Our simulation results suggested that the folding initiation of the medin involved the formation of β-sheets around medin30-41 and medin42-50, with subsequent capping of other segments to their β-sheet edges. Medin monomers typically consisted of three or four β-strands, along with a dynamic N-terminal helix. Two isolated medin peptides readily aggregated into a β-sheet-rich dimer, displaying a strong aggregation propensity. Dimerization of medin not only enhanced the β-sheet conformations but also led to the formation of β-barrel oligomers. The aggregation tendencies of medin1-18 and medin19-29 were relatively weak. However, the segments of medin30-41 and medin42-50 played a crucial role as they primarily formed a β-sheet core and facilitated medin1-18 and medin19-29 to form intra- and interpeptide β-sheets. The findings highlight the critical role of the medin30-41 and medin42-50 regions in stabilizing the monomer structure and driving the medin amyloid aggregation. These regions could potentially serve as promising targets for designing antiamyloid inhibitors against amyloid aggregation of medin. Additionally, our study provides a full picture of the monomer conformations and dimerization dynamics for medin, which will help better understand the pathology of medin aggregation.
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Affiliation(s)
- Fengjuan Huang
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China
| | - Xinjie Fan
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Ying Wang
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
| | - Chuang Wang
- School of Medicine, Ningbo University, Ningbo 315211, China
| | - Yu Zou
- Department of Sport and Exercise Science, Zhejiang University, Hangzhou 310058, China
| | - Jiangfang Lian
- Ningbo Institute of Innovation for Combined Medicine and Engineering (NIIME), Ningbo Medical Center Lihuili Hospital, Ningbo 315211, China
| | - Feng Ding
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
| | - Yunxiang Sun
- School of Physical Science and Technology, Ningbo University, Ningbo 315211, China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, United States
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