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Dai Z, Ben-Younis A, Vlachaki A, Raleigh D, Thalassinos K. Understanding the structural dynamics of human islet amyloid polypeptide: Advancements in and applications of ion-mobility mass spectrometry. Biophys Chem 2024; 312:107285. [PMID: 38941872 PMCID: PMC11260546 DOI: 10.1016/j.bpc.2024.107285] [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: 01/19/2024] [Revised: 05/30/2024] [Accepted: 06/23/2024] [Indexed: 06/30/2024]
Abstract
Human islet amyloid polypeptide (hIAPP) forms amyloid deposits that contribute to β-cell death in pancreatic islets and are considered a hallmark of Type II diabetes Mellitus (T2DM). Evidence suggests that the early oligomers of hIAPP formed during the aggregation process are the primary pathological agent in islet amyloid induced β-cell death. The self-assembly mechanism of hIAPP, however, remains elusive, largely due to limitations in conventional biophysical techniques for probing the distribution or capturing detailed structures of the early, structurally dynamic oligomers. The advent of Ion-mobility Mass Spectrometry (IM-MS) has enabled the characterisation of hIAPP early oligomers in the gas phase, paving the way towards a deeper understanding of the oligomerisation mechanism and the correlation of structural information with the cytotoxicity of the oligomers. The sensitivity and the rapid structural characterisation provided by IM-MS also show promise in screening hIAPP inhibitors, categorising their modes of inhibition through "spectral fingerprints". This review delves into the application of IM-MS to the dissection of the complex steps of hIAPP oligomerisation, examining the inhibitory influence of metal ions, and exploring the characterisation of hetero-oligomerisation with different hIAPP variants. We highlight the potential of IM-MS as a tool for the high-throughput screening of hIAPP inhibitors, and for providing insights into their modes of action. Finally, we discuss advances afforded by recent advancements in tandem IM-MS and the combination of gas phase spectroscopy with IM-MS, which promise to deliver a more sensitive and higher-resolution structural portrait of hIAPP oligomers. Such information may help facilitate a new era of targeted therapeutic strategies for islet amyloidosis in T2DM.
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Affiliation(s)
- Zijie Dai
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK
| | - Aisha Ben-Younis
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK
| | - Anna Vlachaki
- Department of Clinical Neurosciences, John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK
| | - Daniel Raleigh
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK; Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States.
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, Division of Bioscience, University College London, London WC1E 6BT, UK; Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, UK.
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2
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Dasari AK, Sengupta U, Viverette E, Borgnia MJ, Kayed R, Lim KH. Characterization of α-synuclein oligomers formed in the presence of lipid vesicles. Biochem Biophys Rep 2024; 38:101687. [PMID: 38545462 PMCID: PMC10965497 DOI: 10.1016/j.bbrep.2024.101687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 05/23/2024] Open
Abstract
Aggregation of α-synuclein into oligomers and fibrils is associated with numerous neurodegenerative diseases such as Parkinson's disease (PD). Although the identity of the pathogenic species formed during the aggregation process is still under active debate, mounting evidence suggests that small oligomeric species rather than fibrillar aggregates are real toxic species. Isolation and characterization of small oligomers is essential to developing therapeutic strategies to prevent oligomer formation. Preparation of misfolded oligomeric species for biophysical characterization is, however, a great challenge due to their heterogenous, transient nature. Here we report the preparation of toxic and non-toxic α-synuclein oligomeric species formed at different pH values in the presence of lipid vesicles that mimic mitochondria membranes containing cardiolipin. Biophysical characterization of the lipid-induced α-synuclein oligomeric assemblies revealed that α-synuclein oligomers formed at pH 7.4 have higher surface hydrophobicity than the aggregates formed at pH 6.0. In addition, the high-pH oligomers were shown to exhibit higher toxicity than the low-pH aggregates. Structural, dynamic properties of the oligomers were also investigated by using circular dichroism (CD) and NMR spectroscopy. Our CD analyses revealed that the two oligomeric species have distinct molecular conformations, and 2D 1H/15N HSQC NMR experiments suggested that the high-pH oligomers have more extended dynamic regions than the low-pH aggregates. The distinct structural and dynamic properties of the oligomers might be associated with their different cytotoxic properties.
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Affiliation(s)
- Anvesh K.R. Dasari
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
| | - Urmi Sengupta
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Elizabeth Viverette
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Mario J. Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, 27709, USA
| | - Rakez Kayed
- Departments of Neurology, Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, NC, 27858, USA
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3
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Ghosh D, Biswas A, Radhakrishna M. Advanced computational approaches to understand protein aggregation. BIOPHYSICS REVIEWS 2024; 5:021302. [PMID: 38681860 PMCID: PMC11045254 DOI: 10.1063/5.0180691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/18/2024] [Indexed: 05/01/2024]
Abstract
Protein aggregation is a widespread phenomenon implicated in debilitating diseases like Alzheimer's, Parkinson's, and cataracts, presenting complex hurdles for the field of molecular biology. In this review, we explore the evolving realm of computational methods and bioinformatics tools that have revolutionized our comprehension of protein aggregation. Beginning with a discussion of the multifaceted challenges associated with understanding this process and emphasizing the critical need for precise predictive tools, we highlight how computational techniques have become indispensable for understanding protein aggregation. We focus on molecular simulations, notably molecular dynamics (MD) simulations, spanning from atomistic to coarse-grained levels, which have emerged as pivotal tools in unraveling the complex dynamics governing protein aggregation in diseases such as cataracts, Alzheimer's, and Parkinson's. MD simulations provide microscopic insights into protein interactions and the subtleties of aggregation pathways, with advanced techniques like replica exchange molecular dynamics, Metadynamics (MetaD), and umbrella sampling enhancing our understanding by probing intricate energy landscapes and transition states. We delve into specific applications of MD simulations, elucidating the chaperone mechanism underlying cataract formation using Markov state modeling and the intricate pathways and interactions driving the toxic aggregate formation in Alzheimer's and Parkinson's disease. Transitioning we highlight how computational techniques, including bioinformatics, sequence analysis, structural data, machine learning algorithms, and artificial intelligence have become indispensable for predicting protein aggregation propensity and locating aggregation-prone regions within protein sequences. Throughout our exploration, we underscore the symbiotic relationship between computational approaches and empirical data, which has paved the way for potential therapeutic strategies against protein aggregation-related diseases. In conclusion, this review offers a comprehensive overview of advanced computational methodologies and bioinformatics tools that have catalyzed breakthroughs in unraveling the molecular basis of protein aggregation, with significant implications for clinical interventions, standing at the intersection of computational biology and experimental research.
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Affiliation(s)
- Deepshikha Ghosh
- Department of Biological Sciences and Engineering, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
| | - Anushka Biswas
- Department of Chemical Engineering, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gujarat 382355, India
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4
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Antón R, Treviño MÁ, Pantoja-Uceda D, Félix S, Babu M, Cabrita EJ, Zweckstetter M, Tinnefeld P, Vera AM, Oroz J. Alternative low-populated conformations prompt phase transitions in polyalanine repeat expansions. Nat Commun 2024; 15:1925. [PMID: 38431667 PMCID: PMC10908835 DOI: 10.1038/s41467-024-46236-5] [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: 06/16/2023] [Accepted: 02/19/2024] [Indexed: 03/05/2024] Open
Abstract
Abnormal trinucleotide repeat expansions alter protein conformation causing malfunction and contribute to a significant number of incurable human diseases. Scarce structural insights available on disease-related homorepeat expansions hinder the design of effective therapeutics. Here, we present the dynamic structure of human PHOX2B C-terminal fragment, which contains the longest polyalanine segment known in mammals. The major α-helical conformation of the polyalanine tract is solely extended by polyalanine expansions in PHOX2B, which are responsible for most congenital central hypoventilation syndrome cases. However, polyalanine expansions in PHOX2B additionally promote nascent homorepeat conformations that trigger length-dependent phase transitions into solid condensates that capture wild-type PHOX2B. Remarkably, HSP70 and HSP90 chaperones specifically seize PHOX2B alternative conformations preventing phase transitions. The precise observation of emerging polymorphs in expanded PHOX2B postulates unbalanced phase transitions as distinct pathophysiological mechanisms in homorepeat expansion diseases, paving the way towards the search of therapeutics modulating biomolecular condensates in central hypoventilation syndrome.
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Affiliation(s)
- Rosa Antón
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Miguel Á Treviño
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - David Pantoja-Uceda
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain
| | - Sara Félix
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - María Babu
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
| | - Eurico J Cabrita
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
- UCIBIO, Department of Chemistry, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2819-516, Caparica, Portugal
| | - Markus Zweckstetter
- German Center for Neurodegenerative Diseases (DZNE), 37075, Göttingen, Germany
- Department for NMR-based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, 37077, Göttingen, Germany
| | - Philip Tinnefeld
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Andrés M Vera
- Department of Chemistry and Center for NanoScience, Ludwig-Maximilians-Universität München, München, 81377, Germany
| | - Javier Oroz
- Instituto de Química Física Blas Cabrera (IQF), CSIC, E-28006, Madrid, Spain.
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Cheng L, De Leon-Rodriguez LM, Gilbert EP, Loo T, Petters L, Yang Z. Self-assembly and hydrogelation of a potential bioactive peptide derived from quinoa proteins. Int J Biol Macromol 2024; 259:129296. [PMID: 38199549 DOI: 10.1016/j.ijbiomac.2024.129296] [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: 11/29/2023] [Revised: 12/25/2023] [Accepted: 01/05/2024] [Indexed: 01/12/2024]
Abstract
In this work the identification of peptides derived from quinoa proteins which could potentially self-assemble, and form hydrogels was carried out with TANGO, a statistical mechanical based algorithm that predicts β-aggregate propensity of peptides. Peptides with the highest aggregate propensity were subjected to gelling screening experiments from which the most promising bioactive peptide with sequence KIVLDSDDPLFGGF was selected. The self-assembling and hydrogelation properties of the C-terminal amidated peptide (KIVLDSDDPLFGGF-NH2) were studied. The effect of concentration, pH, and temperature on the secondary structure of the peptide were probed by circular dichroism (CD), while its nanostructure was studied by transmission electron microscopy (TEM) and small-angle neutron scattering (SANS). Results revealed the existence of random coil, α-helix, twisted β-sheet, and well-defined β-sheet secondary structures, with a range of nanostructures including elongated fibrils and bundles, whose proportion was dependant on the peptide concentration, pH, or temperature. The self-assembly of the peptide is demonstrated to follow established models of amyloid formation, which describe the unfolded peptide transiting from an α-helix-containing intermediate into β-sheet-rich protofibrils. The self-assembly is promoted at high concentrations, elevated temperatures, and pH values close to the peptide isoelectric point, and presumably mediated by hydrogen bond, hydrophobic and electrostatic interactions, and π-π interactions (from the F residue). At 15 mg/mL and pH 3.5, the peptide self-assembled and formed a self-supporting hydrogel exhibiting viscoelastic behaviour with G' (1 Hz) ~2300 Pa as determined by oscillatory rheology measurements. The study describes a straightforward method to monitor the self-assembly of plant protein derived peptides; further studies are needed to demonstrate the potential application of the formed hydrogels in food and biomedicine.
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Affiliation(s)
- Lirong Cheng
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand
| | | | - Elliot Paul Gilbert
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, NSW, Australia; Centre for Nutrition and Food Sciences, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Trevor Loo
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Ludwig Petters
- School of Natural Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Zhi Yang
- School of Food and Advanced Technology, Massey University, Auckland 0632, New Zealand.
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Roy R, Paul S. Exploring the Curvature-Dependence of Boron Nitride Nanoparticles on the Inhibition of hIAPP Aggregation. J Phys Chem B 2023; 127:7558-7570. [PMID: 37616499 DOI: 10.1021/acs.jpcb.3c02689] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Nanoparticles, particularly carbon nanoparticles, have gathered significant interest in the field of anti-aggregation research. However, due to their cytotoxicity, the exploration of biocompatible nanoparticles has become a new frontier in the quest for drugs against human amyloid diseases. The application of non-cytotoxic and biocompatible boron nitride (BN) nanoparticles against amyloid aggregation has been probed to tackle this issue. BN nanoparticles displayed inhibitory activity against the aggregation of Aβ and α-syn peptides. In this work, the effect of BN nanoparticles on the dimerization of hIAPP, which is associated with the pathogenesis of type 2 diabetes, is studied. BN nanoparticles prevent the misfolding of hIAPP into β-sheet-rich aggregates. On varying the curvature, the nanoparticles display variation in the interaction preference with hIAPP. Interestingly, as the hydrophobicity of the nanoparticles increases from (5,5) BN nanotube to BN nanosheet, the interaction propensity shifts from N-terminal to the amyloid prone C-terminal of hIAPP. The hydrophobic and aromatic stacking interactions are a contributing factor toward the binding between hIAPP and BN. Due to this, the flat surface of the nanosheet shows better interaction potential toward hIAPP, compared to the nanotubes. Further, the nanoparticles can also disassemble preformed hIAPP fibrils, and the effect is more pronounced for (5,5) nanotube and the nanosheet. This study provides insight into the inhibitory mechanism of hIAPP aggregation by boron nitride nanoparticles and also an understanding of the significance of the curvature of nanoparticles in their interaction with amyloid peptides, which is valuable for the design of antiamyloid drugs.
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Affiliation(s)
- Rituparna Roy
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam-781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam-781039, India
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7
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Chuang Y, Chang Y, Tu L. Investigating the inhibitory property of DM hCT on hCT fibrillization via its relevant peptide fragments. Protein Sci 2023; 32:e4711. [PMID: 37354016 PMCID: PMC10360389 DOI: 10.1002/pro.4711] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 06/17/2023] [Accepted: 06/21/2023] [Indexed: 06/25/2023]
Abstract
The irreversible aggregation of proteins or peptides greatly limits their bioavailability; therefore, effective inhibition using small molecules or biocompatible materials is very difficult. Human calcitonin (hCT), a hormone polypeptide with 32 residues, is secreted by the C-cells of the thyroid gland. The biological function of this hormone is to regulate calcium and phosphate concentrations in the blood via several different pathways. One of these is to inhibit the activity of osteoclasts; thus, calcitonin could be used to treat osteoporosis and Paget's disease of the bone. However, hCT is prone to aggregation in aqueous solution and forms amyloid fibrils. Salmon and eel calcitonin are currently used as clinical substitutes for hCT. In a previous study, we found that the replacement of two residues at positions 12 and 17 of hCT with amino acids that appear in the salmon sequence can greatly suppress peptide aggregation. The double mutations of hCT (DM hCT) also act as good inhibitors by disrupting wild-type hCT fibrillization, although the inhibition mechanism is not clear. More importantly, we demonstrated that DM hCT is biologically active in interacting with the calcitonin receptor. To further understand the inhibitory effect of DM hCT on hCT fibrillization, we created four relevant peptide fragments based on the DM hCT sequence. Our examination revealed that the formation of a helix of DM hCT was possibly a key component contributing to its inhibitory effect. This finding could help in the development of peptide-based inhibitors and in understanding the aggregation mechanism of hCT.
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Affiliation(s)
- Ya‐Ping Chuang
- Department of ChemistryNational Taiwan Normal UniversityTaipeiTaiwan
| | - Yu‐Pei Chang
- Department of ChemistryNational Taiwan Normal UniversityTaipeiTaiwan
| | - Ling‐Hsien Tu
- Department of ChemistryNational Taiwan Normal UniversityTaipeiTaiwan
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8
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Kaur G, Mankoo OK, Goyal D, Goyal B. Unveiling How Hydroxytyrosol Destabilizes α-Syn Oligomers Using Molecular Simulations. J Phys Chem B 2023. [PMID: 37319389 DOI: 10.1021/acs.jpcb.3c02434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The etiology of Parkinson's disease (PD) is mainly linked to the α-synuclein (α-Syn) fibrillogenesis. Hydroxytyrosol (HT), also known as 3,4-dihydroxyphenylethanol, is a naturally occurring polyphenol, found in extra virgin olive oil, and has been shown to have cardioprotective, anticancer, antiobesity, and antidiabetic properties. HT has neuroprotective benefits in neurodegenerative diseases and lessens the severity of PD by reducing the aggregation of α-Syn and destabilizing the preformed toxic α-Syn oligomers. However, the molecular mechanism by which HT destabilizes α-Syn oligomers and alleviates the accompanying cytotoxicity remains unexplored. The impact of HT on the α-Syn oligomer structure and its potential binding mechanism was examined in this work by employing molecular dynamics (MD) simulations. The secondary structure analysis depicted that HT significantly reduces the β-sheet and concomitantly increases the coil content of α-Syn trimer. Visualization of representative conformations from the clustering analysis depicted the hydrogen bond interactions of the hydroxyl groups in HT with the N-terminal and nonamyloid-β component (NAC) region residues of α-Syn trimer, which, in turn, leads to the weakening of interchain interactions in α-Syn trimer and resulted in the disruption of the α-Syn oligomer. The binding free energy calculations depict that HT binds favorably to α-Syn trimer (ΔGbinding = -23.25 ± 7.86 kcal/mol) and a notable reduction in the interchain binding affinity of α-Syn trimer on the incorporation of HT, which, in turn, highlights its potential to disrupt α-Syn oligomers. The current research provided mechanistic insights into the destabilization of α-Syn trimer by HT, which, in turn, will provide new clues for developing therapeutics against PD.
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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
| | - Deepti Goyal
- Department of Chemistry, DAV College, Sector 10, Chandigarh-160011, India
| | - Bhupesh Goyal
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147004, Punjab, India
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9
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Understanding the mechanism of amylin aggregation: From identifying crucial segments to tracing dominant sequential events to modeling potential aggregation suppressors. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2023; 1871:140866. [PMID: 36272537 DOI: 10.1016/j.bbapap.2022.140866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/07/2022] [Accepted: 10/13/2022] [Indexed: 11/13/2022]
Abstract
One of the most abundant, prevailing, and life-threatening human diseases that are currently baffling the scientific community is type 2 diabetes (T2D). The self-association of human amylin has been implicated in the pathogenesis of T2D, though with an inconclusive understanding of the mechanism. Hence, we focused on the characterization of the conformational ensembles of all the species that are believed to define the structural polymorphism of the aggregation process - the functional monomeric, the initially self-associated oligomeric, and the structured protofibril - by employing near-equilibrium, non-equilibrium, and equilibrium atomistic simulations on the sporadic, two familial variants (S20G and G33R), and their proline-substituted forms (S20P and G33P). The dynamic near-equilibrium assays hint toward - the abundance of helical conformation in the monomeric state, the retainment of the helicity in the initial self-associated oligomeric phase pointing toward the existence of the helix-helix association mechanism, the difference in preference of specific segments to have definite secondary structural features, the phase-dependent variability in the dominance of specific segments and mutation sites, and the simultaneous presence of generic and unique features among various sequences. Furthermore, the non-equilibrium pulling assays exemplify a generic sequential unzipping mechanism of the protofibrils, however, the sequence-dependent uniqueness comes from the difference in location and magnitude of the control of a specific terminus. Importantly, the equilibrium thermodynamic assays efficiently rank order the potential of aggregability among sequences and consequently suggests the probability of designing effective aggregation suppressors against sporadic and familial amylin variants incorporating proline as the mutation.
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Pal T, Sahoo S, Prasad Ghanta K, Bandyopadhyay S. Computational Investigation of Conformational Fluctuations of Aβ42 Monomers in Aqueous Ionic Liquid Mixtures. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Dasari AKR, Yi S, Coats MF, Wi S, Lim KH. Toxic Misfolded Transthyretin Oligomers with Different Molecular Conformations Formed through Distinct Oligomerization Pathways. Biochemistry 2022; 61:2358-2365. [PMID: 36219173 PMCID: PMC9665167 DOI: 10.1021/acs.biochem.2c00390] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein aggregation is initiated by structural changes from native polypeptides to cytotoxic oligomers, which form cross-β structured amyloid. Identification and characterization of oligomeric intermediates are critically important for understanding not only the molecular mechanism of aggregation but also the cytotoxic nature of amyloid oligomers. Preparation of misfolded oligomers for structural characterization is, however, challenging because of their transient, heterogeneous nature. Here, we report two distinct misfolded transthyretin (TTR) oligomers formed through different oligomerization pathways. A pathogenic TTR variant with a strong aggregation propensity (L55P) was used to prepare misfolded oligomers at physiological pH. Our mechanistic studies showed that the full-length TTR initially forms small oligomers, which self-assemble into short protofibrils at later stages. Enzymatic cleavage of the CD loop was also used to induce the formation of N-terminally truncated oligomers, which was detected in ex vivo cardiac TTR aggregates extracted from the tissues of patients. Structural characterization of the oligomers using solid-state nuclear magnetic resonance and circular dichroism revealed that the two TTR misfolded oligomers have distinct molecular conformations. In addition, the proteolytically cleaved TTR oligomers exhibit a higher surface hydrophobicity, suggesting the presence of distinct oligomerization pathways for TTR oligomer formation. Cytotoxicity assays also revealed that the cytotoxicity of cleaved oligomers is stronger than that of the full-length TTR oligomers, indicating that hydrophobicity might be an important property of toxic oligomers. These comparative biophysical analyses suggest that the toxic cleaved TTR oligomers formed through a different misfoling pathway may adopt distinct structural features that produce higher surface hydrophobicity, leading to the stronger cytotoxic activities.
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Affiliation(s)
- Anvesh K. R. Dasari
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Sujung Yi
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Matthew F. Coats
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
| | - Sungsool Wi
- Interdisciplinary Magnetic Resonance (CIMAR), National High Magnetic Field Laboratory (NHMFL), 1800 East, Paul Dirac Dr., Tallahassee, FL 32310, USA
| | - Kwang Hun Lim
- Department of Chemistry, East Carolina University, Greenville, NC 27858, USA
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12
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Sonar K, Mancera RL. Characterization of the Conformations of Amyloid Beta 42 in Solution That May Mediate Its Initial Hydrophobic Aggregation. J Phys Chem B 2022; 126:7916-7933. [PMID: 36179370 DOI: 10.1021/acs.jpcb.2c04743] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intrinsically disordered peptides, such as amyloid β42 (Aβ42), lack a well-defined structure in solution. Aβ42 can undergo abnormal aggregation and amyloidogenesis in the brain, forming fibrillar plaques, a hallmark of Alzheimer's disease. The insoluble fibrillar forms of Aβ42 exhibit well-defined, cross β-sheet structures at the molecular level and are less toxic than the soluble, intermediate disordered oligomeric forms. However, the mechanism of initial interaction of monomers and subsequent oligomerization is not well understood. The structural disorder of Aβ42 adds to the challenges of determining the structural properties of its monomers, making it difficult to understand the underlying molecular mechanism of pathogenic aggregation. Certain regions of Aβ42 are known to exhibit helical propensity in different physiological conditions. NMR spectroscopy has shown that the Aβ42 monomer at lower pH can adopt an α-helical conformation and as the pH is increased, the peptide switches to β-sheet conformation and aggregation occurs. CD spectroscopy studies of aggregation have shown the presence of an initial spike in the amount of α-helical content at the start of aggregation. Such an increase in α-helical content suggests a mechanism wherein the peptide can expose critical non-polar residues for interaction, leading to hydrophobic aggregation with other interacting peptides. We have used molecular dynamics simulations to characterize in detail the conformational landscape of monomeric Aβ42 in solution to identify molecular properties that may mediate the early stages of oligomerization. We hypothesized that conformations with α-helical structure have a higher probability of initiating aggregation because they increase the hydrophobicity of the peptide. Although random coil conformations were found to be the most dominant, as expected, α-helical conformations are thermodynamically accessible, more so than β-sheet conformations. Importantly, for the first time α-helical conformations are observed to increase the exposure of aromatic and hydrophobic residues to the aqueous solvent, favoring their hydrophobically driven interaction with other monomers to initiate aggregation. These findings constitute a first step toward characterizing the mechanism of formation of disordered, low-order oligomers of Aβ42.
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Affiliation(s)
- Krushna Sonar
- Curtin Medical School, Curtin Health Innovation Research Institute, Curtin Institute for Computation, Curtin University, P. O. Box U1987, Perth, Western Australia6845, Australia
| | - Ricardo L Mancera
- Curtin Medical School, Curtin Health Innovation Research Institute, Curtin Institute for Computation, Curtin University, P. O. Box U1987, Perth, Western Australia6845, Australia
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13
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Garg DK, Bhat R. Modulation of assembly of TDP-43 low-complexity domain by heparin: From droplets to amyloid fibrils. Biophys J 2022; 121:2568-2582. [PMID: 35644946 PMCID: PMC9300664 DOI: 10.1016/j.bpj.2022.05.042] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 09/03/2021] [Accepted: 05/25/2022] [Indexed: 11/02/2022] Open
Abstract
TAR DNA-binding protein 43 (TDP-43) is an RNA-regulating protein that carries out many cellular functions through liquid-liquid phase separation (LLPS). The LLPS of TDP-43 is mediated by its C-terminal low-complexity domain (TDP43-LCD) corresponding to the region 267-414. In neurodegenerative disorders amyotrophic lateral sclerosis and frontotemporal dementia, pathological inclusions of the TDP-43 are found that are rich in the C-terminal fragments of ∼25 and ∼35 kDa, of which TDP43-LCD is a part. Thus, understanding the assembly process of TDP43-LCD is essential, given its involvement in the formation of both functional liquid-like assemblies and solid- or gel-like pathological aggregates. Here, we show that the solution pH and salt modulate TDP43-LCD LLPS. A gradual reduction in the pH below its isoelectric point of 9.8 results in a monotonic decrease of TDP43-LCD LLPS due to charge-charge repulsion between monomers, while at pH 6 and below no LLPS was observed. The addition of heparin to TDP43-LCD solution at pH 6, at a 1:2 heparin-to-TDP43-LCD molar ratio, promotes TDP43-LCD LLPS, while at higher concentration, it disrupts LLPS through a reentrant phase transition. Upon incubation at pH 6, TDP43-LCD undergoes gelation without phase separation. However, in the reentrant regime in the presence of a high heparin concentration, it forms thick amyloid aggregates that are significantly more SDS resistant than the gel. The results indicate that the material nature of the TDP43-LCD assembly products can be modulated by heparin which is significant in the context of liquid-to-solid phase transition observed in TDP-43 proteinopathies. Our findings are also crucial in relation to similar transitions that could occur due to alteration in the molecular level interactions among various multivalent biomolecules involving other LCDs and RNAs.
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Affiliation(s)
| | - Rajiv Bhat
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.
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14
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Lin Y, Ito D, Yoo JM, Lim MH, Yu W, Kawata Y, Lee YH. Dual Effects of Presynaptic Membrane Mimetics on α-Synuclein Amyloid Aggregation. Front Cell Dev Biol 2022; 10:707417. [PMID: 35747692 PMCID: PMC9209734 DOI: 10.3389/fcell.2022.707417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 05/11/2022] [Indexed: 12/25/2022] Open
Abstract
Aggregation of intrinsically disordered α-synuclein (αSN) under various conditions is closely related to synucleinopathies. Although various biological membranes have shown to alter the structure and aggregation propensity of αSN, a thorough understanding of the molecular and mechanical mechanism of amyloidogenesis in membranes remains unanswered. Herein, we examined the structural changes, binding properties, and amyloidogenicity of three variations of αSN mutants under two types of liposomes, 1,2-Dioleoyl-sn-glycero-3-Phosphocholine (DOPC) and presynaptic vesicle mimetic (Mimic) membranes. While neutrally charged DOPC membranes elicited marginal changes in the structure and amyloid fibrillation of αSNs, negatively charged Mimic membranes induced dramatic helical folding and biphasic amyloid generation. At low concentration of Mimic membranes, the amyloid fibrillation of αSNs was promoted in a dose-dependent manner. However, further increases in the concentration constrained the fibrillation process. These results suggest the dual effect of Mimic membranes on regulating the amyloidogenesis of αSN, which is rationalized by the amyloidogenic structure of αSN and condensation-dilution of local αSN concentration. Finally, we propose physicochemical properties of αSN and membrane surfaces, and their propensity to drive electrostatic interactions as decisive factors of amyloidogenesis.
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Affiliation(s)
- Yuxi Lin
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, South Korea
- Institute for Protein Research, Osaka University, Suita, Japan
- *Correspondence: Yuxi Lin, ; Young-Ho Lee,
| | - Dai Ito
- Department of Brain and Cognitive Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Je Min Yoo
- Biographene, Los Angeles, CA, United States
| | - Mi Hee Lim
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Wookyung Yu
- Department of Brain and Cognitive Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
- Core Protein Resources Center, Daegu Gyeongbuk Institute of Science and Technology, Daegu, South Korea
| | - Yasushi Kawata
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori, Japan
| | - Young-Ho Lee
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, South Korea
- Institute for Protein Research, Osaka University, Suita, Japan
- Bio-Analytical Science, University of Science and Technology, Daejeon, South Korea
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, South Korea
- Research Headquarters, Korea Brain Research Institute, Daegu, South Korea
- *Correspondence: Yuxi Lin, ; Young-Ho Lee,
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15
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Kusova A, Abramova M, Skvortsova P, Yulmetov A, Mukhametzyanov T, Klochkov V, Blokhin D. Structure of amyloidogenic PAP(85-120) peptide by high-resolution NMR spectroscopy. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.132294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Arghavani P, Badiei A, Ghadami SA, Habibi-Rezaei M, Moosavi-Movahedi F, Delphi L, Moosavi-Movahedi AA. Inhibiting mTTR Aggregation/Fibrillation by a Chaperone-like Hydrophobic Amino Acid-Conjugated SPION. J Phys Chem B 2022; 126:1640-1654. [PMID: 35090112 DOI: 10.1021/acs.jpcb.1c08796] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Transthyretin (TTR) aggregation via misfolding of a mutant or wild-type protein leads to systemic or partial amyloidosis (ATTR). Here, we utilized variable biophysical assays to characterize two distinct aggregation pathways for mTTR (a synthesized monomer TTR incapable of association into a tetramer) at pH 4.3 and also pH 7.4 with agitation, referred to as mTTR aggregation and fibrillation, respectively. The findings suggest that early-stage conformational changes termed monomer activation here determine the aggregation pathway, resulting in developing either amorphous aggregates or well-organized fibrils. Less packed partially unfolded monomers consisting of more non-regular secondary structures that were rapidly produced via a mildly acidic condition form amorphous aggregates. Meanwhile, more hydrophobic and packed monomers consisting of rearranged β sheets and increased helical content developed well-organized fibrils. Conjugating superparamagnetic iron oxide nanoparticles (SPIONs) with leucine and glutamine (L-SPIONs and G-SPIONs in order) via a trimethoxysilane linker provided the chance to study the effect of hydrophobic/hydrophilic surfaces on mTTR aggregation. The results indicated a powerful inhibitory effect of hydrophobic L-SPIONs on both mTTR aggregation and fibrillation. Monomer depletion was introduced as the governing mechanism for inhibiting mTTR aggregation, while a chaperone-like property of L-SPIONs by maintaining an mTTR native structure and adsorbing oligomers suppressed the progression of further fibril formation.
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Affiliation(s)
- Payam Arghavani
- Institute of Biochemistry and Biophysics, University of Tehran, Tehran 1417466191, Iran
| | - Alireza Badiei
- School of Chemistry, College of Science, University of Tehran, Tehran 1417614411, Iran
| | - Seyyed Abolghasem Ghadami
- Department of Biotechnology, Faculty of Biological Sciences, Alzahra University, Tehran 1993893973, Iran
| | - Mehran Habibi-Rezaei
- School of Biology, College of Science, University of Tehran, Tehran 1417614411, Iran
| | | | - Ladan Delphi
- Department of Animal Biology, College of Science, University of Tehran, Tehran 1417614411, Iran
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17
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Bhattacharya S, Xu L, Thompson D. Characterization of Amyloidogenic Peptide Aggregability in Helical Subspace. Methods Mol Biol 2022; 2340:401-448. [PMID: 35167084 DOI: 10.1007/978-1-0716-1546-1_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Prototypical amyloidogenic peptides amyloid-β (Aβ) and α-synuclein (αS) can undergo helix-helix associations via partially folded helical conformers, which may influence pathological progression to Alzheimer's (AD) and Parkinson's disease (PD), respectively. At the other extreme, stable folded helical conformers have been reported to resist self-assembly and amyloid formation. Experimental characterisation of such disparities in aggregation profiles due to subtle differences in peptide stabilities is precluded by the conformational heterogeneity of helical subspace. The diverse physical models used in molecular simulations allow sampling distinct regions of the phase space and are extensive in capturing the ensemble of rich helical subspace. Robust and powerful computational predictive methods utilizing network theory and free energy mapping can model the origin of helical population shifts in amyloidogenic peptides, which highlight their inherent aggregability. In this chapter, we discuss computational models, methods, design rules, and strategies to identify the driving force behind helical self-assembly and the molecular origin of aggregation resistance in helical intermediates of Aβ42 and αS. By extensive multiscale mapping of intrapeptide interactions, we show that the computational models can capture features that are otherwise imperceptible to experiments. Our models predict that targeting terminal residues may allow modulation and control of initial pathogenic aggregability of amyloidogenic peptides.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, Ireland.
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18
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Sorout N, Chandra A. Interactions of the Aβ(1-42) Peptide with Boron Nitride Nanoparticles of Varying Curvature in an Aqueous Medium: Different Pathways to Inhibit β-Sheet Formation. J Phys Chem B 2021; 125:11159-11178. [PMID: 34605235 DOI: 10.1021/acs.jpcb.1c05805] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The aggregation of amyloid β (Aβ) peptide triggered by its conformational changes leads to the commonly known neurodegenerative disease of Alzheimer's. It is believed that the formation of β sheets of the peptide plays a key role in its aggregation and subsequent fibrillization. In the current study, we have investigated the interactions of the Aβ(1-42) peptide with boron nitride nanoparticles and the effects of the latter on conformational transitions of the peptide through a series of molecular dynamics simulations. In particular, the effects of curvature of the nanoparticle surface are studied by considering boron nitride nanotubes (BNNTs) of varying diameter and also a planar boron nitride nanosheet (BNNS). Altogether, the current study involves the generation and analysis of 9.5 μs of dynamical trajectories of peptide-BNNT/BNNS pairs in an aqueous medium. It is found that BN nanoparticles of different curvatures that are studied in the present work inhibit the conformational transition of the peptide to its β-sheet form. However, such an inhibition effect follows different pathways for BN nanoparticles of different curvatures. For the BNNT with the highest surface curvature, i.e., (3,3) BNNT, the nanoparticle is found to inhibit β-sheet formation by stabilizing the helical structure of the peptide, whereas for planar BNNS, the β-sheet formation is prevented by making more favorable pathways available for transitions of the peptide to conformations of random coils and turns. The BNNTs with intermediate curvatures are found to exhibit diverse pathways of their interactions with the peptide, but in all cases, essentially no formation of the β sheet is found whereas substantial β-sheet formation is observed for Aβ(1-42) in water in the absence of any nanoparticle. The current study shows that BN nanoparticles have the potential to act as effective tools to prevent amyloid formation from Aβ peptides.
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Affiliation(s)
- Nidhi Sorout
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, India 208016
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, India 208016
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19
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Imanbekova M, Suarasan S, Rojalin T, Mizenko RR, Hilt S, Mathur M, Lepine P, Nicouleau M, Mohamed NV, Durcan TM, Carney RP, Voss JC, Wachsmann-Hogiu S. Identification of amyloid beta in small extracellular vesicles via Raman spectroscopy. NANOSCALE ADVANCES 2021; 3:4119-4132. [PMID: 34355118 PMCID: PMC8276787 DOI: 10.1039/d1na00330e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/07/2021] [Indexed: 05/20/2023]
Abstract
One of the hallmarks of Alzheimer's disease (AD) pathogenesis is believed to be the production and deposition of amyloid-beta (Aβ) peptide into extracellular plaques. Existing research indicates that extracellular vesicles (EVs) can carry Aβ associated with AD. However, characterization of the EVs-associated Aβ and its conformational variants has yet to be realized. Raman spectroscopy is a label-free and non-destructive method that is able to assess the biochemical composition of EVs. This study reports for the first time the Raman spectroscopic fingerprint of the Aβ present in the molecular cargo of small extracellular vesicles (sEVs). Raman spectra were measured from sEVs isolated from Alzheimer's disease cell culture model, where secretion of Aβ is regulated by tetracycline promoter, and from midbrain organoids. The averaged spectra of each sEV group showed considerable variation as a reflection of the biochemical content of sEVs. Spectral analysis identified more intense Raman peaks at 1650 cm-1 and 2930 cm-1 attributable to the Aβ peptide incorporated in sEVs produced by the Alzheimer's cell culture model. Subsequent analysis of the spectra by principal component analysis differentiated the sEVs of the Alzheimer's disease cell culture model from the control groups of sEVs. Moreover, the results indicate that Aβ associated with secreted sEVs has a α-helical secondary structure and the size of a monomer or small oligomer. Furthermore, by analyzing the lipid content of sEVs we identified altered fatty acid chain lengths in sEVs that carry Aβ that may affect the fluidity of the EV membrane. Overall, our findings provide evidence supporting the use of Raman spectroscopy for the identification and characterization of sEVs associated with potential biomarkers of neurological disorders such as toxic proteins.
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Affiliation(s)
| | - Sorina Suarasan
- Department of Bioengineering, McGill University Montreal QC H3A 0E9 Canada
| | - Tatu Rojalin
- Department of Biomedical Engineering, University of California Davis CA 95616 USA
| | - Rachel R Mizenko
- Department of Biomedical Engineering, University of California Davis CA 95616 USA
| | - Silvia Hilt
- Department of Biochemistry & Molecular Medicine, University of California Davis CA 95616 USA
| | - Meghna Mathur
- The Early Drug Discovery Unit (EDDU), Montreal Neurological Institute and Hospital, McGill University Montreal QC H3A 2B4 Canada
| | - Paula Lepine
- The Early Drug Discovery Unit (EDDU), Montreal Neurological Institute and Hospital, McGill University Montreal QC H3A 2B4 Canada
| | - Michael Nicouleau
- The Early Drug Discovery Unit (EDDU), Montreal Neurological Institute and Hospital, McGill University Montreal QC H3A 2B4 Canada
| | - Nguyen-Vi Mohamed
- The Early Drug Discovery Unit (EDDU), Montreal Neurological Institute and Hospital, McGill University Montreal QC H3A 2B4 Canada
| | - Thomas M Durcan
- The Early Drug Discovery Unit (EDDU), Montreal Neurological Institute and Hospital, McGill University Montreal QC H3A 2B4 Canada
| | - Randy P Carney
- Department of Biomedical Engineering, University of California Davis CA 95616 USA
| | - John C Voss
- Department of Biochemistry & Molecular Medicine, University of California Davis CA 95616 USA
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20
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Palanikumar L, Karpauskaite L, Al-Sayegh M, Chehade I, Alam M, Hassan S, Maity D, Ali L, Kalmouni M, Hunashal Y, Ahmed J, Houhou T, Karapetyan S, Falls Z, Samudrala R, Pasricha R, Esposito G, Afzal AJ, Hamilton AD, Kumar S, Magzoub M. Protein mimetic amyloid inhibitor potently abrogates cancer-associated mutant p53 aggregation and restores tumor suppressor function. Nat Commun 2021; 12:3962. [PMID: 34172723 PMCID: PMC8233319 DOI: 10.1038/s41467-021-23985-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 05/26/2021] [Indexed: 02/05/2023] Open
Abstract
Missense mutations in p53 are severely deleterious and occur in over 50% of all human cancers. The majority of these mutations are located in the inherently unstable DNA-binding domain (DBD), many of which destabilize the domain further and expose its aggregation-prone hydrophobic core, prompting self-assembly of mutant p53 into inactive cytosolic amyloid-like aggregates. Screening an oligopyridylamide library, previously shown to inhibit amyloid formation associated with Alzheimer's disease and type II diabetes, identified a tripyridylamide, ADH-6, that abrogates self-assembly of the aggregation-nucleating subdomain of mutant p53 DBD. Moreover, ADH-6 targets and dissociates mutant p53 aggregates in human cancer cells, which restores p53's transcriptional activity, leading to cell cycle arrest and apoptosis. Notably, ADH-6 treatment effectively shrinks xenografts harboring mutant p53, while exhibiting no toxicity to healthy tissue, thereby substantially prolonging survival. This study demonstrates the successful application of a bona fide small-molecule amyloid inhibitor as a potent anticancer agent.
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Affiliation(s)
- L Palanikumar
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Laura Karpauskaite
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Mohamed Al-Sayegh
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Ibrahim Chehade
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Maheen Alam
- Department of Biology, SBA School of Science and Engineering, Lahore University of Management Sciences, Lahore, Pakistan
| | - Sarah Hassan
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Debabrata Maity
- Department of Chemistry, New York University, New York, NY, USA
| | - Liaqat Ali
- Core Technology Platforms, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Mona Kalmouni
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Yamanappa Hunashal
- Chemistry Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.,DAME, Università di Udine, Udine, Italy
| | - Jemil Ahmed
- Department of Chemistry and Biochemistry and Knoebel Institute for Healthy Aging, The University of Denver, Denver, CO, USA
| | - Tatiana Houhou
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Shake Karapetyan
- Physics Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Zackary Falls
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), Buffalo, NY, USA
| | - Ram Samudrala
- Department of Biomedical Informatics, School of Medicine and Biomedical Sciences, State University of New York (SUNY), Buffalo, NY, USA
| | - Renu Pasricha
- Core Technology Platforms, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | - Gennaro Esposito
- Chemistry Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.,INBB, Rome, Italy
| | - Ahmed J Afzal
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates
| | | | - Sunil Kumar
- Department of Chemistry and Biochemistry and Knoebel Institute for Healthy Aging, The University of Denver, Denver, CO, USA.
| | - Mazin Magzoub
- Biology Program, Division of Science, New York University Abu Dhabi, Saadiyat Island Campus, Abu Dhabi, United Arab Emirates.
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21
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Savioli M, Antonelli L, Bocchinfuso G, Cavalieri F, Cimino R, Gatto E, Placidi E, Fernandez Masso JR, Garay Perez H, Santana H, Guerra-Vallespi M, Venanzi M. Formulation matters! A spectroscopic and molecular dynamics investigation on the peptide CIGB552 as itself and in its therapeutical formulation. J Pept Sci 2021; 28:e3356. [PMID: 34114297 DOI: 10.1002/psc.3356] [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: 02/05/2021] [Revised: 04/28/2021] [Accepted: 05/21/2021] [Indexed: 11/08/2022]
Abstract
Synthetic therapeutic peptides (STP) are intensively studied as new-generation drugs, characterized by high purity, biocompatibility, selectivity and stereochemical control. However, most of the studies are focussed on the bioactivity of STP without considering how the formulation actually used for therapy administration could alter the physico-chemical properties of the active principle. The aggregation properties of a 20-mer STP (Ac-His-Ala-Arg-Ile-Lys-D-Pro-Thr-Phe-Arg-Arg-D-Leu-Lys-Trp-Lys-Tyr-Lys-Gly-Lys-Phe-Trp-NH2 ), showing antitumor activity, were investigated by optical spectroscopy and atomic force microscopy imaging, as itself (CIGB552) and in its therapeutic formulation (CIGB552TF). It has found that the therapeutic formulation deeply affects the aggregation properties of the investigated peptide and the morphology of the aggregates formed on mica by deposition of CIGB552 and CIGB552TF millimolar solutions. Molecular dynamics simulations studied the first steps of CIGB552 aggregation under physiological ionic strength conditions (NaCl 150 mM), showing that peptide oligomers, from dimers to tetramers, are preferentially formed in this environment. Interestingly, cell viability assays performed on H-460 cell lines indicate a major antiproliferative activity of the peptide in its therapeutic formulation with respect to the peptide aqueous solution.
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Affiliation(s)
- Marco Savioli
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Lorenzo Antonelli
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Gianfranco Bocchinfuso
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Francesca Cavalieri
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy.,School of Science, RMIT University, Melbourne, Victoria, Australia
| | - Rita Cimino
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Emanuela Gatto
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
| | - Ernesto Placidi
- Department of Physics, University of Rome 'Sapienza', Rome, Italy
| | | | | | - Hector Santana
- Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | | | - Mariano Venanzi
- PEPSA-LAB, Department of Chemical Sciences and Technology, University of Rome Tor Vergata, Rome, Italy
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22
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Jain K, Ghribi O, Delhommelle J. Folding Free-Energy Landscape of α-Synuclein (35-97) Via Replica Exchange Molecular Dynamics. J Chem Inf Model 2020; 61:432-443. [PMID: 33350818 DOI: 10.1021/acs.jcim.0c01278] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The misfolding and aggregation of α-synuclein (α-syn) in Lewy bodies are implicated in the pathogenesis of various neurodegenerative disorders, such as Parkinson's disease and dementia. The formation of α-syn fibrils is a complex process, involving various intermediates and oligomeric forms. These intermediates establish at an early stage of aggregation and subsequently lead to fibrillation. Determining which conformations are accessible to monomeric α-syn and especially, as shown in a recent work, to the central amino acids from residue 35 to residue 97 (63 residues) is thus crucial to understand the formation of these oligomers. Here, we carry out extensive replica exchange molecular dynamics (total time-18 μs) with an all-atom model and explicit solvent to characterize the free-energy landscape of human α-syn (residue 35 to residue 97). The simulation results lead us to identify two free-energy basins. Clustering analysis for the deepest free-energy minimum reveals a compact structure, with a secondary structure predominantly α-helix, while the shallower minimum corresponds to an elongated conformation, also predominantly α-helix. Furthermore, at physiological temperature, we find that conformational rearrangements happen via helix breaks due to the presence of glycine. We also show that the most likely conformations are characterized by the α-helix structure rather than the β-hairpin structure (for residue 38 to residue 53), in contrast with prior simulation studies using coarse-grained models or an implicit solvent. For higher temperatures, we observe a shift in secondary structure with a decrease in the population of α-helix in favor of random coils, β-bend, and β-turns.
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Affiliation(s)
- Karnesh Jain
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Othman Ghribi
- Department of Biomedical Sciences, School of Medicine & Health Sciences, University of North Dakota, Grand Forks, North Dakota 58202, United States
| | - Jerome Delhommelle
- Department of Chemistry, University of North Dakota, Grand Forks, North Dakota 58202, United States
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23
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Saini RK, Goyal D, Goyal B. Targeting Human Islet Amyloid Polypeptide Aggregation and Toxicity in Type 2 Diabetes: An Overview of Peptide-Based Inhibitors. Chem Res Toxicol 2020; 33:2719-2738. [PMID: 33124419 DOI: 10.1021/acs.chemrestox.0c00416] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Type 2 diabetes (T2D) is a chronic metabolic disease characterized by insulin resistance and a progressive loss of pancreatic islet β-cell mass, which leads to insufficient secretion of insulin and hyperglycemia. Emerging evidence suggests that toxic oligomers and fibrils of human islet amyloid polypeptide (hIAPP) contribute to the death of β-cells and lead to T2D pathogenesis. These observations have opened new avenues for the development of islet amyloid therapies for the treatment of T2D. The peptide-based inhibitors are of great value as therapeutic agents against hIAPP aggregation in T2D owing to their biocompatibility, feasibility of synthesis and modification, high specificity, low toxicity, proteolytic stability (modified peptides), and weak immunogenicity as well as the large size of involved interfaces during self-aggregation of hIAPP. An understanding of what has been done and achieved will provide key insights into T2D pathology and assist in the discovery of more potent drug candidates for the treatment of T2D. In this article, we review various peptide-based inhibitors of hIAPP aggregation, including those derived from the hIAPP sequence and those not based on the sequence, consisting of both natural as well as unnatural amino acids and their derivatives. The present review will be beneficial in advancing the field of peptide medicine for the treatment of T2D.
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Affiliation(s)
- Rajneet Kaur Saini
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab India
| | - Deepti Goyal
- Department of Chemistry, Faculty of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib 140406, Punjab India
| | - Bhupesh Goyal
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab India
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24
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Lieblein T, Zangl R, Martin J, Hoffmann J, Hutchison MJ, Stark T, Stirnal E, Schrader T, Schwalbe H, Morgner N. Structural rearrangement of amyloid-β upon inhibitor binding suppresses formation of Alzheimer's disease related oligomers. eLife 2020; 9:59306. [PMID: 33095161 PMCID: PMC7682991 DOI: 10.7554/elife.59306] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 10/22/2020] [Indexed: 01/24/2023] Open
Abstract
The formation of oligomers of the amyloid-β peptide plays a key role in the onset of Alzheimer's disease. We describe herein the investigation of disease-relevant small amyloid-β oligomers by mass spectrometry and ion mobility spectrometry, revealing functionally relevant structural attributes. In particular, we can show that amyloid-β oligomers develop in two distinct arrangements leading to either neurotoxic oligomers and fibrils or non-toxic amorphous aggregates. Comprehending the key-attributes responsible for those pathways on a molecular level is a pre-requisite to specifically target the peptide's tertiary structure with the aim to promote the emergence of non-toxic aggregates. Here, we show for two fibril inhibiting ligands, an ionic molecular tweezer and a hydrophobic peptide that despite their different interaction mechanisms, the suppression of the fibril pathway can be deduced from the disappearance of the corresponding structure of the first amyloid-β oligomers.
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Affiliation(s)
- Tobias Lieblein
- JW Goethe-University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | - Rene Zangl
- JW Goethe-University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | - Janosch Martin
- JW Goethe-University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | - Jan Hoffmann
- JW Goethe-University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
| | - Marie J Hutchison
- JW Goethe-University, Institute for Organic Chemistry and Chemical Biology and Center for Biomolecular Magnetic Resonance, Frankfurt am Main, Germany
| | - Tina Stark
- JW Goethe-University, Institute for Organic Chemistry and Chemical Biology and Center for Biomolecular Magnetic Resonance, Frankfurt am Main, Germany
| | - Elke Stirnal
- JW Goethe-University, Institute for Organic Chemistry and Chemical Biology and Center for Biomolecular Magnetic Resonance, Frankfurt am Main, Germany
| | - Thomas Schrader
- University of Duisburg-Essen, Institute of Organic Chemistry, Essen, Germany
| | - Harald Schwalbe
- JW Goethe-University, Institute for Organic Chemistry and Chemical Biology and Center for Biomolecular Magnetic Resonance, Frankfurt am Main, Germany
| | - Nina Morgner
- JW Goethe-University, Institute of Physical and Theoretical Chemistry, Frankfurt, Germany
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25
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Landeck N, Strathearn KE, Ysselstein D, Buck K, Dutta S, Banerjee S, Lv Z, Hulleman JD, Hindupur J, Lin LK, Padalkar S, Stanciu LA, Lyubchenko YL, Kirik D, Rochet JC. Two C-terminal sequence variations determine differential neurotoxicity between human and mouse α-synuclein. Mol Neurodegener 2020; 15:49. [PMID: 32900375 PMCID: PMC7487555 DOI: 10.1186/s13024-020-00380-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND α-Synuclein (aSyn) aggregation is thought to play a central role in neurodegenerative disorders termed synucleinopathies, including Parkinson's disease (PD). Mouse aSyn contains a threonine residue at position 53 that mimics the human familial PD substitution A53T, yet in contrast to A53T patients, mice show no evidence of aSyn neuropathology even after aging. Here, we studied the neurotoxicity of human A53T, mouse aSyn, and various human-mouse chimeras in cellular and in vivo models, as well as their biochemical properties relevant to aSyn pathobiology. METHODS Primary midbrain cultures transduced with aSyn-encoding adenoviruses were analyzed immunocytochemically to determine relative dopaminergic neuron viability. Brain sections prepared from rats injected intranigrally with aSyn-encoding adeno-associated viruses were analyzed immunohistochemically to determine nigral dopaminergic neuron viability and striatal dopaminergic terminal density. Recombinant aSyn variants were characterized in terms of fibrillization rates by measuring thioflavin T fluorescence, fibril morphologies via electron microscopy and atomic force microscopy, and protein-lipid interactions by monitoring membrane-induced aSyn aggregation and aSyn-mediated vesicle disruption. Statistical tests consisted of ANOVA followed by Tukey's multiple comparisons post hoc test and the Kruskal-Wallis test followed by a Dunn's multiple comparisons test or a two-tailed Mann-Whitney test. RESULTS Mouse aSyn was less neurotoxic than human aSyn A53T in cell culture and in rat midbrain, and data obtained for the chimeric variants indicated that the human-to-mouse substitutions D121G and N122S were at least partially responsible for this decrease in neurotoxicity. Human aSyn A53T and a chimeric variant with the human residues D and N at positions 121 and 122 (respectively) showed a greater propensity to undergo membrane-induced aggregation and to elicit vesicle disruption. Differences in neurotoxicity among the human, mouse, and chimeric aSyn variants correlated weakly with differences in fibrillization rate or fibril morphology. CONCLUSIONS Mouse aSyn is less neurotoxic than the human A53T variant as a result of inhibitory effects of two C-terminal amino acid substitutions on membrane-induced aSyn aggregation and aSyn-mediated vesicle permeabilization. Our findings highlight the importance of membrane-induced self-assembly in aSyn neurotoxicity and suggest that inhibiting this process by targeting the C-terminal domain could slow neurodegeneration in PD and other synucleinopathy disorders.
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Affiliation(s)
- Natalie Landeck
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Katherine E. Strathearn
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Fujifilm Irvine Scientific, Santa Ana, CA USA
| | - Daniel Ysselstein
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Northwestern University Feinberg School of Medicine, Chicago, IL USA
| | - Kerstin Buck
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
- Present address: AbbVie Deutschland GmbH & Co KG, Ludwigshafen, Germany
| | - Sayan Dutta
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
| | - Siddhartha Banerjee
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
| | - Zhengjian Lv
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
- Present address: Bruker Nanosurfaces Division, Goleta, Santa Barbara, CA USA
| | - John D. Hulleman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Departments of Ophthalmology and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Jagadish Hindupur
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Liveon Biolabs Pvt. Ltd., Tumakuru, Karnataka India
| | - Li-Kai Lin
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
| | - Sonal Padalkar
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
- Present address: Department of Mechanical Engineering, Iowa State University, Ames, IA USA
| | - Lia A. Stanciu
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
| | - Yuri L. Lyubchenko
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
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26
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Zheng Q, Carty SN, Lazo ND. Helix Dipole and Membrane Electrostatics Delineate Conformational Transitions in the Self-Assembly of Amyloidogenic Peptides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:8389-8397. [PMID: 32628488 PMCID: PMC8095063 DOI: 10.1021/acs.langmuir.0c00723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The self-assembly of amyloidogenic peptides on membrane surfaces is associated with the death of neurons and β-cells in Alzheimer's disease and type 2 diabetes, respectively. The early events of self-assembly in vivo are not known, but there is increasing evidence for the importance of the α-helix. To test the hypothesis that electrostatic interactions involving the helix dipole play a key role in membrane-mediated peptide self-assembly, we studied IAPP[11-25(S20G)-NH2] (R11LANFLVHSGNNFGA25-NH2), which under certain conditions self-assembles in hydro to form β-sheet assemblies through an α-helix-containing intermediate. In the presence of small unilamellar vesicles composed solely of zwitterionic lipids, the peptide does not self-assemble presumably because of the absence of stabilizing electrostatic interactions between the membrane surface and the helix dipole. In the presence of vesicles composed solely of anionic lipids, the peptide forms a long-lived α-helix presumably stabilized by dipole-dipole interactions between adjacent helix dipoles. This helix represents a kinetic trap that inhibits β-sheet formation. Intriguingly, when the amount of anionic lipids was decreased to mimic the ratio of zwitterionic and anionic lipids in cells, the α-helix was short-lived and underwent an α-helix to β-sheet conformational transition. Our work suggests that the helix dipole and membrane electrostatics delineate the conformational transitions occurring along the self-assembly pathway to the amyloid.
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Affiliation(s)
- Qiuchen Zheng
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
| | - Senegal N Carty
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
| | - Noel D Lazo
- Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, United States
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27
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Bhattacharya S, Xu L, Thompson D. Long-range Regulation of Partially Folded Amyloidogenic Peptides. Sci Rep 2020; 10:7597. [PMID: 32371882 PMCID: PMC7200734 DOI: 10.1038/s41598-020-64303-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 04/15/2020] [Indexed: 01/20/2023] Open
Abstract
Neurodegeneration involves abnormal aggregation of intrinsically disordered amyloidogenic peptides (IDPs), usually mediated by hydrophobic protein-protein interactions. There is mounting evidence that formation of α-helical intermediates is an early event during self-assembly of amyloid-β42 (Aβ42) and α-synuclein (αS) IDPs in Alzheimer’s and Parkinson’s disease pathogenesis, respectively. However, the driving force behind on-pathway molecular assembly of partially folded helical monomers into helical oligomers assembly remains unknown. Here, we employ extensive molecular dynamics simulations to sample the helical conformational sub-spaces of monomeric peptides of both Aβ42 and αS. Our computed free energies, population shifts, and dynamic cross-correlation network analyses reveal a common feature of long-range intra-peptide modulation of partial helical folds of the amyloidogenic central hydrophobic domains via concerted coupling with their charged terminal tails (N-terminus of Aβ42 and C-terminus of αS). The absence of such inter-domain fluctuations in both fully helical and completely unfolded (disordered) states suggests that long-range coupling regulates the dynamicity of partially folded helices, in both Aβ42 and αS peptides. The inter-domain coupling suggests a form of intra-molecular allosteric regulation of the aggregation trigger in partially folded helical monomers. This approach could be applied to study the broad range of amyloidogenic peptides, which could provide a new path to curbing pathogenic aggregation of partially folded conformers into oligomers, by inhibition of sites far from the hydrophobic core.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick, V94 T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick, V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick, V94 T9PX, Ireland.
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28
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Sorout N, Chandra A. Effects of Boron Nitride Nanotube on the Secondary Structure of Aβ(1–42) Trimer: Possible Inhibitory Effect on Amyloid Formation. J Phys Chem B 2020; 124:1928-1940. [DOI: 10.1021/acs.jpcb.9b11986] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Nidhi Sorout
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Amalendu Chandra
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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29
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Kurimitsu N, Mizuguchi C, Fujita K, Taguchi S, Ohgita T, Nishitsuji K, Shimanouchi T, Saito H. Phosphatidylethanolamine accelerates aggregation of the amyloidogenic N-terminal fragment of apoA-I. FEBS Lett 2020; 594:1443-1452. [PMID: 31968125 DOI: 10.1002/1873-3468.13737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/28/2019] [Accepted: 01/02/2020] [Indexed: 12/13/2022]
Abstract
Membrane lipid composition is known to influence aggregation and fibril formation of many amyloidogenic proteins. Here, we found that phosphatidylethanolamine (PE) accelerates aggregation of the N-terminal 1-83 fragment of an amyloidogenic G26R variant of apoA-I on lipid membranes. Circular dichroism and isothermal titration calorimetry measurements demonstrated that PE does not affect the α-helical structure and lipid binding property of apoA-I 1-83/G26R. Rather, fluorescence measurements indicated that PE induces more ordered lipid packing at the interfacial and acyl chain regions, providing more hydrophobic environments especially around the highly amyloidogenic regions in apoA-I on the membrane surface. These results suggest that PE promotes aggregation of the amyloidogenic N-terminal fragment of apoA-I on lipid membranes by inducing hydrophobic membrane environments.
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Affiliation(s)
- Naoko Kurimitsu
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Chiharu Mizuguchi
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kaho Fujita
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Suzuno Taguchi
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Takashi Ohgita
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
| | | | - Toshinori Shimanouchi
- Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan
| | - Hiroyuki Saito
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, Kyoto, Japan
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30
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Mohankumar T, Chandramohan V, Lalithamba HS, Jayaraj RL, Kumaradhas P, Sivanandam M, Hunday G, Vijayakumar R, Balakrishnan R, Manimaran D, Elangovan N. Design and Molecular dynamic Investigations of 7,8-Dihydroxyflavone Derivatives as Potential Neuroprotective Agents Against Alpha-synuclein. Sci Rep 2020; 10:599. [PMID: 31953434 PMCID: PMC6969171 DOI: 10.1038/s41598-020-57417-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/28/2019] [Indexed: 11/09/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder caused due to loss of dopaminergic neurons in substantia nigra pars compacta, which occurs the presence of Lewy bodies made up of Alpha-synuclein (ASN) aggregation resulting in neuronal death. This study aims to identify potent 7,8-Dihydroxyflavone (DHF) derivatives to inhibit the ASN aggregation from in silico analysis. Molecular docking study reveals that carbamic ester derivatives of DHF [DHF-BAHPC (8q), DHF-BAHPEC (8s), DHF-BAHEC (8p), DHF-BDOPC (8c), DHF-BAPEC (8n) and DHF-BAMC (8h)] have good binding affinity towards ASN, when compared with DHF and L-DOPA; their docking score values are -16.3120, -16.1875, -15.2223, -14.3118, -14.2893, -14.2810, -14.0383, and -9.1560 kcal/mol respectively. The in silico pharmacological evaluation shows that these molecules exhibit the drug-likeness and ADMET properties. Molecular dynamics simulation confirms the stability of the molecules with ASN. The intermolecular interaction analyzed under the dynamic condition, allows to identify the candidate which potentially inhibits ASN aggregation. Hence, we propose that DHF derivatives are the potential lead drug molecules and preclinical studies are needed to confirm the promising therapeutic ability against PD.
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Affiliation(s)
- Thangavel Mohankumar
- Department of Biotechnology, School of Biosciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Vivek Chandramohan
- Department of Biotechnology, Siddaganga Institute of Technology, Tumakuru, 572103, Karnataka, India
| | | | - Richard L Jayaraj
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, Al-Ain, Abudhabi, 17666, United Arab Emirates
| | - Poomani Kumaradhas
- Department of Physics, School of Physical Sciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Magudeeswaran Sivanandam
- Department of Physics, School of Physical Sciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Govindasamy Hunday
- Department of Physics, School of Physical Sciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Rajendran Vijayakumar
- Department of Biology, College of Science in Zulfi, Majmaah University, Majmaah, 11952, Saudi Arabia
| | - Rangasamy Balakrishnan
- Department of Biotechnology, School of Biosciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Dharmar Manimaran
- Department of Biotechnology, School of Biosciences, Periyar University, Salem, 636011, Tamilnadu, India
| | - Namasivayam Elangovan
- Department of Biotechnology, School of Biosciences, Periyar University, Salem, 636011, Tamilnadu, India.
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31
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Vincenzi M, Mercurio FA, Leone M. About TFE: Old and New Findings. Curr Protein Pept Sci 2019; 20:425-451. [PMID: 30767740 DOI: 10.2174/1389203720666190214152439] [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: 07/04/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 01/28/2023]
Abstract
The fluorinated alcohol 2,2,2-Trifluoroethanol (TFE) has been implemented for many decades now in conformational studies of proteins and peptides. In peptides, which are often disordered in aqueous solutions, TFE acts as secondary structure stabilizer and primarily induces an α -helical conformation. The exact mechanism through which TFE plays its stabilizing roles is still debated and direct and indirect routes, relying either on straight interaction between TFE and molecules or indirect pathways based on perturbation of solvation sphere, have been proposed. Another still unanswered question is the capacity of TFE to favor in peptides a bioactive or a native-like conformation rather than simply stimulate the raise of secondary structure elements that reflect only the inherent propensity of a specific amino-acid sequence. In protein studies, TFE destroys unique protein tertiary structure and often leads to the formation of non-native secondary structure elements, but, interestingly, gives some hints about early folding intermediates. In this review, we will summarize proposed mechanisms of TFE actions. We will also describe several examples, in which TFE has been successfully used to reveal structural properties of different molecular systems, including antimicrobial and aggregation-prone peptides, as well as globular folded and intrinsically disordered proteins.
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Affiliation(s)
- Marian Vincenzi
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy
| | - Flavia A Mercurio
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy.,Cirpeb, InterUniversity Research Centre on Bioactive Peptides, University of Naples "Federico II", Via Mezzocannone 16, 80134 Naples, Italy
| | - Marilisa Leone
- Institute of Biostructures and Bioimaging, National Research Council (CNR), Via Mezzocannone 16, 80134 Naples, Italy.,Cirpeb, InterUniversity Research Centre on Bioactive Peptides, University of Naples "Federico II", Via Mezzocannone 16, 80134 Naples, Italy
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32
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Lin Y, Sahoo BR, Ozawa D, Kinoshita M, Kang J, Lim MH, Okumura M, Huh YH, Moon E, Jang JH, Lee HJ, Ryu KY, Ham S, Won HS, Ryu KS, Sugiki T, Bang JK, Hoe HS, Fujiwara T, Ramamoorthy A, Lee YH. Diverse Structural Conversion and Aggregation Pathways of Alzheimer's Amyloid-β (1-40). ACS NANO 2019; 13:8766-8783. [PMID: 31310506 DOI: 10.1021/acsnano.9b01578] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Complex amyloid aggregation of amyloid-β (1-40) (Aβ1-40) in terms of monomer structures has not been fully understood. Herein, we report the microscopic mechanism and pathways of Aβ1-40 aggregation with macroscopic viewpoints through tuning its initial structure and solubility. Partial helical structures of Aβ1-40 induced by low solvent polarity accelerated cytotoxic Aβ1-40 amyloid fibrillation, while predominantly helical folds did not aggregate. Changes in the solvent polarity caused a rapid formation of β-structure-rich protofibrils or oligomers via aggregation-prone helical structures. Modulation of the pH and salt concentration transformed oligomers to protofibrils, which proceeded to amyloid formation. We reveal diverse molecular mechanisms underlying Aβ1-40 aggregation with conceptual energy diagrams and propose that aggregation-prone partial helical structures are key to inducing amyloidogenesis. We demonstrate that context-dependent protein aggregation is comprehensively understood using the macroscopic phase diagram, which provides general insights into differentiation of amyloid formation and phase separation from unfolded and folded structures.
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Affiliation(s)
- Yuxi Lin
- Department of Chemistry , Sookmyung Women's University , Cheongpa-ro 47-gil 100 , Yongsan-gu, Seoul 04310 , South Korea
| | - Bikash R Sahoo
- Biophysics Program and Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Daisaku Ozawa
- Department of Neurotherapeutics , Osaka University Graduate School of Medicine , 2-2 Yamadaoka , Suita , Osaka 565-0871 , Japan
| | - Misaki Kinoshita
- Frontier Research Institute for Interdisciplinary Sciences , Tohoku University , 6-3 Aramaki-Aza-Aoba , Aoba-ku, Sendai 980-8578 , Japan
| | - Juhye Kang
- Department of Chemistry , Korea Advanced Institute of Science and Technology , Daejeon 34141 , South Korea
- Department of Chemistry , Ulsan National Institute of Science and Technology , Ulsan 44919 , South Korea
| | - Mi Hee Lim
- Department of Chemistry , Korea Advanced Institute of Science and Technology , Daejeon 34141 , South Korea
| | - Masaki Okumura
- Frontier Research Institute for Interdisciplinary Sciences , Tohoku University , 6-3 Aramaki-Aza-Aoba , Aoba-ku, Sendai 980-8578 , Japan
| | | | | | | | - Hyun-Ju Lee
- Department of Neural Development and Disease , Korea Brain Research Institute , 61 Cheomdan-ro , Dong-gu, Daegu 41068 , South Korea
| | - Ka-Young Ryu
- Department of Neural Development and Disease , Korea Brain Research Institute , 61 Cheomdan-ro , Dong-gu, Daegu 41068 , South Korea
| | - Sihyun Ham
- Department of Chemistry , Sookmyung Women's University , Cheongpa-ro 47-gil 100 , Yongsan-gu, Seoul 04310 , South Korea
| | - Hyung-Sik Won
- Department of Biotechnology, Research Institute and College of Biomedical and Health Science , Konkuk University , Chungju , Chungbuk 27478 , South Korea
| | | | - Toshihiko Sugiki
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
| | | | - Hyang-Sook Hoe
- Department of Neural Development and Disease , Korea Brain Research Institute , 61 Cheomdan-ro , Dong-gu, Daegu 41068 , South Korea
| | - Toshimichi Fujiwara
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
| | - Ayyalusamy Ramamoorthy
- Biophysics Program and Department of Chemistry, Biomedical Engineering, and Macromolecular Science and Engineering , University of Michigan , Ann Arbor , Michigan 48109-1055 , United States
| | - Young-Ho Lee
- Institute for Protein Research , Osaka University , Yamadaoka 3-2 , Suita , Osaka 565-0871 , Japan
- Bio-Analytical Science , University of Science and Technology , Daejeon 34113 , South Korea
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33
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John T, Dealey TJA, Gray NP, Patil NA, Hossain MA, Abel B, Carver JA, Hong Y, Martin LL. The Kinetics of Amyloid Fibrillar Aggregation of Uperin 3.5 Is Directed by the Peptide’s Secondary Structure. Biochemistry 2019; 58:3656-3668. [DOI: 10.1021/acs.biochem.9b00536] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Torsten John
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
- Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, 04318 Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - Tiara J. A. Dealey
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Nicholas P. Gray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Nitin A. Patil
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Mohammed A. Hossain
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Bernd Abel
- Leibniz Institute of Surface Engineering (IOM), Permoserstraße 15, 04318 Leipzig, Germany
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Linnéstraße 3, 04103 Leipzig, Germany
| | - John A. Carver
- Research School of Chemistry, The Australian National University, Acton, Australian Capital Territory 2601, Australia
| | - Yuning Hong
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Lisandra L. Martin
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
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34
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Bhattacharya S, Xu L, Thompson D. Molecular Simulations Reveal Terminal Group Mediated Stabilization of Helical Conformers in Both Amyloid-β42 and α-Synuclein. ACS Chem Neurosci 2019; 10:2830-2842. [PMID: 30917651 DOI: 10.1021/acschemneuro.9b00053] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The presence of partially structured helices in natively unfolded amyloid-β42 (Aβ42) and α-synuclein (αS) has been shown to accelerate fibrillation in the onset of Alzheimer's and Parkinson's disease, respectively. At the other extreme, folded stable helical conformers have also been reported to resist amyloid formation. Recent studies indicate that amyloidogenic aggregation can be impeded using small molecules that stabilize the α-helical monomers and switch off the neurotoxic pathway. We predict a common intrapeptide route to stabilization based on the plasticity of helical conformations of Aβ42 and αS as assessed through extensive atomistic molecular dynamics (MD) computer simulations (∼36 μs) across ten distinct protein force field and water model combinations. Computed free energies and interaction maps (not obtainable from experiments alone) show that flexible terminal groups (N-terminus of Aβ42 and C-terminus of αS) show a tendency to stabilize folded helical conformations in both peptides via primary hydrophobic interactions with central hydrophobic domains, and secondary salt bridges with other domains. These interactions confer aggregation resistance by decreasing the population of partially structured helices and are absent in control simulations of complete unfolding. Computed helical stability is also significantly reduced in terminal-deleted variants. The models suggest new strategies to tackle neurodegeneration by rationally re-engineering terminal groups to optimize their predicted ability to deactivate helical monomers.
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Affiliation(s)
- Shayon Bhattacharya
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Damien Thompson
- Department of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
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Khatua P, Mondal S, Bandyopadhyay S. Effects of Metal Ions on Aβ 42 Peptide Conformations from Molecular Simulation Studies. J Chem Inf Model 2019; 59:2879-2893. [PMID: 31095382 DOI: 10.1021/acs.jcim.9b00098] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In this study, we investigate the conformational characteristics of full-length Aβ42 peptide monomers in the presence of Na+ and Zn2+ metal ions using atomistic molecular dynamics (MD) simulations with an aim to explore the possible driving forces behind enhanced aggregation rates of the peptides in the presence of salts. The calculations reveal that the presence of metal ions shifts the conformational equilibrium more toward the compact ordered Aβ structures. Such compact ordered structures stabilized by distant nonlocal contacts between two crucial hydrophobic segments, hp1 and hp2, primarily through two important hydrophobic aromatic residues, Phe-19 and Phe-20, are expected to trigger the aggregation process at a faster rate by populating and stabilizing the aggregation prone structures. Formation of a significant number of such distant contacts in the presence of Na+ ions has also been found to result in breaking of the N-terminal helix. On the contrary, binding of Zn2+ ion to Aβ peptide is highly specific, which stabilizes the N-terminal helix instead of breaking it. This explains why the aggregation rate of Aβ peptides is higher in the presence of divalent Zn2+ ions than monovalent Na+ ions. Relatively higher overall stability of the most populated Aβ peptide monomers in the presence of Zn2+ ions has been found to be associated with specific Zn2+-Aβ binding and significant free energy gain.
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Affiliation(s)
- Prabir Khatua
- Molecular Modeling Laboratory, Department of Chemistry , Indian Institute of Technology , Kharagpur 721302 , India
| | - Souvik Mondal
- Molecular Modeling Laboratory, Department of Chemistry , Indian Institute of Technology , Kharagpur 721302 , India
| | - Sanjoy Bandyopadhyay
- Molecular Modeling Laboratory, Department of Chemistry , Indian Institute of Technology , Kharagpur 721302 , India.,Centre for Computational and Data Sciences , Indian Institute of Technology , Kharagpur 721302 , India
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Sun Y, Kakinen A, Xing Y, Faridi P, Nandakumar A, Purcell AW, Davis TP, Ke PC, Ding F. Amyloid Self-Assembly of hIAPP8-20 via the Accumulation of Helical Oligomers, α-Helix to β-Sheet Transition, and Formation of β-Barrel Intermediates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1805166. [PMID: 30908844 PMCID: PMC6499678 DOI: 10.1002/smll.201805166] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 02/21/2019] [Indexed: 05/19/2023]
Abstract
The self-assembly of human islet amyloid polypeptide (hIAPP) into β-sheet-rich nanofibrils is associated with the pathogeny of type 2 diabetes. Soluble hIAPP is intrinsically disordered with N-terminal residues 8-17 as α-helices. To understand the contribution of the N-terminal helix to the aggregation of full-length hIAPP, here the oligomerization dynamics of the hIAPP fragment 8-20 (hIAPP8-20) are investigated with combined computational and experimental approaches. hIAPP8-20 forms cross-β nanofibrils in silico from isolated helical monomers via the helical oligomers and α-helices to β-sheets transition, as confirmed by transmission electron microscopy, atomic force microscopy, circular dichroism spectroscopy, Fourier transform infrared spectroscopy, and reversed-phase high performance liquid chromatography. The computational results also suggest that the critical nucleus of aggregation corresponds to hexamers, consistent with a recent mass-spectroscopy study of hIAPP8-20 aggregation. hIAPP8-20 oligomers smaller than hexamers are helical and unstable, while the α-to-β transition starts from the hexamers. Converted β-sheet-rich oligomers first form β-barrel structures as intermediates before aggregating into cross-β nanofibrils. This study uncovers a complete picture of hIAPP8-20 peptide oligomerization, aggregation nucleation via conformational conversion, formation of β-barrel intermediates, and assembly of cross-β protofibrils, thereby shedding light on the aggregation of full-length hIAPP, a hallmark of pancreatic beta-cell degeneration.
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Affiliation(s)
- Yunxiang Sun
- Department of Physics, Faculty of Science, Ningbo University, Ningbo 315211, China
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Aleksandr Kakinen
- 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
| | - Yanting Xing
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29634, USA
| | - Pouya Faridi
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Aparna Nandakumar
- 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
| | - Anthony W. Purcell
- Infection and Immunity Program & Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - 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
| | - 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 29634, USA
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Martial B, Lefèvre T, Buffeteau T, Auger M. Vibrational Circular Dichroism Reveals Supramolecular Chirality Inversion of α-Synuclein Peptide Assemblies upon Interactions with Anionic Membranes. ACS NANO 2019; 13:3232-3242. [PMID: 30811930 DOI: 10.1021/acsnano.8b08932] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Parkinson's disease is an incurable neurodegenerative disorder caused by the aggregation of α-synuclein (AS). This amyloid protein contains a 12-residue-long segment, AS71-82, that triggers AS pathological aggregation. This peptide is then essential to better understand the polymorphism and the dynamics of formation of AS fibrillar structures. In this work, vibrational circular dichroism showed that AS71-82 is random coil in solution and forms parallel β-sheet fibrillar aggregates in the presence of anionic vesicles. Vibrational circular dichroism, with transmission electronic microscopy, revealed that the fibrillar structures exhibit a nanoscale tape-like morphology with a preferential supramolecular helicity. Whereas the structure handedness of some other amyloid peptides has been shown to be driven by pH, that of AS71-82 is controlled by peptide concentration and peptide-to-lipid (P:L) molar ratio. At low concentrations and low P:L molar ratios, AS71-82 assemblies have a left-twisted handedness, whereas at high concentrations and high P:L ratios, a right-twisted handedness is adopted. Left-twisted assemblies interconvert into right-twisted ones with time, suggesting a maturation of the amyloid structures. As fibril species with two chiralities have also been reported previously in Parkinson's disease Lewy bodies and fibrils, the present results seem relevant to better understand AS amyloid assembly and fibrillization in vivo. From a diagnosis or therapeutic point of view, it becomes essential that future fibril probes, inhibitors, or breakers target pathological assemblies with specific chirality and morphology, in particular, because they may change with the stage of the disease.
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Affiliation(s)
- Benjamin Martial
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF) , Université Laval , Québec , QC G1 V 0A6 , Canada
| | - Thierry Lefèvre
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF) , Université Laval , Québec , QC G1 V 0A6 , Canada
| | - Thierry Buffeteau
- Université Bordeaux , Institut des Sciences Moléculaires, CNRS UMR 5255, 33405 Talence , France
| | - Michèle Auger
- Department of Chemistry, Regroupement québécois de recherche sur la fonction, l'ingénierie et les applications des protéines (PROTEO), Centre de recherche sur les matériaux avancés (CERMA), Centre québécois sur les matériaux fonctionnels (CQMF) , Université Laval , Québec , QC G1 V 0A6 , Canada
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Su X, Wang K, Liu N, Chen J, Li Y, Duan M. All‐atom structure ensembles of islet amyloid polypeptides determined by enhanced sampling and experiment data restraints. Proteins 2019; 87:541-550. [DOI: 10.1002/prot.25677] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/22/2018] [Accepted: 02/17/2019] [Indexed: 01/28/2023]
Affiliation(s)
- Xinyue Su
- CAS Key Laboratory of magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in WuhanWuhan Institute of Physics and Mathematics, Chinese Academy of Sciences Wuhan China
- Department of PhysicsCentral China Normal University Wuhan China
| | - Ke Wang
- CAS Key Laboratory of magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in WuhanWuhan Institute of Physics and Mathematics, Chinese Academy of Sciences Wuhan China
- Department of ChemistryUniversity of Chinese Academy of Sciences Beijing China
| | - Na Liu
- CAS Key Laboratory of magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in WuhanWuhan Institute of Physics and Mathematics, Chinese Academy of Sciences Wuhan China
- Department of ChemistryUniversity of Chinese Academy of Sciences Beijing China
| | - Jiawen Chen
- CAS Key Laboratory of magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in WuhanWuhan Institute of Physics and Mathematics, Chinese Academy of Sciences Wuhan China
| | - Yong Li
- Department of PhysicsCentral China Normal University Wuhan China
| | - Mojie Duan
- CAS Key Laboratory of magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in WuhanWuhan Institute of Physics and Mathematics, Chinese Academy of Sciences Wuhan China
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Synthesis and identification of novel pyridazinylpyrazolone based diazo compounds as inhibitors of human islet amyloid polypeptide aggregation. Bioorg Chem 2019; 84:339-346. [DOI: 10.1016/j.bioorg.2018.11.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 11/17/2018] [Accepted: 11/24/2018] [Indexed: 02/06/2023]
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40
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Kumar V, Gour S, Verma N, Kumar S, Gadhave K, Mishra PM, Goyal P, Pandey J, Giri R, Yadav JK. The mechanism of phosphatidylcholine-induced interference of PAP (248-286) aggregation. J Pept Sci 2019; 25:e3152. [PMID: 30784133 DOI: 10.1002/psc.3152] [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: 11/06/2018] [Revised: 01/02/2019] [Accepted: 01/02/2019] [Indexed: 12/29/2022]
Abstract
Seminal amyloids are well known for their role in enhancing HIV infection. Among all the amyloidogenic peptides identified in human semen, PAP248-286 was found to be the most active and was termed as semen-derived enhancer of viral infection (SEVI). Although amyloidogenic nature of the peptide is mainly linked with enhancement of the viral infection, the most active physiological conformation of the aggregated peptide remains inconclusive. Lipids are known to modulate aggregation pathway of a variety of proteins and peptides and constitute one of the most abundant biomolecules in human semen. PAP248-286 significantly differs from the other known amyloidogenic peptides, including Aβ and IAPP, in terms of critical concentration, surface charge, fibril morphology, and structural transition during aggregation. Hence, in the present study, we aimed to assess the effect of a lipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), on PAP248-286 aggregation and the consequent conformational outcomes. Our initial observation suggested that the presence of the lipid considerably influenced the aggregation of PAP248-286 . Further, ZDOCK and MD simulation studies of peptide multimerization have suggested that the hydrophobic residues at C-terminus are crucial for PAP248-286 aggregation and are anticipated to be major DOPC-interacting partners. Therefore, we further assessed the aggregation behaviour of C-terminal (PAP273-286 ) fragment of PAP248-286 and observed that DOPC possesses the ability to interfere with the aggregation behaviour of both the peptides used in the current study. Mechanistically, we propose that the presence of DOPC causes considerable inhibition of the peptide aggregation by interfering with the peptide's disordered state to β-sheet transition.
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Affiliation(s)
- Vijay Kumar
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Shalini Gour
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Nidhi Verma
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Suman Kumar
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Kundlik Gadhave
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, India
| | | | - Pankaj Goyal
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Janmejay Pandey
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
| | - Rajanish Giri
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, India
| | - Jay Kant Yadav
- Department of Biotechnology, Central University of Rajasthan, Ajmer, India
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41
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Modulation of the aggregation of an amyloidogenic sequence by flanking-disordered region in the intrinsically disordered antigen merozoite surface protein 2. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 48:99-110. [PMID: 30443712 DOI: 10.1007/s00249-018-1337-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/31/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
The abundant Plasmodium falciparum merozoite surface protein MSP2, a potential malaria vaccine candidate, is an intrinsically disordered protein with some nascent secondary structure present in its conserved N-terminal region. This relatively ordered region has been implicated in both membrane interactions and amyloid-like aggregation of the protein, while the significance of the flanking-disordered region is unclear. In this study, we show that aggregation of the N-terminal conserved region of MSP2 is influenced in a length- and sequence-dependent fashion by the disordered central variable sequences. Intriguingly, MSP2 peptides containing the conserved region and the first five residues of the variable disordered regions aggregated more rapidly than a peptide corresponding to the conserved region alone. In contrast, MSP2 peptides extending 8 or 12 residues into the disordered region aggregated more slowly, consistent with the expected inhibitory effect of flanking-disordered sequences on the aggregation of amyloidogenic ordered sequences. Computational analyses indicated that the helical propensity of the ordered region of MSP2 was modulated by the adjacent disordered five residues in a sequence-dependent manner. Nuclear magnetic resonance and circular dichroism spectroscopic studies with synthetic peptides confirmed the computational predictions, emphasizing the correlation between aggregation propensity and conformation of the ordered region and the effects thereon of the adjacent disordered region. These results show that the effects of flanking-disordered sequences on a more ordered sequence may include enhancement of aggregation through modulation of the conformational properties of the more ordered sequence.
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42
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An in-silico method for identifying aggregation rate enhancer and mitigator mutations in proteins. Int J Biol Macromol 2018; 118:1157-1167. [DOI: 10.1016/j.ijbiomac.2018.06.102] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 12/27/2022]
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43
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Analysis of multiply charged monomers and dimers of human islet amyloid polypeptide by collision-induced dissociation with electrospray ionization mass spectrometry. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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44
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IAPP in type II diabetes: Basic research on structure, molecular interactions, and disease mechanisms suggests potential intervention strategies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018. [DOI: 10.1016/j.bbamem.2018.02.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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45
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Moore SJ, Sonar K, Bharadwaj P, Deplazes E, Mancera RL. Characterisation of the Structure and Oligomerisation of Islet Amyloid Polypeptides (IAPP): A Review of Molecular Dynamics Simulation Studies. Molecules 2018; 23:E2142. [PMID: 30149632 PMCID: PMC6225196 DOI: 10.3390/molecules23092142] [Citation(s) in RCA: 23] [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: 08/08/2018] [Revised: 08/21/2018] [Accepted: 08/22/2018] [Indexed: 12/26/2022] Open
Abstract
Human islet amyloid polypeptide (hIAPP) is a naturally occurring, intrinsically disordered protein whose abnormal aggregation into amyloid fibrils is a pathological feature in type 2 diabetes, and its cross-aggregation with amyloid beta has been linked to an increased risk of Alzheimer's disease. The soluble, oligomeric forms of hIAPP are the most toxic to β-cells in the pancreas. However, the structure of these oligomeric forms is difficult to characterise because of their intrinsic disorder and their tendency to rapidly aggregate into insoluble fibrils. Experimental studies of hIAPP have generally used non-physiological conditions to prevent aggregation, and they have been unable to describe its soluble monomeric and oligomeric structure at physiological conditions. Molecular dynamics (MD) simulations offer an alternative for the detailed characterisation of the monomeric structure of hIAPP and its aggregation in aqueous solution. This paper reviews the knowledge that has been gained by the use of MD simulations, and its relationship to experimental data for both hIAPP and rat IAPP. In particular, the influence of the choice of force field and water models, the choice of initial structure, and the configurational sampling method used, are discussed in detail. Characterisation of the solution structure of hIAPP and its mechanism of oligomerisation is important to understanding its cellular toxicity and its role in disease states, and may ultimately offer new opportunities for therapeutic interventions.
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Affiliation(s)
- Sandra J Moore
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Krushna Sonar
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Prashant Bharadwaj
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
- Centre of Excellence for Alzheimer's Disease Research and Care, School of Medical and Health Sciences, 270 Joondalup Drive, Edith Cowan University, Joondalup, WA 6027, Australia.
| | - Evelyne Deplazes
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
| | - Ricardo L Mancera
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
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46
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Kar RK, Brender JR, Ghosh A, Bhunia A. Nonproductive Binding Modes as a Prominent Feature of Aβ 40 Fiber Elongation: Insights from Molecular Dynamics Simulation. J Chem Inf Model 2018; 58:1576-1586. [PMID: 30047732 DOI: 10.1021/acs.jcim.8b00169] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The formation of amyloid fibers has been implicated in a number of neurodegenerative diseases. The growth of amyloid fibers is strongly thermodynamically favorable, but kinetic traps exist where the incoming monomer binds in an incompatible conformation that blocks further elongation. Unfortunately, this process is difficult to follow experimentally at the atomic level. It is also too complex to simulate in full detail and to date has been explored either through coarse-grained simulations, which may miss many important interactions, or full atomic simulations, in which the incoming peptide is constrained to be near the ideal fiber geometry. Here we use an alternate approach starting from a docked complex in which the monomer is from an experimental NMR structure of one of the major conformations in the unbound ensemble, a largely unstructured peptide with the central hydrophobic region in a 310 helix. A 1000 ns full atomic simulation in explicit solvent shows the formation of a metastable intermediate by sequential, concerted movements of both the fiber and the monomer. A Markov state model shows that the unfolded monomer is trapped at the end of the fiber in a set of interconverting antiparallel β-hairpin conformations. The simulation here may serve as a model for the binding of other non-β-sheet conformations to amyloid fibers.
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Affiliation(s)
- Rajiv K Kar
- Department of Biophysics , Bose Institute , P-1/12 CIT Scheme VII (M) , Kolkata 700054 , India
| | - Jeffrey R Brender
- Radiation Biology Branch , National Institutes of Health , Bethesda , Maryland 20814 , United States
| | - Anirban Ghosh
- Department of Biophysics , Bose Institute , P-1/12 CIT Scheme VII (M) , Kolkata 700054 , India
| | - Anirban Bhunia
- Department of Biophysics , Bose Institute , P-1/12 CIT Scheme VII (M) , Kolkata 700054 , India
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47
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Xu L, Bhattacharya S, Thompson D. Re-designing the α-synuclein tetramer. Chem Commun (Camb) 2018; 54:8080-8083. [PMID: 29971274 DOI: 10.1039/c8cc04054k] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A computationally re-designed molecular loop optimizes helical packing of α-synuclein monomers to seal the aggregation-resistant low-weight tetramer, a key target for Parkinson's disease. Helical monomers are pushed into active conformations during supramolecular assembly, and familial missense mutations double the energy barrier to tetramerization, preserving the pool of potentially amyloidogenic monomers.
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Affiliation(s)
- Liang Xu
- Department of Physics, Bernal Institute, University of Limerick, V94 T9PX, Ireland.
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48
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Abedini A, Derk J, Schmidt AM. The receptor for advanced glycation endproducts is a mediator of toxicity by IAPP and other proteotoxic aggregates: Establishing and exploiting common ground for novel amyloidosis therapies. Protein Sci 2018; 27:1166-1180. [PMID: 29664151 PMCID: PMC6032365 DOI: 10.1002/pro.3425] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 12/23/2022]
Abstract
Proteotoxicity plays a key role in many devastating human disorders, including Alzheimer's, Huntington's and Parkinson's diseases; type 2 diabetes; systemic amyloidosis; and cardiac dysfunction, to name a few. The cellular mechanisms of proteotoxicity in these disorders have been the focus of considerable research, but their role in prevalent and morbid disorders, such as diabetes, is less appreciated. There is a large body of literature on the impact of glucotoxicity and lipotoxicity on insulin-producing pancreatic β-cells, and there is increasing recognition that proteotoxicty plays a key role. Pancreatic islet amyloidosis by the hormone IAPP, the production of advanced glycation endproducts (AGE), and insulin misprocessing into cytotoxic aggregates are all sources of β-cell proteotoxicity in diabetes. AGE, produced by the reaction of reducing sugars with proteins and lipids are ligands for the receptor for AGE (RAGE), as are the toxic pre-fibrillar aggregates of IAPP produced during amyloid formation. The mechanisms of amyloid formation by IAPP in vivo or in vitro are not well understood, and the cellular mechanisms of IAPP-induced β-cell death are not fully defined. Here, we review recent findings that illuminate the factors and mechanisms involved in β-cell proteotoxicity in diabetes. Together, these new insights have far-reaching implications for the establishment of unifying mechanisms by which pathological amyloidoses imbue their injurious effects in vivo.
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Affiliation(s)
- Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
| | - Julia Derk
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Department of MedicineNew York University Medical Center, 550 First Avenue, Smilow 906New YorkNew York10016
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Ridgway Z, Zhang X, Wong AG, Abedini A, Schmidt AM, Raleigh DP. Analysis of the Role of the Conserved Disulfide in Amyloid Formation by Human Islet Amyloid Polypeptide in Homogeneous and Heterogeneous Environments. Biochemistry 2018; 57:3065-3074. [PMID: 29697253 DOI: 10.1021/acs.biochem.8b00017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human islet amyloid polypeptide (hIAPP) is a hormone secreted from β-cells in the Islets of Langerhans in response to the same stimuli that lead to insulin secretion. hIAPP plays an adaptive role in glucose homeostasis but misfolds to form insoluble, fibrillar aggregates in type II diabetes that are associated with the disease. Along the misfolding pathway, hIAPP forms species that are toxic to β-cells, resulting in reduced β-cell mass. hIAPP contains a strictly conserved disulfide bond between residues 2 and 7, which forms a small loop at the N-terminus of the molecule. The loop is located outside of the cross β-core in all models of the hIAPP amyloid fibrils. Mutations in this region are rare, and the disulfide loop plays a role in receptor binding; however, the contribution of this region to the aggregation of hIAPP is not well understood. We define the role of the disulfide by analyzing a collection of analogues that remove the disulfide, by mutation of Cys to Ser, by reduction and modification of the Cys residues, or by deletion of the first seven residues. The cytotoxic properties of hIAPP are retained in the Cys to Ser disulfide-free mutant. Removal of the disulfide bond accelerates amyloid formation in all constructs, both in solution and in the presence of model membranes. Removal of the disulfide weakens the ability of hIAPP to induce leakage of vesicles consisting of POPS and POPC. Smaller effects are observed with vesicles that contain 40 mol % cholesterol, although N-terminal truncation still reduces the extent of leakage.
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Affiliation(s)
- Zachary Ridgway
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Xiaoxue Zhang
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Amy G Wong
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States
| | - Andisheh Abedini
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine , New York University School of Medicine , New York , New York 10016 , United States
| | - Ann Marie Schmidt
- Diabetes Research Program, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine , New York University School of Medicine , New York , New York 10016 , United States
| | - Daniel P Raleigh
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794-3400 , United States.,Laufer Center for Quantitative Biology , Stony Brook University , Stony Brook , New York 11794-3400 , United States
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50
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Malishev R, Tayeb-Fligelman E, David S, Meijler MM, Landau M, Jelinek R. Reciprocal Interactions between Membrane Bilayers and S. aureus PSMα3 Cross-α Amyloid Fibrils Account for Species-Specific Cytotoxicity. J Mol Biol 2018; 430:1431-1441. [DOI: 10.1016/j.jmb.2018.03.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 03/19/2018] [Accepted: 03/22/2018] [Indexed: 01/08/2023]
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