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Shen YX, Lee PS, Teng MC, Huang JH, Wang CC, Fan HF. Influence of Cigarette Aerosol in Alpha-Synuclein Oligomerization and Cell Viability in SH-SY5Y: Implications for Parkinson's Disease. ACS Chem Neurosci 2024; 15:1484-1500. [PMID: 38483468 PMCID: PMC10995954 DOI: 10.1021/acschemneuro.3c00771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Abstract
Although cigarette aerosol exposure is associated with various adverse health issues, its impact on Parkinson's disease (PD) remains elusive. Here, we investigated the effect of cigarette aerosol extract (CAE) on SH-SY5Y cells for the first time, both with and without α-synuclein (α-Syn) overexpression. We found that α-Syn aggravates CAE-induced cell death, oxidative stress, and mitochondrial dysfunction. Fluorescence cross-correlation spectroscopy (FCCS) revealed a dual distribution of α-Syn within the cells, with homogeneous regions indicative of monomeric α-Syn and punctated regions, suggesting the formation of oligomers. Moreover, we observed colocalization of α-Syn oligomers with lysosomes along with a reduction in autophagy activity. These findings suggest that α-Syn overexpression exacerbates CAE-induced intracellular cytotoxicity, mitochondrial dysfunction, and autophagy dysregulation, leading to elevated cell mortality. Our findings provide new insights into the pathogenic mechanisms linking exposure to cigarette aerosols with neurodegenerative diseases.
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Affiliation(s)
- Yu-Xin Shen
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Pe-Shuen Lee
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Ming-Chu Teng
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Jhih-Hong Huang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Chia C. Wang
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
| | - Hsiu-Fang Fan
- Institute
of Medical Science and Technology, National
Sun Yat-sen University, Kaohsiung 804, Taiwan
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Aerosol
Science Research Center, National Sun Yat-sen
University, Kaohsiung 804, Taiwan
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Aigbogun OP, Nwabufo CK, Owens MN, Allen KJH, Lee JS, Phenix CP, Krol ES. An HPLC-UV validated bioanalytical method for measurement of in vitro phase 1 kinetics of α-synuclein binding bifunctional compounds. Xenobiotica 2022; 52:916-927. [PMID: 36282181 DOI: 10.1080/00498254.2022.2140315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Aggregates of the protein α-synuclein are associated with pathophysiology of Parkinson's disease and are present in Lewy Bodies found in the brains of Parkinson's patients. We previously demonstrated that bifunctional compounds composed of caffeine linked via a six carbon chain to either 1-aminoindan (C8-6-I) or nicotine (C8-6-N) bind α-synuclein and protect yeast cells from α-synuclein mediated toxicity.A critical step in development of positron emission tomography (PET) probes for neurodegenerative diseases is evaluation of their metabolic stability. We determined that C8-6-I, and C8-6-N both undergo phase 1 P450 metabolism in mouse, rat, and human liver microsomes. We utilised this metabolic information to guide the design of fluorinated analogues for use as PET probes and determined that the fluorine in 19F-C8-6-I and 19F-C8-6-N is stable to P450 enzymes.We have developed and validated an analytical HPLC-UV method following FDA and EMA guidelines to measure in vitro phase 1 kinetics of these compounds and determine their Vmax, KM and CLint,u in mouse liver microsomes. We found that C8-6-I and 19F-C8-6-I have a two- to fourfold lower CLint,u than C8-6-N, and 19F-C8-6-N. Our approach shows a simple, specific, and effective system to design and develop compounds as PET probes.
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Affiliation(s)
- Omozojie P Aigbogun
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Madeline N Owens
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Kevin J H Allen
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jeremy S Lee
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Christopher P Phenix
- Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Ed S Krol
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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3
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Nwabufo CK, Aigbogun OP. Diagnostic and therapeutic agents that target alpha-synuclein in Parkinson's disease. J Neurol 2022; 269:5762-5786. [PMID: 35831620 PMCID: PMC9281355 DOI: 10.1007/s00415-022-11267-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 12/14/2022]
Abstract
The development of disease-modifying drugs and differential diagnostic agents is an urgent medical need in Parkinson’s disease. Despite the complex pathophysiological pathway, the misfolding of alpha-synuclein has been identified as a putative biomarker for detecting the onset and progression of the neurodegeneration associated with Parkinson’s disease. Identifying the most appropriate alpha-synuclein-based diagnostic modality with clinical translation will revolutionize the diagnosis of Parkinson’s. Likewise, molecules that target alpha-synuclein could alter the disease pathway that leads to Parkinson’s and may serve as first-in class therapeutics compared to existing treatment options such as levodopa and dopamine agonist that do not necessarily modify the disease pathway. Notwithstanding the promising benefits that alpha-synuclein presents to therapeutics and diagnostics development for Parkinson’s disease, finding ways to address potential challenges such as inadequate preclinical models, safety and efficacy will be paramount to achieving clinical translation. In this comprehensive review paper, we described the role of alpha-synuclein in the pathogenesis of Parkinson’s disease, as well as how its structure and function relationship delineate disease onset and progression. We further discussed different alpha-synuclein-based diagnostic modalities including biomolecular assays and molecular imaging. Finally, we presented current small molecules and biologics that are being developed as disease-modifying drugs or positron emission tomography imaging probes for Parkinson’s disease.
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Affiliation(s)
- Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada. .,Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, M5S 3M2, Canada.
| | - Omozojie P Aigbogun
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada.,Department of Chemistry, University of Saskatchewan, Saskatoon, Canada
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Jakova E, Moutaoufik MT, Lee JS, Babu M, Cayabyab FS. Adenosine A1 receptor ligands bind to α-synuclein: implications for α-synuclein misfolding and α-synucleinopathy in Parkinson's disease. Transl Neurodegener 2022; 11:9. [PMID: 35139916 PMCID: PMC8830172 DOI: 10.1186/s40035-022-00284-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/21/2022] [Indexed: 12/20/2022] Open
Abstract
Background Accumulating α-synuclein (α-syn) aggregates in neurons and glial cells are the staples of many synucleinopathy disorders, such as Parkinson’s disease (PD). Since brain adenosine becomes greatly elevated in ageing brains and chronic adenosine A1 receptor (A1R) stimulation leads to neurodegeneration, we determined whether adenosine or A1R receptor ligands mimic the action of known compounds that promote α-syn aggregation (e.g., the amphetamine analogue 2-aminoindan) or inhibit α-syn aggregation (e.g., Rasagiline metabolite 1-aminoindan). In the present study, we determined whether adenosine, A1R receptor agonist N6-Cyclopentyladenosine (CPA) and antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) could directly interact with α-syn to modulate α-syn aggregation and neurodegeneration of dopaminergic neurons in the substantia nigra (SN). Methods Nanopore analysis and molecular docking were used to test the binding properties of CPA and DPCPX with α-syn in vitro. Sprague–Dawley rats were administered with 7-day intraperitoneal injections of the A1R ligands and 1- and 2-aminoindan, and levels of α-syn aggregation and neurodegeneration were examined in the SN pars compacta and hippocampal regions using confocal imaging and Western blotting. Results Using nanopore analysis, we showed that the A1R agonists (CPA and adenosine) interacted with the N-terminus of α-syn, similar to 2-aminoindan, which is expected to promote a “knot” conformation and α-syn misfolding. In contrast, the A1R antagonist DPCPX interacted with the N- and C-termini of α-syn, similar to 1-aminoindan, which is expected to promote a “loop” conformation that prevents α-syn misfolding. Molecular docking studies revealed that adenosine, CPA and 2-aminoindan interacted with the hydrophobic core of α-syn N-terminus, whereas DPCPX and 1-aminoindan showed direct binding to the N- and C-terminal hydrophobic pockets. Confocal imaging and Western blot analyses revealed that chronic treatments with CPA alone or in combination with 2-aminoindan increased α-syn expression/aggregation and neurodegeneration in both SN pars compacta and hippocampus. In contrast, DPCPX and 1-aminoindan attenuated the CPA-induced α-syn expression/aggregation and neurodegeneration in SN and hippocampus. Conclusions The results indicate that A1R agonists and drugs promoting a “knot” conformation of α-syn can cause α-synucleinopathy and increase neuronal degeneration, whereas A1R antagonists and drugs promoting a “loop” conformation of α-syn can be harnessed for possible neuroprotective therapies to decrease α-synucleinopathy in PD. Supplementary Information The online version contains supplementary material available at 10.1186/s40035-022-00284-3.
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Affiliation(s)
- Elisabet Jakova
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Mohamed Taha Moutaoufik
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK, Canada
| | - Jeremy S Lee
- Department of Biochemistry, Microbiology and Immunology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Mohan Babu
- Department of Chemistry and Biochemistry, Faculty of Science, University of Regina, Regina, SK, Canada
| | - Francisco S Cayabyab
- Department of Surgery, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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Nwabufo CK, Aigbogun OP, Allen KJH, Owens MN, Lee JS, Phenix CP, Krol ES. Employing in vitro metabolism to guide design of F-labelled PET probes of novel α-synuclein binding bifunctional compounds. Xenobiotica 2021; 51:885-900. [PMID: 34187286 DOI: 10.1080/00498254.2021.1943566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A challenge in the development of novel 18F-labelled positron emission tomography (PET) imaging probes is identification of metabolically stable sites to incorporate the 18F radioisotope. Metabolic loss of 18F from PET probes in vivo can lead to misleading biodistribution data as displaced 18F can accumulate in various tissues.In this study we report on in vitro hepatic microsomal metabolism of novel caffeine containing bifunctional compounds (C8-6-I, C8-6-N, C8-6-C8) that can prevent in vitro aggregation of α-synuclein, which is associated with the pathophysiology of Parkinson's disease. The metabolic profile obtained guided us to synthesize stable isotope 19F-labelled analogues in which the fluorine was introduced at the metabolically stable N7 of the caffeine moiety.An in vitro hepatic microsomal metabolism study of the 19F-labelled analogues resulted in similar metabolites to the unlabelled compounds and demonstrated that the fluorine was metabolically stable, suggesting that these analogues are appropriate PET imaging probes. This straightforward in vitro strategy is valuable for avoiding costly stability failures when designing radiolabelled compounds for PET imaging.
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Affiliation(s)
- Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
| | | | - Kevin J H Allen
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
| | - Madeline N Owens
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | - Jeremy S Lee
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Canada
| | | | - Ed S Krol
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
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6
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Nwabufo CK, El-Aneed A, Krol ES. Tandem mass spectrometric analysis of novel caffeine scaffold-based bifunctional compounds for Parkinson's disease. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:1792-1803. [PMID: 31351020 DOI: 10.1002/rcm.8540] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/19/2019] [Accepted: 07/20/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE Novel bifunctional compounds composed of a caffeine scaffold attached to nicotine (C8 -6-N), 1-aminoindan (C8 -6-I), or caffeine (C8 -6-C8 ) were designed as therapeutics or diagnostics for Parkinson's disease (PD). In order to probe their pharmacological and toxicological profile, an appropriate analytical method is required. The goal of this study is to establish a tandem mass spectrometric fingerprint for the development of quantitative and qualitative methods that will aid future assessment of the in vitro and in vivo absorption, distribution, metabolism, excretion (ADME) and pharmacokinetic properties of these lead bifunctional compounds for PD. METHODS Accurate mass measurement was performed using a hybrid quadrupole orthogonal time-of-flight mass spectrometer while multistage MS/MS and MS3 analyses were conducted using a triple quadrupole linear ion trap mass spectrometer. Both instruments are equipped with an electrospray ionization (ESI) source and were operated in the positive ion mode. The source and compound parameters were optimized for all three tested bifunctional compounds. RESULTS The MS/MS analysis indicates that the fragmentation of C8 -6-N and C8 -6-I is driven by the dissociation of the nicotine and 1-aminoindan moieties, respectively, but not caffeine. A significant observation in the MS/MS fragmentation of C8 -6-C8 suggests that a previously reported loss of acetaldehyde during caffeine dissociation is instead a loss of CO2 . CONCLUSIONS The collision-induced tandem mass spectrometry (CID-MS/MS) analysis of these novel bifunctional compounds revealed compound-specific diagnostic product ions and neutral losses for all three tested bifunctional compounds. The established MS/MS fingerprint will be applied to the future development of qualitative and quantitative methods.
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Affiliation(s)
- Chukwunonso K Nwabufo
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Anas El-Aneed
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ed S Krol
- Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
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7
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Emerging neuroprotective effect of metformin in Parkinson's disease: A molecular crosstalk. Pharmacol Res 2019; 152:104593. [PMID: 31843673 DOI: 10.1016/j.phrs.2019.104593] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/20/2019] [Accepted: 12/11/2019] [Indexed: 02/07/2023]
Abstract
Parkinson's disease (PD) is a devastating neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and Lewy pathology. PD is a major concern of today's aging population and has emerged as a global health burden. Despite the rapid advances in PD research over the past decades, the gold standard therapy provides only symptomatic relief and fails to halt disease progression. Therefore, exploring novel disease-modifying therapeutic strategies is highly demanded. Metformin, which is currently used as a first-line therapy for type 2 diabetes mellitus (T2DM), has recently demonstrated to exert a neuroprotective role in several neurodegenerative disorders including PD, both in vitro and in vivo. In this review, we explore the neuroprotective potential of metformin based on emerging evidence from pre-clinical and clinical studies. Regarding the underlying molecular mechanisms, metformin has been shown to inhibit α-synuclein (SNCA) phosphorylation and aggregation, prevent mitochondrial dysfunction, attenuate oxidative stress, modulate autophagy mainly via AMP-activated protein kinase (AMPK) activation, as well as prevent neurodegeneration and neuroinflammation. Overall, the neuroprotective effects of metformin in PD pathogenesis present a novel promising therapeutic strategy that might overcome the limitations of current PD treatment.
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Ferrie JJ, Haney CM, Yoon J, Pan B, Lin YC, Fakhraai Z, Rhoades E, Nath A, Petersson EJ. Using a FRET Library with Multiple Probe Pairs To Drive Monte Carlo Simulations of α-Synuclein. Biophys J 2019; 114:53-64. [PMID: 29320696 DOI: 10.1016/j.bpj.2017.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/21/2017] [Accepted: 11/06/2017] [Indexed: 01/24/2023] Open
Abstract
We describe a strategy for experimentally-constraining computational simulations of intrinsically disordered proteins (IDPs), using α-synuclein, an IDP with a central role in Parkinson's disease pathology, as an example. Previously, data from single-molecule Förster Resonance Energy Transfer (FRET) experiments have been effectively utilized to generate experimentally constrained computational models of IDPs. However, the fluorophores required for single-molecule FRET experiments are not amenable to the study of short-range (<30 Å) interactions. Using ensemble FRET measurements allows one to acquire data from probes with multiple distance ranges, which can be used to constrain Monte Carlo simulations in PyRosetta. To appropriately employ ensemble FRET data as constraints, we optimized the shape and weight of constraining potentials to afford ensembles of structures that are consistent with experimental data. We also used this approach to examine the structure of α-synuclein in the presence of the compacting osmolyte trimethylamine-N-oxide. Despite significant compaction imparted by 2 M trimethylamine-N-oxide, the underlying ensemble of α-synuclein remains largely disordered and capable of aggregation, also in agreement with experimental data. These proof-of-concept experiments demonstrate that our modeling protocol enables one to efficiently generate experimentally constrained models of IDPs that incorporate atomic-scale detail, allowing one to study an IDP under a variety of conditions.
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Affiliation(s)
- John J Ferrie
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Conor M Haney
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jimin Yoon
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Buyan Pan
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Yi-Chih Lin
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zahra Fakhraai
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth Rhoades
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Abhinav Nath
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, Washington
| | - E James Petersson
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania.
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9
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Afitska K, Fucikova A, Shvadchak VV, Yushchenko DA. Modification of C Terminus Provides New Insights into the Mechanism of α-Synuclein Aggregation. Biophys J 2017; 113:2182-2191. [PMID: 28939194 DOI: 10.1016/j.bpj.2017.08.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 08/12/2017] [Accepted: 08/14/2017] [Indexed: 10/18/2022] Open
Abstract
Aggregation of neuronal protein α-synuclein leads to the formation of amyloid fibrils, which are associated with the development of Parkinson's disease. The mechanism of α-synuclein pathology is not fully understood and is a subject of active research in the field. To tackle this problem, the fusions of fluorescent proteins to α-synuclein C-terminus are often used in cellular and animal studies. The effects induced by such α-synuclein sequence extension on α-synuclein aggregation propensity are, however, not systematically examined despite the evidence that the negatively charged C-terminus plays a critical role in the regulation of α-synuclein aggregation. In this work, we investigated how the charge and length variations of the C-terminus affect the aggregation propensity of α-synuclein. To address these questions, we prepared mutants of α-synuclein carrying additional moieties of different charge and length at the protein C-terminus. We determined the rates of two different aggregation stages (primary nucleation and elongation) based on a thioflavin T kinetic assay. We observed that all mutants bearing neutrally charged moieties of different length fibrilized slower than wild-type α-synuclein. The primary nucleation and elongation rates strongly decreased with increase of the C-terminal extension length. Meanwhile, charge variation of the C-terminus significantly changed the rate of α-synuclein nucleation, but did not markedly affect the rate of fibril elongation. Our data demonstrate that both the charge and length of the C-terminus play an important role at the stage of initial fibril formation, but the stage of fibril elongation is affected mainly by the length of C-terminal extension. In addition, our results suggest that there are at least two steps of incorporation of α-synuclein monomers into the amyloid fibril: namely, the initial monomer binding to the fibril end (charge-dependent, relatively fast), and the subsequent conformational change of the protein (charge-independent, relatively slow, and thus the rate-limiting step).
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Affiliation(s)
- Kseniia Afitska
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Anna Fucikova
- Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
| | - Volodymyr V Shvadchak
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Dmytro A Yushchenko
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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Roozbahani GM, Chen X, Zhang Y, Xie R, Ma R, Li D, Li H, Guan X. Peptide-Mediated Nanopore Detection of Uranyl Ions in Aqueous Media. ACS Sens 2017; 2:703-709. [PMID: 28580428 PMCID: PMC5450019 DOI: 10.1021/acssensors.7b00210] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/04/2017] [Indexed: 01/31/2023]
Abstract
![]()
Uranium
is one of the most common radioactive contaminants in the
environment. As a major nuclear material in production, environmental
samples (like soil and groundwater) can provide signatures on uranium
production activity inside the facility. Thus, developing a new and
portable analytical technology for uranium in aqueous media is significant
not only for environmental monitoring, but also for nonproliferation.
In this work, a label-free method for the detection of uranyl (UO22+) ions is developed by monitoring the translocation
of a peptide probe in a nanopore. Based on the difference in the number
of peptide events in the absence and presence of uranyl ions, nanomolar
concentration of UO22+ ions could be detected
in minutes. The method is highly selective; micromolar concentrations
of Cd2+, Cu2+, Zn2+, Ni2+, Pb2+, Hg2+, Th4+, Mg2+, and Ca2+ would not interfere with the detection of UO22+ ions. In addition, simulated water samples were
successfully analyzed.
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Affiliation(s)
- Golbarg M. Roozbahani
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Xiaohan Chen
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Youwen Zhang
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Ruiqi Xie
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Rui Ma
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
| | - Dien Li
- Environmental
Sciences and Biotechnology, Savannah River National Laboratory, Aiken, South Carolina 29808, United States
| | - Huazhong Li
- Henan Jintai Biological Technology Co., Ltd., ZhengZhou, Henan, 450016, PR China
| | - Xiyun Guan
- Department
of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, Illinois 60616, United States
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11
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Zhang X, Su L, Qiu L, Fan Z, Zhang X, Lin S, Huang Q. Palladium-catalyzed C–H olefination of uracils and caffeines using molecular oxygen as the sole oxidant. Org Biomol Chem 2017; 15:3499-3506. [DOI: 10.1039/c7ob00616k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The palladium-catalyzed oxidative C–H olefination of uracils or caffeines with alkenes using an atmospheric pressure of molecular oxygen as the sole oxidant has been disclosed.
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Affiliation(s)
- Xinyu Zhang
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Lv Su
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Lin Qiu
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Zhenwei Fan
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Xiaofeng Zhang
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Shen Lin
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
| | - Qiufeng Huang
- College of Chemistry & Chemical Engineering
- Fujian Normal University
- Fuzhou 350007
- People's Republic of China
- Fujian Key Laboratory of Polymer Materials
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