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Shaikh A, Sahoo S, Marder SR, Barlow S, Mohapatra SK. Reductive dimerization of benzothiazolium salts. Org Biomol Chem 2024; 22:2115-2123. [PMID: 38376182 DOI: 10.1039/d3ob01871g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
Three different types of reaction products were obtained from the reduction of 2-substituted 3-methylbenzothiazolium salts using Na : Hg (1 wt%). Depending on the 2-substituents, two types of dimeric compounds were obtained: the 2-cyclohexyl-, 2-phenyl-, and 2-(p-tolyl)-substituted species are reduced to the corresponding 2,2'-bibenzo[d]thiazoles, while their 2-((p-OMe)C6H4)- and 2-((p-NMe2)C6H4)-substituted derivatives afford cis-[1,4]benzothiazino[3,2-b][1,4]benzothiazines. Furthermore, in the presence of molecular O2, new disulfide derivatives were obtained from the bibenzo[d]thiazoles. The products were obtained in a moderate to good yield, and the structures were confirmed using single-crystal X-ray diffraction. The electrochemistry and further reactivity towards different oxidants of the dimeric compounds were studied; the 2,2'-bibenzo[d]thiazoles show oxidation potentials similar to that of ferrocene and are converted back to the corresponding benzothiazolium cations by mild oxidants such as TCNQ. In contrast, the benzothiazino-benzothiazines show no oxidations in the solvent window of THF.
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Affiliation(s)
- Aijaz Shaikh
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology-Indian Oil Odisha Campus, IIT Kharagpur Extension Center, Bhubaneswar, Odisha 751013, India.
| | - Satyajit Sahoo
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology-Indian Oil Odisha Campus, IIT Kharagpur Extension Center, Bhubaneswar, Odisha 751013, India.
| | - Seth R Marder
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, USA
- Department of Chemistry and of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Stephen Barlow
- Renewable and Sustainable Energy Institute (RASEI), University of Colorado Boulder, Boulder, Colorado 80309, USA
| | - Swagat K Mohapatra
- Department of Industrial and Engineering Chemistry, Institute of Chemical Technology-Indian Oil Odisha Campus, IIT Kharagpur Extension Center, Bhubaneswar, Odisha 751013, India.
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2
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Morozova OV, Manuvera VA, Barinov NA, Subcheva EN, Laktyushkin VS, Ivanov DA, Lazarev VN, Klinov DV. Self-assembling amyloid-like nanostructures from SARS-CoV-2 S1, S2, RBD and N recombinant proteins. Arch Biochem Biophys 2024; 752:109843. [PMID: 38072298 DOI: 10.1016/j.abb.2023.109843] [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: 10/02/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/26/2023]
Abstract
Self-assembling nanoparticles (saNP) and nanofibers were found in the recombinant coronavirus SARS-CoV-2 S1, S2, RBD and N proteins purified by affinity chromatography using Ni Sepharose. Scanning electron (SEM), atomic force (AFM) microscopy on mica or graphite surface and in liquid as well as dynamic light scattering (DLS) revealed nanostructures of various sizes. AFM in liquid cell without drying on the surface showed mean height of S1 saNP 80.03 nm, polydispersity index (PDI) 0.006; for S2 saNP mean height 93.32 nm, PDI = 0.008; for N saNP mean height 16.71 nm, PDI = 0.99; for RBD saNP mean height 16.25 nm, PDI = 0.55. Ratios between the height and radius of each saNP in the range 0.1-0.5 suggested solid protein NP but not vesicles with internal empty spaces. The solid but not empty structures of the protein saNP were also confirmed by STEM after treatment of saNP with the standard contrasting agent uranyl acetate. The saNP remained stable after multiple freeze-thaw cycles in water and hyperosmotic solutions for 2 years at -20 °C. Receptor-mediated penetration of the SARS-CoV-2 S1 and RBD saNP in the African green mokey kidney Vero cells with the specific receptors for β-coronavirus reproduction was more efficient compared to unspecific endocytosis into MDCK cells without the specific receptors. Amyloid-like structures were revealed in the SARS-CoV-2 S1, S2, RBD and N saNP by means of their interaction with Thioflavin T and Congo Red dyes. Taken together, spontaneous formation of the amyloid-like self-assembling nanostructures due to the internal affinity of the SARS-CoV-2 virion proteins might induce proteinopathy in patients, including conformational neurodegenerative diseases, change stability of vaccines and diagnostic systems.
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Affiliation(s)
- Olga V Morozova
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Street, 119435, Moscow, Russian Federation; Ivanovsky Institute of Virology of the National Research Center of Epidemiology and Microbiology of N.F. Gamaleya of the Russian Ministry of Health, 16 Gamaleya Street, 123098, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutsky Per., 141700, Dolgoprudny, Moscow Region, Russian Federation; Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation.
| | - Valentin A Manuvera
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Street, 119435, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutsky Per., 141700, Dolgoprudny, Moscow Region, Russian Federation
| | - Nikolay A Barinov
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Street, 119435, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutsky Per., 141700, Dolgoprudny, Moscow Region, Russian Federation; Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation
| | - Elena N Subcheva
- Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation
| | - Victor S Laktyushkin
- Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation
| | - Dimitri A Ivanov
- Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation; Lomonosov Moscow State University, Leninskie Gory 1 bld. 2, 119991 Moscow, Russian Federation; Institut de Sciences des Matériaux de Mulhouse - IS2M, CNRS UMR7361, 15 Jean Starcky, Mulhouse, 68057, France
| | - Vassili N Lazarev
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Street, 119435, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutsky Per., 141700, Dolgoprudny, Moscow Region, Russian Federation
| | - Dmitry V Klinov
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1a Malaya Pirogovskaya Street, 119435, Moscow, Russian Federation; Moscow Institute of Physics and Technology, 9 Institutsky Per., 141700, Dolgoprudny, Moscow Region, Russian Federation; Sirius University of Science and Technology, Olimpiyskiy ave. b.1, township Sirius, Krasnodar region, 354340, Russian Federation
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3
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Pandit E, Das L, Das AK, Dolui S, Saha S, Pal U, Mondal A, Chowdhury J, Biswas SC, Maiti NC. Single point mutations at the S129 residue of α-synuclein and their effect on structure, aggregation, and neurotoxicity. Front Chem 2023; 11:1145877. [PMID: 37304685 PMCID: PMC10250651 DOI: 10.3389/fchem.2023.1145877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/10/2023] [Indexed: 06/13/2023] Open
Abstract
Parkinson's disease is an age-related neurological disorder, and the pathology of the disease is linked to different types of aggregates of α-synuclein or alpha-synuclein (aS), which is an intrinsically disordered protein. The C-terminal domain (residues 96-140) of the protein is highly fluctuating and possesses random/disordered coil conformation. Thus, the region plays a significant role in the protein's solubility and stability by an interaction with other parts of the protein. In the current investigation, we examined the structure and aggregation behavior of two artificial single point mutations at a C-terminal residue at position 129 that represent a serine residue in the wild-type human aS (wt aS). Circular Dichroism (CD) and Raman spectroscopy were performed to analyse the secondary structure of the mutated proteins and compare it to the wt aS. Thioflavin T assay and atomic force microscopy imaging helped in understanding the aggregation kinetics and type of aggregates formed. Finally, the cytotoxicity assay gave an idea about the toxicity of the aggregates formed at different stages of incubation due to mutations. Compared to wt aS, the mutants S129A and S129W imparted structural stability and showed enhanced propensity toward the α-helical secondary structure. CD analysis showed proclivity of the mutant proteins toward α-helical conformation. The enhancement of α-helical propensity lengthened the lag phase of fibril formation. The growth rate of β-sheet-rich fibrillation was also reduced. Cytotoxicity tests on SH-SY5Y neuronal cell lines established that the S129A and S129W mutants and their aggregates were potentially less toxic than wt aS. The average survivability rate was ∼40% for cells treated with oligomers (presumably formed after 24 h of incubation of the freshly prepared monomeric protein solution) produced from wt aS and ∼80% for cells treated with oligomers obtained from mutant proteins. The relative structural stability with α-helical propensity of the mutants could be a plausible reason for their slow rate of oligomerization and fibrillation, and this was also the possible reason for reduced toxicity to neuronal cells.
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Affiliation(s)
- Esha Pandit
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | - Lopamudra Das
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | - Anoy Kumar Das
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Sandip Dolui
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | - Saumen Saha
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | - Uttam Pal
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | - Animesh Mondal
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
| | | | - Subhas C. Biswas
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, Kolkata, India
| | - Nakul C. Maiti
- Structural Biology and Bioinformatics Division, Indian Institute of Chemical Biology, Council of Scientific and Industrial Research, Kolkata, India
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Pandey SP, Desai AM, Singh PK. A molecular rotor based ratiometric detection scheme for aluminium ions in water. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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5
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Slow Evolution toward “Super-Aggregation” of the Oligomers Formed through the Swapping of RNase A N-Termini: A Wish for Amyloidosis? Int J Mol Sci 2022; 23:ijms231911192. [PMID: 36232496 PMCID: PMC9569824 DOI: 10.3390/ijms231911192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/17/2022] Open
Abstract
Natively monomeric RNase A can oligomerize upon lyophilization from 40% acetic acid solutions or when it is heated at high concentrations in various solvents. In this way, it produces many dimeric or oligomeric conformers through the three-dimensional domain swapping (3D-DS) mechanism involving both RNase A N- or/and C-termini. Here, we found many of these oligomers evolving toward not negligible amounts of large derivatives after being stored for up to 15 months at 4 °C in phosphate buffer. We call these species super-aggregates (SAs). Notably, SAs do not originate from native RNase A monomer or from oligomers characterized by the exclusive presence of the C-terminus swapping of the enzyme subunits as well. Instead, the swapping of at least two subunits’ N-termini is mandatory to produce them. Through immunoblotting, SAs are confirmed to derive from RNase A even if they retain only low ribonucleolytic activity. Then, their interaction registered with Thioflavin-T (ThT), in addition to TEM analyses, indicate SAs are large and circular but not “amyloid-like” derivatives. This confirms that RNase A acts as an “auto-chaperone”, although it displays many amyloid-prone short segments, including the 16–22 loop included in its N-terminus. Therefore, we hypothesize the opening of RNase A N-terminus, and hence its oligomerization through 3D-DS, may represent a preliminary step favoring massive RNase A aggregation. Interestingly, this process is slow and requires low temperatures to limit the concomitant oligomers’ dissociation to the native monomer. These data and the hypothesis proposed are discussed in the light of protein aggregation in general, and of possible future applications to contrast amyloidosis.
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Alghamdi A, Birch DJS, Vyshemirsky V, Rolinski OJ. Impact of the Flavonoid Quercetin on β-Amyloid Aggregation Revealed by Intrinsic Fluorescence. J Phys Chem B 2022; 126:7229-7237. [PMID: 36121408 PMCID: PMC9527748 DOI: 10.1021/acs.jpcb.2c02763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We report the effects of quercetin, a flavonoid present in the human diet, on early stage beta-amyloid (Aβ) aggregation, a seminal event in Alzheimer's disease. Molecular level changes in Aβ arrangements are monitored by time-resolved emission spectral (TRES) measurements of the fluorescence of Aβ's single tyrosine intrinsic fluorophore (Tyr). The results suggest that quercetin binds β-amyloid oligomers at early stages of their aggregation, which leads to the formation of modified oligomers and hinders the creation of β-sheet structures, potentially preventing the onset of Alzheimer's disease.
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Affiliation(s)
- Abeer Alghamdi
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - David J S Birch
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
| | - Vladislav Vyshemirsky
- School of Mathematics and Statistics, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Olaf J Rolinski
- Photophysics Group, Centre for Molecular Nanometrology, Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, 107 Rottenrow East, Glasgow G4 0NG, United Kingdom
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7
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Xiang S, Wagner J, Lückerath T, Müllen K, Ng DYW, Hedrich J, Weil T. Reversing Aβ Fibrillation and Inhibiting Aβ Primary Neuronal Cell Toxicity Using Amphiphilic Polyphenylene Dendrons. Adv Healthc Mater 2022; 11:e2101854. [PMID: 34748685 DOI: 10.1002/adhm.202101854] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/29/2021] [Indexed: 11/07/2022]
Abstract
Uncontrolled amyloid-beta (Aβ) fibrillation leads to the deposition of neurotoxic amyloid plaques and is associated with Alzheimer's disease. Inhibiting Aβ monomer fibrillation and dissociation of the formed fibers is regarded as a promising therapeutic strategy. Here, amphiphilic polyphenylene dendrons (APDs) are demonstrated to interrupt Aβ assembly and reduce Aβ-cell interactions. Containing alternating negatively charged sulfonic acid and hydrophobic n-propyl peripheral groups, APDs bind to the secondary structure of the Aβ aggregates, inhibiting fibrillation and disassemble the already formed Aβ fibrils. APDs reveal vesicular cellular uptake in endosomes as well as cell compatibility for endothelial and neuronal cells, and significantly reduce Aβ-induced neuron cytotoxicity in vitro. Moreover, they are transported into the brain and successfully cross the blood-brain barrier after systemic application in mice, indicating their high potential to inhibit Aβ fibrillation in vivo, which can be beneficial for developing therapeutic strategy for Alzheimer's disease.
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Affiliation(s)
- Siyuan Xiang
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - Jessica Wagner
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - Thorsten Lückerath
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - David Y. W. Ng
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - Jana Hedrich
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
| | - Tanja Weil
- Max Planck Institute for Polymer Research Ackermannweg 10 Mainz 55128 Germany
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8
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Desai AM, Pandey SP, Singh PK. Effect of counter-anions on the aggregation of Thioflavin-T. Phys Chem Chem Phys 2021; 23:9948-9961. [PMID: 33861224 DOI: 10.1039/d1cp00193k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The aggregation of small molecules in aqueous solution is known to be influenced by the ionic strength of the medium; however, the role played by the identity of salt in the phenomenon of small molecule aggregation is rarely investigated. In the present contribution, we have investigated the effect of counter-anions on the aggregation of a popular cationic amyloid sensing probe, Thioflavin-T (ThT), by taking six different anions, viz. chloride, bromide, acetate, iodide, tetrafluoroborate, and perchlorate. Our results clearly indicate that it is not the ionic strength of the medium which solely controls aggregation of small molecules but distinct ions behave distinctly with regard to the organization. In fact, distinct ion effects play a major role in the salt induced organization of fluorophores. Using detailed steady-state emission, time-resolved emission, and ground-state absorption measurements, the optical properties of salt induced aggregates of ThT have been characterized. We have rationalized our observations on the basis of the theory of matching water affinity, which suggests that the matching free hydration energy is a critical aspect for the formation of contact ion pairs, which eventually results in aggregation. In brief, a larger sized anion, perchlorate, has a lower free energy of hydration and forms a suitable contact ion pair, with a larger organic cation, ThT, having weaker hydration. This contact ion-pair formation subsequently leads to the formation of an aggregate assembly which is found to be emissive in nature. Therefore, it is possible to induce aggregation of ThT by selecting the right counterion with the appropriate size, which may help us to evaluate the false positive signals when high ionic strength and specific counterions are present in the sensing matrix.
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Affiliation(s)
- Akshat M Desai
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
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9
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10
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Warerkar OD, Mudliar NH, Singh PK. A hemicyanine based fluorescence turn-on sensor for amyloid fibril detection in the far-red region. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Lu J, Xue Y, Bernardino K, Zhang NN, Gomes WR, Ramesar NS, Liu S, Hu Z, Sun T, de Moura AF, Kotov NA, Liu K. Enhanced optical asymmetry in supramolecular chiroplasmonic assemblies with long-range order. Science 2021; 371:1368-1374. [DOI: 10.1126/science.abd8576] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 02/09/2021] [Indexed: 12/12/2022]
Affiliation(s)
- Jun Lu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yao Xue
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | - Kalil Bernardino
- Institute of Chemistry, University of São Paulo, 05508-000, São Paulo, SP, Brazil
| | - Ning-Ning Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | - Weverson R. Gomes
- Department of Chemistry, Federal University of São Carlos, 13565-905, São Carlos, SP, Brazil
| | - Naomi S. Ramesar
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shuhan Liu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Institute of Immunology, The First Hospital, Jilin University, Changchun, China
| | - Zheng Hu
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Institute of Immunology, The First Hospital, Jilin University, Changchun, China
| | - Tianmeng Sun
- Key Laboratory of Organ Regeneration and Transplantation of Ministry of Education, Institute of Immunology, The First Hospital, Jilin University, Changchun, China
| | - Andre Farias de Moura
- Department of Chemistry, Federal University of São Carlos, 13565-905, São Carlos, SP, Brazil
| | - Nicholas A. Kotov
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
- Biointerfaces Institute, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Kun Liu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
- Optical Functional Theranostics Joint Laboratory of Medicine and Chemistry, The First Hospital, Jilin University, Changchun, China
- Chiral Nanomaterials Research Center, International Center of Future Science, Jilin University, Changchun, China
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Gobbo D, Cavalli A, Ballone P, Benedetto A. Computational analysis of the effect of [Tea][Ms] and [Tea][H 2PO 4] ionic liquids on the structure and stability of Aβ(17-42) amyloid fibrils. Phys Chem Chem Phys 2021; 23:6695-6709. [PMID: 33710213 DOI: 10.1039/d0cp06434c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental studies have reported the possibility of affecting the growth/dissolution of amyloid fibres by the addition of organic salts of the room-temperature ionic-liquid family, raising the tantalizing prospect of controlling these processes under physiological conditions. The effect of [Tea][Ms] and [Tea][H2PO4] at various concentrations on the structure and stability of a simple model of Aβ42 fibrils has been investigated by computational means. Free energy computations show that both [Tea][Ms] and [Tea][H2PO4] decrease the stability of fibrils with respect to isolated peptides in solution, and the effect is significantly stronger for [Tea][Ms]. The secondary structure of fibrils is not much affected, but single peptides in solution show a marked decrease in their β-strand character and an increase in α-propensity, again especially for [Tea][Ms]. These observations, consistent with the experimental picture, can be traced to two primary effects, i.e., the difference in the ionicity of the [Tea][Ms] and [Tea][H2PO4] water solutions and the remarkable affinity of peptides for [Ms]- anions, due to the multiplicity of H-bonds.
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Affiliation(s)
- D Gobbo
- Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia, Genova, Italy.
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A serine protease secreted from Bacillus subtilis cleaves human plasma transthyretin to generate an amyloidogenic fragment. Commun Biol 2020; 3:764. [PMID: 33311636 PMCID: PMC7733459 DOI: 10.1038/s42003-020-01493-0] [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: 05/08/2020] [Accepted: 11/16/2020] [Indexed: 12/14/2022] Open
Abstract
Aggregation of human wild-type transthyretin (hTTR), a homo-tetrameric plasma protein, leads to acquired senile systemic amyloidosis (SSA), recently recognised as a major cause of cardiomyopathies in 1-3% older adults. Fragmented hTTR is the standard composition of amyloid deposits in SSA, but the protease(s) responsible for amyloidogenic fragments generation in vivo is(are) still elusive. Here, we show that subtilisin secreted from Bacillus subtilis, a gut microbiota commensal bacterium, translocates across a simulated intestinal epithelium and cleaves hTTR both in solution and human plasma, generating the amyloidogenic fragment hTTR(59-127), which is also found in SSA amyloids in vivo. To the best of our knowledge, these findings highlight a novel pathogenic mechanism for SSA whereby increased permeability of the gut mucosa, as often occurs in elderly people, allows subtilisin (and perhaps other yet unidentified bacterial proteases) to reach the bloodstream and trigger generation of hTTR fragments, acting as seeding nuclei for preferential amyloid fibrils deposition in the heart.
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14
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Mudliar NH, Dongre PM, Singh PK. A Heparin based dual ratiometric sensor for Thrombin. Int J Biol Macromol 2020; 167:1371-1378. [PMID: 33202269 DOI: 10.1016/j.ijbiomac.2020.11.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/05/2020] [Accepted: 11/12/2020] [Indexed: 02/06/2023]
Abstract
Thrombin is an important enzyme that plays a pivotal role in the blood clotting pathways. An imbalance in the activity of this enzyme is clinically known to be associated with various diseases, such as thrombosis, inflammation, atherosclerosis, and haemophilia, suggesting the need to devise sensors for Thrombin detection. However, the majority of the fluorescence-based Thrombin assays rely on fluorescence labelling assays or Thrombin specific recognition biomolecules, such as, aptamers or antibody which requires sophisticated techniques and makes it very expensive. Herein, we report a simple, selective, sensitive and label-free fluorescence detection scheme for Thrombin which is based on the interaction between Thrombin and a fluorescent complex of Heparin with a molecular rotor dye, Thioflavin-T. The detection scheme exploits selective interaction between cationic Thrombin and anionic Heparin to modulate the monomer-aggregate equilibrium of the Thioflavin-T-Heparin system. Importantly, the present system offers a ratiometric response that has the ability for robust quantification of Thrombin concentration even in complex medium. The involvement of all commercially available components is a crucial advantage of this detection scheme. Further, the detection scheme also shows reasonable response in diluted serum matrix.
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Affiliation(s)
- Niyati H Mudliar
- Department of Biophysics, University of Mumbai, Vidyanagari, Kalina, Mumbai 400098, India
| | - Prabhakar M Dongre
- Department of Biophysics, University of Mumbai, Vidyanagari, Kalina, Mumbai 400098, India
| | - Prabhat K Singh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India.
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15
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A novel supramolecule-based fluorescence turn-on and ratiometric sensor for highly selective detection of glutathione over cystein and homocystein. Mikrochim Acta 2020; 187:631. [PMID: 33125575 DOI: 10.1007/s00604-020-04602-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 10/12/2020] [Indexed: 02/07/2023]
Abstract
A cyclodextrin-based fluorescence light-up and ratiometric sensor is reported for highly selective and sensitive recognition of glutathione over cystein and homocystein. The sensing scheme developed builds up on a supramolecular assembly formed between a molecular rotor dye (ThT) and a polyanionic supramolecular host (sulfated-β-cyclodextrin, SCD). The detection scheme is accomplished as follows: firstly, the bivalent Cu2+ quenches the emission from ThT-SCD assembly by causing the dissociation of ThT molecules from SCD surface. Secondly, when GSH is added to the copper-quenched system, owing to specific interaction between Cu2+ and GSH, Cu2+ is removed from the SCD which again allows the formation of ThT-SCD assembly. Indeed, this scheme of disassembly and reassembly successively caused by Cu2+ and GSH in the aqueous solution empowers our sensor framework to work as a good ratiometric sensor for the detection of GSH. The sensor scheme shows a linear response in the range 0-250 μM with a LOD of 2.4 ± 0.2 μM in aqueous solution and 13.6 ± 0.5 μM in diluted human serum sample. The sensor system is excited at 410 nm and the emission signal is plotted as a ratio of intensity at 545 nm (aggregate band) and 490 nm (monomer band). This ratiometric sensor system is highly selective to glutathione over cystein, homocystein, and other amino acids. Additionally, response of the sensor system towards GSH in complex biological media of serum samples demonstrates its potential for practical utility. Graphical abstract.
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16
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An anionic polyelectrolyte induced aggregate assembly of Thioflavin-T: A prospective platform for Protamine sensing. Int J Biol Macromol 2020; 164:1174-1182. [PMID: 32710965 DOI: 10.1016/j.ijbiomac.2020.07.182] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/08/2020] [Accepted: 07/16/2020] [Indexed: 12/23/2022]
Abstract
Protamine, a polycation, is biologically and medically relevant protein. Protamine exhibits a wide array of functions in biological processes like gene transfer, tissue and organogenesis, cell reproduction, etc. Medically, Protamine is the only clinically approved antidote for Heparin and is routinely used in various surgical interventions, and hence controlling Protamine dosing in patients is very crucial. Taking into account the medical significance of Protamine, designing simple, reliable and sensitive fluorescence sensors is highly desirable. In this work, we propose one such sensitive and reliable fluorescent sensor which is based on a template of dye-polyelectrolyte assembly constituting a molecular rotor dye, Thioflavin-T and an anionic synthetic polyelectrolyte, polystyrene sulfonate. The addition of Protamine, prompts drastic modulations in spectral features of dye-polyelectrolyte assembly which enables sensitive detection of Protamine in aqueous solution. Apart from sensitive detection, our sensing platform aids in highly selective sensing of Protamine compared to other proteins. Moreover, our sensor system is constructed on label-free, inexpensive, commercially available molecules posing as an advantage over other sensor systems which involve laborious synthesis protocols. Most importantly, our sensor template is able to sense Protamine in diluted serum sample, indicating the potential practical utility of our sensor system.
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17
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Kumar B, Ghosh R, Mora AK, Nath S. Anthryl Benzothiazolium Molecular Rotor-Based Turn-On DNA Probe: Detailed Mechanistic Studies. J Phys Chem B 2019; 123:7518-7527. [DOI: 10.1021/acs.jpcb.9b05570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Bhupesh Kumar
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Rajib Ghosh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400085, India
| | - Aruna K. Mora
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400085, India
| | - Sukhendu Nath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400085, India
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18
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Varejão JOS, Varejão EVV, Fernandes SA. Synthesis and Derivatization of Julolidine: A Powerful Heterocyclic Structure. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900398] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Jodieh Oliveira Santana Varejão
- Grupo de Química Supramolecular e Biomimética (GQSB); Departamento de Química; Universidade Federal de Viçosa; 36570-900 Brazil
| | - Eduardo Vinícius Vieira Varejão
- Grupo de Química Supramolecular e Biomimética (GQSB); Departamento de Química; Universidade Federal de Viçosa; 36570-900 Brazil
| | - Sergio Antonio Fernandes
- Grupo de Química Supramolecular e Biomimética (GQSB); Departamento de Química; Universidade Federal de Viçosa; 36570-900 Brazil
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19
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Shelkovnikov VV, Kargapolova IY, Korotaev SV, Orlova NA, Rybalova TV, Chuikov IP. Three-color luminescent transformation of the julolidine pyrylo/pyridocyanine dyes in the adsorbed state. J Photochem Photobiol A Chem 2019. [DOI: 10.1016/j.jphotochem.2019.02.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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20
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Senapak W, Saeeng R, Jaratjaroonphong J, Sirion U. Brönsted acid-surfactant-combined ionic liquid catalyzed green synthesis of 2-alkyl and 2-arylbenzothiazoles in water: Reusable catalyst and metal-free conditions. MOLECULAR CATALYSIS 2018. [DOI: 10.1016/j.mcat.2018.06.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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21
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Kim J, Kim DE, Joo T. Excited-State Dynamics of Thioflavin T: Planar Stable Intermediate Revealed by Nuclear Wave Packet Spectroscopies. J Phys Chem A 2018; 122:1283-1290. [DOI: 10.1021/acs.jpca.7b11951] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- JunWoo Kim
- Department
of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Dong Eon Kim
- Physics
Department, Center for Attosecond Science and Technology, and Max
Planck Center for Attosecond Science, POSTECH, Pohang 37673, South Korea
| | - Taiha Joo
- Department
of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
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22
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Wójcik S, Birol M, Rhoades E, Miranker AD, Levine ZA. Targeting the Intrinsically Disordered Proteome Using Small-Molecule Ligands. Methods Enzymol 2018; 611:703-734. [DOI: 10.1016/bs.mie.2018.09.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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23
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Zheng X, Xu Z, Li H, Fu H. A sensitive probe for amyloid fibril detection with strong fluorescence and early response. RSC Adv 2018; 8:15870-15875. [PMID: 35542196 PMCID: PMC9080103 DOI: 10.1039/c8ra00751a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/29/2018] [Indexed: 02/05/2023] Open
Abstract
We synthesized a new probe, 4-[2-(2-naphthyl)-(E)-ethenyl]-benzyl(triphenyl)phosphonium bromide (NEB), to detect the formation of amyloid fibrils of bovine insulin. The fluorescence intensity of NEB in the presence of insulin fibrils was 30 times higher than that before fibrillation, with the fluorescence quantum yield increased from 2.5% to 78%. In comparison with the commercially available probe, thioflavin T (ThT), NEB exhibits a 10 times stronger fluorescence and a shorter identification lag phase for detecting insulin fibrillation, indicating a higher sensitivity in detection of insulin oligomers and fibrils. We synthesized a new probe, 4-[2-(2-naphthyl)-(E)-ethenyl]-benzyl(triphenyl)phosphonium bromide (NEB), to detect the formation of amyloid fibrils of bovine insulin.![]()
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Affiliation(s)
- Xiaolin Zheng
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- People's Republic of China
| | - Zhenzhen Xu
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- People's Republic of China
| | - Haiyang Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- People's Republic of China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- People's Republic of China
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24
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Bagrov D, Gazizova Y, Podgorsky V, Udovichenko I, Danilkovich A, Prusakov K, Klinov D. Morphology and aggregation of RADA-16-I peptide Studied by AFM, NMR and molecular dynamics simulations. Biopolymers 2017; 106:72-81. [PMID: 26501800 DOI: 10.1002/bip.22755] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 08/31/2015] [Accepted: 10/17/2015] [Indexed: 01/25/2023]
Abstract
RADA-16-I is a self-assembling peptide which forms biocompatible fibrils and hydrogels. We used molecular dynamics simulations, atomic-force microscopy, NMR spectroscopy, and thioflavin T binding assay to examine size, structure, and morphology of RADA-16-I aggregates. We used the native form of RADA-16-I (H-(ArgAlaAspAla)4 -OH) rather than the acetylated one commonly used in the previous studies. At neutral pH, RADA-16-I is mainly in the fibrillar form, the fibrils consist of an even number of stacked β-sheets. At acidic pH, RADA-16-I fibrils disassemble into monomers, which form an amorphous monolayer on graphite and monolayer lamellae on mica. RADA-16-I fibrils were compared with the fibrils of a similar peptide RLDL-16-I. Thickness of β-sheets measured by AFM was in excellent agreement with the molecular dynamics simulations. A pair of RLDL-16-I β-sheets was thicker (2.3 ± 0.4 nm) than a pair of RADA-16-I β-sheets (1.9 ± 0.1 nm) due to the volume difference between alanine and leucine residues.
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Affiliation(s)
- Dmitry Bagrov
- Scientific Research Institute of Physical-Chemical Medicine, Malaya Pirogovskaya, 1a Moscow, 119435, Russian Federation.,Faculty of Biology, Department of Bioengineering, M.V. Lomonosov Moscow State University, Leninskie Gory, 1/73, Moscow, 111991, Russian Federation
| | - Yuliya Gazizova
- Scientific Research Institute of Physical-Chemical Medicine, Malaya Pirogovskaya, 1a Moscow, 119435, Russian Federation.,Department of Biological and Medical Physics, Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny, Moscow Region, 141700, Russian Federation
| | - Victor Podgorsky
- Scientific Research Institute of Physical-Chemical Medicine, Malaya Pirogovskaya, 1a Moscow, 119435, Russian Federation
| | - Igor Udovichenko
- Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospect Nauki-6, Pushchino, 142290, Russian Federation.,Pushchino State Institute of Natural Science, Prospect Nauki-3, Pushchino, 142290, Russian Federation
| | - Alexey Danilkovich
- Branch of Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Prospect Nauki-6, Pushchino, 142290, Russian Federation.,Pushchino State Institute of Natural Science, Prospect Nauki-3, Pushchino, 142290, Russian Federation
| | - Kirill Prusakov
- Scientific Research Institute of Physical-Chemical Medicine, Malaya Pirogovskaya, 1a Moscow, 119435, Russian Federation
| | - Dmitry Klinov
- Scientific Research Institute of Physical-Chemical Medicine, Malaya Pirogovskaya, 1a Moscow, 119435, Russian Federation.,Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya, 16/10, Moscow, 117997, Russian Federation
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25
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Xue C, Lin TY, Chang D, Guo Z. Thioflavin T as an amyloid dye: fibril quantification, optimal concentration and effect on aggregation. ROYAL SOCIETY OPEN SCIENCE 2017. [PMID: 28280572 DOI: 10.5061/dryad.b8c4r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Formation of amyloid fibrils underlies a wide range of human disorders, including Alzheimer's and prion diseases. The amyloid fibrils can be readily detected thanks to thioflavin T (ThT), a small molecule that gives strong fluorescence upon binding to amyloids. Using the amyloid fibrils of Aβ40 and Aβ42 involved in Alzheimer's disease, and of yeast prion protein Ure2, here we study three aspects of ThT binding to amyloids: quantification of amyloid fibrils using ThT, the optimal ThT concentration for monitoring amyloid formation and the effect of ThT on aggregation kinetics. We show that ThT fluorescence correlates linearly with amyloid concentration over ThT concentrations ranging from 0.2 to 500 µM. At a given amyloid concentration, the plot of ThT fluorescence versus ThT concentration exhibits a bell-shaped curve. The maximal fluorescence signal depends mostly on the total ThT concentration, rather than amyloid to ThT ratio. For the three proteins investigated, the maximal fluorescence is observed at ThT concentrations of 20-50 µM. Aggregation kinetics experiments in the presence of different ThT concentrations show that ThT has little effect on aggregation at concentrations of 20 µM or lower. ThT at concentrations of 50 µM or more could affect the shape of the aggregation curves, but this effect is protein-dependent and not universal.
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Affiliation(s)
- Christine Xue
- Department of Neurology, Brain Research Institute, Molecular Biology Institute , University of California , Los Angeles, CA 90095 , USA
| | - Tiffany Yuwen Lin
- Department of Neurology, Brain Research Institute, Molecular Biology Institute , University of California , Los Angeles, CA 90095 , USA
| | - Dennis Chang
- Department of Neurology, Brain Research Institute, Molecular Biology Institute , University of California , Los Angeles, CA 90095 , USA
| | - Zhefeng Guo
- Department of Neurology, Brain Research Institute, Molecular Biology Institute , University of California , Los Angeles, CA 90095 , USA
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26
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Ghosh R, Manna B. Comparative photophysics and ultrafast dynamics of dimethylaminochalcone and a structurally rigid derivative: experimental identification of TICT coordinate. Phys Chem Chem Phys 2017; 19:23078-23084. [DOI: 10.1039/c7cp03461j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Restriction of torsional relaxation and solvent dependent competing photophysical dynamics of free and rigid dimethylaminochalcones were investigated by time resolved spectroscopy.
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Affiliation(s)
- Rajib Ghosh
- Radiation and Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Biswajit Manna
- Radiation and Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
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27
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Xue C, Lin TY, Chang D, Guo Z. Thioflavin T as an amyloid dye: fibril quantification, optimal concentration and effect on aggregation. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160696. [PMID: 28280572 PMCID: PMC5319338 DOI: 10.1098/rsos.160696] [Citation(s) in RCA: 408] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/28/2016] [Indexed: 05/18/2023]
Abstract
Formation of amyloid fibrils underlies a wide range of human disorders, including Alzheimer's and prion diseases. The amyloid fibrils can be readily detected thanks to thioflavin T (ThT), a small molecule that gives strong fluorescence upon binding to amyloids. Using the amyloid fibrils of Aβ40 and Aβ42 involved in Alzheimer's disease, and of yeast prion protein Ure2, here we study three aspects of ThT binding to amyloids: quantification of amyloid fibrils using ThT, the optimal ThT concentration for monitoring amyloid formation and the effect of ThT on aggregation kinetics. We show that ThT fluorescence correlates linearly with amyloid concentration over ThT concentrations ranging from 0.2 to 500 µM. At a given amyloid concentration, the plot of ThT fluorescence versus ThT concentration exhibits a bell-shaped curve. The maximal fluorescence signal depends mostly on the total ThT concentration, rather than amyloid to ThT ratio. For the three proteins investigated, the maximal fluorescence is observed at ThT concentrations of 20-50 µM. Aggregation kinetics experiments in the presence of different ThT concentrations show that ThT has little effect on aggregation at concentrations of 20 µM or lower. ThT at concentrations of 50 µM or more could affect the shape of the aggregation curves, but this effect is protein-dependent and not universal.
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Affiliation(s)
| | | | | | - Zhefeng Guo
- Author for correspondence: Zhefeng Guo e-mail:
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28
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Mora AK, Murudkar S, Alamelu A, Singh PK, Chattopadhyay S, Nath S. Benzothiazole-Based Neutral Ratiometric Fluorescence Sensor for Amyloid Fibrils. Chemistry 2016; 22:16505-16512. [DOI: 10.1002/chem.201602981] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Aruna K. Mora
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre, Trombay; Mumbai 400 085 India
| | - Sushant Murudkar
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre, Trombay; Mumbai 400 085 India
| | - A. Alamelu
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre, Trombay; Mumbai 400 085 India
- Cardomom Planters Association College, Bodinayakanur; Tamil Nadu India
| | - Prabhat K. Singh
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre, Trombay; Mumbai 400 085 India
| | | | - Sukhendu Nath
- Radiation & Photochemistry Division; Bhabha Atomic Research Centre, Trombay; Mumbai 400 085 India
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29
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Stsiapura VI, Kurhuzenkau SA, Kuzmitsky VA, Bouganov OV, Tikhomirov SA. Solvent Polarity Effect on Nonradiative Decay Rate of Thioflavin T. J Phys Chem A 2016; 120:5481-96. [DOI: 10.1021/acs.jpca.6b02577] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Valery A. Kuzmitsky
- Institute for Command Engineers of the Ministry for Emergencies of the Republic of Belarus, Minsk, Belarus
| | - Oleg V. Bouganov
- Institute
of Physics, National Academy of Sciences of Belarus, Minsk, Belarus
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30
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Kargapolova IY, Orlova NA, Erin KD, Shelkovnikov VV. Synthesis of unsymmetrical thioflavylium dyes from julolidine derivatives and polyfluorinated triphenyldihydropyrazoles. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1070428016010073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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Labed A, Jiang F, Labed I, Lator A, Peters M, Achard M, Kabouche A, Kabouche Z, Sharma GVM, Bruneau C. Iridium-Catalyzed Sustainable Access to Functionalized Julolidines through Hydrogen Autotransfer. ChemCatChem 2015. [DOI: 10.1002/cctc.201500051] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Singh PK, Murudkar S, Mora AK, Nath S. Ultrafast torsional dynamics of Thioflavin-T in an anionic cyclodextrin cavity. J Photochem Photobiol A Chem 2015. [DOI: 10.1016/j.jphotochem.2014.10.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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33
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Freire S, Rodríguez‐Prieto F, Ríos Rodríguez MC, Penedo JC, Al‐Soufi W, Novo M. Towards Ratiometric Sensing of Amyloid Fibrils In Vitro. Chemistry 2015; 21:3425-34. [DOI: 10.1002/chem.201406110] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Sonia Freire
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
| | - Flor Rodríguez‐Prieto
- Department of Physical Chemistry, Faculty of Chemistry and CIQUS, Campus Santiago de Compostela, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)
| | - M. Carmen Ríos Rodríguez
- Department of Physical Chemistry, Faculty of Chemistry and CIQUS, Campus Santiago de Compostela, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain)
| | - J. Carlos Penedo
- SUPA School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (UK)
| | - Wajih Al‐Soufi
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
| | - Mercedes Novo
- Department of Physical Chemistry, Faculty of Science, Campus Lugo, University of Santiago de Compostela, Campus Universitario s/n, 27001 Lugo (Spain)
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34
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Singh PK, Mora AK, Nath S. Ultrafast fluorescence spectroscopy reveals a dominant weakly-emissive population of fibril bound thioflavin-T. Chem Commun (Camb) 2015; 51:14042-5. [DOI: 10.1039/c5cc04256a] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ultrafast fluorescence spectroscopy reveals that the majority of insulin fibril bound thioflavin-T remains weakly emissive and undergoes efficient ultrafast conformational relaxation.
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Affiliation(s)
- Prabhat K. Singh
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Aruna K. Mora
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
| | - Sukhendu Nath
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400085
- India
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35
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Murudkar S, Mora AK, Singh PK, Bandyopadhyay T, Nath S. An ultrafast molecular rotor based ternary complex in a nanocavity: a potential “turn on” fluorescence sensor for the hydrocarbon chain. Phys Chem Chem Phys 2015; 17:5691-703. [DOI: 10.1039/c4cp04636f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Formation of a ternary complex by an ultrafast molecular rotor (UMR) with a macrocyclic cavitand has been investigated for the sensitive detection of the alkyl chain of a surfactant.
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Affiliation(s)
- Sushant Murudkar
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
| | - Aruna K. Mora
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
| | - Prabhat K. Singh
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
| | - Tusar Bandyopadhyay
- Theoretical Chemistry Section
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
| | - Sukhendu Nath
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085
- India
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36
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Murudkar S, Mora AK, Jakka S, Singh PK, Nath S. Ultrafast molecular rotor based DNA sensor: An insight into the mode of interaction. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2014.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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37
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Ghosh R, Palit DK. Ultrafast twisting dynamics of thioflavin-T: spectroscopy of the twisted intramolecular charge-transfer state. Chemphyschem 2014; 15:4126-31. [PMID: 25251013 DOI: 10.1002/cphc.201402317] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 06/23/2014] [Indexed: 11/11/2022]
Abstract
Understanding the excited-state properties of thioflavin-T (ThT) has been of immense importance, because of its efficient amyloid-sensing ability related to neurodegenerative disorders. The excited-state dynamics of ThT is studied by using sub-pico- and nanosecond time-resolved transient absorption techniques as well as density functional theory (DFT)/time-dependent DFT calculations. Barrierless twisting around the central C-C bond between two aromatic moieties is the dominant process that contributes to the ultrafast dynamics of the S1 state. The spectroscopic properties of the intramolecular charge-transfer state are characterized for the first time. The energetics of the S0 and S1 states has also been correlated with the experimentally observed spectroscopic parameters and structural dynamics. A longer-lived transient state populated with a very low yield has been characterized as the triplet state.
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Affiliation(s)
- Rajib Ghosh
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)
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38
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Hayne DJ, Lim S, Donnelly PS. Metal complexes designed to bind to amyloid-β for the diagnosis and treatment of Alzheimer's disease. Chem Soc Rev 2014; 43:6701-15. [PMID: 24671229 DOI: 10.1039/c4cs00026a] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease is the most common form of age-related neurodegenerative dementia. The disease is characterised by the presence of plaques in the cerebral cortex. The major constituent of these plaques is aggregated amyloid-β peptide. This review focuses on the molecular aspects of metal complexes designed to bind to amyloid-β. The development of radioactive metal-based complexes of copper and technetium designed as diagnostic imaging agents to detect amyloid burden in the brain is discussed. Separate sections of the review discuss the use of luminescent metal complexes to act as non-conventional probes of amyloid formation and recent research into the use of metal complexes as inhibitors of amyloid formation and toxicity.
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Affiliation(s)
- David J Hayne
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, 3010, Australia.
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Singh PK, Nath S. Ultrafast torsional dynamics in nanoconfined water pool: Comparison between neutral and charged reverse micelles. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.08.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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40
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Singh PK, Sujana J, Mora AK, Nath S. Probing the DNA–ionic liquid interaction using an ultrafast molecular rotor. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.07.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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41
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Murudkar S, Mora AK, Singh PK, Nath S. Ultrafast molecular rotor: an efficient sensor for premelting of natural DNA. Chem Commun (Camb) 2012; 48:5301-3. [DOI: 10.1039/c2cc30895a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Faulhaber K, Granzhan A, Ihmels H, Otto D, Thomas L, Wells S. Studies of the fluorescence light-up effect of amino-substituted benzo[b]quinolizinium derivatives in the presence of biomacromolecules. Photochem Photobiol Sci 2011; 10:1535-45. [PMID: 21720633 DOI: 10.1039/c1pp05106g] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A comparative study of the ability of amino-substituted benzo[b]quinolizinium derivatives to act as DNA- or protein-sensitive fluorescent probes is presented. Spectrophotometric titrations, DNA denaturation studies and viscometric titrations showed that all tested aminobenzo[b]quinolizinium derivatives intercalate into DNA with binding constants K(b) = 10(4)-10(5) M(-1). The intense fluorescence of the 9-aminobenzo[b]quinolizinium (Φ(fl) = 0.41) as well as the intrinsically very weak emission of the 7-aminobenzo[b]quinolizinium (Φ(fl) < 0.005) are quenched by the addition of DNA, most likely caused by a photoinduced electron transfer (PET) between the excited intercalated ligand and the DNA bases. The 6-aminobenzo[b]quinolizinium (1b) and the 6-amino-9-bromobenzo[b]quinolizinium (1c) exhibit very low fluorescence intensity in water (Φ(fl) < 0.005). However, in water-glycerol mixtures the emission intensity increases by factors of 56 (1b) and 27 (1c) with increasing glycerol content of the solution (0-100 wt%), which indicates the radiationless deactivation of the excited state of 1b and 1c due to a torsional relaxation, i.e. rotation about the exocyclic C(ar)-NH(2) bond. In the case of the bromo-substituted derivative 1c, a viscosity-independent heavy-atom-effect of the bromo substituent leads to additional quenching. The association of 1b and 1c with ds DNA leads to a restricted conformational flexibility of the intercalated ligand and results in an increase of fluorescence intensity. This effect is particularly strong in the presence of poly[dA-dT]-poly[dA-dT]. Upon association with ct DNA or poly[dG-dC]-poly[dG-dC] only very small enhancement of emission intensity (1b) or even a slight quenching (1c) of the fluorescence was observed because of the interfering PET reaction with the guanine residues. Preliminary experiments reveal that the 6-aminobenzo[b]quinolizinium derivatives 1b and 1c may also be employed as protein-sensitive probes, because their emission intensity increases upon association with selected albumins.
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Affiliation(s)
- Katja Faulhaber
- University of Würzburg, Institute of Organic Chemistry, Am Hubland, 94047, Würzburg, Germany
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Abstract
Alzheimer's disease (AD) is a common neurodegenerative disorder characterized by the deposition of amyloids in the brain. One prominent form of amyloid is composed of repeating units of the amyloid-β (Aβ) peptide. Over the past decade, it has become clear that these Aβ amyloids are not homogeneous; rather, they are composed of a series of structures varying in their overall size and shape and the number of Aβ peptides they contain. Recent theories suggest that these different amyloid conformations may play distinct roles in disease, although their relative contributions are still being discovered. Here, we review how chemical probes, such as Congo red, thioflavin T and their derivatives, have been powerful tools for the better understanding of amyloid structure and function. Moreover, we discuss how design and deployment of conformationally selective probes might be used to test emerging models of AD.
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Affiliation(s)
- Ashley A Reinke
- Department of Biological Chemistry, Pathology and the Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109-2216, USA
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Singh PK, Kumbhakar M, Pal H, Nath S. Confined ultrafast torsional dynamics of Thioflavin-T in a nanocavity. Phys Chem Chem Phys 2011; 13:8008-14. [PMID: 21445410 DOI: 10.1039/c0cp02635b] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The influence of confinement in the supramolecular β-cyclodextrin nanocavity on the excited state torsional dynamics of the amyloid fibril sensor, Thioflavin-T, is explored using subpicosecond fluorescence up-conversion spectroscopy. In the presence of β-cyclodextrin, the emission intensity and the fluorescence lifetime of Thioflavin-T significantly increases, indicating the confinement effect of the nanocage on the photophysical behaviour of the dye. Detailed time-resolved fluorescence studies show an appreciable dynamic Stokes' shift for the dye in the β-cyclodextrin nanocavity. Analysis of the time-resolved area normalized emission spectra (TRANES) indicates the formation of an emissive TICT state. The rate of formation of the TICT state, as calculated from the time dependent changes in the peak frequency and the width of the emission spectra, is found to be substantially slower in the β-cyclodextrin nanocavity compared to that in bulk water. Present results indicate that ultrafast torsional motion in Thioflavin-T is significantly retarded due to confinement by the β-cyclodextrin nanocavity.
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Affiliation(s)
- Prabhat K Singh
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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