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Hasegawa M, Ishii A. Thin-film formation for promoting the potential of luminescent lanthanide coordination complexes. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213458] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Dong C, Garen CR, Mercier P, Petersen NO, Woodside MT. Characterizing the inhibition of α-synuclein oligomerization by a pharmacological chaperone that prevents prion formation by the protein PrP. Protein Sci 2019; 28:1690-1702. [PMID: 31306510 DOI: 10.1002/pro.3684] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022]
Abstract
Aggregation of the disordered protein α-synuclein into amyloid fibrils is a central feature of synucleinopathies, neurodegenerative disorders that include Parkinson's disease. Small, pre-fibrillar oligomers of misfolded α-synuclein are thought to be the key toxic entities, and α-synuclein misfolding can propagate in a prion-like way. We explored whether a compound with anti-prion activity that can bind to unfolded parts of the protein PrP, the cyclic tetrapyrrole Fe-TMPyP, was also active against α-synuclein aggregation. Observing the initial stages of aggregation via fluorescence cross-correlation spectroscopy, we found that Fe-TMPyP inhibited small oligomer formation in a dose-dependent manner. Fe-TMPyP also inhibited the formation of mature amyloid fibrils in vitro, as detected by thioflavin T fluorescence. Isothermal titration calorimetry indicated Fe-TMPyP bound to monomeric α-synuclein with a stoichiometry of 2, and two-dimensional heteronuclear single quantum coherence NMR spectra revealed significant interactions between Fe-TMPyP and the C-terminus of the protein. These results suggest commonalities among aggregation mechanisms for α-synuclein and the prion protein may exist that can be exploited as therapeutic targets.
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Affiliation(s)
- Chunhua Dong
- Department of Physics, University of Alberta, Edmonton, Alberta, Canada
| | - Craig R Garen
- Department of Physics, University of Alberta, Edmonton, Alberta, Canada
| | - Pascal Mercier
- National High Field Nuclear Magnetic Resonance Centre (NANUC), Edmonton, Alberta, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
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Li X, Dong C, Hoffmann M, Garen CR, Cortez LM, Petersen NO, Woodside MT. Early stages of aggregation of engineered α-synuclein monomers and oligomers in solution. Sci Rep 2019; 9:1734. [PMID: 30741954 PMCID: PMC6370846 DOI: 10.1038/s41598-018-37584-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/10/2018] [Indexed: 12/15/2022] Open
Abstract
α-Synuclein is a protein that aggregates as amyloid fibrils in the brains of patients with Parkinson's disease and dementia with Lewy bodies. Small oligomers of α-synuclein are neurotoxic and are thought to be closely associated with disease. Whereas α-synuclein fibrillization and fibril morphologies have been studied extensively with various methods, the earliest stages of aggregation and the properties of oligomeric intermediates are less well understood because few methods are able to detect and characterize early-stage aggregates. We used fluorescence spectroscopy to investigate the early stages of aggregation by studying pairwise interactions between α-synuclein monomers, as well as between engineered tandem oligomers of various sizes (dimers, tetramers, and octamers). The hydrodynamic radii of these engineered α-synuclein species were first determined by fluorescence correlation spectroscopy and dynamic light scattering. The rate of pairwise aggregation between different species was then monitored using dual-color fluorescence cross-correlation spectroscopy, measuring the extent of association between species labelled with different dyes at various time points during the early aggregation process. The aggregation rate and extent increased with tandem oligomer size. Self-association of the tandem oligomers was found to be the preferred pathway to form larger aggregates: interactions between oligomers occurred faster and to a greater extent than interactions between oligomers and monomers, indicating that the oligomers were not as efficient in seeding further aggregation by addition of monomers. These results suggest that oligomer-oligomer interactions may play an important role in driving aggregation during its early stages.
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Affiliation(s)
- Xi Li
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada.,Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Chunhua Dong
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada.,Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Marion Hoffmann
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Craig R Garen
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Leonardo M Cortez
- Division of Neurology, Department of Medicine, Centre for Prions and Protein Folding Diseases, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2M8, Canada
| | - Nils O Petersen
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada.
| | - Michael T Woodside
- Department of Physics, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
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Oura M, Yamamoto J, Ishikawa H, Mikuni S, Fukushima R, Kinjo M. Polarization-dependent fluorescence correlation spectroscopy for studying structural properties of proteins in living cell. Sci Rep 2016; 6:31091. [PMID: 27489044 PMCID: PMC4973283 DOI: 10.1038/srep31091] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/14/2016] [Indexed: 11/10/2022] Open
Abstract
Rotational diffusion measurement is predicted as an important method in cell biology because the rotational properties directly reflect molecular interactions and environment in the cell. To prove this concept, polarization-dependent fluorescence correlation spectroscopy (pol-FCS) measurements of purified fluorescent proteins were conducted in viscous solution. With the comparison between the translational and rotational diffusion coefficients obtained from pol-FCS measurements, the hydrodynamic radius of an enhanced green fluorescent protein (EGFP) was estimated as a control measurement. The orientation of oligomer EGFP in living cells was also estimated by pol-FCS and compared with Monte Carlo simulations. The results of this pol-FCS experiment indicate that this method allows an estimation of the molecular orientation using the characteristics of rotational diffusion. Further, it can be applied to analyze the degree of molecular orientation and multimerization or detection of tiny aggregation of aggregate-prone proteins.
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Affiliation(s)
- Makoto Oura
- Laboratory of Molecular Cell Dynamics, Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Johtaro Yamamoto
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Hideto Ishikawa
- Laboratory of Molecular Cell Dynamics, Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Shintaro Mikuni
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Ryousuke Fukushima
- Laboratory of Molecular Cell Dynamics, Graduate School of Life Science, Hokkaido University, Sapporo, 001-0021, Japan
| | - Masataka Kinjo
- Laboratory of Molecular Cell Dynamics, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
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Lee J, Kim SW. Analysis of the Fluorescence Correlation Function of Quantum Rods with Different Lengths. J Fluoresc 2015; 25:1813-8. [PMID: 26399538 DOI: 10.1007/s10895-015-1671-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/14/2015] [Indexed: 11/29/2022]
Abstract
We built a polarization fluorescence correlation spectroscopy system to analyze the variation of the correlation function in rotational diffusion based on the length of rod-like fluorescent particles. Because the rotational diffusion of particles in liquid depends on the relative polarization states of the laser source and particle fluorescence, we compared the amplitudes of the rotational diffusion using the autocorrelation function in different polarization states. For experiments that depend on the length of the fluorescent particles, we prepared three kinds of quantum rod samples with a width of 6.5 ± 0.5 nm and lengths of 17 ± 3, 40 ± 3, and 46 ± 3 nm. Through the experiment, we obtained the hydrodynamic radii of each particle using the rotational diffusion coefficient: 10.7 ± 0.8, 13.4 ± 0.7, and 14.1 ± 0.4 nm with the length of the particles. All the obtained values for radii are 3 nm larger than the calculated equivalent radii of spheres with the same volume as the rod samples. Through a fraction analysis by polarization state, we confirmed that the ratio of rotational fraction for polarization increases with the aspect ratio of the actual particle.
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Affiliation(s)
- Jaeran Lee
- Department of Physics, University of Ulsan, Ulsan, 680-749, South Korea
| | - Sok Won Kim
- Department of Physics, University of Ulsan, Ulsan, 680-749, South Korea.
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Hu H, Huang X, Ren J. Studies on the formation and stability of triplex DNA using fluorescence correlation spectroscopy. LUMINESCENCE 2015; 31:830-6. [DOI: 10.1002/bio.3030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 08/17/2015] [Accepted: 08/17/2015] [Indexed: 12/17/2022]
Affiliation(s)
- Hongyan Hu
- College of Chemistry & Chemical Engineering; Shanghai Jiao Tong University; Shanghai People's Republic of China
| | - Xiangyi Huang
- College of Chemistry & Chemical Engineering; Shanghai Jiao Tong University; Shanghai People's Republic of China
| | - Jicun Ren
- College of Chemistry & Chemical Engineering; Shanghai Jiao Tong University; Shanghai People's Republic of China
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Lee D, Kim M, Kim SY, Shin H, Kim SW, Park I. Investigation of the nanoviscosity effect of a G-quadruplex and single-strand DNA using fluorescence correlation spectroscopy. J Chem Phys 2015; 142:025101. [PMID: 25591385 DOI: 10.1063/1.4905113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Guanine (G)-quadruplexes are of interest because of their presence in the telomere sequence and the oncogene promoter region. Their diffusion and change of structure, especially in high viscosity solutions, are important for understanding their dynamics. G-quadruplexes may have less effective viscosity (nanoviscosity) when they are smaller than the solvent molecules. In this paper, we report the difference in the diffusion dynamics of the G-rich DNA sequences of single-strand DNA (ssDNA) and the G-quadruplex in aqueous, sucrose, and polyethylene glycol (PEG) solutions. From experiments with aqueous and sucrose solutions, we confirm that a simple diffusion model according to the viscosity is appropriate. In the PEG experiments, the nanoviscosity effect is observed according to PEG's molecular weight. In the PEG 200 solution, both the ssDNA and the G-quadruplex possess macroviscosity. In the PEG 10,000 solution, the G-quadruplex possesses nanoviscosity and the ssDNA possesses macroviscosity, whereas, in the PEG 35,000 solution, both ssDNA and the G-quadruplex possess nanoviscosity. The experimental results are consistent with the theoretical predictions.
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Affiliation(s)
- Dongkeun Lee
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
| | - Minjung Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
| | - Soo Yong Kim
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
| | - Hyosup Shin
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, South Korea
| | - Sok Won Kim
- Department of Physics, University of Ulsan, Ulsan 680-749, South Korea
| | - Inho Park
- Department of Physics, University of Incheon, Incheon 406-772, South Korea
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