1
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Melle C, Hoffmann B, Wiesenburg A, Biskup C. FLIM-FRET-based analysis of S100A11/annexin interactions in living cells. FEBS Open Bio 2024; 14:626-642. [PMID: 38408765 PMCID: PMC10988696 DOI: 10.1002/2211-5463.13782] [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: 06/17/2023] [Revised: 02/05/2024] [Accepted: 02/16/2024] [Indexed: 02/28/2024] Open
Abstract
Proteins achieve their biological functions in cells by cooperation in protein complexes. In this study, we employed fluorescence lifetime imaging microscopy (FLIM)-based Förster resonance energy transfer (FRET) measurements to investigate protein complexes comprising S100A11 and different members of the annexin (ANX) family, such as ANXA1, ANXA2, ANXA4, ANXA5, and AnxA6, in living cells. Using an S100A11 mutant without the capacity for Ca2+ binding, we found that Ca2+ binding of S100A11 is important for distinct S100A11/ANXA2 complex formation; however, ANXA1-containing complexes were unaffected by this mutant. An increase in the intracellular calcium concentration induced calcium ionophores, which strengthened the ANXA2/S100A11 interaction. Furthermore, we were able to show that S100A11 also interacts with ANXA4 in living cells. The FLIM-FRET approach used here can serve as a tool to analyze interactions between S100A11 and distinct annexins under physiological conditions in living cells.
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Affiliation(s)
- Christian Melle
- Biomolecular Photonics Group, Jena University HospitalFriedrich Schiller University JenaGermany
| | - Birgit Hoffmann
- Biomolecular Photonics Group, Jena University HospitalFriedrich Schiller University JenaGermany
| | - Annett Wiesenburg
- Biomolecular Photonics Group, Jena University HospitalFriedrich Schiller University JenaGermany
| | - Christoph Biskup
- Biomolecular Photonics Group, Jena University HospitalFriedrich Schiller University JenaGermany
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2
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Xue X, Persson H, Ye L. Polydopamine functionalized dendritic fibrous silica nanoparticles as a generic platform for nucleic acid-based biosensing. Mikrochim Acta 2024; 191:180. [PMID: 38443718 PMCID: PMC10914921 DOI: 10.1007/s00604-024-06234-2] [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: 11/06/2023] [Accepted: 02/13/2024] [Indexed: 03/07/2024]
Abstract
Accurate and rapid detection of nucleic acid sequences is of utmost importance in various fields, including disease monitoring, clinical treatment, gene analysis and drug discovery. In this study, we developed a "turn-on" fluorescence biosensor that enables simple and highly efficient detection of nucleic acid biomarkers. Our approach involves the utilization of 6-carboxyfluorescein modified single-stranded DNA (FAM-ssDNA) as molecular recognition element, along with polydopamine-functionalized dendritic fibrous nanosilica (DFNS). FAM-ssDNA serves as both specific molecular recognition element for the target analyte and reporter capable of transducing a detectable signal through Watson-Crick base pairing. The polydopamine-functionalized DFNS (DFNS@DA) exhibits strong binding to FAM-ssDNA via polyvalent metal mediated coordination leading to effective quenching by fluorescence resonance energy transfer. In the presence of a complementary target sequence, FAM-ssDNA forms hybridized structure and detaches from DFNS@DA, which causes an increased fluorescence emission. The analytical system based on FAM-ssDNA and DFNS@DA demonstrates exceptional sensitivity, selectivity, and rapid response for the detection of nucleic acid sequences, leveraging the high adsorption and quenching properties of DFNS@DA. For the first proof of concept, we demonstrated the successful detection of microRNA (miR-21) in cancer cells using the FAM-ssDNA/DFNS@DA system. Our results highlight the promising capabilities of DFNS@DA and nucleic acid-based biosensors, offering a generic and cost-effective solution for the detection of nucleic acid-related biomarkers.
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Affiliation(s)
- Xiaoting Xue
- Division of Pure and Applied Biochemistry, Department of Chemistry, Lund University, 22100, Lund, Sweden
| | - Helena Persson
- Division of Oncology, Department of Clinical Sciences, Lund University Cancer Center, 22381, Lund, Sweden
| | - Lei Ye
- Division of Pure and Applied Biochemistry, Department of Chemistry, Lund University, 22100, Lund, Sweden.
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3
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Yan W, Qin X, Sang X, Zhou X, Zheng Y, Yuan Y, Zhang Y. DNAzyme amplified dispersion state change of gold nanoparticles and its dual optical channels for ultrasensitive and facile detection of lead ion in preserved eggs. Food Chem 2024; 435:137538. [PMID: 37774625 DOI: 10.1016/j.foodchem.2023.137538] [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: 08/04/2023] [Revised: 09/13/2023] [Accepted: 09/18/2023] [Indexed: 10/01/2023]
Abstract
A dual-mode sensing platform for Pb2+ was constructed based on the dual optical channels of Au NPs system with the amplification of DNAzyme, and it was successfully applied for Pb2+ determination in preserved egg with satisfactory results. The presence of Pb2+ activated the DNAzyme and induced the dispersion change of Au NPs in high salt concentration. The sequent absorption change of Au NPs was translated to the fluorescence change of carbon dots through FRET, and the scattering change was transferred to grey value of images involving the Tyndall effect. Thus, a sensing platform based on fluorescence and colorimetric dual-technique was achieved for Pb2+ detection, under the optimized conditions. With the assistance of DNAzyme, the linear range of fluorometric and colorimetric method were 2.0 × 10-14 ∼ 8.0 × 10-10 mol/L and 2.4 × 10-13 ∼ 9.5 × 10-9 mol/L, respectively. The dual-mode sensing platform demonstrated its promising application in the environmental monitoring and food safety field.
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Affiliation(s)
- Wenju Yan
- Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China; College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
| | - Xuefei Qin
- College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
| | - Xueqing Sang
- College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
| | - Xueying Zhou
- Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China; College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
| | - Yanying Zheng
- Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China; College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
| | - Yali Yuan
- Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China; College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China.
| | - Yun Zhang
- Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China; College of Chemistry and Bioengineering, Guilin University of Technology, 12 Jiangan Road, Guilin 541004, China
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4
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Strotmann VI, Stahl Y. Visualization of in vivo protein-protein interactions in plants. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:3866-3880. [PMID: 35394544 PMCID: PMC9232200 DOI: 10.1093/jxb/erac139] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/01/2022] [Indexed: 06/14/2023]
Abstract
Molecular processes depend on the concerted and dynamic interactions of proteins, either by one-on-one interactions of the same or different proteins or by the assembly of larger protein complexes consisting of many different proteins. Here, not only the protein-protein interaction (PPI) itself, but also the localization and activity of the protein of interest (POI) within the cell is essential. Therefore, in all cell biological experiments, preserving the spatio-temporal state of one POI relative to another is key to understanding the underlying complex and dynamic regulatory mechanisms in vivo. In this review, we examine some of the applicable techniques to measure PPIs in planta as well as recent combinatorial advances of PPI methods to measure the formation of higher order complexes with an emphasis on in vivo imaging techniques. We compare the different methods and discuss their benefits and potential pitfalls to facilitate the selection of appropriate techniques by providing a comprehensive overview of how to measure in vivo PPIs in plants.
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Affiliation(s)
- Vivien I Strotmann
- Institute for Developmental Genetics, Heinrich-Heine University, Universitätsstr. 1, D-40225 Düsseldorf, Germany
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5
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Yang G, Liu Y, Teng J, Zhao CX. FRET Ratiometric Nanoprobes for Nanoparticle Monitoring. BIOSENSORS 2021; 11:505. [PMID: 34940262 PMCID: PMC8699184 DOI: 10.3390/bios11120505] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 05/11/2023]
Abstract
Fluorescence labelling is often used for tracking nanoparticles, providing a convenient assay for monitoring nanoparticle drug delivery. However, it is difficult to be quantitative, as many factors affect the fluorescence intensity. Förster resonance energy transfer (FRET), taking advantage of the energy transfer from a donor fluorophore to an acceptor fluorophore, provides a distance ruler to probe NP drug delivery. This article provides a review of different FRET approaches for the ratiometric monitoring of the self-assembly and formation of nanoparticles, their in vivo fate, integrity and drug release. We anticipate that the fundamental understanding gained from these ratiometric studies will offer new insights into the design of new nanoparticles with improved and better-controlled properties.
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Affiliation(s)
- Guangze Yang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia; (G.Y.); (Y.L.); (J.T.)
- ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Yun Liu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia; (G.Y.); (Y.L.); (J.T.)
| | - Jisi Teng
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia; (G.Y.); (Y.L.); (J.T.)
| | - Chun-Xia Zhao
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia; (G.Y.); (Y.L.); (J.T.)
- ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Chemical Engineering and Advanced Materials, Faculty of Engineering, Computer and Mathematical Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
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6
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Chen K, Li X, Yu X, Zhang T, Ye Q, Xiao W, Chen L, Huang B, Peng Y. Copper-cysteamine nanoparticles encapsulating fluorocoumarin silicon(IV) phthalocyanines: synthesis, characterization, and photophysical properties. J COORD CHEM 2019. [DOI: 10.1080/00958972.2019.1703184] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kuizhi Chen
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Xia Li
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Xinxin Yu
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Tiantian Zhang
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Qiuhao Ye
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Wenling Xiao
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
| | - Limin Chen
- Affiliate Hospital of Fujian Medical University, Fujian Medical University, Fuzhou, China
| | - Baoquan Huang
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou, China
| | - Yiru Peng
- College of Chemistry & Engineering, Fujian Provincial Key Laboratory of Polymer Materials, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou, China
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7
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Multispectral Depth-Resolved Fluorescence Lifetime Spectroscopy Using SPAD Array Detectors and Fiber Probes. SENSORS 2019; 19:s19122678. [PMID: 31200569 PMCID: PMC6631026 DOI: 10.3390/s19122678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 01/29/2023]
Abstract
Single Photon Avalanche Diode (SPAD) arrays are increasingly exploited and have demonstrated potential in biochemical and biomedical research, both for imaging and single-point spectroscopy applications. In this study, we explore the application of SPADs together with fiber-optic-based delivery and collection geometry to realize fast and simultaneous single-point time-, spectral-, and depth-resolved fluorescence measurements at 375 nm excitation light. Spectral information is encoded across the columns of the array through grating-based dispersion, while depth information is encoded across the rows thanks to a linear arrangement of probe collecting fibers. The initial characterization and validation were realized against layered fluorescent agarose-based phantoms. To verify the practicality and feasibility of this approach in biological specimens, we measured the fluorescence signature of formalin-fixed rabbit aorta samples derived from an animal model of atherosclerosis. The initial results demonstrate that this detection configuration can report fluorescence spectral and lifetime contrast originating at different depths within the specimens. We believe that our optical scheme, based on SPAD array detectors and fiber-optic probes, constitute a powerful and versatile approach for the deployment of multidimensional fluorescence spectroscopy in clinical applications where information from deeper tissue layers is important for diagnosis.
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8
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Li H, He H, Yu J, Cui Y, Yang Y, Qian G. Dual-band simultaneous lasing in MOFs single crystals with Fabry-Perot microcavities. Sci China Chem 2019. [DOI: 10.1007/s11426-019-9485-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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9
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Schwarz J, J Leopold H, Leighton R, Miller RC, Aplin CP, Boersma AJ, Heikal AA, Sheets ED. Macromolecular crowding effects on energy transfer efficiency and donor-acceptor distance of hetero-FRET sensors using time-resolved fluorescence. Methods Appl Fluoresc 2019; 7:025002. [PMID: 30690439 DOI: 10.1088/2050-6120/ab0242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Living cells are crowded with macromolecules and organelles, which affect a myriad of biochemical processes. As a result, there is a need for sensitive molecular sensors for quantitative, site-specific assessment of macromolecular crowding. Here, we investigated the excited-state dynamics of recently developed hetero-FRET sensors (mCerulean3-linker-mCitrine) in homogeneous and heterogeneous environments using time-resolved fluorescence measurements, which are compatible with fluorescence lifetime imaging microscopy (FLIM). The linker in these FRET constructs, which tether the mCerulean3 (the donor) and mCitrine (the acceptor), vary in both length and flexibility. Glycerol and Ficoll-70 solutions were used for homogeneous and heterogeneous environments, respectively, at variable concentrations. The wavelength-dependent studies suggest that the 425-nm excitation and the 475-nm emission of the donor are best suited for quantitative assessment of the energy transfer efficiency and the donor-acceptor distance of these FRET probes. Under the same experimental conditions, the enzymatically cleaved counterpart of these probes was used as a control as well as a means to account for the changes in the environmental refractive indices. Our results indicate that the energy transfer efficiency of these FRET probes increases as the linker becomes shorter and more flexible in pure buffer at room temperature. In addition, the FRET probes favor a compact structure with enhanced energy transfer efficiency and a shorter donor-acceptor distance in the heterogeneous, polymer-crowded environment due to steric hindrance. In contrast, the stretched conformation of these FRET probes is more favorable in the viscous, homogeneous environment with a reduced energy transfer efficiency and relatively larger donor-acceptor distance as compared with those in pure buffer, which was attributed to a reduced structural fluctuation of the mCerulean3-mCitrine FRET pair in the viscous, more restrictive glycerol-enriched buffer. Our findings will help to advance the potential of these hetero-FRET probes using FLIM for spatio-temporal assessment of the compartmentalized crowding in living cells.
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Affiliation(s)
- Jacob Schwarz
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, MN, United States of America
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10
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Leopold HJ, Leighton R, Schwarz J, Boersma AJ, Sheets ED, Heikal AA. Crowding Effects on Energy-Transfer Efficiencies of Hetero-FRET Probes As Measured Using Time-Resolved Fluorescence Anisotropy. J Phys Chem B 2019; 123:379-393. [PMID: 30571116 DOI: 10.1021/acs.jpcb.8b09829] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Macromolecular crowding is prevalent in all living cells due to the presence of large biomolecules and organelles. Cellular crowding is heterogeneous and is known to influence biomolecular transport, biochemical reactions, and protein folding. Emerging evidence suggests that some cell pathologies may be correlated with compartmentalized crowding. As a result, there is a need for robust biosensors that are sensitive to crowding as well as quantitative, noninvasive fluorescence methods that are compatible with living cells studies. Here, we have developed a model that describes the rotational dynamics of hetero-Förster resonance energy transfer (FRET) biosensors as a means to determine the energy-transfer efficiency and donor-acceptor distance. The model was tested on wavelength-dependent time-resolved fluorescence anisotropy of hetero-FRET probes (mCerulean3-linker-mCitrine) with variable linkers in both crowded (Ficoll-70) and viscous (glycerol) solutions at room temperature. Our results indicate that the energy-transfer efficiencies of these FRET probes increase as the linker becomes shorter and more flexible in pure buffer at room temperature. In addition, the FRET probes favor compact structures with enhanced energy-transfer efficiencies and a shorter donor-acceptor distance in the heterogeneous, polymer-crowded environment due to steric hindrance. In contrast, the extended conformation of these FRET probes is more favorable in viscous, homogeneous environments with a reduced energy-transfer efficiency compared to those in pure buffer, which we attribute to reduced structural fluctuations of the mCerulean3-mCitrine FRET pair in the glycerol-enriched buffer. Our results represent an important step toward the application of quantitative and noninvasive time-resolved fluorescence anisotropy of hetero-FRET probes to investigate compartmentalized macromolecular crowding and protein-protein interactions in living cells as well as in controlled environments.
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Affiliation(s)
- Hannah J Leopold
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering , University of Minnesota Duluth , Duluth , Minnesota 55812 , United States
| | - Ryan Leighton
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering , University of Minnesota Duluth , Duluth , Minnesota 55812 , United States
| | - Jacob Schwarz
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering , University of Minnesota Duluth , Duluth , Minnesota 55812 , United States
| | - Arnold J Boersma
- DW1-Leibniz Institute for Interactive Materials , Forckenbeckstr. 50 , 52056 Aachen , Germany
| | - Erin D Sheets
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering , University of Minnesota Duluth , Duluth , Minnesota 55812 , United States
| | - Ahmed A Heikal
- Department of Chemistry and Biochemistry, Swenson College of Science and Engineering , University of Minnesota Duluth , Duluth , Minnesota 55812 , United States
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11
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Peulen TO, Opanasyuk O, Seidel CAM. Combining Graphical and Analytical Methods with Molecular Simulations To Analyze Time-Resolved FRET Measurements of Labeled Macromolecules Accurately. J Phys Chem B 2017; 121:8211-8241. [PMID: 28709377 PMCID: PMC5592652 DOI: 10.1021/acs.jpcb.7b03441] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
![]()
Förster resonance energy transfer
(FRET) measurements from
a donor, D, to an acceptor, A, fluorophore are frequently used in vitro and in live cells to reveal information on the
structure and dynamics of DA labeled macromolecules. Accurate descriptions
of FRET measurements by molecular models are complicated because the
fluorophores are usually coupled to the macromolecule via flexible
long linkers allowing for diffusional exchange between multiple states
with different fluorescence properties caused by distinct environmental
quenching, dye mobilities, and variable DA distances. It is often
assumed for the analysis of fluorescence intensity decays that DA
distances and D quenching are uncorrelated (homogeneous quenching
by FRET) and that the exchange between distinct fluorophore states
is slow (quasistatic). This allows us to introduce the FRET-induced
donor decay, εD(t), a function solely
depending on the species fraction distribution of the rate constants
of energy transfer by FRET, for a convenient joint analysis of fluorescence
decays of FRET and reference samples by integrated graphical and analytical
procedures. Additionally, we developed a simulation toolkit to model
dye diffusion, fluorescence quenching by the protein surface, and
FRET. A benchmark study with simulated fluorescence decays of 500
protein structures demonstrates that the quasistatic homogeneous model
works very well and recovers for single conformations the average
DA distances with an accuracy of < 2%. For more complex
cases, where proteins adopt multiple conformations with significantly
different dye environments (heterogeneous case), we introduce a general
analysis framework and evaluate its power in resolving heterogeneities
in DA distances. The developed fast simulation methods, relying on
Brownian dynamics of a coarse-grained dye in its sterically accessible
volume, allow us to incorporate structural information in the decay
analysis for heterogeneous cases by relating dye states with protein
conformations to pave the way for fluorescence and FRET-based dynamic
structural biology. Finally, we present theories and simulations to
assess the accuracy and precision of steady-state and time-resolved
FRET measurements in resolving DA distances on the single-molecule
and ensemble level and provide a rigorous framework for estimating
approximation, systematic, and statistical errors.
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Affiliation(s)
- Thomas-Otavio Peulen
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität , Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Oleg Opanasyuk
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität , Universitätsstraße 1, 40225 Düsseldorf, Germany
| | - Claus A M Seidel
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität , Universitätsstraße 1, 40225 Düsseldorf, Germany
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12
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Currie M, Leopold H, Schwarz J, Boersma AJ, Sheets ED, Heikal AA. Fluorescence Dynamics of a FRET Probe Designed for Crowding Studies. J Phys Chem B 2017; 121:5688-5698. [DOI: 10.1021/acs.jpcb.7b01306] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Megan Currie
- Department
of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Hannah Leopold
- Department
of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Jacob Schwarz
- Department
of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Arnold J. Boersma
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Erin D. Sheets
- Department
of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Ahmed A. Heikal
- Department
of Chemistry and Biochemistry, Swenson College of Science and Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
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13
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Weidtkamp-Peters S, Stahl Y. The Use of FRET/FLIM to Study Proteins Interacting with Plant Receptor Kinases. Methods Mol Biol 2017; 1621:163-175. [PMID: 28567653 DOI: 10.1007/978-1-4939-7063-6_16] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The investigation of protein interactions in living plant tissue has become of increasing importance in recent years. A high spatial and temporal resolution for the observation of in vivo protein interaction is needed, e.g., in order to follow changes of plant receptor kinase interactions and complex formation over time. In vivo fluorescence or Förster resonance energy transfer (FRET) measurements allow for detailed analyses of interacting proteins in their natural environment at a subcellular level. Especially FRET-FLIM (fluorescence lifetime imaging microscopy) measurements provide an extremely powerful and reliable tool meeting the demands for investigating in vivo protein interaction quantitatively and with high precision. Here, we will describe in detail how to practically perform in vivo FRET measurements of receptor kinases in plants and discuss potential pitfalls and points of consideration.
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Affiliation(s)
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich-Heine University, Düsseldorf, Germany.
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14
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Tran LH, Lee C, Kang TJ, Jang SH. Graphene Oxide-mediated Fluorescence Quenching of Green Fluorescent Protein for Biomedical Applications. B KOREAN CHEM SOC 2016. [DOI: 10.1002/bkcs.10850] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Lan-Huong Tran
- Department of Biomedical Science and Center for Bio-Nanomaterials; Daegu University; Gyeongsan 38453 Korea
| | - ChangWoo Lee
- Department of Biomedical Science and Center for Bio-Nanomaterials; Daegu University; Gyeongsan 38453 Korea
| | - Tai Jong Kang
- Department of Chemistry and Applied Chemistry; Daegu University; Gyeongsan 38453 Korea
| | - Sei-Heon Jang
- Department of Biomedical Science and Center for Bio-Nanomaterials; Daegu University; Gyeongsan 38453 Korea
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15
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Chen W, Avezov E, Schlachter SC, Gielen F, Laine RF, Harding HP, Hollfelder F, Ron D, Kaminski CF. A method to quantify FRET stoichiometry with phasor plot analysis and acceptor lifetime ingrowth. Biophys J 2016; 108:999-1002. [PMID: 25762312 PMCID: PMC4375440 DOI: 10.1016/j.bpj.2015.01.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/23/2014] [Accepted: 01/09/2015] [Indexed: 11/26/2022] Open
Abstract
FRET is widely used for the study of protein-protein interactions in biological samples. However, it is difficult to quantify both the FRET efficiency (E) and the affinity (Kd) of the molecular interaction from intermolecular FRET signals in samples of unknown stoichiometry. Here, we present a method for the simultaneous quantification of the complete set of interaction parameters, including fractions of bound donors and acceptors, local protein concentrations, and dissociation constants, in each image pixel. The method makes use of fluorescence lifetime information from both donor and acceptor molecules and takes advantage of the linear properties of the phasor plot approach. We demonstrate the capability of our method in vitro in a microfluidic device and also in cells, via the determination of the binding affinity between tagged versions of glutathione and glutathione S-transferase, and via the determination of competitor concentration. The potential of the method is explored with simulations.
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Affiliation(s)
- WeiYue Chen
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Edward Avezov
- The Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Simon C Schlachter
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Fabrice Gielen
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Romain F Laine
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Heather P Harding
- The Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Florian Hollfelder
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - David Ron
- The Wellcome Trust Medical Research Council Institute of Metabolic Science and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Clemens F Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom.
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FUKUDA T, KURABAYASHI T, FUNAKI N, UDAKA H, SUZUKI M. Precise Fractionation of CdSe/ZnS Quantum Dot-Organic-Dye Conjugates Using a Gel Filtration Column. ANAL SCI 2016; 32:529-34. [DOI: 10.2116/analsci.32.529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Takeshi FUKUDA
- Department of Functional Materials Science, Saitama University
| | | | - Nayuta FUNAKI
- Department of Functional Materials Science, Saitama University
| | - Hikari UDAKA
- Department of Functional Materials Science, Saitama University
| | - Miho SUZUKI
- Department of Functional Materials Science, Saitama University
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17
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Hussain S, Malik AH, Iyer PK. FRET-assisted selective detection of flavins via cationic conjugated polyelectrolyte under physiological conditions. J Mater Chem B 2016; 4:4439-4446. [DOI: 10.1039/c6tb01350c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Cationic conjugated polyelectrolyte PMI performs ppb level detection and discrimination of flavins (RF, FMN and FAD) in aqueous media as well as in biological medium like serum.
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Affiliation(s)
- Sameer Hussain
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati-781039
- India
| | - Akhtar Hussain Malik
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati-781039
- India
| | - Parameswar Krishnan Iyer
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Guwahati-781039
- India
- Centre for Nanotechnology
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18
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Chen SJ, Sinsuebphon N, Intes X. Assessment of Gate Width Size on Lifetime-Based Förster Resonance Energy Transfer Parameter Estimation. PHOTONICS 2015; 2:1027-1042. [PMID: 26557647 PMCID: PMC4636205 DOI: 10.3390/photonics2041027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Förster Resonance Energy Transfer (FRET) enables the observation of interactions at the nanoscale level through the use of fluorescence optical imaging techniques. In FRET, fluorescence lifetime imaging can be used to quantify the fluorescence lifetime changes of the donor molecule, which are associated with proximity between acceptor and donor molecules. Among the FRET parameters derived from fluorescence lifetime imaging, the percentage of donor that interacts with the acceptor (in proximity) can be estimated via model-based fitting. However, estimation of the lifetime parameters can be affected by the acquisition parameters such as the temporal characteristics of the imaging system. Herein, we investigate the effect of various gate widths on the accuracy of estimation of FRET parameters with focus on the near-infrared spectral window. Experiments were performed in silico, in vitro, and in vivo with gate width sizes ranging from 300 ps to 1000 ps in intervals of 100 ps. For all cases, the FRET parameters were retrieved accurately and the imaging acquisition time was decreased three-fold. These results indicate that increasing the gate width up to 1000 ps still allows for accurate quantification of FRET interactions even in the case of short lifetimes such as those encountered with near-infrared FRET pairs.
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Affiliation(s)
| | | | - Xavier Intes
- Author to whom correspondence should be addressed; ; Tel.: +1-518-276-6964
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19
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Helmfors L, Boman A, Civitelli L, Nath S, Sandin L, Janefjord C, McCann H, Zetterberg H, Blennow K, Halliday G, Brorsson AC, Kågedal K. Protective properties of lysozyme on β-amyloid pathology: implications for Alzheimer disease. Neurobiol Dis 2015; 83:122-33. [PMID: 26334479 DOI: 10.1016/j.nbd.2015.08.024] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 08/03/2015] [Accepted: 08/21/2015] [Indexed: 01/24/2023] Open
Abstract
The hallmarks of Alzheimer disease are amyloid-β plaques and neurofibrillary tangles accompanied by signs of neuroinflammation. Lysozyme is a major player in the innate immune system and has recently been shown to prevent the aggregation of amyloid-β1-40 in vitro. In this study we found that patients with Alzheimer disease have increased lysozyme levels in the cerebrospinal fluid and lysozyme co-localized with amyloid-β in plaques. In Drosophila neuronal co-expression of lysozyme and amyloid-β1-42 reduced the formation of soluble and insoluble amyloid-β species, prolonged survival and improved the activity of amyloid-β1-42 transgenic flies. This suggests that lysozyme levels rise in Alzheimer disease as a compensatory response to amyloid-β increases and aggregation. In support of this, in vitro aggregation assays revealed that lysozyme associates with amyloid-β1-42 and alters its aggregation pathway to counteract the formation of toxic amyloid-β species. Overall, these studies establish a protective role for lysozyme against amyloid-β associated toxicities and identify increased lysozyme in patients with Alzheimer disease. Therefore, lysozyme has potential as a new biomarker as well as a therapeutic target for Alzheimer disease.
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Affiliation(s)
- Linda Helmfors
- Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden
| | - Andrea Boman
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden
| | - Livia Civitelli
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden
| | - Sangeeta Nath
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden
| | - Linnea Sandin
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden
| | - Camilla Janefjord
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden
| | - Heather McCann
- Neuroscience Research Australia and University of New South Wales, Randwick New South Wales 2031, Australia
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, Sahlgrenska University Hospital, 431 30 Mölndal, Sweden; UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
| | - Kaj Blennow
- Clinical Neurochemistry Laboratory, Department of Neuroscience and Physiology, Sahlgrenska University Hospital, 431 30 Mölndal, Sweden
| | - Glenda Halliday
- Neuroscience Research Australia and University of New South Wales, Randwick New South Wales 2031, Australia
| | - Ann-Christin Brorsson
- Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linköping University, 581 83 Linköping, Sweden.
| | - Katarina Kågedal
- Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, 581 85 Linköping, Sweden.
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20
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Hoffmann B, Klöcker N, Benndorf K, Biskup C. Visualization of the dynamics of PSD-95 and Kir2.1 interaction by fluorescence lifetime-based resonance energy transfer imaging. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.medpho.2014.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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21
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22
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Becker W. Fluorescence lifetime imaging by multi-dimensional time correlated single photon counting. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.medpho.2015.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Abstract
Optical imaging assays, especially fluorescence molecular assays, are minimally invasive if not completely noninvasive, and thus an ideal technique to be applied to live specimens. These fluorescence imaging assays are a powerful tool in biomedical sciences as they allow the study of a wide range of molecular and physiological events occurring in biological systems. Furthermore, optical imaging assays bridge the gap between the in vitro cell-based analysis of subcellular processes and in vivo study of disease mechanisms in small animal models. In particular, the application of Förster resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM), well-known techniques widely used in microscopy, to the optical imaging assay toolbox, will have a significant impact in the molecular study of protein-protein interactions during cancer progression. This review article describes the application of FLIM-FRET to the field of optical imaging and addresses their various applications, both current and potential, to anti-cancer drug delivery and cancer research.
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Affiliation(s)
- Shilpi Rajoria
- Albany Medical College, The Center for Cardiovascular Sciences, Albany, NY, 12208
| | - Lingling Zhao
- Rensselaer Polytechnic Institute, Biomedical imaging Center and Department of Biomedical Engineering, Troy, NY 12180
| | - Xavier Intes
- Rensselaer Polytechnic Institute, Biomedical imaging Center and Department of Biomedical Engineering, Troy, NY 12180
| | - Margarida Barroso
- Albany Medical College, The Center for Cardiovascular Sciences, Albany, NY, 12208
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24
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Sun Y, Periasamy A. Localizing protein-protein interactions in living cells using fluorescence lifetime imaging microscopy. Methods Mol Biol 2015; 1251:83-107. [PMID: 25391796 DOI: 10.1007/978-1-4939-2080-8_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In the past decade, advances in fluorescence lifetime imaging have extensively applied in the life sciences, from fundamental biological investigations to advanced clinical diagnosis. Fluorescence lifetime imaging microscopy (FLIM) is now routinely used in the biological sciences to monitor dynamic signaling events inside living cells, e.g., Protein-Protein interactions. In this chapter, we describe the calibration of both time-correlated single-photon counting (TCSPC) and frequency domain (FD) FLIM systems and the acquisition and analysis of FLIM-FRET data for investigating Protein-Protein interactions in living cells.
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Affiliation(s)
- Yuansheng Sun
- W.M. Keck Center for Cellular Imaging, Biology, University of Virginia, B005 Physical and Life Sciences Building, White Head Road, Charlottesville, VA, 22904, USA
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25
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Tamborini D, Portaluppi D, Villa F, Tisa S, Tosi A. Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:114703. [PMID: 25430129 DOI: 10.1063/1.4900863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.
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Affiliation(s)
- D Tamborini
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - D Portaluppi
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - F Villa
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - S Tisa
- Micro Photon Devices, via Stradivari 4, 39100 Bolzano, Italy
| | - A Tosi
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
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26
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Fereidouni F, Blab GA, Gerritsen HC. Phasor based analysis of FRET images recorded using spectrally resolved lifetime imaging. Methods Appl Fluoresc 2014; 2:035001. [DOI: 10.1088/2050-6120/2/3/035001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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27
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Boso G, Tosi A, Dalla Mora A, Zappa F. High-throughput gated photon counter with two detection windows programmable down to 70 ps width. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:013107. [PMID: 24517745 DOI: 10.1063/1.4862060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present the design and characterization of a high-throughput gated photon counter able to count electrical pulses occurring within two well-defined and programmable detection windows. We extensively characterized and validated this instrument up to 100 Mcounts/s and with detection window width down to 70 ps. This instrument is suitable for many applications and proves to be a cost-effective and compact alternative to time-correlated single-photon counting equipment, thanks to its easy configurability, user-friendly interface, and fully adjustable settings via a Universal Serial Bus (USB) link to a remote computer.
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Affiliation(s)
- Gianluca Boso
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Alberto Dalla Mora
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
| | - Franco Zappa
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy
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Nosi D, Mercatelli R, Chellini F, Soria S, Pini A, Formigli L, Quercioli F. A molecular imaging analysis of Cx43 association with Cdo during skeletal myoblast differentiation. JOURNAL OF BIOPHOTONICS 2013; 6:612-621. [PMID: 22930637 DOI: 10.1002/jbio.201200063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/12/2012] [Accepted: 07/30/2012] [Indexed: 06/01/2023]
Abstract
Cell-to-cell contacts are crucial for cell differentiation. The promyogenic cell surface protein, Cdo, functions as a component of multiprotein clusters to mediate cell adhesion signaling. Connexin 43, the main connexin forming gap junctions, also plays a key role in myogenesis. At least part of its effects is independent of the intercellular channel function, but the mechanisms underlying are unknown. Here, using multiple optical approaches, we provided the first evidence that Cx43 physically interacts with Cdo to form dynamic complexes during myoblast differentiation, offering clues for considering this interaction a structural basis of the channel-independent function of Cx43.
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Affiliation(s)
- Daniele Nosi
- Dipartimento di Anatomia, Istologia e Medicina Legale, Università di Firenze, Largo Brambilla 3 - Firenze, Italy
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29
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Sun Y, Rombola C, Jyothikumar V, Periasamy A. Förster resonance energy transfer microscopy and spectroscopy for localizing protein-protein interactions in living cells. Cytometry A 2013; 83:780-93. [PMID: 23813736 DOI: 10.1002/cyto.a.22321] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 04/08/2013] [Accepted: 05/23/2013] [Indexed: 12/15/2022]
Abstract
The fundamental theory of Förster resonance energy transfer (FRET) was established in the 1940s. Its great power was only realized in the past 20 years after different techniques were developed and applied to biological experiments. This success was made possible by the availability of suitable fluorescent probes, advanced optics, detectors, microscopy instrumentation, and analytical tools. Combined with state-of-the-art microscopy and spectroscopy, FRET imaging allows scientists to study a variety of phenomena that produce changes in molecular proximity, thereby leading to many significant findings in the life sciences. In this review, we outline various FRET imaging techniques and their strengths and limitations; we also provide a biological model to demonstrate how to investigate protein-protein interactions in living cells using both intensity- and fluorescence lifetime-based FRET microscopy methods.
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Affiliation(s)
- Yuansheng Sun
- The W.M. Keck Center for Cellular Imaging (KCCI), Department of Biology, Physical and Life Sciences Building, University of Virginia, Charlottesville, Virginia
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30
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Markovic B, Tamborini D, Villa F, Tisa S, Tosi A, Zappa F. 10 ps resolution, 160 ns full scale range and less than 1.5% differential non-linearity time-to-digital converter module for high performance timing measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:074703. [PMID: 22852708 DOI: 10.1063/1.4733705] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We present a compact high performance time-to-digital converter (TDC) module that provides 10 ps timing resolution, 160 ns dynamic range and a differential non-linearity better than 1.5% LSB(rms). The TDC can be operated either as a general-purpose time-interval measurement device, when receiving external START and STOP pulses, or in photon-timing mode, when employing the on-chip SPAD (single photon avalanche diode) detector for detecting photons and time-tagging them. The instrument precision is 15 ps(rms) (i.e., 36 ps(FWHM)) and in photon timing mode it is still better than 70 ps(FWHM). The USB link to the remote PC allows the easy setting of measurement parameters, the fast download of acquired data, and their visualization and storing via an user-friendly software interface. The module proves to be the best candidate for a wide variety of applications such as: fluorescence lifetime imaging, time-of-flight ranging measurements, time-resolved positron emission tomography, single-molecule spectroscopy, fluorescence correlation spectroscopy, diffuse optical tomography, optical time-domain reflectometry, quantum optics, etc.
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Affiliation(s)
- B Markovic
- Politecnico di Milano, Dipartimento di Elettronica e Informazione, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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32
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Adbul Rahim NA, Pelet S, Kamm RD, So PTC. Methodological considerations for global analysis of cellular FLIM/FRET measurements. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:026013. [PMID: 22463045 PMCID: PMC3382354 DOI: 10.1117/1.jbo.17.2.026013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 12/18/2011] [Accepted: 12/27/2011] [Indexed: 05/29/2023]
Abstract
Global algorithms can improve the analysis of fluorescence energy transfer (FRET) measurement based on fluorescence lifetime microscopy. However, global analysis of FRET data is also susceptible to experimental artifacts. This work examines several common artifacts and suggests remedial experimental protocols. Specifically, we examined the accuracy of different methods for instrument response extraction and propose an adaptive method based on the mean lifetime of fluorescent proteins. We further examined the effects of image segmentation and a priori constraints on the accuracy of lifetime extraction. Methods to test the applicability of global analysis on cellular data are proposed and demonstrated. The accuracy of global fitting degrades with lower photon count. By systematically tracking the effect of the minimum photon count on lifetime and FRET prefactors when carrying out global analysis, we demonstrate a correction procedure to recover the correct FRET parameters, allowing us to obtain protein interaction information even in dim cellular regions with photon counts as low as 100 per decay curve.
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Affiliation(s)
- Nur Aida Adbul Rahim
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Serge Pelet
- Massachusetts Institute of Technology, Department of Biological Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Roger D. Kamm
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
- Massachusetts Institute of Technology, Department of Biological Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
| | - Peter T. C. So
- Massachusetts Institute of Technology, Department of Mechanical Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
- Massachusetts Institute of Technology, Department of Biological Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139
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Abstract
Fluorescence lifetime imaging (FLI) has been used widely for measuring biomedical samples. Practical guidelines on taking successful FLI data are provided to avoid common errors that arise during the measurement. Several methods for analyzing and interpreting FLI results are also introduced; e.g., a model-free data analysis method called the polar plot allows visualization and analysis of FLI data without iterative fitting, and an image denoising algorithm called variance-stabilizing-transform TI Haar helps to elucidate the information of a complex biomedical sample. The instrument considerations and data analysis of Spectral-FLI are also discussed.
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34
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Sun Y, Day RN, Periasamy A. Investigating protein-protein interactions in living cells using fluorescence lifetime imaging microscopy. Nat Protoc 2011; 6:1324-40. [PMID: 21886099 PMCID: PMC3169422 DOI: 10.1038/nprot.2011.364] [Citation(s) in RCA: 175] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) is now routinely used for dynamic measurements of signaling events inside living cells, including detection of protein-protein interactions. An understanding of the basic physics of fluorescence lifetime measurements is required to use this technique. In this protocol, we describe both the time-correlated single photon counting and the frequency-domain methods for FLIM data acquisition and analysis. We describe calibration of both FLIM systems, and demonstrate how they are used to measure the quenched donor fluorescence lifetime that results from Förster resonance energy transfer (FRET). We then show how the FLIM-FRET methods are used to detect the dimerization of the transcription factor CCAAT/enhancer binding protein-α in live mouse pituitary cell nuclei. Notably, the factors required for accurate determination and reproducibility of lifetime measurements are described. With either method, the entire protocol including specimen preparation, imaging and data analysis takes ∼2 d.
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Affiliation(s)
- Yuansheng Sun
- W.M. Keck Center for Cellular Imaging, Department of Biology, University of Virginia, Charlottesville, Virginia, USA
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35
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Ma B, Xu M, Zeng F, Huang L, Wu S. Micelle nanoparticles for FRET-based ratiometric sensing of mercury ions in water, biological fluids and living cells. NANOTECHNOLOGY 2011; 22:065501. [PMID: 21212478 DOI: 10.1088/0957-4484/22/6/065501] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A fluorescence resonance energy transfer (FRET) based ratiometric sensing system for mercury ions is built in nano-sized core/corona micelles formed by a poly(ethylene oxide)-b-polystyrene diblock copolymer. For this system, a hydrophobic fluorescein derivative (FLS-C12), which serves as the energy transfer donor, is incorporated into the micelle core during the micelle formation; and a spirolactam-rhodamine derivative (RhB-CS) as a probe for mercury ions is located at the micelle core/corona interface. An efficient ring-opening reaction of RhB-CS induced by mercury ions generates the long-wavelength rhodamine B fluorophore which can act as the energy acceptor, affording the micelle nanoparticles the water-dispersible FRET-based ratiometric detection system for mercury ions, with a detection limit of 0.1 µM in water. The donor and the probe fluorophores, with their structure being appropriately modified, can strongly bind (non-covalently) to the specific sites of the micelles and form a stable ratiometric sensor in water and in some biological fluids. In addition, with the water-soluble and biocompatible poly(ethylene oxide) (PEO) as the corona of the micelles, the nano-sized sensing system can readily permeate through cell membrane and detect intracellular Hg(2+) level changes.
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Affiliation(s)
- Boling Ma
- College of Materials Science & Engineering, South China University of Technology, Guangzhou, People's Republic of China
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36
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Moeno S, Antunes E, Nyokong T. The determination of the photosensitizing properties of mercapto substituted phthalocyanine derivatives in the presence of quantum dots capped with mercaptopropionic acid. J Photochem Photobiol A Chem 2011. [DOI: 10.1016/j.jphotochem.2010.12.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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37
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Fang G, Xu M, Zeng F, Wu S. β-cyclodextrin as the vehicle for forming ratiometric mercury ion sensor usable in aqueous media, biological fluids, and live cells. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:17764-17771. [PMID: 20958017 DOI: 10.1021/la103368z] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The selective and sensitive detection methods for toxic transition-metal ions, which are rapid, facile, and applicable to the environmental and biological milieus, are of great importance. In this study, we designed a β-CD-based ratiometric sensor for detecting mercury ions in aqueous media, some biological fluids, and live cells. In this sensing platform, the thiocarbamido-containing probe dye was covalently linked onto the hydrophilic β-CD rim, which is conducive to complexing with metal ion, while the donor dye was anchored inside hydrophobic β-CD cavity via the adamantyl moiety, which is good for avoiding self-aggregation and enhancing the quantum yield of the donor dye. Upon associating with mercury ion, the probe dye undergoes ring-opening process and serves as the energy acceptor and constitutes the FRET system with the donor dye; by this way ratiometric detection of mercury ion in water can be realized with the detection limit of 10 nM. The cyclodextrin plays a crucial role for the sensing system; it not only accommodates both the donor dye and the probe dye which can form FRET system upon addition of Hg(2+) but also makes the sensor water-soluble and cell membrane permeable. This nontoxic sensing platform can be used for mercury ion detection in aqueous medium, biological fluids, and live cells (L929 and Hela). We also found that, upon being taken up by L929 cells, the sensor exhibited no cytotoxicity, and the cell proliferation was not affected.
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Affiliation(s)
- Gang Fang
- College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China
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Xu M, Wu S, Zeng F, Yu C. Cyclodextrin supramolecular complex as a water-soluble ratiometric sensor for ferric ion sensing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:4529-4534. [PMID: 19852476 DOI: 10.1021/la9033244] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Heightened concern for human health and environmental protection has stimulated active research on the potential impact of transition-metal ions and their toxic effects, thus it is very demanding to design transition-metal ion detection methods that are cost-effective, rapid, facile, and applicable to the environmental and biological milieus. In this study, we demonstrated an alternative strategy for constructing a water-soluble FRET-based ratiometric sensor for ferric ion detection by forming a supramolecular beta-cyclodextrin/dye complex. This water-soluble FRET system consists of a dansyl-linked beta-cyclodextrin (beta-CD-DNS) and a spirolactam rhodamine-linked adamantane (AD-SRhB). The dansyl moiety serves as the donor, and the spirolactam-rhodamine B derivative (SRhB) was chosen as a sensitive, selective chemosensor for Fe(III) ions and a very efficient ring-opening reaction induced by Fe(III) generates the long-wavelength rhodamine B fluorophore that can act as the energy acceptor. Moreover, the adamantyl (AD) group, which is known for its capability to form stable host-guest inclusion complexes with beta-CD derivatives, was covalently linked to the spirolactam rhodamine, thus the adamantyl moiety of the ion-recognition element can be anchored inside the CD cavity. In this way, the donor-acceptor separation can be kept within the critical Forster distance; accordingly, energy transfer can take place from the donor (dansyl) to the acceptor (rhodamine derivative/Fe(III) complex), and thus ratiometric detection for Fe(III) in an aqueous medium can be fulfilled. This FRET-based supramolecular sensor can be readily formed via an inclusion process using the donor part and the acceptor part, hence this strategy could afford a robust approach for constructing a wide range of FRET-based water-soluble sensing systems simply by assembling a specifically predesigned donor-linked CD and acceptor-linked adamantane.
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Affiliation(s)
- Meiyun Xu
- College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China
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Kwaaitaal M, Keinath NF, Pajonk S, Biskup C, Panstruga R. Combined bimolecular fluorescence complementation and Forster resonance energy transfer reveals ternary SNARE complex formation in living plant cells. PLANT PHYSIOLOGY 2010; 152:1135-47. [PMID: 20071602 PMCID: PMC2832253 DOI: 10.1104/pp.109.151142] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 01/08/2010] [Indexed: 05/18/2023]
Abstract
Various fluorophore-based microscopic methods, comprising Förster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC), are suitable to study pairwise interactions of proteins in living cells. The analysis of interactions between more than two protein partners using these methods, however, remains difficult. In this study, we report the successful application of combined BiFC-FRET-fluorescence lifetime imaging microscopy and BiFC-FRET-acceptor photobleaching measurements to visualize the formation of ternary soluble N-ethylmaleimide-sensitive factor attachment receptor complexes in leaf epidermal cells. This method expands the repertoire of techniques to study protein-protein interactions in living plant cells by a procedure capable of visualizing simultaneously interactions between three fluorophore-tagged polypeptide partners.
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Weidtkamp-Peters S, Felekyan S, Bleckmann A, Simon R, Becker W, Kühnemuth R, Seidel CAM. Multiparameter fluorescence image spectroscopy to study molecular interactions. Photochem Photobiol Sci 2009; 8:470-80. [PMID: 19337660 DOI: 10.1039/b903245m] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiparameter Fluorescence Image Spectroscopy (MFIS) is used to monitor simultaneously a variety of fluorescence parameters in confocal fluorescence microscopy. As the photons are registered one by one, MFIS allows for fully parallel recording of Fluorescence Correlation/Cross Correlation Spectroscopy (FCS/FCCS), fluorescence lifetime and pixel/image information over time periods of hours with picosecond accuracy. The analysis of the pixel fluorescence information in higher-dimensional histograms maximizes the selectivity of fluorescence microscopic methods. Moreover it facilitates a statistically-relevant data analysis of the pixel information which makes an efficient detection of heterogeneities possible. The reliability of MFIS has been demonstrated for molecular interaction studies in different complex environments: (I) detecting the heterogeneity of diffusion properties of the dye Rhodamine 110 in a sepharose bead, (II) Förster Resonance Energy Transfer (FRET) studies in mammalian HEK293 cells, and (III) FRET study of the homodimerisation of the transcription factor BIM1 in plant cells. The multidimensional analysis of correlated changes of several parameters measured by FRET, FCS, fluorescence lifetime and anisotropy increases the robustness of the analysis significantly. The economic use of photon information allows one to keep the expression levels of fluorescent protein-fusion proteins as low as possible (down to the single-molecule level).
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Affiliation(s)
- Stefanie Weidtkamp-Peters
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, 40225, Düsseldorf, Germany.
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Kelbauskas L, Woodbury N, Lohr D. DNA sequence-dependent variation in nucleosome structure, stability, and dynamics detected by a FRET-based analysisThis paper is one of a selection of papers published in this Special Issue, entitled 29th Annual International Asilomar Chromatin and Chromosomes Conference, and has undergone the Journal’s usual peer review process. Biochem Cell Biol 2009; 87:323-35. [DOI: 10.1139/o08-126] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Förster resonance energy transfer (FRET) techniques provide powerful and sensitive methods for the study of conformational features in biomolecules. Here, we review FRET-based studies of nucleosomes, focusing particularly on our work comparing the widely used nucleosome standard, 5S rDNA, and 2 promoter-derived regulatory element-containing nucleosomes, mouse mammary tumor virus (MMTV)-B and GAL10. Using several FRET approaches, we detected significant DNA sequence-dependent structure, stability, and dynamics differences among the three. In particular, 5S nucleosomes and 5S H2A/H2B-depleted nucleosomal particles have enhanced stability and diminished DNA dynamics, compared with MMTV-B and GAL10 nucleosomes and particles. H2A/H2B-depleted nucleosomes are of interest because they are produced by the activities of many transcription-associated complexes. Significant location-dependent (intranucleosomal) stability and dynamics variations were also observed. These also vary among nucleosome types. Nucleosomes restrict regulatory factor access to DNA, thereby impeding genetic processes. Eukaryotic cells possess mechanisms to alter nucleosome structure, to generate DNA access, but alterations often must be targeted to specific nucleosomes on critical regulatory DNA elements. By endowing specific nucleosomes with intrinsically higher DNA accessibility and (or) enhanced facility for conformational transitions, DNA sequence-dependent nucleosome dynamics and stability variations have the potential to facilitate nucleosome recognition and, thus, aid in the crucial targeting process. This and other nucleosome structure and function conclusions from FRET analyses are discussed.
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Affiliation(s)
- L. Kelbauskas
- Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA
| | - N. Woodbury
- Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA
| | - D. Lohr
- Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA
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FLIM and emission spectral analysis of caspase-3 activation inside single living cell during anticancer drug-induced cell death. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:447-56. [DOI: 10.1007/s00249-008-0390-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 12/05/2008] [Accepted: 12/07/2008] [Indexed: 01/11/2023]
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Selective detection of NADPH oxidase in polymorphonuclear cells by means of NAD(P)H-based fluorescence lifetime imaging. JOURNAL OF BIOPHYSICS 2008; 2008:602639. [PMID: 20107577 PMCID: PMC2809359 DOI: 10.1155/2008/602639] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Accepted: 09/02/2008] [Indexed: 11/18/2022]
Abstract
NADPH oxidase (NOX2) is a multisubunit membrane-bound enzyme complex that, upon assembly in activated cells,
catalyses the reduction of free oxygen to its superoxide anion, which further leads to reactive oxygen species (ROS) that are
toxic to invading pathogens, for example, the fungus Aspergillus fumigatus. Polymorphonuclear cells (PMNs) employ both
nonoxidative and oxidative mechanisms to clear this fungus from the lung. The oxidative mechanisms mainly depend on the
proper assembly and function of NOX2. We identified for the first time the NAD(P)H-dependent enzymes involved in such
oxidative mechanisms by means of biexponential NAD(P)H-fluorescence lifetime imaging (FLIM). A specific fluorescence
lifetime of 3670±140 picoseconds as compared to 1870 picoseconds for NAD(P)H bound to mitochondrial enzymes could be
associated with NADPH bound to oxidative enzymes in activated PMNs. Due to its predominance in PMNs and due to the
use of selective activators and inhibitors, we strongly believe that this specific lifetime mainly originates from NOX2. Our
experiments also revealed the high site specificity of the NOX2 assembly and, thus, of the ROS production as well as the
dynamic nature of these phenomena. On the example of NADPH oxidase, we demonstrate the potential of NAD(P)H-based
FLIM in selectively investigating enzymes during their cellular function.
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Hoffmann B, Zimmer T, Klöcker N, Kelbauskas L, König K, Benndorf K, Biskup C. Prolonged irradiation of enhanced cyan fluorescent protein or Cerulean can invalidate Forster resonance energy transfer measurements. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:031205. [PMID: 18601529 DOI: 10.1117/1.2937829] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Since its discovery, green fluorescent protein (GFP) and its variants have proven to be a good and convenient fluorescent label for proteins: GFP and other visible fluorescent proteins (VFPs) can be fused selectively to the protein of interest by simple cloning techniques and develop fluorescence without additional cofactors. Among the steadily growing collection of VFPs, several pairs can be chosen that can serve as donor and acceptor fluorophores in Forster resonance energy transfer (FRET) experiments. Among them, the cyan fluorescent proteins (ECFP/Cerulean) and the enhanced yellow fluorescent protein (EYFP) are most commonly used. We show that ECFP and Cerulean have some disadvantages despite their common use: Upon irradiation with light intensities that are commonly used for intensity- and lifetime-based FRET measurements, both the fluorescence intensity and the fluorescence lifetime of ECFP and Cerulean decrease. This can hamper both intensity- and lifetime-based FRET measurements and emphasizes the need for control measurements to exclude these artifacts.
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Affiliation(s)
- Birgit Hoffmann
- Universitatsklinikum Jena, Institut fur Physiologie II, Kollegiengasse 9 07740 Jena, Germany
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Kofoed EM, Guerbadot M, Schaufele F. Dimerization between aequorea fluorescent proteins does not affect interaction between tagged estrogen receptors in living cells. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:031207. [PMID: 18601531 PMCID: PMC2581880 DOI: 10.1117/1.2940366] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Forster resonance energy transfer (FRET) detection of protein interaction in living cells is commonly measured following the expression of interacting proteins genetically fused to the cyan (CFP) and yellow (YFP) derivatives of the Aequorea victoria fluorescent protein (FP). These FPs can dimerize at mM concentrations, which may introduce artifacts into the measurement of interaction between proteins that are fused with the FPs. Here, FRET analysis of the interaction between estrogen receptors (alpha isoform, ERalpha) labeled with "wild-type" CFP and YFP is compared with that of ERalpha labeled with "monomeric" A206K mutants of CFP and YFP. The intracellular equilibrium dissociation constant for the hormone-induced ERalpha-ERalpha interaction is similar for ERalpha labeled with wild-type or monomeric FPs. However, the measurement of energy transfer measured for ERalpha-ERalpha interaction in each cell is less consistent with the monomeric FPs. Thus, dimerization of the FPs does not affect the kinetics of ERalpha-ERalpha interaction but, when brought close together via ERalpha-ERalpha interaction, FP dimerization modestly improves FRET measurement.
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Affiliation(s)
- Eric M Kofoed
- University of California, San Francisco, Diabetes Center and Department of Medicine, S-1230, 513 Parnassus, San Francisco, California 94143-0540, USA
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Niesner RA, Andresen V, Gunzer M. Intravital two-photon microscopy: focus on speed and time resolved imaging modalities. Immunol Rev 2008; 221:7-25. [PMID: 18275472 DOI: 10.1111/j.1600-065x.2008.00582.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Initially used mainly in the neurosciences, two-photon microscopy has become a powerful tool for the analysis of immunological processes. Here, we describe currently available two-photon microscopy techniques with a focus on novel approaches that allow very high image acquisition rates compared with state-of-the-art systems. This improvement is achieved through a parallelization of the excitation process: multiple beams scan the sample simultaneously, and the fluorescence is collected with sensitive charge-coupled device (CCD)-based line or field detectors. The new technique's performance is compared with conventional single beam laser-scanning systems that detect signals by means of photomultipliers. We also discuss the use of time- and polarization-resolved fluorescence detection, especially fluorescence lifetime imaging (FLIM), which goes beyond simple detection of cells and tissue structures and allows insight into cellular physiology. We focus on the analysis of endogenous fluorophores such as NAD(P)H as a way to analyze the redox status in cells with subcellular resolution. Here, high-speed imaging setups in combination with novel ways of data analysis allow the generation of FLIM data sets almost in real time. The implications of this technology for the analysis of immune reactions and other cellular processes are discussed.
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Affiliation(s)
- Raluca A Niesner
- Junior Research Group Immunodynamics, Helmholtz Centre for Infection Research, Braunschweig, Germany
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Lalonde S, Ehrhardt DW, Loqué D, Chen J, Rhee SY, Frommer WB. Molecular and cellular approaches for the detection of protein-protein interactions: latest techniques and current limitations. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:610-635. [PMID: 18269572 DOI: 10.1111/j.1365-313x.2007.03332.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Homotypic and heterotypic protein interactions are crucial for all levels of cellular function, including architecture, regulation, metabolism, and signaling. Therefore, protein interaction maps represent essential components of post-genomic toolkits needed for understanding biological processes at a systems level. Over the past decade, a wide variety of methods have been developed to detect, analyze, and quantify protein interactions, including surface plasmon resonance spectroscopy, NMR, yeast two-hybrid screens, peptide tagging combined with mass spectrometry and fluorescence-based technologies. Fluorescence techniques range from co-localization of tags, which may be limited by the optical resolution of the microscope, to fluorescence resonance energy transfer-based methods that have molecular resolution and can also report on the dynamics and localization of the interactions within a cell. Proteins interact via highly evolved complementary surfaces with affinities that can vary over many orders of magnitude. Some of the techniques described in this review, such as surface plasmon resonance, provide detailed information on physical properties of these interactions, while others, such as two-hybrid techniques and mass spectrometry, are amenable to high-throughput analysis using robotics. In addition to providing an overview of these methods, this review emphasizes techniques that can be applied to determine interactions involving membrane proteins, including the split ubiquitin system and fluorescence-based technologies for characterizing hits obtained with high-throughput approaches. Mass spectrometry-based methods are covered by a review by Miernyk and Thelen (2008; this issue, pp. 597-609). In addition, we discuss the use of interaction data to construct interaction networks and as the basis for the exciting possibility of using to predict interaction surfaces.
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Affiliation(s)
- Sylvie Lalonde
- Carnegie Institution, 260 Panama Street, Stanford, CA 94305, USA.
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Orthaus S, Biskup C, Hoffmann B, Hoischen C, Ohndorf S, Benndorf K, Diekmann S. Assembly of the Inner Kinetochore Proteins CENP-A and CENP-B in Living Human Cells. Chembiochem 2008; 9:77-92. [DOI: 10.1002/cbic.200700358] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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