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Buenaventura A, Saito T, Kanao T, Matsunaga D, Matsui TS, Deguchi S. Intracellular Macromolecular Crowding within Individual Stress Fibers Analyzed by Fluorescence Correlation Spectroscopy. Cell Mol Bioeng 2024; 17:165-176. [PMID: 39050511 PMCID: PMC11263330 DOI: 10.1007/s12195-024-00803-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/06/2024] [Indexed: 07/27/2024] Open
Abstract
Introduction The diffusion of cell components such as proteins is crucial to the function of all living cells. The abundance of macromolecules in cells is likely to cause a state of macromolecular crowding, but its effects on the extent of diffusion remain poorly understood. Methods Here we investigate the diffusion rate in three distinct locations in mesenchymal cell types, namely the open cytoplasm, the stress fibers in the open cytoplasm, and those below the nucleus using three kinds of biologically inert green fluorescent proteins (GFPs), namely a monomer, dimer, and trimer GFP. Fluorescence correlation spectroscopy (FCS) was used to determine the diffusion coefficients. Results We show that diffusion tends to be lowered on average in stress fibers and is significantly lower in those located below the nucleus. Our data suggest that the diffusive properties of GFPs, and potentially other molecules as well, are hindered by macromolecular crowding. However, although the size dependence on protein diffusion was also studied for monomer, dimer, and trimer GFPs, there was no significant difference in the diffusion rates among the GFPs of these sizes. These results could be attributed to the lack of significant change in protein size among the selected GFP multimers. Conclusion The data presented here would provide a basis for better understanding of the complex protein diffusion in the nonuniform cytoplasm, shedding light on cellular responses to mechanical stress, their local mechanical properties, and reduced turnover in senescent cells.
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Affiliation(s)
- Aria Buenaventura
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Takumi Saito
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, 980-0812 Japan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
- Nanobiology Institute, Yale University, West Haven, USA
| | - Taiga Kanao
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Daiki Matsunaga
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Tsubasa S. Matsui
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Shinji Deguchi
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
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2
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Clark BS, Silvernail I, Gordon K, Castaneda JF, Morgan AN, Rolband LA, LeBlanc SJ. A practical guide to time-resolved fluorescence microscopy and spectroscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577300. [PMID: 38586000 PMCID: PMC10996486 DOI: 10.1101/2024.01.25.577300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Time-correlated single photon counting (TCSPC) coupled with confocal microscopy is a versatile biophysical tool that enables real-time monitoring of biomolecular dynamics across many timescales. With TCSPC, Fluorescence correlation spectroscopy (FCS) and pulsed interleaved excitation-Förster resonance energy transfer (PIE-FRET) are collected simultaneously on diffusing molecules to extract diffusion characteristics and proximity information. This article is a guide to calibrating FCS and PIE-FRET measurements with several biological samples including liposomes, streptavidin-coated quantum dots, proteins, and nucleic acids for reliable determination of diffusion coefficients and FRET efficiency. The FRET efficiency results are also compared to surface-attached single molecules using fluorescence lifetime imaging microscopy (FLIM-FRET). Combining the methods is a powerful approach to revealing mechanistic details of biological processes and pathways.
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Ludtke T, Simó C, Gimenez Reyes S, Martinez Moro M, Salvador C, Ritacco H, Andreozzi P, Llop J, Moya SE. A study of complexation and biological fate of polyethyleneimine-siRNA polyplexes in vitro and in vivo by fluorescence correlation spectroscopy and positron emission tomography imaging. NANOSCALE 2024; 16:3525-3533. [PMID: 38273800 DOI: 10.1039/d3nr04026g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
A deeper knowledge on the formation and biological fate of polymer based gene vectors is needed for their translation into therapy. Here, polyplexes of polyethyleneimine (PEI) and silencing RNA (siRNA) are formed with theoretical N/P ratios of 2, 4 and 12. Fluorescence correlation spectroscopy (FCS) is used to study the formation of polyplexes from fluorescently labelled PEI and siRNA. FCS proves the presence of free PEI. From the analysis of the autocorrelation functions it was possible to determine the actual stoichiometry of polyplexes. FCS and fluorescence cross correlation spectroscopy (FCCS) are used to follow the fate of the polyplexes intracellularly. Polyplexes disassemble after 1 day inside cells. Positron emission tomography (PET) studies are conducted with radiolabelled polyplexes prepared with siRNA or PEI labelled with 2,3,5,6-tetrafluorophenyl 6-[18F]-fluoronicotinate ([18F]F-PyTFP). PET studies in healthy mice show that [18F]siRNA/PEI and siRNA/[18F]PEI polyplexes show similar biodistribution patterns with limited circulation in the bloodstream and accumulation in the liver. Higher activity for [18F]PEI in the kidney and bladder suggests the presence of free PEI.
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Affiliation(s)
- Tanja Ludtke
- Soft Matter Nanotechnology, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
| | - Cristina Simó
- Soft Matter Nanotechnology, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
- Radiochemistry and Nuclear Imaging laboratory, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
| | - Santiago Gimenez Reyes
- Soft Matter Nanotechnology, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
- Instituto de Fisica del Sur (IFISUR-CONICET), Av. Alem, Bahia Blanca, Argentina
| | - Marta Martinez Moro
- Soft Matter Nanotechnology, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
| | - Cristian Salvador
- CIDETEC, Basque Research and Technology Alliance (BRTA), Parque Científico y Tecnológico de Gipuzkoa, Miramon Pasealekua, 196, Donostia-San Sebastián 20014, Spain
| | - Hernan Ritacco
- Instituto de Fisica del Sur (IFISUR-CONICET), Av. Alem, Bahia Blanca, Argentina
| | - Patrizia Andreozzi
- Department of Chemistry 'Ugo Schiff', University of Florence, Via della Lastruccia 3, 50019 Sesto Fiorentino, FI, Italy
| | - Jordi Llop
- Radiochemistry and Nuclear Imaging laboratory, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
| | - Sergio E Moya
- Soft Matter Nanotechnology, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramon 194, 20014, Donostia-San Sebastián, Spain.
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García Fernández F, Huet S, Miné-Hattab J. Multi-Scale Imaging of the Dynamic Organization of Chromatin. Int J Mol Sci 2023; 24:15975. [PMID: 37958958 PMCID: PMC10649806 DOI: 10.3390/ijms242115975] [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: 09/19/2023] [Revised: 10/27/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023] Open
Abstract
Chromatin is now regarded as a heterogeneous and dynamic structure occupying a non-random position within the cell nucleus, where it plays a key role in regulating various functions of the genome. This current view of chromatin has emerged thanks to high spatiotemporal resolution imaging, among other new technologies developed in the last decade. In addition to challenging early assumptions of chromatin being regular and static, high spatiotemporal resolution imaging made it possible to visualize and characterize different chromatin structures such as clutches, domains and compartments. More specifically, super-resolution microscopy facilitates the study of different cellular processes at a nucleosome scale, providing a multi-scale view of chromatin behavior within the nucleus in different environments. In this review, we describe recent imaging techniques to study the dynamic organization of chromatin at high spatiotemporal resolution. We also discuss recent findings, elucidated by these techniques, on the chromatin landscape during different cellular processes, with an emphasis on the DNA damage response.
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Affiliation(s)
- Fabiola García Fernández
- Laboratory of Computational and Quantitative Biology, CNRS, Institut de Biologie Paris-Seine, Sorbonne Université, 75005 Paris, France;
| | - Sébastien Huet
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, 35000 Rennes, France;
- Institut Universitaire de France, 75231 Paris, France
| | - Judith Miné-Hattab
- Laboratory of Computational and Quantitative Biology, CNRS, Institut de Biologie Paris-Seine, Sorbonne Université, 75005 Paris, France;
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Zentout S, Smith R, Jacquier M, Huet S. New Methodologies to Study DNA Repair Processes in Space and Time Within Living Cells. Front Cell Dev Biol 2021; 9:730998. [PMID: 34589495 PMCID: PMC8473836 DOI: 10.3389/fcell.2021.730998] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/25/2021] [Indexed: 01/02/2023] Open
Abstract
DNA repair requires a coordinated effort from an array of factors that play different roles in the DNA damage response from recognizing and signaling the presence of a break, creating a repair competent environment, and physically repairing the lesion. Due to the rapid nature of many of these events, live-cell microscopy has become an invaluable method to study this process. In this review we outline commonly used tools to induce DNA damage under the microscope and discuss spatio-temporal analysis tools that can bring added information regarding protein dynamics at sites of damage. In particular, we show how to go beyond the classical analysis of protein recruitment curves to be able to assess the dynamic association of the repair factors with the DNA lesions as well as the target-search strategies used to efficiently find these lesions. Finally, we discuss how the use of mathematical models, combined with experimental evidence, can be used to better interpret the complex dynamics of repair proteins at DNA lesions.
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Affiliation(s)
- Siham Zentout
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, Rennes, France
| | - Rebecca Smith
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, Rennes, France
| | - Marine Jacquier
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, Rennes, France
| | - Sébastien Huet
- Univ Rennes, CNRS, IGDR (Institut de Génétique et Développement de Rennes)-UMR 6290, BIOSIT-UMS 3480, Rennes, France
- Institut Universitaire de France, Paris, France
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6
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Stein JAC, Ianeselli A, Braun D. Kinetic Microscale Thermophoresis for Simultaneous Measurement of Binding Affinity and Kinetics. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Julian A. C. Stein
- Systems Biophysics Department of Physics Ludwig-Maximilians-Universität München and Center for NanoScience Amalienstasse 54 80799 München Germany
| | - Alan Ianeselli
- Systems Biophysics Department of Physics Ludwig-Maximilians-Universität München and Center for NanoScience Amalienstasse 54 80799 München Germany
| | - Dieter Braun
- Systems Biophysics Department of Physics Ludwig-Maximilians-Universität München and Center for NanoScience Amalienstasse 54 80799 München Germany
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7
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Stein JAC, Ianeselli A, Braun D. Kinetic Microscale Thermophoresis for Simultaneous Measurement of Binding Affinity and Kinetics. Angew Chem Int Ed Engl 2021; 60:13988-13995. [PMID: 33793031 PMCID: PMC8251828 DOI: 10.1002/anie.202101261] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/16/2021] [Indexed: 12/11/2022]
Abstract
Microscale thermophoresis (MST) is a versatile technique to measure binding affinities of binder-ligand systems, based on the directional movement of molecules in a temperature gradient. We extended MST to measure binding kinetics as well as binding affinity in a single experiment by increasing the thermal dissipation of the sample. The kinetic relaxation fingerprints were derived from the fluorescence changes during thermodynamic re-equilibration of the sample after local heating. Using this method, we measured DNA hybridization on-rates and off-rates in the range 104 -106 m-1 s-1 and 10-4 -10-1 s-1 , respectively. We observed the expected exponential dependence of the DNA hybridization off-rates on salt concentration, strand length and inverse temperature. The measured on-rates showed a linear dependence on salt concentration and weak dependence on strand length and temperature. For biomolecular interactions with large enthalpic contributions, the kinetic MST technique offers a robust, cost-effective and immobilization-free determination of kinetic rates and binding affinity simultaneously, even in crowded solutions.
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Affiliation(s)
- Julian A C Stein
- Systems Biophysics, Department of Physics, Ludwig-Maximilians-Universität München and Center for NanoScience, Amalienstasse 54, 80799, München, Germany
| | - Alan Ianeselli
- Systems Biophysics, Department of Physics, Ludwig-Maximilians-Universität München and Center for NanoScience, Amalienstasse 54, 80799, München, Germany
| | - Dieter Braun
- Systems Biophysics, Department of Physics, Ludwig-Maximilians-Universität München and Center for NanoScience, Amalienstasse 54, 80799, München, Germany
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8
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Huang Y, Deng L, Su D, Huang X, Ren J. Highly sensitive detection of DNA methyltransferase activity and its inhibitor screening by coupling fluorescence correlation spectroscopy with polystyrene polymer dots. Analyst 2021; 146:3623-3632. [PMID: 33929479 DOI: 10.1039/d0an02362k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
DNA methylation is a critical part of epigenetics and plays a vital role in maintaining normal cell function, genetic imprinting, and human tumorigenesis. Thus, it is important to develop a sensitive method for the determination of DNA methyltransferase (MTase) activity. Here, we present a simple and sensitive method based on single molecule fluorescence correlation spectroscopy (FCS) and polystyrene polymer dots (PS Pdots) for the quantitative detection of DNA adenine methylation (Dam) MTase activity and its inhibitor screening in homogeneous solution without separation. Its principle is based on the measurement of the characteristic diffusion time (τD) of unmethylated and methylated DNA-fluorescent probes by FCS. A hairpin DNA probe including the 5'-GATC-3' sequence is used by doubly labelling fluorophore Alexa Fluor 488 (Alexa 488) and biotin at the 5'- and 3'-terminus, respectively. Dam MTase catalyzed the methylation of the sequence of 5'-GATC-3', and DpnI cleaved the sequence of 5'-G-Am-TC-3'. Streptavidin conjugated PS Pdots were used to react with DNA probes without methylation to further increase the difference in τD values between methylated and unmethylated DNA-Alexa 488 probes. We used the FCS method to measure the τD values of DNA-Alexa 488 probes and further obtained the activity of Dam MTase. It is found that the τD value of the methylated DNA probe is negatively correlated with the logarithm of Dam MTase concentration in the range from 0.025 U mL-1 to 3 U mL-1. The detection limit is as low as 0.025 U mL-1. Furthermore, we evaluated the inhibition effect of drug-related DNA methylation and the half-maximal inhibitory concentration (IC50) value is consistent with a previous study. The results demonstrated that our proposed method will become a promising platform for the determination of Dam MTase activity and inhibitor screening.
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Affiliation(s)
- Yuyang Huang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
| | - Liyun Deng
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
| | - Di Su
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
| | - Xiangyi Huang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
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9
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Abstract
Several techniques are currently available to quickly and accurately quantify the number of virus particles in a sample, taking advantage of advanced technologies improving old techniques or generating new ones, generally relying on partial detection methods or structural analysis. Therefore, characterization of virus infectivity in a sample is often essential, and classical virological methods are extremely powerful in providing accurate results even in an old-fashioned way. In this chapter, we describe in detail the techniques routinely used to estimate the number of viable infectious coronavirus particles in a given sample. All these techniques are serial dilution assays, also known as titrations or end-point dilution assays (EPDA).
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10
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Fluorescence correlation spectroscopy as a tool for the study of the intracellular dynamics and biological fate of protein corona. Biophys Chem 2019; 253:106218. [PMID: 31325709 DOI: 10.1016/j.bpc.2019.106218] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 07/03/2019] [Indexed: 11/20/2022]
Abstract
In biological fluids, nanoparticles (NPs) are in contact with proteins and other biomolecules. Proteins adsorb to NPs and form a coating called a protein corona (PC). The PC is known to greatly affect the interaction of NPs with biological systems. A comprehensive knowledge of the protein nanoparticle interaction is essential to understand the biological fate of NPs and for the design of NPs for biomedicine. Fluorescence correlation spectroscopy (FCS) and fluorescence cross-correlation spectroscopy (FCCS) are sensitive spectroscopy techniques that measure fluorescence intensity fluctuations of single molecules inside a femtoliter confocal volume. Both techniques are suitable for studying the formation of protein corona around NPs and for examining corona stability in situ in biological matrixes. In this review we provide a short description of FCS/FCCS and their application in PC studies, highlighting results from our work about the impact of surface chemistry of NPs on corona formation and NP intracellular fate.
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11
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Su D, Hou Y, Dong C, Ren J. Fluctuation correlation spectroscopy and its applications in homogeneous analysis. Anal Bioanal Chem 2019; 411:4523-4540. [DOI: 10.1007/s00216-019-01884-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/12/2019] [Accepted: 04/29/2019] [Indexed: 12/11/2022]
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12
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Abstract
Receptor tyrosine kinases (RTKs) play important roles in cell growth, motility, differentiation, and survival. These single-pass membrane proteins are grouped into subfamilies based on the similarity of their extracellular domains. They are generally thought to be activated by ligand binding, which promotes homodimerization and then autophosphorylation in trans. However, RTK interactions are more complicated, as RTKs can interact in the absence of ligand and heterodimerize within and across subfamilies. Here, we review the known cross-subfamily RTK heterointeractions and their possible biological implications, as well as the methodologies which have been used to study them. Moreover, we demonstrate how thermodynamic models can be used to study RTKs and to explain many of the complicated biological effects which have been described in the literature. Finally, we discuss the concept of the RTK interactome: a putative, extensive network of interactions between the RTKs. This RTK interactome can produce unique signaling outputs; can amplify, inhibit, and modify signaling; and can allow for signaling backups. The existence of the RTK interactome could provide an explanation for the irreproducibility of experimental data from different studies and for the failure of some RTK inhibitors to produce the desired therapeutic effects. We argue that a deeper knowledge of RTK interactome thermodynamics can lead to a better understanding of fundamental RTK signaling processes in health and disease. We further argue that there is a need for quantitative, thermodynamic studies that probe the strengths of the interactions between RTKs and their ligands and between different RTKs.
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Affiliation(s)
- Michael D. Paul
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore MD 21218
| | - Kalina Hristova
- Department of Materials Science and Engineering, Institute for NanoBioTechnology, and Program in Molecular Biophysics, Johns Hopkins University, Baltimore MD 21218
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13
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Li X, Shi X, Kaliszewski MJ, Smith AW. Fluorescence cross-correlation spectroscopy of lipid-peptide interactions on supported lipid bilayers. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2019. [DOI: 10.1016/bs.abl.2019.01.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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14
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Dominguez-Medina S, Chen S, Blankenburg J, Swanglap P, Landes CF, Link S. Measuring the Hydrodynamic Size of Nanoparticles Using Fluctuation Correlation Spectroscopy. Annu Rev Phys Chem 2017; 67:489-514. [PMID: 27215820 DOI: 10.1146/annurev-physchem-040214-121510] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Fluctuation correlation spectroscopy (FCS) is a well-established analytical technique traditionally used to monitor molecular diffusion in dilute solutions, the dynamics of chemical reactions, and molecular processes inside living cells. In this review, we present the recent use of FCS for measuring the size of colloidal nanoparticles in solution. We review the theoretical basis and experimental implementation of this technique and its advantages and limitations. In particular, we show examples of the use of FCS to measure the size of gold nanoparticles, monitor the rotational dynamics of gold nanorods, and investigate the formation of protein coronas on nanoparticles.
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Affiliation(s)
| | - Sishan Chen
- Department of Chemistry, Rice University, Houston, Texas 77005;
| | - Jan Blankenburg
- Department of Chemistry, Rice University, Houston, Texas 77005;
| | | | - Christy F Landes
- Department of Chemistry, Rice University, Houston, Texas 77005; .,Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005.,Laboratory for Nanophotonics, Rice University, Houston, Texas 77005.,Smalley-Curl Institute, Rice University, Houston, Texas 77005
| | - Stephan Link
- Department of Chemistry, Rice University, Houston, Texas 77005; .,Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005.,Laboratory for Nanophotonics, Rice University, Houston, Texas 77005.,Smalley-Curl Institute, Rice University, Houston, Texas 77005
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15
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Quantifying transcription factor–DNA binding in single cells in vivo with photoactivatable fluorescence correlation spectroscopy. Nat Protoc 2017; 12:1458-1471. [DOI: 10.1038/nprot.2017.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Kracke B, Cole JT, Kaiser CJO, Hellenkamp B, Krysiak S, Ghoorchian A, Braun GB, Holland NB, Hugel T. Thermoswitchable Nanoparticles Based on Elastin-like Polypeptides. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00932] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Bettina Kracke
- Central
Institute for Medical Engineering (IMETUM), TU München, Boltzmannstraße
11, 85748 Garching, Germany
| | - James T. Cole
- Chemical and Biomedical Engineering Department, Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
| | | | - Björn Hellenkamp
- Institute of Physical Chemistry, University of Freiburg, Albertstraße 23a, 79104 Freiburg, Germany
| | - Stefanie Krysiak
- Central
Institute for Medical Engineering (IMETUM), TU München, Boltzmannstraße
11, 85748 Garching, Germany
| | - Ali Ghoorchian
- Chemical and Biomedical Engineering Department, Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
- NSF Research Triangle Materials Research Science and Engineering
Center, Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Gary B. Braun
- Cancer Research Center, Sanford Burnham Prebys Medical Discovery Institute, 10901 N. Torrey Pines Rd., La Jolla, California 92037, United States
| | - Nolan B. Holland
- Chemical and Biomedical Engineering Department, Cleveland State University, 2121 Euclid Avenue, Cleveland, Ohio 44115, United States
| | - Thorsten Hugel
- Institute of Physical Chemistry, University of Freiburg, Albertstraße 23a, 79104 Freiburg, Germany
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Kim SH, Kim SY, Jung KH, Kim D. DNA binding activity of Anabaena sensory rhodopsin transducer probed by fluorescence correlation spectroscopy. Biosci Biotechnol Biochem 2015; 79:1070-4. [PMID: 25755018 DOI: 10.1080/09168451.2015.1015950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Anabaena sensory rhodopsin transducer (ASRT) is believed to be a major player in the photo-signal transduction cascade, which is triggered by Anabaena sensory rhodopsin. Here, we characterized DNA binding activity of ASRT probed by using fluorescence correlation spectroscopy. We observed clear decrease of diffusion coefficient of DNA upon binding of ASRT. The dissociation constant, K(D), of ASRT to 20 bp-long DNA fragments lied in micro-molar range and varied moderately with DNA sequence. Our results suggest that ASRT may interact with several different regions of DNA with different binding affinity for global regulation of several genes that need to be activated depending on the light illumination.
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Affiliation(s)
- Sung Hyun Kim
- a Department of Physics , Sogang University , Seoul , Korea
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18
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Maier HJ, Bickerton E, Britton P. Quantification of infectious bronchitis coronavirus by titration in vitro and in ovo. Methods Mol Biol 2014; 1282:89-98. [PMID: 25720474 PMCID: PMC7121424 DOI: 10.1007/978-1-4939-2438-7_9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Quantification of the number of infectious viruses in a sample is a basic virological technique. In this chapter we provide a detailed description of three techniques to estimate the number of viable infectious avian coronaviruses in a sample. All three techniques are serial dilution assays, better known as titrations.
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Affiliation(s)
| | | | - Paul Britton
- The Pirbright Institute, Compton, United Kingdom
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Bacia K, Haustein E, Schwille P. Fluorescence correlation spectroscopy: principles and applications. Cold Spring Harb Protoc 2014; 2014:709-25. [PMID: 24987147 DOI: 10.1101/pdb.top081802] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Fluorescence correlation spectroscopy (FCS) is used to study the movements and the interactions of biomolecules at extremely dilute concentrations, yielding results with good spatial and temporal resolutions. Using a number of technical developments, FCS has become a versatile technique that can be used to study a variety of sample types and can be advantageously combined with other methods. Unlike other fluorescence-based techniques, the analysis of FCS data is not based on the average intensity of the fluorescence emission but examines the minute intensity fluctuations caused by spontaneous deviations from the mean at thermal equilibrium. These fluctuations can result from variations in local concentrations owing to molecular mobility or from characteristic intermolecular or intramolecular reactions of fluorescently labeled biomolecules present at low concentrations. Here, we provide a basic introduction to FCS, including its technical development and theoretical basis, experimental setup of an FCS system, adjustment of a setup, data acquisition, and analysis of FCS measurements. Finally, the application of FCS to the study of lipid bilayer membranes and to living cells is discussed.
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20
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Four-colour FRET reveals directionality in the Hsp90 multicomponent machinery. Nat Commun 2014; 5:4192. [PMID: 24947016 DOI: 10.1038/ncomms5192] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 05/22/2014] [Indexed: 12/24/2022] Open
Abstract
In living organisms, most proteins work in complexes to form multicomponent protein machines. The function of such multicomponent machines is usually addressed by dividing them into a collection of two state systems at equilibrium. Many molecular machines, like Hsp90, work far from equilibrium by utilizing the energy of ATP hydrolysis. In these cases, important information is gained from the observation of the succession of more than two states in a row. We developed a four-colour single-molecule FRET system to observe the succession of states in the heat shock protein 90 (Hsp90) system, consisting of an Hsp90 dimer, the cochaperone p23 and nucleotides. We show that this multicomponent system is a directional ATP-dependent machinery. This reveals a previously undescribed mechanism on how cochaperones can modify Hsp90, namely by strengthening of the coupling between ATP hydrolysis and a kinetic step involved in the Hsp90 system resulting in a stronger directionality.
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21
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Biomolecular dynamics and binding studies in the living cell. Phys Life Rev 2014; 11:1-30. [DOI: 10.1016/j.plrev.2013.11.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 11/20/2013] [Indexed: 11/22/2022]
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22
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Langguth L, Punj D, Wenger J, Koenderink AF. Plasmonic band structure controls single-molecule fluorescence. ACS NANO 2013; 7:8840-8. [PMID: 24020654 DOI: 10.1021/nn4033008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plasmonics and photonic crystals are two complementary approaches to tailor single-emitter fluorescence, using strong local field enhancements near metals on one hand and spatially extended photonic band structure effects on the other hand. Here, we explore the emergence of spontaneous emission control by finite-sized hexagonal arrays of nanoapertures milled in gold film. We demonstrate that already small lattices enable highly directional and enhanced emission from single fluorescent molecules in the central aperture. Even for clusters just four unit cells across, the directionality is set by the plasmonic crystal band structure, as confirmed by full-wave numerical simulations. This realization of plasmonic phase array antennas driven by single quantum emitters opens a flexible toolbox to engineer fluorescence and its detection.
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Affiliation(s)
- Lutz Langguth
- Center for Nanophotonics, FOM Institute for Atomic and Molecular Physics (AMOLF) , Science Park 104, 1098 XG Amsterdam, The Netherlands
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Xiang D, Zhang B, Doll D, Shen K, Kloecker G, Freter C. Lung cancer screening: from imaging to biomarker. Biomark Res 2013; 1:4. [PMID: 24252206 PMCID: PMC3776246 DOI: 10.1186/2050-7771-1-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 09/27/2012] [Indexed: 01/02/2023] Open
Abstract
Despite several decades of intensive effort to improve the imaging techniques for lung cancer diagnosis and treatment, primary lung cancer is still the number one cause of cancer death in the United States and worldwide. The major causes of this high mortality rate are distant metastasis evident at diagnosis and ineffective treatment for locally advanced disease. Indeed, approximately forty percent of newly diagnosed lung cancer patients have distant metastasis. Currently, the only potential curative therapy is surgical resection of early stage lung cancer. Therefore, early detection of lung cancer could potentially increase the chance of cure by surgery and underlines the importance of screening and detection of lung cancer. In the past fifty years, screening of lung cancer by chest X-Ray (CXR), sputum cytology, computed tomography (CT), fluorescence endoscopy and low-dose spiral CT (LDCT) has not improved survival except for the recent report in 2010 by the National Lung Screening Trial (NLST), which showed a 20 percent mortality reduction in high risk participants screened with LDCT compared to those screened with CXRs. Furthermore, serum biomarkers for detection of lung cancer using free circulating DNA and RNA, exosomal microRNA, circulating tumor cells and various lung cancer specific antigens have been studied extensively and novel screening methods are being developed with encouraging results. The history of lung cancer screening trials using CXR, sputum cytology and LDCT, as well as results of trials involving various serum biomarkers, are reviewed herein.
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Affiliation(s)
- Dong Xiang
- Division of Hematology and Medical Oncology, Ellis Fischel Cancer Center, University of Missouri, Columbia, MO, USA.
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24
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Geeraerts A, Hsiu-Fang F, Zimmermann P, Engelborghs Y. The characterization of the nuclear dynamics of syntenin-2, a PIP2binding PDZ protein. Cytometry A 2013; 83:866-75. [DOI: 10.1002/cyto.a.22246] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 10/26/2012] [Accepted: 11/29/2012] [Indexed: 11/11/2022]
Affiliation(s)
| | - Fan Hsiu-Fang
- Department of Chemistry; Faculty of Science; University of Leuven; Leuven; Belgium
| | - Pascale Zimmermann
- Department of Human Genetics; Faculty of Medicine; University of Leuven; Leuven; Belgium
| | - Yves Engelborghs
- Department of Chemistry; Faculty of Science; University of Leuven; Leuven; Belgium
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25
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Digman MA, Stakic M, Gratton E. Raster Image Correlation Spectroscopy and Number and Brightness Analysis. Methods Enzymol 2013; 518:121-44. [DOI: 10.1016/b978-0-12-388422-0.00006-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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26
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Abstract
Peripheral proteins transiently interact with cellular membranes where they regulate important cellular events such as signal transduction. A number of peripheral proteins harbor lipid-binding modules that not only bind selectively with nanomolar affinity to biological membranes but also oligomerize on the membrane surface. In some cases, specific lipid binding or specific lipid compositions can induce peripheral protein oligomerization on cellular membranes. These oligomers serve different roles in biological signaling such as regulating protein-protein interactions, induction of membrane bending, or facilitating membrane scission. A number of technologies have been employed to study protein oligomerization with fluctuation analysis of fluorescently labeled molecules recently developed for use with commercial laser-scanning microscopes. In this chapter, the approach of raster image correlation spectroscopy coupled with number and brightness (N&B) analysis to investigate protein oligomerization on cellular membranes in live cells is presented. Important considerations are discussed for designing experiments, collecting data, and performing analysis. N&B analysis provides a robust method for assessing membrane binding and assembly properties of peripheral proteins and lipid-binding modules.
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Yuan H, Khatua S, Zijlstra P, Yorulmaz M, Orrit M. Thousand-fold Enhancement of Single-Molecule Fluorescence Near a Single Gold Nanorod. Angew Chem Int Ed Engl 2012; 52:1217-21. [DOI: 10.1002/anie.201208125] [Citation(s) in RCA: 157] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Indexed: 11/06/2022]
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28
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Yuan H, Khatua S, Zijlstra P, Yorulmaz M, Orrit M. Thousand-fold Enhancement of Single-Molecule Fluorescence Near a Single Gold Nanorod. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201208125] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Schaeffel D, Staff RH, Butt HJ, Landfester K, Crespy D, Koynov K. Fluorescence correlation spectroscopy directly monitors coalescence during nanoparticle preparation. NANO LETTERS 2012; 12:6012-6017. [PMID: 23094753 DOI: 10.1021/nl303581q] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Dual color fluorescence cross-correlation spectroscopy (DC FCCS) experiments were conducted to study the coalescence and aggregation during the formation of nanoparticles. To assess the generality of the method, three completely different processes were selected to prepare the nanoparticles. Polymeric nanoparticles were formed either by solvent evaporation from emulsion nanodroplets of polymer solutions or by miniemulsion polymerization. Inorganic nanocapsules were formed by polycondensation of alkoxysilanes at the interface of nanodroplets. In all cases, DC FCCS provided fast and unambiguous information about the occurrence of coalescence and thus a deeper insight into the mechanism of nanoparticle formation. In particular, it was found that coalescence played a minor role for the emulsion-solvent evaporation process and the miniemulsion polymerization, whereas substantial coalescence was detected during the formation of the inorganic nanocapsules. These findings demonstrate that DC FCCS is a powerful tool for monitoring nanoparticles genesis.
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Affiliation(s)
- David Schaeffel
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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30
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Azizi A, Mironov GG, Muharemagic D, Wehbe M, Bell JC, Berezovski MV. Viral quantitative capillary electrophoresis for counting and quality control of RNA viruses. Anal Chem 2012; 84:9585-91. [PMID: 23046075 DOI: 10.1021/ac302525y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The world of health care has witnessed an explosive boost to its capacity within the past few decades due to the introduction of viral therapeutics to its medicinal arsenal. As a result, a need for new methods of viral quantification has arisen to accommodate this rapid advancement in virology and associated requirements for efficiency, speed, and quality control. In this work, we apply viral quantitative capillary electrophoresis (viral qCE) to determine (i) the number of intact virus particles (ivp) in viral samples, (ii) the amount of DNA contamination, and (iii) the degree of viral degradation after sonication, vortexing, and freeze-thaw cycles. This quantification method is demonstrated on an RNA-based vesicular stomatitis virus (VSV) with oncolytic properties. A virus sample contains intact VSV particles as well as residual DNA from host cells, which is regulated by WHO guidelines, and may include some carried-over RNA. We use capillary zone electrophoresis with laser-induced fluorescent detection to separate intact virus particles from DNA and RNA impurities. YOYO-1 dye is used to stain all DNA and RNA in the sample. After soft lysis of VSV with proteinase K digestion of viral capsid and ribonucleoproteins, viral RNA is released. Therefore, the initial concentration of intact virus is calculated based on the gain of a nucleic acid peak and an RNA calibration curve. After additional NaOH treatment of the virus sample, RNA is hydrolyzed leaving residual DNA only, which is also calculated by a DNA calibration curve made by the same CE instrument. Viral qCE works in a wide dynamic range of virus concentrations from 10(8) to 10(13) ivp/mL. It can be completed in a few hours and requires minimum optimization of CE separation.
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Affiliation(s)
- Afnan Azizi
- Department of Chemistry, University of Ottawa, Ottawa, Ontario, Canada
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31
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Brinkmeier M, Dörre K, Stephan J, Eigen M. Two-beam cross-correlation: a method to characterize transport phenomena in micrometer-sized structures. Anal Chem 2012; 71:609-16. [PMID: 21662718 DOI: 10.1021/ac980820i] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To determine flow properties, namely, the velocity and angle of the flow in microstructured channels, an experimental realization based on fluorescence correlation spectroscopy is described. For this purpose, two micrometer-sized spatially separated volume elements have been created. The cross-correlation signal from these has been recorded and evaluated mathematically. In addition to previous results, two-beam cross-correlation allows for fast and easy determination of even small (down to 200 μm/s) flow velocities, as well as simultaneous measurement of diffusion properties of single dye molecules within a rather short detection time of 5-100 s and an error rate of less than 20%. The spatial flow resolution is around 1-2 μm, limited by the diameter of the volume element. Furthermore, vectorial flow data can be obtained and evaluated. A discussion of the theoretical background and an experimental verification of the theoretical results is performed. The feasibility of fast and easy data processing is shown if the flow time is the only desired information. Possible applications of this precise and simple method are the determination of transportation effects within artificial microstructures for CE and HPLC, fast chemical kinetics, and high-throughput screening.
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Affiliation(s)
- M Brinkmeier
- Max-Planck-Institut für biophysikalische Chemie, Am Fassberg, D-37077 Göttingen, Germany
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32
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Steffen PA, Fonseca JP, Ringrose L. Epigenetics meets mathematics: towards a quantitative understanding of chromatin biology. Bioessays 2012; 34:901-13. [PMID: 22911103 DOI: 10.1002/bies.201200076] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
How fast? How strong? How many? So what? Why do numbers matter in biology? Chromatin binding proteins are forever in motion, exchanging rapidly between bound and free pools. How do regulatory systems whose components are in constant flux ensure stability and flexibility? This review explores the application of quantitative and mathematical approaches to mechanisms of epigenetic regulation. We discuss methods for measuring kinetic parameters and protein quantities in living cells, and explore the insights that have been gained by quantifying and modelling dynamics of chromatin binding proteins.
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Geissbuehler M, Bonacina L, Shcheslavskiy V, Bocchio NL, Geissbuehler S, Leutenegger M, Märki I, Wolf JP, Lasser T. Nonlinear correlation spectroscopy (NLCS). NANO LETTERS 2012; 12:1668-72. [PMID: 22372559 DOI: 10.1021/nl300070n] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We present a novel concept for optical spectroscopy called nonlinear correlation spectroscopy (NLCS). NLCS analyses coherent field fluctuations of the second and third harmonic light generated by diffusing nanoparticles. Particles based on noncentrosymmetric nonlinear materials such as KNbO(3) show a strong second as well as third harmonic response. The method and the theory are introduced and experimental NLCS results in fetal calf serum are presented showing the promising selectivity of this technique for measurement in complex biological environments.
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Affiliation(s)
- Matthias Geissbuehler
- Laboratoire d'Optique Biomédicale LOB, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
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34
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Vuletić T, Babić SD, Grgičin D, Aumiler D, Rädler J, Livolant F, Tomić S. Manning free counterion fraction for a rodlike polyion: aqueous solutions of short DNA fragments in presence of very low added salt. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:041803. [PMID: 21599194 DOI: 10.1103/physreve.83.041803] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Indexed: 05/30/2023]
Abstract
We quantified the Manning free (uncondensed) counterions fraction θ for dilute aqueous solutions of rodlike polyions: 150 bp DNA fragments, in the presence of a very low concentration of monovalent salt c(salt)<0.05 mM. Conductivity measurements of these solutions for DNA base pair concentration range 0.015≤c≤8 mM were complemented by fluorescence correlation spectroscopy (FCS) measurements of the DNA polyion diffusion coefficient D(p)(c). We observed a crossover in the normalized conductivity σ(c)/c that nearly halved across the c=0.05-1 mM range, while D(p)(c) remained rather constant, as we established by FCS. Analyzing these data we extracted θ(c)=0.30-0.45, and taking the Manning asymmetry field effect on polyelectrolyte conductivity into account we got θ(c)=0.40-0.60. We relate the θ(c) variation to gradual DNA denaturation occurring, in the very low salt environment, with the decrease in DNA concentration itself. The extremes of the experimental θ(c) range occur toward the highest, above 1 mM, and the lowest, below 0.05 mM, DNA concentrations and correspond to the theoretical θ values for dsDNA and ssDNA, respectively. Therefore, we confirmed Manning condensation and conductivity models to be valuable in description of dilute solutions of rodlike polyions.
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Affiliation(s)
- T Vuletić
- Institut za fiziku, 10000 Zagreb, Croatia.
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35
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Košovan P, Uhlík F, Kuldová J, Štěpánek M, Limpouchová Z, Procházka K, Benda A, Humpolíčková J, Hof M. Monte Carlo simulation of fluorescence correlation spectroscopy data. ACTA ACUST UNITED AC 2011. [DOI: 10.1135/cccc2009526] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We employed the Monte Carlo simulation methodology to emulate the diffusion of fluorescently labeled particles and understand the source of differences between values of diffusion coefficients (and consequently hydrodynamic radii) of fluorescently labeled nanoparticles measured by fluorescence correlation spectroscopy (FCS) and dynamic light scattering (DLS). We used the simulation program developed in our laboratory and studied the diffusion of spherical particles of different sizes, which are labeled on their surface. In this study, we focused on two complicating effects: (i) multiple labeling and (ii) rotational diffusion which affect the fluorescence signal from large particles and hinder the analysis of autocorrelation functions according to simple analytical models. We have shown that the fluorescence fluctuations can be well fitted using the analytical model for small point-like particles, but the obtained parameters deviate in some cases significantly from the real ones. It means that the current data treatment yields apparent values of diffusion coefficients and other parameters only and the interpretation of experimental results for systems of particles with sizes comparable to the size of the active illuminated volume requires great care and precaution.
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36
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Stasevich TJ, Mueller F, Michelman-Ribeiro A, Rosales T, Knutson JR, McNally JG. Cross-validating FRAP and FCS to quantify the impact of photobleaching on in vivo binding estimates. Biophys J 2011; 99:3093-101. [PMID: 21044608 DOI: 10.1016/j.bpj.2010.08.059] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 07/24/2010] [Accepted: 08/19/2010] [Indexed: 11/19/2022] Open
Abstract
Binding can now be quantified in live cells, but the accuracy of such measurements remains uncertain. To address this uncertainty, we compare fluorescence recovery after photobleaching (FRAP) and fluorescence correlation spectroscopy (FCS) measurements of the binding kinetics of a transcription factor, the glucocorticoid receptor, in the nuclei of live cells. We find that the binding residence time measured by FRAP is 15 times longer than that obtained by FCS. We show that this discrepancy is not likely due to the significant differences in concentrations typically used for FRAP and FCS, nor is it likely due to spatial heterogeneity of the nucleus, improper calibration of the FCS focal volume, or the intentional FRAP photobleach. Instead, our data indicate that photobleaching of bound molecules in FCS is mainly responsible. When this effect is minimized, FRAP and FCS measurements nearly agree, although cross-validation by other approaches is now required to rule out mutual errors. Our results demonstrate the necessity of a photobleach correction for FCS measurements of GFP-tagged molecules that are bound for >0.25 s, and represent an important step forward in establishing a gold standard for in vivo binding measurements.
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Affiliation(s)
- Timothy J Stasevich
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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37
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Glauner H, Ruttekolk IR, Hansen K, Steemers B, Chung YD, Becker F, Hannus S, Brock R. Simultaneous detection of intracellular target and off-target binding of small molecule cancer drugs at nanomolar concentrations. Br J Pharmacol 2010; 160:958-70. [PMID: 20590591 DOI: 10.1111/j.1476-5381.2010.00732.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND AND PURPOSE In vitro assays that determine activities of drug candidates with isolated targets have only limited predictive value for activities in cellular assays. Poor membrane permeability and off-target binding are major reasons for such discrepancies. However, it still difficult to directly analyse off-target binding at the same time as target binding, on a subcellular level. Here, we present a combination of fluorescence correlation spectroscopy (FCS) and fluorescence cross-correlation spectroscopy (FCCS) as a solution to this problem. EXPERIMENTAL APPROACH The well-established dihydrofolate reductase inhibitor methotrexate and the kinase inhibitors PD173956 and purvalanol B were conjugated via polyethylene glycol linkers with the fluorophore Cy5. The cellular uptake and subcellular distribution of these compounds in single human cancer-derived cells were investigated by confocal laser scanning microscopy. In addition, molecular interactions inside the cell with the respective target proteins and off-target binding were detected simultaneously in the nanomolar range by FCCS and FCS, respectively, using cells expressing green fluorescent protein fusion proteins of dihydrofolate reductase and Abelson kinase 1. KEY RESULTS Large differences in the interaction patterns were found for these compounds. For methotrexate-Cy5, drug-target interactions could be detected and dissociation constants determined. In contrast, PD173956-Cy5 showed strong interactions with intracellular high-molecular weight structures, other than its target. CONCLUSIONS AND IMPLICATIONS The combination of FCS and FCCS provides a powerful means to assess subcellular pharmacokinetics and dynamics of drug candidates at nanomolar concentrations.
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Affiliation(s)
- Heike Glauner
- Department of Biochemistry, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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Diffusion measurements inside biofilms by image-based fluorescence recovery after photobleaching (FRAP) analysis with a commercial confocal laser scanning microscope. Appl Environ Microbiol 2010; 76:5860-9. [PMID: 20639359 DOI: 10.1128/aem.00754-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Research about the reactional and structural dynamics of biofilms at the molecular level has made great strides, owing to efficient fluorescence imaging methods in terms of spatial resolution and fast acquisition time but also to noninvasive conditions of observation consistent with in situ biofilm studies. In addition to conventional fluorescence intensity imaging, the fluorescence recovery after photobleaching (FRAP) module can now be routinely implemented on commercial confocal laser scanning microscopes (CLSMs). This method allows measuring of local diffusion coefficients in biofilms and could become an alternative to fluorescence correlation spectroscopy (FCS). We present here an image-based FRAP protocol to improve the accuracy of FRAP measurements inside "live" biofilms and the corresponding analysis. An original kymogram representation allows control of the absence of perturbing bacterial movement during image acquisition. FRAP data analysis takes into account molecular diffusion during the bleach phase and uses the image information to extract molecular diffusion coefficients. The fluorescence spatial intensity profile analysis used here for the first time with biofilms is supported both by our own mathematical model and by a previously published one. This approach was validated to FRAP experiments on fluorescent-dextran diffusion inside Lactococcus lactis and Stenotrophomonas maltophilia biofilms, and the results were compared to previously published FCS measurements.
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Ghosh S, Adhikari A, Sen Mojumdar S, Bhattacharyya K. A Fluorescence Correlation Spectroscopy Study of the Diffusion of an Organic Dye in the Gel Phase and Fluid Phase of a Single Lipid Vesicle. J Phys Chem B 2010; 114:5736-41. [DOI: 10.1021/jp911971p] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Subhadip Ghosh
- Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Aniruddha Adhikari
- Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Supratik Sen Mojumdar
- Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Kankan Bhattacharyya
- Physical Chemistry Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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40
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Fluorescence Spectroscopy as a Tool for Investigating the Self-Organized Polyelectrolyte Systems. SELF ORGANIZED NANOSTRUCTURES OF AMPHIPHILIC BLOCK COPOLYMERS I 2010. [DOI: 10.1007/12_2010_56] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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41
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Schulz B, Täuber D, Friedriszik F, Graaf H, Schuster J, von Borczyskowski C. Optical detection of heterogeneous single molecule diffusion in thin liquid crystal films. Phys Chem Chem Phys 2010; 12:11555-64. [PMID: 20676458 DOI: 10.1039/c004042h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- B Schulz
- Institute of Physics and nanoMA (Center for nanostructured Materials and Analytics), Chemnitz University of Technology, 09107 Chemnitz, Germany
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42
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Vámosi G, Damjanovich S, Szöllosi J, Vereb G. Measurement of molecular mobility with fluorescence correlation spectroscopy. ACTA ACUST UNITED AC 2009; Chapter 2:Unit2.15. [PMID: 19816923 DOI: 10.1002/0471142956.cy0215s50] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Fluorescence correlation spectroscopy (FCS) is a fluctuation method established three decades ago, whose application to cellular systems became popular in the last decade. Fluctuations of fluorescence emission are observed from a small, femtoliter to sub-femtoliter, usually confocal volume at high time resolution. A time-dependent autocorrelation function is generated and evaluated to obtain time constants of photophysical and photochemical reactions, as well as of molecular diffusion and in the observation volume. Molecules in various subcellular compartments-including the nucleus, the cytoplasm, and the membrane-can be observed after labeling them with antibodies, ligands, or fluorescent proteins. The anomaly of diffusion, the local concentration, and the average fluorescence per diffusing particle can also be determined, all of which can be characteristic of molecular interactions. A two-color version of FCS, fluorescence cross-correlation spectroscopy, can also be applied to observe co-diffusion, i.e., stable association of two distinct molecular species in their cellular environment.
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Affiliation(s)
- György Vámosi
- Cell Biology and Signaling Research Group of the Hungarian Academy of Sciences, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
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Digman MA, Gratton E. Fluorescence correlation spectroscopy and fluorescence cross-correlation spectroscopy. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2009; 1:273-282. [PMID: 20835996 PMCID: PMC3086279 DOI: 10.1002/wsbm.5] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This article focuses on methods based on fluctuation correlation spectroscopy to determine the formation of protein complexes in living cells. We present the principles of the fluctuation method applied to cells. We discuss the novelty and the promises of this approach. The emphasis is in the discussion of the underlying statistical assumptions of the image correlation spectroscopy analysis rather than in reviewing applications of the method. Although one example of the application of the fluctuation method is given, this article also contains simulations that are better suited to illustrate and support the basic assumptions of the method.
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Affiliation(s)
- Michelle A. Digman
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, CA 92697, USA
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Rüttinger S, Kapusta P, Patting M, Wahl M, Macdonald R. On the Resolution Capabilities and Limits of Fluorescence Lifetime Correlation Spectroscopy (FLCS) Measurements. J Fluoresc 2009; 20:105-14. [DOI: 10.1007/s10895-009-0528-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Accepted: 06/29/2009] [Indexed: 11/25/2022]
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Jameson DM, Ross JA, Albanesi JP. Fluorescence fluctuation spectroscopy: ushering in a new age of enlightenment for cellular dynamics. Biophys Rev 2009; 1:105-118. [PMID: 21547245 DOI: 10.1007/s12551-009-0013-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Originally developed for applications in physics and physical chemistry, fluorescence fluctuation spectroscopy is becoming widely used in cell biology. This review traces the development of the method and describes some of the more important applications. Specifically, the methods discussed include fluorescence correlation spectroscopy (FCS), scanning FCS, dual color cross-correlation FCS, the photon counting histogram and fluorescence intensity distribution analysis approaches, the raster scanning image correlation spectroscopy method, and the Number and Brightness technique. The physical principles underlying these approaches will be delineated, and each of the methods will be illustrated using examples from the literature.
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Affiliation(s)
- David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo St., BSB 222, Honolulu, HI 96813, USA
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Palhano FL, Rocha CB, Bernardino A, Weissmuller G, Masuda CA, Montero-Lomelí M, Gomes AM, Chien P, Fernandes PMB, Foguel D. A fluorescent mutant of the NM domain of the yeast prion Sup35 provides insight into fibril formation and stability. Biochemistry 2009; 48:6811-23. [PMID: 19530740 DOI: 10.1021/bi9000276] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Sup35 protein of Saccharomyces cerevisiae forms a prion that generates the [PSI(+)] phenotype. Its NM region governs prion status, forming self-seeding amyloid fibers in vivo and in vitro. A tryptophan mutant of Sup35 (NM(F117W)) was used to probe its aggregation. Four indicators of aggregation, Trp 117 maximum emission, Trp polarization, thio-T binding, and light scattering increase, revealed faster aggregation at 4 degrees C than at 25 degrees C, and all indicators changed in a concerted fashion at the former temperature. Curiously, at 25 degrees C the changes were not synchronized; the first two indicators, which reflect nucleation, changed more quickly than the last two, which reflect fibril formation. These results suggest that nucleation is insensitive to temperature, whereas fibril extension is temperature dependent. As expected, aggregation is accelerated when a small fraction (5%) of the nuclei produced at 4 or 25 degrees C are added to a suspension containing the soluble NM domain, although these nuclei do not seem to propagate any structural information to the growing fibrils. Fibrils grown at 4 degrees C were less stable in GdmCl than those grown at higher temperature. However, they were both resistant to high pressure; in fact, both sets of fibrils responded to high pressure by adopting an altered conformation with a higher capacity for thio-T binding. From these data, we calculated the change in volume and free energy associated with this conformational change. AFM revealed that the fibrils grown at 4 degrees C were statistically smaller than those grown at 25 degrees C. In conclusion, the introduction of Trp 117 allowed us to more carefully dissect the effects of temperature on the aggregation of the Sup35 NM domain.
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Affiliation(s)
- Fernando L Palhano
- Instituto de Bioquimica Medica, Programa de Biologia Estrutural e Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-590, Brazil
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Michelman-Ribeiro A, Mazza D, Rosales T, Stasevich TJ, Boukari H, Rishi V, Vinson C, Knutson JR, McNally JG. Direct measurement of association and dissociation rates of DNA binding in live cells by fluorescence correlation spectroscopy. Biophys J 2009; 97:337-46. [PMID: 19580772 PMCID: PMC2711375 DOI: 10.1016/j.bpj.2009.04.027] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Revised: 04/07/2009] [Accepted: 04/22/2009] [Indexed: 10/20/2022] Open
Abstract
Measurement of live-cell binding interactions is vital for understanding the biochemical reactions that drive cellular processes. Here, we develop, characterize, and apply a new procedure to extract information about binding to an immobile substrate from fluorescence correlation spectroscopy (FCS) autocorrelation data. We show that existing methods for analyzing such data by two-component diffusion fits can produce inaccurate estimates of diffusion constants and bound fractions, or even fail altogether to fit FCS binding data. By analyzing live-cell FCS measurements, we show that our new model can satisfactorily account for the binding interactions introduced by attaching a DNA binding domain to the dimerization domain derived from a site-specific transcription factor (the vitellogenin binding protein (VBP)). We find that our FCS estimates are quantitatively consistent with our fluorescence recovery after photobleaching (FRAP) measurements on the same VBP domains. However, due to the fast binding interactions introduced by the DNA binding domain, FCS generates independent estimates for the diffusion constant (6.7 +/- 2.4 microm2/s) and the association (2 +/- 1.2 s(-1)) and dissociation (19 +/- 7 s(-1)) rates, whereas FRAP produces only a single, but a consistent, estimate, the effective-diffusion constant (4.4 +/- 1.4 microm2/s), which depends on all three parameters. We apply this new FCS method to evaluate the efficacy of a potential anticancer drug that inhibits DNA binding of VBP in vitro and find that in vivo the drug inhibits DNA binding in only a subset of cells. In sum, we provide a straightforward approach to directly measure binding rates from FCS data.
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Affiliation(s)
- Ariel Michelman-Ribeiro
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Davide Mazza
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Tilman Rosales
- Laboratory of Molecular Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - Timothy J. Stasevich
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Hacene Boukari
- Laboratory of Cell Biophysics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Vikas Rishi
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Charles Vinson
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
| | - Jay R. Knutson
- Laboratory of Molecular Biophysics, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
| | - James G. McNally
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
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Szymański J, Mayer C, Hoffmann-Rohrer U, Kalla C, Grummt I, Weiss M. Dynamic subcellular partitioning of the nucleolar transcription factor TIF-IA under ribotoxic stress. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:1191-8. [PMID: 19450626 DOI: 10.1016/j.bbamcr.2009.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 04/09/2009] [Accepted: 05/11/2009] [Indexed: 01/04/2023]
Abstract
TIF-IA is a basal transcription factor of RNA polymerase I (Pol I) that is a major target of the JNK2 signaling pathway in response to ribotoxic stress. Using advanced fluorescence microscopy and kinetic modeling we elucidated the subcellular localization of TIF-IA and its exchange dynamics between the nucleolus, nucleoplasm and cytoplasm upon ribotoxic stress. In steady state, the majority of (GFP-tagged) TIF-IA was in the cytoplasm and the nucleus, a minor portion (7%) localizing to the nucleoli. We observed a rapid shuttling of GFP-TIF-IA between the different cellular compartments with a mean residence time of approximately 130 s in the nucleus and only approximately 30 s in the nucleoli. The import rate from the cytoplasm to the nucleus was approximately 3-fold larger than the export rate, suggesting an importin/exportin-mediated transport rather than a passive diffusion. Upon ribotoxic stress, GFP-TIF-IA was released from the nucleoli with a half-time of approximately 24 min. Oxidative stress and inhibition of protein synthesis led to a relocation of GFP-TIF-IA with slower kinetics while osmotic stress had no effect. The observed relocation was much slower than the nucleo-cytoplasmic and nucleus-nucleolus exchange rates of GFP-TIF-IA, indicating a time-limiting step upstream of the JNK2 pathway. In support of this, time-course experiments on the activity of JNK2 revealed the activation of the JNK kinase as the rate-limiting step.
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Affiliation(s)
- Jedrzej Szymański
- Cellular Biophysics Group, German Cancer Research Center, D-69120 Heidelberg, Germany
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Clegg RM. Chapter 1 Förster resonance energy transfer—FRET what is it, why do it, and how it's done. FRET AND FLIM TECHNIQUES 2009. [DOI: 10.1016/s0075-7535(08)00001-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Díaz-Mejía JJ, Babu M, Emili A. Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome. FEMS Microbiol Rev 2008; 33:66-97. [PMID: 19054114 PMCID: PMC2704936 DOI: 10.1111/j.1574-6976.2008.00141.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The bacterial cell-envelope consists of a complex arrangement of lipids, proteins and carbohydrates that serves as the interface between a microorganism and its environment or, with pathogens, a human host. Escherichia coli has long been investigated as a leading model system to elucidate the fundamental mechanisms underlying microbial cell-envelope biology. This includes extensive descriptions of the molecular identities, biochemical activities and evolutionary trajectories of integral transmembrane proteins, many of which play critical roles in infectious disease and antibiotic resistance. Strikingly, however, only half of the c. 1200 putative cell-envelope-related proteins of E. coli currently have experimentally attributed functions, indicating an opportunity for discovery. In this review, we summarize the state of the art of computational and proteomic approaches for determining the components of the E. coli cell-envelope proteome, as well as exploring the physical and functional interactions that underlie its biogenesis and functionality. We also provide a comprehensive comparative benchmarking analysis on the performance of different bioinformatic and proteomic methods commonly used to determine the subcellular localization of bacterial proteins.
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Affiliation(s)
- Juan Javier Díaz-Mejía
- Banting and Best Department of Medical Research, Terrence Donnelly Center for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
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