1
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Herrera-Ochoa D, Bravo I, Garzón-Ruiz A. Monitoring cancer treatments in melanoma cells using a fluorescence lifetime nanoprobe based on a CdSe/ZnS quantum dot functionalized with a peptide containing D-penicillamine and histidine. Colloids Surf B Biointerfaces 2024; 245:114265. [PMID: 39321721 DOI: 10.1016/j.colsurfb.2024.114265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 09/12/2024] [Accepted: 09/21/2024] [Indexed: 09/27/2024]
Abstract
Anticancer therapies with cisplatin and volasertib (BI-6727) were monitored by fluorescence lifetime imaging microscopy (FLIM) in live SK-Mel-2 melanoma cells. A CdSe/ZnS quantum dot functionalized with a peptide containing D-penicillamine and histidine (CdSe/ZnS-PH) was used as intracellular pH fluorescent probe. A faster cytosol acidification was observed for cells treated with cisplatin when compared to volasertib. The first changes in the intracellular pH were found after 2 hours of treatment with cisplatin and 8 hours with volasertib. Additionally, the relationship between cytosol acidification and apoptosis was investigated using an innovative methodology based on time-resolved fluorescence measurements. Similar low percentages of apoptotic cells were observed after short incubation periods (2 - 8 hours) with both drugs. In contrast, late apoptosis and death were found for a large fraction of cells during 24-hour incubation with cisplatin but not volasertib. Thus, the early acidification observed in cisplatin treatment could accelerate apoptosis and cell death. Despite volasertib treatment shows slower mechanism of action than cisplatin, similar inhibitory effects were found for both drugs at longer incubation periods (72 hours). This study proves the potential of CdSe/ZnS-PH nanoparticle as a fluorescence lifetime probe in the study of the mechanism of action of antitumor drugs.
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Affiliation(s)
- Diego Herrera-Ochoa
- Departamento de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María Sánchez Ibáñez, s/n, Albacete 02071, Spain
| | - Iván Bravo
- Departamento de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María Sánchez Ibáñez, s/n, Albacete 02071, Spain; Centro Regional de Investigaciones Biomédicas (CRIB), Unidad Asociada de Biomedicina (UCLM-CSIC), C/ Almansa, 14, Albacete 02008, Spain
| | - Andrés Garzón-Ruiz
- Departamento de Química Física, Facultad de Farmacia, Universidad de Castilla-La Mancha, Av. Dr. José María Sánchez Ibáñez, s/n, Albacete 02071, Spain.
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2
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Kenward C, Vuckovic M, Paetzel M, Strynadka NCJ. Kinetic comparison of all eleven viral polyprotein cleavage site processing events by SARS-CoV-2 main protease using a linked protein FRET platform. J Biol Chem 2024; 300:107367. [PMID: 38750796 PMCID: PMC11209022 DOI: 10.1016/j.jbc.2024.107367] [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: 02/22/2024] [Revised: 04/30/2024] [Accepted: 05/09/2024] [Indexed: 06/13/2024] Open
Abstract
The main protease (Mpro) remains an essential therapeutic target for COVID-19 post infection intervention given its critical role in processing the majority of viral proteins encoded by the genome of severe acute respiratory syndrome related coronavirus 2 (SARS-CoV-2). Upon viral entry, the +ssRNA genome is translated into two long polyproteins (pp1a or the frameshift-dependent pp1ab) containing all the nonstructural proteins (nsps) required by the virus for immune modulation, replication, and ultimately, virion assembly. Included among these nsps is the cysteine protease Mpro (nsp5) which self-excises from the polyprotein, dimerizes, then sequentially cleaves 11 of the 15 cut-site junctions found between each nsp within the polyprotein. Many structures of Mpro (often bound to various small molecule inhibitors or peptides) have been detailed recently, including structures of Mpro bound to each of the polyprotein cleavage sequences, showing that Mpro can accommodate a wide range of targets within its active site. However, to date, kinetic characterization of the interaction of Mpro with each of its native cleavage sequences remains incomplete. Here, we present a robust and cost-effective FRET based system that benefits from a more consistent presentation of the substrate that is also closer in organization to the native polyprotein environment compared to previously reported FRET systems that use chemically modified peptides. Using this system, we were able to show that while each site maintains a similar Michaelis constant, the catalytic efficiency of Mpro varies greatly between cut-site sequences, suggesting a clear preference for the order of nsp processing.
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Affiliation(s)
- Calem Kenward
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Marija Vuckovic
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Mark Paetzel
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada.
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3
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Lin Z, Zhang Y, Ding L, Wang XD. Ultraphotostable Phosphorescent Nanosensors for Sensing the Lysosomal pH at the Single-Cell Level over Long Durations. Anal Chem 2024; 96:8622-8629. [PMID: 38717175 DOI: 10.1021/acs.analchem.4c00696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Ultraphotostable phosphorescent nanosensors have been designed for continuously sensing the lysosome pH over a long duration. The nanosensors exhibited excellent photostability, high accuracy, and capability to measure pH values during cell proliferation for up to 7 days. By arranging a metal-ligand complex of long phosphorescence lifetime and pH indicator in silica nanoparticles, we discover efficient Förster resonance energy transfer, which converts the pH-responsive UV-vis absorption signal of the pH indicator into a phosphorescent signal. Both the phosphorescent intensity and lifetime change at different pH values, and intracellular pH values can be accurately measured by our custom-built rapid phosphorescent lifetime imaging microscopy. The excellent photostability, high accuracy, and good biocompatibility prove that these nanosensors are a useful tool for tracing the fluctuation of pH values during endocytosis. The methodology can be easily adapted to design new nanosensors with different pKa or for different kinds of intracellular ions, as there are hundreds of pH and ion indicators readily available.
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Affiliation(s)
- Zhenzhen Lin
- Department of Chemistry and Human Phenome Institute, Fudan University, Shanghai 200438, P. R. China
| | - Yinglu Zhang
- Department of Chemistry and Human Phenome Institute, Fudan University, Shanghai 200438, P. R. China
| | - Longjiang Ding
- Department of Chemistry and Human Phenome Institute, Fudan University, Shanghai 200438, P. R. China
| | - Xu-Dong Wang
- Department of Chemistry and Human Phenome Institute, Fudan University, Shanghai 200438, P. R. China
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4
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Belashov AV, Zhikhoreva AA, Salova AV, Belyaeva TN, Litvinov IK, Kornilova ES, Semenova IV, Vasyutinskii OS. Automatic segmentation of lysosomes and analysis of intracellular pH with Radachlorin photosensitizer and FLIM. Biochem Biophys Res Commun 2024; 710:149835. [PMID: 38574457 DOI: 10.1016/j.bbrc.2024.149835] [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: 01/23/2024] [Revised: 03/17/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024]
Abstract
We report application of the fluorescence lifetime imaging microscopy (FLIM) for analysis of distributions of intracellular acidity using a chlorin-e6 based photosensitizer Radachlorin. An almost two-fold increase of the photosensitizer fluorescence lifetime in alkaline microenvironments as compared to acidic ones allowed for clear distinguishing between acidic and alkaline intracellular structures. Clusterization of a phasor plot calculated from fits of the FLIM raw data by two Gaussian distributions provided accurate automatic segmentation of lysosomes featuring acidic contents. The approach was validated in colocalization experiments with LysoTracker fluorescence in living cells of four established lines. The dependence of photosensitizer fluorescence lifetime on microenvironment acidity allowed for estimation of pH inside the cells, except for the nuclei, where photosensitizer does not penetrate. The developed method is promising for combined application of the photosensitizer for both photodynamic treatment and diagnostics.
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Affiliation(s)
- A V Belashov
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A A Zhikhoreva
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A V Salova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - T N Belyaeva
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I K Litvinov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - E S Kornilova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I V Semenova
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia.
| | - O S Vasyutinskii
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
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5
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Li W, Chen S, Xie S, Lu X, Li Z, Lv Y, Luo D. A light-sensitive protein-based wearable pH biometer. J Mater Chem B 2024; 12:1208-1216. [PMID: 38229580 DOI: 10.1039/d3tb02466k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Bacteriorhodopsin is a biological material with excellent photosensitivity properties. It can directly convert optical signals into electrical signals and is widely used in various biosensors. Here, we present a bR-based wearable pH biometer that can be used to monitor wound infection. The mechanism of the pH-sensitive effect of the bR electrode is explained, which generates a transient photovoltage under light irradiation and a negative photovoltage when the lamp is turned off. Since the photoelectric signal of bR is affected by different pH values, the photovoltage is changed by adjusting the pH value. The ratio (Vn/Vp) of negative photovoltage (Vn) to positive photovoltage (Vp) has a good linear relationship (R2 = 0.9911) in the pH range of 4.0-10.0. In vitro experiments using rats as a model confirmed that this wearable pH biometer can monitor pH changes that occur in wound infection.
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Affiliation(s)
- Wenxue Li
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
| | - Siyuan Chen
- Shanghai Pinghe School, Shanghai, 201203, China
| | - Shiwang Xie
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
| | - Xianmao Lu
- School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
| | - Zhou Li
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
| | - Yujia Lv
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
| | - Dan Luo
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 101400, China.
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6
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Li SA, Meng XY, Zhang YJ, Chen CL, Jiao YX, Zhu YQ, Liu PP, Sun W. Progress in pH-Sensitive sensors: essential tools for organelle pH detection, spotlighting mitochondrion and diverse applications. Front Pharmacol 2024; 14:1339518. [PMID: 38269286 PMCID: PMC10806205 DOI: 10.3389/fphar.2023.1339518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 12/20/2023] [Indexed: 01/26/2024] Open
Abstract
pH-sensitive fluorescent proteins have revolutionized the field of cellular imaging and physiology, offering insight into the dynamic pH changes that underlie fundamental cellular processes. This comprehensive review explores the diverse applications and recent advances in the use of pH-sensitive fluorescent proteins. These remarkable tools enable researchers to visualize and monitor pH variations within subcellular compartments, especially mitochondria, shedding light on organelle-specific pH regulation. They play pivotal roles in visualizing exocytosis and endocytosis events in synaptic transmission, monitoring cell death and apoptosis, and understanding drug effects and disease progression. Recent advancements have led to improved photostability, pH specificity, and subcellular targeting, enhancing their utility. Techniques for multiplexed imaging, three-dimensional visualization, and super-resolution microscopy are expanding the horizon of pH-sensitive protein applications. The future holds promise for their integration into optogenetics and drug discovery. With their ever-evolving capabilities, pH-sensitive fluorescent proteins remain indispensable tools for unravelling cellular dynamics and driving breakthroughs in biological research. This review serves as a comprehensive resource for researchers seeking to harness the potential of pH-sensitive fluorescent proteins.
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Affiliation(s)
- Shu-Ang Li
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiao-Yan Meng
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Ying-Jie Zhang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Cai-Li Chen
- Department of Immunology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China
| | - Yu-Xue Jiao
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yong-Qing Zhu
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The Academy of Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Pei-Pei Liu
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wei Sun
- Department of Burn and Repair Reconstruction, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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7
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Mo Y, Zhou H, Xu J, Chen X, Li L, Zhang S. Genetically encoded fluorescence lifetime biosensors: overview, advances, and opportunities. Analyst 2023; 148:4939-4953. [PMID: 37721109 DOI: 10.1039/d3an01201h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Genetically encoded biosensors based on fluorescent proteins (FPs) are powerful tools for tracking analytes and cellular events with high spatial and temporal resolution in living cells and organisms. Compared with intensiometric readout and ratiometric readout, fluorescence lifetime readout provides absolute measurements, independent of the biosensor expression level and instruments. Thus, genetically encoded fluorescence lifetime biosensors play a vital role in facilitating accurate quantitative assessments within intricate biological systems. In this review, we first provide a concise description of the categorization and working mechanism of genetically encoded fluorescence lifetime biosensors. Subsequently, we elaborate on the combination of the fluorescence lifetime imaging technique and lifetime analysis methods with fluorescence lifetime biosensors, followed by their application in monitoring the dynamics of environment parameters, analytes and cellular events. Finally, we discuss worthwhile considerations for the design, optimization and development of fluorescence lifetime-based biosensors from three representative cases.
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Affiliation(s)
- Yidan Mo
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Huangmei Zhou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Jinming Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Xihang Chen
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
| | - Lei Li
- School of Science, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China.
| | - Sanjun Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, No. 500, Dongchuan Rd, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
- NYU-ECNU Institute of Physics at NYU Shanghai, No. 3663, North Zhongshan Rd, Shanghai 200062, China.
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8
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Barroso M, Monaghan MG, Niesner R, Dmitriev RI. Probing organoid metabolism using fluorescence lifetime imaging microscopy (FLIM): The next frontier of drug discovery and disease understanding. Adv Drug Deliv Rev 2023; 201:115081. [PMID: 37647987 PMCID: PMC10543546 DOI: 10.1016/j.addr.2023.115081] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/20/2023] [Accepted: 08/24/2023] [Indexed: 09/01/2023]
Abstract
Organoid models have been used to address important questions in developmental and cancer biology, tissue repair, advanced modelling of disease and therapies, among other bioengineering applications. Such 3D microenvironmental models can investigate the regulation of cell metabolism, and provide key insights into the mechanisms at the basis of cell growth, differentiation, communication, interactions with the environment and cell death. Their accessibility and complexity, based on 3D spatial and temporal heterogeneity, make organoids suitable for the application of novel, dynamic imaging microscopy methods, such as fluorescence lifetime imaging microscopy (FLIM) and related decay time-assessing readouts. Several biomarkers and assays have been proposed to study cell metabolism by FLIM in various organoid models. Herein, we present an expert-opinion discussion on the principles of FLIM and PLIM, instrumentation and data collection and analysis protocols, and general and emerging biosensor-based approaches, to highlight the pioneering work being performed in this field.
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Affiliation(s)
- Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, NY 12208, USA
| | - Michael G Monaghan
- Department of Mechanical, Manufacturing and Biomedical Engineering, Trinity College Dublin, Dublin 02, Ireland
| | - Raluca Niesner
- Dynamic and Functional In Vivo Imaging, Freie Universität Berlin and Biophysical Analytics, German Rheumatism Research Center, Berlin, Germany
| | - Ruslan I Dmitriev
- Tissue Engineering and Biomaterials Group, Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium; Ghent Light Microscopy Core, Ghent University, 9000 Ghent, Belgium.
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9
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Mamontova AV, Simonyan TR, Bogdanov AM. Prospects of Genetically Encoded Flim Indicators for the Quantitative Assessment of Intracellular Parameters. Mol Biol 2022. [DOI: 10.1134/s0026893322050090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Simonyan TR, Protasova EA, Mamontova AV, Shakhov AM, Lukyanov KA, Maksimov EG, Bogdanov AM. A Single Fluorescent Protein-Based Indicator with a Time-Resolved Fluorescence Readout for Precise pH Measurements in the Alkaline Range. Int J Mol Sci 2022; 23:12907. [PMID: 36361706 PMCID: PMC9658282 DOI: 10.3390/ijms232112907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 09/19/2023] Open
Abstract
The real-time monitoring of the intracellular pH in live cells with high precision represents an important methodological challenge. Although genetically encoded fluorescent indicators can be considered as a probe of choice for such measurements, they are hindered mostly by the inability to determine an absolute pH value and/or a narrow dynamic range of the signal, making them inefficient for recording the small pH changes that typically occur within cellular organelles. Here, we study the pH sensitivity of a green-fluorescence-protein (GFP)-based emitter (EGFP-Y145L/S205V) with the alkaline-shifted chromophore's pKa and demonstrate that, in the pH range of 7.5-9.0, its fluorescence lifetime changes by a factor of ~3.5 in a quasi-linear manner in mammalian cells. Considering the relatively strong lifetime response in a narrow pH range, we proposed the mitochondria, which are known to have a weakly alkaline milieu, as a target for live-cell pH measurements. Using fluorescence lifetime imaging microscopy (FLIM) to visualize the HEK293T cells expressing mitochondrially targeted EGFP-Y145L/S205V, we succeeded in determining the absolute pH value of the mitochondria and recorded the ETC-uncoupler-stimulated pH shift with a precision of 0.1 unit. We thus show that a single GFP with alkaline-shifted pKa can act as a high-precision indicator that can be used in a specific pH range.
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Affiliation(s)
- Tatiana R. Simonyan
- Center of Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Elena A. Protasova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Anastasia V. Mamontova
- Center of Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, 121205 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
| | - Aleksander M. Shakhov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Semenov Federal Research Center for Chemical Physics, 119991 Moscow, Russia
| | | | - Eugene G. Maksimov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Alexey M. Bogdanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia
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11
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Rennick JJ, Nowell CJ, Pouton CW, Johnston APR. Resolving subcellular pH with a quantitative fluorescent lifetime biosensor. Nat Commun 2022; 13:6023. [PMID: 36224168 PMCID: PMC9556823 DOI: 10.1038/s41467-022-33348-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 09/13/2022] [Indexed: 11/24/2022] Open
Abstract
Changes in sub-cellular pH play a key role in metabolism, membrane transport, and triggering cargo release from therapeutic delivery systems. Most methods to measure pH rely on intensity changes of pH sensitive fluorophores, however, these measurements are hampered by high uncertainty in the inferred pH and the need for multiple fluorophores. To address this, here we combine pH dependant fluorescent lifetime imaging microscopy (pHLIM) with deep learning to accurately quantify sub-cellular pH in individual vesicles. We engineer the pH sensitive protein mApple to localise in the cytosol, endosomes, and lysosomes, and demonstrate that pHLIM can rapidly detect pH changes induced by drugs such as bafilomycin A1 and chloroquine. We also demonstrate that polyethylenimine (a common transfection reagent) does not exhibit a proton sponge effect and had no measurable impact on the pH of endocytic vesicles. pHLIM is a simple and quantitative method that will help to understand drug action and disease progression.
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Affiliation(s)
- Joshua J Rennick
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Cameron J Nowell
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Colin W Pouton
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Angus P R Johnston
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
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12
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Valenta H, Dupré-Crochet S, Abdesselem M, Bizouarn T, Baciou L, Nüsse O, Deniset-Besseau A, Erard M. Consequences of the constitutive NOX2 activity in living cells: Cytosol acidification, apoptosis, and localized lipid peroxidation. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119276. [PMID: 35489654 DOI: 10.1016/j.bbamcr.2022.119276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 03/19/2022] [Accepted: 04/12/2022] [Indexed: 06/14/2023]
Abstract
The phagocyte NADPH oxidase (NOX2) is a key enzyme of the innate immune system generating superoxide anions (O2•-), precursors of reactive oxygen species. The NOX2 protein complex is composed of six subunits: two membrane proteins (gp91phox and p22phox) forming the catalytic core, three cytosolic proteins (p67phox, p47phox and p40phox) and a small GTPase Rac. The sophisticated activation mechanism of the NADPH oxidase relies on the assembly of cytosolic subunits with the membrane-bound components. A chimeric protein, called 'Trimera', composed of the essential domains of the cytosolic proteins p47phox (aa 1-286), p67phox (aa 1-212) and full-length Rac1Q61L, enables a constitutive and robust NOX2 activity in cells without the need of any stimulus. We employed Trimera as a single activating protein of the phagocyte NADPH oxidase in living cells and examined the consequences on the cell physiology of this continuous and long-term NOX activity. We showed that the sustained high level of NOX activity causes acidification of the intracellular pH, triggers apoptosis and leads to local peroxidation of lipids in the membrane. These local damages to the membrane correlate with the strong tendency of the Trimera to clusterize in the plasma membrane observed by FRET-FLIM microscopy.
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Affiliation(s)
- Hana Valenta
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Sophie Dupré-Crochet
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Mouna Abdesselem
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Tania Bizouarn
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Laura Baciou
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Oliver Nüsse
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Ariane Deniset-Besseau
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France
| | - Marie Erard
- Institut de Chimie Physique, UMR8000, Université Paris-Saclay, CNRS, 91405 Orsay, France.
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13
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Shimolina L, Potekhina E, Druzhkova I, Lukina M, Dudenkova V, Belousov V, Shcheslavskiy V, Zagaynova E, Shirmanova M. Fluorescence lifetime-based pH mapping of tumors in vivo using new genetically encoded sensor SypHerRed. Biophys J 2022; 121:1156-1165. [PMID: 35218737 PMCID: PMC9034243 DOI: 10.1016/j.bpj.2022.02.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/27/2021] [Accepted: 02/22/2022] [Indexed: 11/18/2022] Open
Abstract
Changes in intracellular pH (pHi) reflect metabolic states of cancer cells during tumor growth and dissemination. Therefore, monitoring of pH is essential for understanding the metabolic mechanisms that support cancer progression. Genetically encoded fluorescent pH sensors have become irreplaceable tools for real-time tracking pH in particular subcellular compartments of living cells. However, ratiometric readout of most of the pH probes is poorly suitable to measure pH in thick samples ex vivo or tissues in vivo including solid tumors. Fluorescence lifetime imaging (FLIM) is a promising alternative to the conventional fluorescent microscopy as it much less depends on light scattering in thick samples. Here, we present a quantitative approach to map intracellular pH in cancer cells and tumors in vivo, relying on fluorescence lifetime readout of a genetically encoded pH sensor SypHerRed. We demonstrate the utility of SypHerRed in visualizing pHi in cancer cell culture and in mouse tumor xenografts using FLIM-microscopy and macroscopy. For the first time, the absolute pHi value is obtained for tumors in vivo by an optical technique. In addition, we demonstrate the possibility of simultaneous detection of pH and endogenous fluorescence of metabolic cofactor NADH, which provides a complementary insight into metabolic aspects of cancer. Fluorescence lifetime-based readout and red-shifted spectra make pH sensor SypHerRed a promising instrument for multiparameter in vivo imaging applications.
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Affiliation(s)
- Liubov Shimolina
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia; Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Ekaterina Potekhina
- Pirogov Russian National Research Medical University, Laboratory of Experimental Oncology, Moscow, Russia
| | - Irina Druzhkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Maria Lukina
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Varvara Dudenkova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Vsevolod Belousov
- Pirogov Russian National Research Medical University, Laboratory of Experimental Oncology, Moscow, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow, Russia
| | - Vladislav Shcheslavskiy
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia; Becker&Hickl GmbH, Nunsdorfer Ring 7-9, 12277 Berlin, Germany.
| | - Elena Zagaynova
- Institute of Biology and Biomedicine, Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia
| | - Marina Shirmanova
- Institute of Experimental Oncology and Biomedical Technologies, Privolzhsky Research Medical University, Nizhny Novgorod, Russia.
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14
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Bousmah Y, Valenta H, Bertolin G, Singh U, Nicolas V, Pasquier H, Tramier M, Merola F, Erard M. tdLanYFP, a Yellow, Bright, Photostable, and pH-Insensitive Fluorescent Protein for Live-Cell Imaging and Förster Resonance Energy Transfer-Based Sensing Strategies. ACS Sens 2021; 6:3940-3947. [PMID: 34676768 DOI: 10.1021/acssensors.1c00874] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Yellow fluorescent proteins (YFPs) are widely used as optical reporters in Förster resonance energy transfer (FRET)-based biosensors. Although great improvements have been done, the sensitivity of the biosensors is still limited by the low photostability and the poor fluorescence performances of YFPs at acidic pH values. Here, we characterize the yellow fluorescent protein tdLanYFP, derived from the tetrameric protein from the cephalochordate Branchiostoma lanceolatum, LanYFP. With a quantum yield of 0.92 and an extinction coefficient of 133,000 mol-1·L·cm-1, it is, to our knowledge, the brightest dimeric fluorescent protein available. Contrasting with EYFP and its derivatives, tdLanYFP has a very high photostability in vitro and in live cells. As a consequence, tdLanYFP allows imaging of cellular structures with subdiffraction resolution using STED nanoscopy and is compatible with the use of spectromicroscopies in single-molecule regimes. Its very low pK1/2 of 3.9 makes tdLanYFP an excellent tag even at acidic pH values. Finally, we show that tdLanYFP is a valuable FRET partner either as a donor or acceptor in different biosensing modalities. Altogether, these assets make tdLanYFP a very attractive yellow fluorescent protein for long-term or single-molecule live-cell imaging including FRET experiments at acidic pH.
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Affiliation(s)
- Yasmina Bousmah
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
| | - Hana Valenta
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
| | - Giulia Bertolin
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)−UMR 6290, 35000 Rennes, France
| | - Utkarsh Singh
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
| | - Valérie Nicolas
- Microscopy Facility (MIPSIT), Ingénierie et Plateformes au Service de l’Innovation Thérapeutique−IPSIT−UMS−US31−UMS3679 (IPSIT), Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Hélène Pasquier
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
| | - Marc Tramier
- Univ Rennes, CNRS, IGDR (Institut de génétique et développement de Rennes)−UMR 6290, 35000 Rennes, France
| | - Fabienne Merola
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
| | - Marie Erard
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, 91405 Orsay, France
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15
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Reyes-Cruzaley AP, Ochoa-Terán A, Tirado-Guízar A, Félix-Navarro RM, Alonso-Núñez G, Pina-Luis G. A fluorescent PET probe based on polyethyleneimine-Ag nanoclusters as a reversible, stable and selective broad-range pH sensor. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:2495-2503. [PMID: 34002195 DOI: 10.1039/d1ay00302j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this work, nanoclusters (NCs) of Cu and Ag capped with hyperbranched polyethyleneimine (PEI) were prepared using chemical reduction by a one-step hydrothermal method. The PEI coated-NCs were characterized by high-resolution transmission electron microscopy, ζ potential, thermogravimetric analysis, dynamic light scattering, Fourier-transform infrared, UV-visible, and fluorescence spectroscopy. The PEI-NCs exhibited strong absorption and fluorescence, high stability, and excellent water dispersibility. The resulting PEI-NCs showed a reversible and linear response of fluorescence intensity with pH over a wide range (3-11); however, PEI-AgNCs showed a better reversibility and sensitivity than PEI-CuNCs. Unlike several types of pH sensors based on modified NCs, which are based on a nanoparticle aggregation/disaggregation mechanism, the response of our sensor is based on a photoinduced electron transfer process, which gives it a high reversibility. This method was successfully applied in pH measurements in tap water and green tea samples, with excellent results, indicating its practical utility for these applications. A visual device was obtained by immobilizing PEI-AgNCs into agarose hydrogels at different pH values. The results show that the proposed sensor can be used as a pH visual detector. Besides, the light emission of the nanosensor was corroborated by fluorescence microscopy, confirming that the nanosensor based on PEI-AgNCs has great potential to be used in cellular imaging.
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Affiliation(s)
- Ana Patricia Reyes-Cruzaley
- Centro de Graduados e Investigación, Tecnológico Nacional de México/Instituto Tecnológico de Tijuana, Bulevar Alberto Limón Padilla S/N, Otay Tecnológico, 22510, Tijuana, B. C., Mexico.
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16
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Dmitriev RI, Intes X, Barroso MM. Luminescence lifetime imaging of three-dimensional biological objects. J Cell Sci 2021; 134:1-17. [PMID: 33961054 PMCID: PMC8126452 DOI: 10.1242/jcs.254763] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A major focus of current biological studies is to fill the knowledge gaps between cell, tissue and organism scales. To this end, a wide array of contemporary optical analytical tools enable multiparameter quantitative imaging of live and fixed cells, three-dimensional (3D) systems, tissues, organs and organisms in the context of their complex spatiotemporal biological and molecular features. In particular, the modalities of luminescence lifetime imaging, comprising fluorescence lifetime imaging (FLI) and phosphorescence lifetime imaging microscopy (PLIM), in synergy with Förster resonance energy transfer (FRET) assays, provide a wealth of information. On the application side, the luminescence lifetime of endogenous molecules inside cells and tissues, overexpressed fluorescent protein fusion biosensor constructs or probes delivered externally provide molecular insights at multiple scales into protein-protein interaction networks, cellular metabolism, dynamics of molecular oxygen and hypoxia, physiologically important ions, and other physical and physiological parameters. Luminescence lifetime imaging offers a unique window into the physiological and structural environment of cells and tissues, enabling a new level of functional and molecular analysis in addition to providing 3D spatially resolved and longitudinal measurements that can range from microscopic to macroscopic scale. We provide an overview of luminescence lifetime imaging and summarize key biological applications from cells and tissues to organisms.
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Affiliation(s)
- Ruslan I. Dmitriev
- Tissue Engineering and Biomaterials Group, Department of
Human Structure and Repair, Faculty of Medicine and Health Sciences,
Ghent University, Ghent 9000,
Belgium
| | - Xavier Intes
- Department of Biomedical Engineering, Center for
Modeling, Simulation and Imaging for Medicine (CeMSIM),
Rensselaer Polytechnic Institute, Troy, NY
12180-3590, USA
| | - Margarida M. Barroso
- Department of Molecular and Cellular
Physiology, Albany Medical College,
Albany, NY 12208, USA
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17
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Pratt EP, Anson KJ, Tapper JK, Simpson DM, Palmer AE. Systematic Comparison of Vesicular Targeting Signals Leads to the Development of Genetically Encoded Vesicular Fluorescent Zn 2+ and pH Sensors. ACS Sens 2020; 5:3879-3891. [PMID: 33305939 DOI: 10.1021/acssensors.0c01231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Genetically encoded fluorescent sensors have been widely used to illuminate secretory vesicle dynamics and the vesicular lumen, including Zn2+ and pH, in living cells. However, vesicular sensors have a tendency to mislocalize and are susceptible to the acidic intraluminal pH. In this study, we performed a systematic comparison of five different vesicular proteins to target the fluorescent protein mCherry and a Zn2+ Förster resonance energy transfer (FRET) sensor to secretory vesicles. We found that motifs derived from vesicular cargo proteins, including chromogranin A (CgA), target vesicular puncta with greater efficacy than transmembrane proteins. To characterize vesicular Zn2+ levels, we developed CgA-Zn2+ FRET sensor fusions with existing sensors ZapCY1 and eCALWY-4 and characterized subcellular localization and the influence of pH on sensor performance. We simultaneously monitored Zn2+ and pH in individual secretory vesicles by leveraging the acceptor fluorescent protein as a pH sensor and found that pH influenced FRET measurements in situ. While unable to characterize vesicular Zn2+ at the single-vesicle level, we were able to monitor Zn2+ dynamics in populations of vesicles and detected high vesicular Zn2+ in MIN6 cells compared to lower levels in the prostate cancer cell line LnCaP. The combination of CgA-ZapCY1 and CgA-eCALWY-4 allows for measurement of Zn2+ from pM to nM ranges.
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Affiliation(s)
- Evan P.S. Pratt
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Kelsie J. Anson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Justin K. Tapper
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - David M. Simpson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Amy E. Palmer
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
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18
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Panigrahi SK, Mishra AK. Total Emission Time Resolved Decay: a Method for Measurement and Resolution of Broad-Band Emission. J Fluoresc 2020; 30:1085-1094. [PMID: 32632718 DOI: 10.1007/s10895-020-02581-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/26/2020] [Indexed: 10/23/2022]
Abstract
This article reports a time-resolved fluorescence data acquisition technique termed as "Total Emission Time Resolved Decay" (TETRD). TETRD is recorded by using zero-order diffraction of emission grating in TCSPC instrument. TETRD decay curve has entire wavelength dependent decay information buried in it. Cut-off filters are used to avoid scattering contamination. Two existing approaches are used for analysing the interconnected TETRD data. (i) First, global analysis: for discretely decaying multiple components, TETRD dataset is analyzed using global analysis. The normalized pre-exponentials (αi) and relative amplitudes (fi) recovered from global analysis reflect the individual component emission more faithfully and resembles with steady-state spectral data as well. (ii) Second, stretched exponential fitting (StrEF): for continuous lifetime distribution systems, StrEF (I(t) = I0 exp[-(t/τ)1/h]) has been used to analyse TETRD data. The average lifetime (τ) of StrEF matches well with the average lifetime of multi-exponential fitting, the heterogeneity factor (h) of StrEF is an additional parameter, which informs about local heterogeneity in the system. It is shown that the lifetimes obtained with TETRD matches well with the lifetimes obtained using conventional time resolved emission spectra (TRES). TETRD holds advantage in rapid data acquisition and facilitates inclusion of another variable (like concentration, solvent composition, pH, excitation wavelength etc.) into experimental design. Further, with the use of an appropriate data analysis tool, the multi-component decay profiles can be resolved conveniently.
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19
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Huang M, Liang X, Zhang Z, Wang J, Fei Y, Ma J, Qu S, Mi L. Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E604. [PMID: 32218205 PMCID: PMC7221822 DOI: 10.3390/nano10040604] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 03/24/2020] [Indexed: 12/11/2022]
Abstract
The monitoring of intracellular pH is of great importance for understanding intracellular trafficking and functions. It has various limitations for biosensing based on the fluorescence intensity or spectra study. In this research, pH-sensitive carbon dots (CDs) were employed for intracellular pH sensing with fluorescence lifetime imaging microscopy (FLIM) for the first time. FLIM is a highly sensitive method that is used to detect a microenvironment and it can overcome the limitations of biosensing methods based on fluorescence intensity. The different groups on the CDs surfaces changing with pH environments led to different fluorescence lifetime values. The CDs aqueous solution had a gradual change from 1.6 ns to 3.7 ns in the fluorescence lifetime with a pH range of 2.6-8.6. Similar fluorescence lifetime changes were found in pH buffer-treated living cells. The detection of lysosomes, cytoplasm, and nuclei in living cells was achieved by measuring the fluorescence lifetime of CDs. In particular, a phasor FLIM analysis was used to improve the pH imaging. Moreover, the effects of the coenzymes, amino acids, and proteins on the fluorescence lifetime of CDs were examined in order to mimic the complex microenvironment inside the cells.
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Affiliation(s)
- Maojia Huang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Xinyue Liang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Zixiao Zhang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jing Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China;
| | - Yiyan Fei
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jiong Ma
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
- Institute of Biomedical Engineering and Technology, Academy for Engineer and Technology, Fudan University, Shanghai 200433, China
- The Multiscale Research Institute of Complex Systems (MRICS), School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Songnan Qu
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China
| | - Lan Mi
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
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20
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Okkelman IA, Papkovsky DB, Dmitriev RI. Estimation of the Mitochondrial Membrane Potential Using Fluorescence Lifetime Imaging Microscopy. Cytometry A 2019; 97:471-482. [PMID: 31486581 DOI: 10.1002/cyto.a.23886] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/11/2019] [Accepted: 08/19/2019] [Indexed: 12/19/2022]
Abstract
Monitoring of cell metabolism represents an important application area for fluorescence lifetime imaging microscopy (FLIM). In particular, assessment of mitochondrial membrane potential (MMP) in complex three-dimensional multicellular in vitro, ex vivo, and in vivo models would enable improved segmentation and functional discrimination of cell types, directly report on the mitochondrial function and complement the quenched-phosphorescence detection of cellular O2 and two-photon excited FLIM of endogenous NAD(P)H. Here, we report the green and orange-emitting fluorescent dyes SYTO and tetramethylrhodamine methyl ester (TMRM) as potential FLIM probes for MMP. In addition to nuclear, SYTO 16 and 24 dyes also display mitochondrial accumulation. FLIM with the culture of human colon cancer HCT116 cells allowed observation of the heterogeneity of mitochondrial polarization during the cell cycle progression. The dyes also demonstrated good performance with 3D cultures of Lgr5-GFP mouse intestinal organoids, providing efficient and quick cell staining and compatibility with two-photon excitation. Multiplexed imaging of Lgr5-GFP, proliferating cells (Hoechst 33342-aided FLIM), and TMRM-FLIM allowed us to identify the population of metabolically active cells in stem cell niche. TMRM-FLIM enabled to visualize the differences in membrane potential between Lgr5-positive and other proliferating and differentiated cell types. Altogether, SYTO 24 and TMRM dyes represent promising markers for advanced FLIM-based studies of cell bioenergetics with complex 3D and in vivo models. © 2019 International Society for Advancement of Cytometry.
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Affiliation(s)
- Irina A Okkelman
- Laboratory of Biophysics and Bioanalysis, ABCRF, School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- Laboratory of Biophysics and Bioanalysis, ABCRF, School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Ruslan I Dmitriev
- Laboratory of Biophysics and Bioanalysis, ABCRF, School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.,Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation
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21
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Shcheslavskiy VI, Shirmanova MV, Jelzow A, Becker W. Multiparametric Time-Correlated Single Photon Counting Luminescence Microscopy. BIOCHEMISTRY (MOSCOW) 2019; 84:S51-S68. [PMID: 31213195 DOI: 10.1134/s0006297919140049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Classic time-correlated single photon counting (TCSPC) technique involves detection of single photons of a periodic optical signal, registration of the photon arrival time in respect to the reference pulse, and construction of photon distribution with regard to the detection times. This technique achieves extremely high time resolution and near-ideal detection efficiency. Modern TCSPC is multi-dimensional, i.e., in addition to the photon arrival time relative to the excitation pulse, spatial coordinates within the image area, wavelength, time from the start of the experiment, and many other parameters are determined for each photon. Hence, the multi-dimensional TCSPC allows generation of photon distributions over these parameters. This review describes both classic and multi-dimensional types of TCSPC microscopy and their application for fluorescence lifetime imaging in different areas of biological studies.
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Affiliation(s)
- V I Shcheslavskiy
- Becker&Hickl GmbH, Berlin, 12277, Germany. .,Privolzhskiy Medical Research University, Nizhny Novgorod, 603005, Russia
| | - M V Shirmanova
- Privolzhskiy Medical Research University, Nizhny Novgorod, 603005, Russia
| | - A Jelzow
- Becker&Hickl GmbH, Berlin, 12277, Germany
| | - W Becker
- Becker&Hickl GmbH, Berlin, 12277, Germany
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22
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Ziegler CS, Bouchab L, Tramier M, Durand D, Fieschi F, Dupré-Crochet S, Mérola F, Nüße O, Erard M. Quantitative live-cell imaging and 3D modeling reveal critical functional features in the cytosolic complex of phagocyte NADPH oxidase. J Biol Chem 2019; 294:3824-3836. [PMID: 30630949 DOI: 10.1074/jbc.ra118.006864] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/08/2019] [Indexed: 01/18/2023] Open
Abstract
Phagocyte NADPH oxidase produces superoxide anions, a precursor of reactive oxygen species (ROS) critical for host responses to microbial infections. However, uncontrolled ROS production contributes to inflammation, making NADPH oxidase a major drug target. It consists of two membranous (Nox2 and p22phox) and three cytosolic subunits (p40phox, p47phox, and p67phox) that undergo structural changes during enzyme activation. Unraveling the interactions between these subunits and the resulting conformation of the complex could shed light on NADPH oxidase regulation and help identify inhibition sites. However, the structures and the interactions of flexible proteins comprising several well-structured domains connected by intrinsically disordered protein segments are difficult to investigate by conventional techniques such as X-ray crystallography, NMR, or cryo-EM. Here, we developed an analytical strategy based on FRET-fluorescence lifetime imaging (FLIM) and fluorescence cross-correlation spectroscopy (FCCS) to structurally and quantitatively characterize NADPH oxidase in live cells. We characterized the inter- and intramolecular interactions of its cytosolic subunits by elucidating their conformation, stoichiometry, interacting fraction, and affinities in live cells. Our results revealed that the three subunits have a 1:1:1 stoichiometry and that nearly 100% of them are present in complexes in living cells. Furthermore, combining FRET data with small-angle X-ray scattering (SAXS) models and published crystal structures of isolated domains and subunits, we built a 3D model of the entire cytosolic complex. The model disclosed an elongated complex containing a flexible hinge separating two domains ideally positioned at one end of the complex and critical for oxidase activation and interactions with membrane components.
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Affiliation(s)
- Cornelia S Ziegler
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France
| | - Leïla Bouchab
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France
| | - Marc Tramier
- the Université Rennes, CNRS, Institut de Génétique et Développement de Rennes - UMR 6290, BIOSIT - UMS 3480, F-35000 Rennes, France
| | - Dominique Durand
- the Institute for Integrative Biology of the Cell, CEA, CNRS UMR 9198, Université Paris-Sud, Université Paris-Saclay, 91190 Gif-sur-Yvette, France, and
| | - Franck Fieschi
- the Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, F-38044 Grenoble, France
| | - Sophie Dupré-Crochet
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France
| | - Fabienne Mérola
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France
| | - Oliver Nüße
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France,
| | - Marie Erard
- From the Laboratoire de Chimie Physique, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405, Orsay France,
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23
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Gabriel GVDM, Yasuno R, Mitani Y, Ohmiya Y, Viviani VR. Novel application ofMacrolampissp2 firefly luciferase for intracellular pH-biosensing in mammalian cells. Photochem Photobiol Sci 2019; 18:1212-1217. [DOI: 10.1039/c8pp00573g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bioluminescence is widely used in biosensors.
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Affiliation(s)
| | - Rie Yasuno
- National Institute of Advanced Industrial Science and Technology (AIST)
- Biomedical Research Institute
- Tsukuba
- Japan
| | - Yasuo Mitani
- National Institute of Advanced Industrial Science and Technology (AIST)
- Bioproduction Research Institute
- Sapporo
- Japan
| | - Yoshihiro Ohmiya
- National Institute of Advanced Industrial Science and Technology (AIST)
- Biomedical Research Institute
- Tsukuba
- Japan
| | - Vadim Ravara Viviani
- Graduate School of Biotechnology and Environmental Monitoring
- Federal University of São Carlos (UFSCar)
- Sorocaba
- Brazil
- Graduate School of Evolutive Genetics and Molecular Biology
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24
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O'Donnell N, Okkelman IA, Timashev P, Gromovykh TI, Papkovsky DB, Dmitriev RI. Cellulose-based scaffolds for fluorescence lifetime imaging-assisted tissue engineering. Acta Biomater 2018; 80:85-96. [PMID: 30261339 DOI: 10.1016/j.actbio.2018.09.034] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/11/2018] [Accepted: 09/23/2018] [Indexed: 12/12/2022]
Abstract
Quantitative measurement of pH and metabolite gradients by microscopy is one of the challenges in the production of scaffold-grown organoids and multicellular aggregates. Herein, we used the cellulose-binding domain (CBD) of the Cellulomonas fimi CenA protein for designing biosensor scaffolds that allow measurement of pH and Ca2+ gradients by fluorescence intensity and lifetime imaging (FLIM) detection modes. By fusing CBD with pH-sensitive enhanced cyan fluorescent protein (CBD-ECFP), we achieved efficient labeling of cellulose-based scaffolds based on nanofibrillar, bacterial cellulose, and decellularized plant materials. CBD-ECFP bound to the cellulose matrices demonstrated pH sensitivity comparable to untagged ECFP (1.9-2.3 ns for pH 6-8), thus making it compatible with FLIM-based analysis of extracellular pH. By using 3D culture of human colon cancer cells (HCT116) and adult stem cell-derived mouse intestinal organoids, we evaluated the utility of the produced biosensor scaffold. CBD-ECFP was sensitive to increases in extracellular acidification: the results showed a decline in 0.2-0.4 pH units in response to membrane depolarization by the protonophore FCCP. With the intestinal organoid model, we demonstrated multiparametric imaging by combining extracellular acidification (FLIM) with phosphorescent probe-based monitoring of cell oxygenation. The described labeling strategy allows for the design of extracellular pH-sensitive scaffolds for multiparametric FLIM assays and their use in engineered live cancer and stem cell-derived tissues. Collectively, this research can help in achieving the controlled biofabrication of 3D tissue models with known metabolic characteristics. STATEMENT OF SIGNIFICANCE: We designed biosensors consisting of a cellulose-binding domain (CBD) and pH- and Ca2+-sensitive fluorescent proteins. CBD-tagged biosensors efficiently label various types of cellulose matrices including nanofibrillar cellulose and decellularized plant materials. Hybrid biosensing cellulose scaffolds designed in this study were successfully tested by multiparameter FLIM microscopy in 3D cultures of cancer cells and mouse intestinal organoids.
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Affiliation(s)
- Neil O'Donnell
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Irina A Okkelman
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Peter Timashev
- Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation; Institute of Photonic Technologies, Research Center 'Crystallography and Photonics', Russian Academy of Sciences, Moscow, Russian Federation
| | - Tatyana I Gromovykh
- Department of Biotechnology, I.M. Sechenov First Moscow State University, Moscow, Russian Federation
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Ruslan I Dmitriev
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland; Institute for Regenerative Medicine, I.M. Sechenov First Moscow State University, Moscow, Russian Federation.
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Shinoda H, Shannon M, Nagai T. Fluorescent Proteins for Investigating Biological Events in Acidic Environments. Int J Mol Sci 2018; 19:E1548. [PMID: 29789517 PMCID: PMC6032295 DOI: 10.3390/ijms19061548] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/18/2018] [Accepted: 05/19/2018] [Indexed: 12/11/2022] Open
Abstract
The interior lumen of acidic organelles (e.g., endosomes, secretory granules, lysosomes and plant vacuoles) is an important platform for modification, transport and degradation of biomolecules as well as signal transduction, which remains challenging to investigate using conventional fluorescent proteins (FPs). Due to the highly acidic luminal environment (pH ~ 4.5⁻6.0), most FPs and related sensors are apt to lose their fluorescence. To address the need to image in acidic environments, several research groups have developed acid-tolerant FPs in a wide color range. Furthermore, the engineering of pH insensitive sensors, and their concomitant use with pH sensitive sensors for the purpose of pH-calibration has enabled characterization of the role of luminal ions. In this short review, we summarize the recent development of acid-tolerant FPs and related functional sensors and discuss the future prospects for this field.
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Affiliation(s)
- Hajime Shinoda
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Japan.
| | - Michael Shannon
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Japan.
| | - Takeharu Nagai
- Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Japan.
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Japan.
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Erard M, Dupré-Crochet S, Nüße O. Biosensors for spatiotemporal detection of reactive oxygen species in cells and tissues. Am J Physiol Regul Integr Comp Physiol 2018; 314:R667-R683. [PMID: 29341828 DOI: 10.1152/ajpregu.00140.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Redox biology has become a major issue in numerous areas of physiology. Reactive oxygen species (ROS) have a broad range of roles from signal transduction to growth control and cell death. To understand the nature of these roles, accurate measurement of the reactive compounds is required. An increasing number of tools for ROS detection is available; however, the specificity and sensitivity of these tools are often insufficient. Furthermore, their specificity has been rarely evaluated in complex physiological conditions. Many ROS probes are sensitive to environmental conditions in particular pH, which may interfere with ROS detection and cause misleading results. Accurate detection of ROS in physiology and pathophysiology faces additional challenges concerning the precise localization of the ROS and the timing of their production and disappearance. Certain ROS are membrane permeable, and certain ROS probes move across cells and organelles. Targetable ROS probes such as fluorescent protein-based biosensors are required for accurate localization. Here we analyze these challenges in more detail, provide indications on the strength and weakness of current tools for ROS detection, and point out developments that will provide improved ROS detection methods in the future. There is no universal method that fits all situations in physiology and cell biology. A detailed knowledge of the ROS probes is required to choose the appropriate method for a given biological problem. The knowledge of the shortcomings of these probes should also guide the development of new sensors.
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Affiliation(s)
- Marie Erard
- Université Paris-Sud, Université Paris-Saclay , Orsay , France.,Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique , Orsay , France
| | - Sophie Dupré-Crochet
- Université Paris-Sud, Université Paris-Saclay , Orsay , France.,Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique , Orsay , France
| | - Oliver Nüße
- Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique , Orsay , France
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27
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Abstract
Fluorescence lifetime (FLT) is a robust intrinsic property and material constant of fluorescent matter. Measuring this important physical indicator has evolved from a laboratory curiosity to a powerful and established technique for a variety of applications in drug discovery, medical diagnostics and basic biological research. This distinct trend was mainly driven by improved and meanwhile affordable laser and detection instrumentation on the one hand, and the development of suitable FLT probes and biological assays on the other. In this process two essential working approaches emerged. The first one is primarily focused on high throughput applications employing biochemical in vitro assays with no requirement for high spatial resolution. The second even more dynamic trend is the significant expansion of assay methods combining highly time and spatially resolved fluorescence data by fluorescence lifetime imaging. The latter approach is currently pursued to enable not only the investigation of immortal tumor cell lines, but also specific tissues or even organs in living animals. This review tries to give an actual overview about the current status of FLT based bioassays and the wide range of application opportunities in biomedical and life science areas. In addition, future trends of FLT technologies will be discussed.
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Affiliation(s)
- Franz-Josef Meyer-Almes
- Department of Chemical Engineering and Biotechnology, University of Applied Sciences Darmstadt, Haardtring 100, D-64295 Darmstadt, Germany
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28
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Hollingshead S, Lin CY, Liu JC. Designing Smart Materials with Recombinant Proteins. Macromol Biosci 2017; 17:10.1002/mabi.201600554. [PMID: 28337848 PMCID: PMC6020822 DOI: 10.1002/mabi.201600554] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/08/2017] [Indexed: 01/07/2023]
Abstract
Recombinant protein design allows modular protein domains with different functionalities and responsive behaviors to be easily combined. Inclusion of these protein domains can enable recombinant proteins to have complex responses to their environment (e.g., temperature-triggered aggregation followed by enzyme-mediated cleavage for drug delivery or pH-triggered conformational change and self-assembly leading to structural stabilization by adjacent complementary residues). These "smart" behaviors can be tuned by amino acid identity and sequence, chemical modifications, and addition of other components. A wide variety of domains and peptides have smart behavior. This review focuses on protein designs for self-assembly or conformational changes due to stimuli such as shifts in temperature or pH.
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Affiliation(s)
- Sydney Hollingshead
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-2100, USA
| | - Charng-Yu Lin
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-2100, USA
| | - Julie C. Liu
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-2100, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907-2032, USA
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29
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Abstract
Genetically encoded fluorescent sensors are essential tools in modern biological research, and recent advances in fluorescent proteins (FPs) have expanded the scope of sensor design and implementation. In this review we compare different sensor platforms, including Förster resonance energy transfer (FRET) sensors, fluorescence-modulated single FP-based sensors, translocation sensors, complementation sensors, and dimerization-based sensors. We discuss elements of sensor design and engineering for each platform, including the incorporation of new types of FPs and sensor screening techniques. Finally, we summarize the wide range of sensors in the literature, exploring creative new sensor architectures suitable for different applications.
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Affiliation(s)
- Lynn Sanford
- University of Colorado Boulder, Boulder, CO, United States
| | - Amy Palmer
- University of Colorado Boulder, Boulder, CO, United States.
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30
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Three-Dimensional Tissue Models and Available Probes for Multi-Parametric Live Cell Microscopy: A Brief Overview. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1035:49-67. [DOI: 10.1007/978-3-319-67358-5_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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31
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Jenkins J, Borisov SM, Papkovsky DB, Dmitriev RI. Sulforhodamine Nanothermometer for Multiparametric Fluorescence Lifetime Imaging Microscopy. Anal Chem 2016; 88:10566-10572. [PMID: 27696826 DOI: 10.1021/acs.analchem.6b02675] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Live cells function within narrow limits of physiological temperature (T) and O2 and metabolite concentrations. We have designed a cell-permeable T-sensitive fluorescence lifetime-based nanoprobe based on lipophilic sulforhodamine, which stains 2D and 3D cell models, shows cytoplasmic localization, and has a robust response to T (∼0.037 ns/K). Subsequently, we evaluated the probe and fluorescence lifetime imaging microscopy (FLIM) technique for combined imaging of T and O2 gradients in metabolically active cells. We found that in adherent 2D culture of HCT116 cells intracellular T and O2 are close to ambient values. However, in 3D spheroid structures having size >200 μm, T and O2 gradients become pronounced. These microgradients can be enhanced by treatment with mitochondrial uncouplers or dissipated by drug-induced disaggregation of the spheroids. Thus, we demonstrate the existence of local microgradients of T in 3D cell models and utility of combined imaging of O2 and T.
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Affiliation(s)
- James Jenkins
- School of Biochemistry and Cell Biology, University College Cork , Cork, Ireland
| | - Sergey M Borisov
- Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology , 8010 Graz, Austria
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork , Cork, Ireland
| | - Ruslan I Dmitriev
- School of Biochemistry and Cell Biology, University College Cork , Cork, Ireland
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32
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Nault L, Bouchab L, Dupré-Crochet S, Nüße O, Erard M. Environmental Effects on Reactive Oxygen Species Detection-Learning from the Phagosome. Antioxid Redox Signal 2016; 25:564-76. [PMID: 27225344 DOI: 10.1089/ars.2016.6747] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
SIGNIFICANCE Reactive oxygen species (ROS) fulfill numerous roles in biology ranging from signal transduction to the induction of cell death. To advance our understanding of these sometimes contradictory roles, quantitative, specific, and sensitive ROS measurements are required. RECENT ADVANCES Several organic or genetically encoded probes were successfully developed for ROS detection. CRITICAL ISSUES In some cases, ROS production occurs in a harsh environment such as low pH or high concentration of proteases. However, the ROS sensor may be sensitive to such environmental conditions and therefore becomes inaccurate. While the sensitivity of many ROS sensors to pH is known, many other environmental conditions remain unexplored. This article illustrates the interference between ROS sensors and their environment using the phagosome as an example. In the phagosome, pH changes, high concentration of ROS, and the presence of many proteases generate a hostile and rapidly changing environment. FUTURE DIRECTIONS Difficulties due to cell movement and continuous formation of new phagosomes can be reduced by ratio measurements, if appropriate dyes are identified. For detection in live cells and subcellular locations, fluorescent proteins (FPs) offer several advantages and are used to create biosensors for ROS. Some FPs are directly sensitive to certain ROS as shown here. Although this may compromise their use in an environment with high levels of ROS, it can also be exploited for ROS measurement directly with the FPs themselves. For all types of ROS detection, we suggest a set of basic guidelines for testing the environmental sensitivity of an ROS sensor. Antioxid. Redox Signal. 25, 564-576.
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Affiliation(s)
- Laurent Nault
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS UMR 8000, Université Paris Saclay , Orsay, France
| | - Leïla Bouchab
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS UMR 8000, Université Paris Saclay , Orsay, France
| | - Sophie Dupré-Crochet
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS UMR 8000, Université Paris Saclay , Orsay, France
| | - Oliver Nüße
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS UMR 8000, Université Paris Saclay , Orsay, France
| | - Marie Erard
- Laboratoire de Chimie Physique, Université Paris-Sud, CNRS UMR 8000, Université Paris Saclay , Orsay, France
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Nakabayashi T, Ohta N. Sensing of intracellular environments by fluorescence lifetime imaging of exogenous fluorophores. ANAL SCI 2016; 31:275-85. [PMID: 25864670 DOI: 10.2116/analsci.31.275] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fluorescence lifetime imaging (FLIM) has been recognized as a powerful microscopy technique to examine environments in living systems. The fluorescence lifetime does not depend on the photobleaching and optical conditions, which allows us to obtain quantitative information on intracellular environments by analyzing the fluorescence lifetime. A variety of exogenous fluorophores have been applied in FLIM measurements to examine cellular processes. Information on the correlation between the fluorescence lifetime and the physiological parameters is essential to elucidate the cellular environments from the fluorescence lifetime measurements of exogenous fluorophores. In this review, exogenous fluorophores used for lifetime-based sensing are summarized, with the expectation that it becomes a basis for selecting the fluorophore used to investigate the intracellular environment with FLIM. Experimental results of the intracellular sensing of pH, metal ions, oxygen, viscosity, and other physiological parameters on the basis of the FLIM measurements are described along with a brief explanation of the mechanism of the change in the fluorescence lifetime.
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34
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pH sensitivity of FRET reporters based on cyan and yellow fluorescent proteins. Anal Bioanal Chem 2015; 407:4183-93. [DOI: 10.1007/s00216-015-8636-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 12/22/2022]
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Dominguez N, Estevez-Herrera J, Borges R, Machado JD. The interaction between chromogranin A and catecholamines governs exocytosis. FASEB J 2014; 28:4657-67. [PMID: 25077558 DOI: 10.1096/fj.14-249607] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Chromogranins (Cgs) are acidic proteins that have been described in the large, dense core vesicles (LDCVs) of adrenal chromaffin cells and that have been shown to promote LDCV formation, even in nonsecretory cells. Catecholamines (CAs) are adsorbed by Cgs in vitro, and the absence of Cgs modifies the storage and exocytosis of CAs in chromaffin cells. In this study, we set out to assess the role of CgA in the accumulation and exocytosis of CAs in cells when the levels of CgA and CA are manipulated. We overexpressed CgA in nonsecretory HEK293 cells and in secretory PC12 cells, to study the formation, movement, and exocytosis of newly formed granules by evanescent wave microscopy. We analyzed the association of Cgs/CA by HPLC and amperometry and their role in the accumulation and exocytosis of amines, both under resting conditions and after l-DOPA overloading. To our knowledge, this is the first demonstration that CgA expression in a nonsecretory cell line facilitates the storage and exocytosis of CA. In addition, CgA overexpression causes a doubling of the accumulation of CA, although it slows down exocytosis in PC12 cells. We propose a model to explain how the CgA/CA complex governs the accumulation and exocytosis of secreted amines.
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Affiliation(s)
- Natalia Dominguez
- Unidad de Farmacologia, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | | | - Ricardo Borges
- Unidad de Farmacologia, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
| | - Jose D Machado
- Unidad de Farmacologia, Facultad de Medicina, Universidad de La Laguna, Tenerife, Spain
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Carroll P, Muwanguzi-Karugaba J, Melief E, Files M, Parish T. Identification of the translational start site of codon-optimized mCherry in Mycobacterium tuberculosis. BMC Res Notes 2014; 7:366. [PMID: 24934902 PMCID: PMC4091752 DOI: 10.1186/1756-0500-7-366] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 06/06/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Fluorescent proteins are used widely as reporter genes in many organisms. We previously codon-optimized mCherry for Mycobacterium tuberculosis and generated expression constructs with high level expression in mycobacteria with multiple uses in vitro and in vivo. However, little is known about the expression of fluorescent proteins in mycobacteria and the translational start codon for mCherry has not been experimentally determined. RESULTS We determined the translational start site for functional (fluorescent) mCherry in mycobacteria. Several potential translational start codons were identified; introduction of downstream stop codons by mutagenesis was used to determine which start codon was utilized in the bacterial cells. Fluorescent protein was expressed from a construct which would allow translation of a protein of 226 amino acids or a protein of 235 amino acids. No fluorescence was seen when a construct which could give rise to a protein of 219 amino acids was used. Similar results were obtained in mycobacteria and in Escherichia coli. Western blotting confirmed that mCherry was expressed from the constructs encoding 235 or 226 amino acids, but not from the plasmid encoding 219 amino acids. N-terminal sequencing and mass determination confirmed that the mature protein was 226 amino acids and commenced with the amino acid sequence AIIKE. CONCLUSION We conclude that mCherry is expressed in M. tuberculosis as a smaller protein than expected lacking the GFP-derived N-terminal sequence designed to allow efficient fusions.
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Affiliation(s)
- Paul Carroll
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Centre for Immunology and Infectious Disease, London, UK
| | - Julian Muwanguzi-Karugaba
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Centre for Immunology and Infectious Disease, London, UK
| | - Eduard Melief
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Megan Files
- Infectious Disease Research Institute, Seattle, Washington, USA
| | - Tanya Parish
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Centre for Immunology and Infectious Disease, London, UK
- Infectious Disease Research Institute, Seattle, Washington, USA
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37
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Mérola F, Fredj A, Betolngar DB, Ziegler C, Erard M, Pasquier H. Newly engineered cyan fluorescent proteins with enhanced performances for live cell FRET imaging. Biotechnol J 2013; 9:180-91. [DOI: 10.1002/biot.201300198] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 09/17/2013] [Accepted: 10/31/2013] [Indexed: 11/06/2022]
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Poëa-Guyon S, Ammar MR, Erard M, Amar M, Moreau AW, Fossier P, Gleize V, Vitale N, Morel N. The V-ATPase membrane domain is a sensor of granular pH that controls the exocytotic machinery. ACTA ACUST UNITED AC 2013; 203:283-98. [PMID: 24165939 PMCID: PMC3812966 DOI: 10.1083/jcb.201303104] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Several studies have suggested that the V0 domain of the vacuolar-type H(+)-adenosine triphosphatase (V-ATPase) is directly implicated in secretory vesicle exocytosis through a role in membrane fusion. We report in this paper that there was a rapid decrease in neurotransmitter release after acute photoinactivation of the V0 a1-I subunit in neuronal pairs. Likewise, inactivation of the V0 a1-I subunit in chromaffin cells resulted in a decreased frequency and prolonged kinetics of amperometric spikes induced by depolarization, with shortening of the fusion pore open time. Dissipation of the granular pH gradient was associated with an inhibition of exocytosis and correlated with the V1-V0 association status in secretory granules. We thus conclude that V0 serves as a sensor of intragranular pH that controls exocytosis and synaptic transmission via the reversible dissociation of V1 at acidic pH. Hence, the V-ATPase membrane domain would allow the exocytotic machinery to discriminate fully loaded and acidified vesicles from vesicles undergoing neurotransmitter reloading.
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Affiliation(s)
- Sandrine Poëa-Guyon
- Centre de Neurosciences Paris-Sud, Centre National de la Recherche Scientifique Unité Mixte de Recherche 8195 and Université Paris-Sud, F-91405 Orsay, France
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Benčina M. Illumination of the spatial order of intracellular pH by genetically encoded pH-sensitive sensors. SENSORS 2013; 13:16736-58. [PMID: 24316570 PMCID: PMC3892890 DOI: 10.3390/s131216736] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 11/27/2013] [Accepted: 11/27/2013] [Indexed: 12/11/2022]
Abstract
Fluorescent proteins have been extensively used for engineering genetically encoded sensors that can monitor levels of ions, enzyme activities, redox potential, and metabolites. Certain fluorescent proteins possess specific pH-dependent spectroscopic features, and thus can be used as indicators of intracellular pH. Moreover, concatenated pH-sensitive proteins with target proteins pin the pH sensors to a definite location within the cell, compartment, or tissue. This study provides an overview of the continually expanding family of pH-sensitive fluorescent proteins that have become essential tools for studies of pH homeostasis and cell physiology. We describe and discuss the design of intensity-based and ratiometric pH sensors, their spectral properties and pH-dependency, as well as their performance. Finally, we illustrate some examples of the applications of pH sensors targeted at different subcellular compartments.
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Affiliation(s)
- Mojca Benčina
- Laboratory of Biotechnology, National Institute of Chemistry, 1000 Ljubljana, Slovenia.
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40
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Berthelot V, Steinmetz V, Alvarez LA, Houée-Levin C, Merola F, Rusconi F, Erard M. An analytical workflow for the molecular dissection of irreversibly modified fluorescent proteins. Anal Bioanal Chem 2013; 405:8789-98. [PMID: 24026516 DOI: 10.1007/s00216-013-7326-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/08/2013] [Accepted: 07/11/2013] [Indexed: 12/01/2022]
Abstract
Owing to their ability to be genetically expressed in live cells, fluorescent proteins have become indispensable markers in cellular and biochemical studies. These proteins can undergo a number of covalent chemical modifications that may affect their photophysical properties. Among other mechanisms, such covalent modifications may be induced by reactive oxygen species (ROS), as generated along a variety of biological pathways or through the action of ionizing radiations. In a previous report [1], we showed that the exposure of cyan fluorescent protein (ECFP) to amounts of (•)OH that mimic the conditions of intracellular oxidative bursts (associated with intense ROS production) leads to observable changes in its photophysical properties in the absence of any direct oxidation of the ECFP chromophore. In the present work, we analyzed the associated structural modifications of the protein in depth. Following the quantified production of (•)OH, we devised a complete analytical workflow based on chromatography and mass spectrometry that allowed us to fully characterize the oxidation events. While methionine, tyrosine, and phenylalanine were the only amino acids that were found to be oxidized, semi-quantitative assessment of their oxidation levels showed that the protein is preferentially oxidized at eight residue positions. To account for the preferred oxidation of a few, poorly accessible methionine residues, we propose a multi-step reaction pathway supported by data from pulsed radiolysis experiments. The described experimental workflow is widely generalizable to other fluorescent proteins, and opens the door to the identification of crucial covalent modifications that affect their photophysics.
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Affiliation(s)
- Vivien Berthelot
- Laboratoire de Chimie Physique, UMR CNRS 8000, Building 350, 91405, Orsay Cedex, France
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