1
|
Socas LB, Ambroggio EE. Introducing the multi-dimensional spectral phasors: a tool for the analysis of fluorescence excitation-emission matrices. Methods Appl Fluoresc 2022; 10. [PMID: 35139496 DOI: 10.1088/2050-6120/ac5389] [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: 09/20/2021] [Accepted: 02/09/2022] [Indexed: 11/12/2022]
Abstract
The use of phasors to analyze fluorescence data was first introduced for time-resolved studies for a simpler mathematical analysis of the fluorescence-decay curves. Recently, this approach was extended to steady-state experiments with the introduction of the spectral phasors (SP), derived from the Fourier transform of the fluorescence emission spectrum. In this work, we revise key mathematical aspects that lead to an interpretation of SP as the characteristic function of a probability distribution. This formalism allows us to introduce a new tool, called multi-dimensional spectral phasor (MdSP) that seize, not only the information from the emission spectrum, but from the full excitation-emission matrix (EEM). In addition, we developed a homemade open-source Java software to facilitate the MdSP data processing. Due to this mathematical conceptualization, we settled a mechanism for the use of MdSP as a tool to tackle spectral signal unmixing problems in a more accurate way than SP. As a proof of principle, with the use of MdSP we approach two important biophysical questions: protein conformational changes and protein-ligand interactions. Specifically, we experimentally measure the EEM changes upon denaturation of human serum albumin (HSA) or during its association with the fluorescence dye 1,8-anilinonaphtalene sulphate (ANS) detected via tryptophan-ANS Förster Resonance Energy Transfer (FRET). In this sense, MdSP allows us to obtain information of the system in a simpler and finer way than the traditional SP. Specifically, understanding a protein's EEM as a molecular fingerprint opens new doors for the use of MdSP as a tool to analyze and comprehend protein conformational changes and interactions.
Collapse
Affiliation(s)
- Luis Bp Socas
- Química Biológica, Centro de Investigaciones en Química Biológica de Córdoba, Haya de la Torre y Medina Allende s/n, Cordoba, Córdoba, X5000HUA, ARGENTINA
| | - Ernesto Esteban Ambroggio
- Química Biológica, CIQUIBIC Química Biológica, Haya de la Torre y Medina Allende s/n, Cordoba, X5000HUA, ARGENTINA
| |
Collapse
|
2
|
Fu L, Qian Y, Zhou J, Zheng L, Wang Y. Fluorescence-based quantitative platform for ultrasensitive food allergen detection: From immunoassays to DNA sensors. Compr Rev Food Sci Food Saf 2020; 19:3343-3364. [PMID: 33337031 DOI: 10.1111/1541-4337.12641] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/12/2020] [Accepted: 09/01/2020] [Indexed: 01/10/2023]
Abstract
Food allergies are global health issue with an increasing prevalence that affect food safety; hence, food allergen detection, labeling, and management are considered to be important priorities in the food industry. In this critical review, we provide a comprehensive overview of several fluorescence-based platforms based on different biorecognition ligands, such as antibodies, DNA, aptamers, and cells, for food allergen quantification. Traditional analytical methods are generally unsuitable for food manufacturers to accomplish the real-time identification of food allergens in food products. Therefore, it is important to develop simple, rapid, inexpensive, accurate, and sensitive methods to improve user accessibility. A fluorescence-based quantitative platform provides an excellent detection platform for food allergens because of its high sensitivity. This review summarizes the traditional antibody-based fluorescent techniques for food allergen detection, such as the time-resolved fluoroimmunoassay , immunofluorescence imaging, fluorescence enzyme-linked immune sorbent assay, flow injection fluoroimmunoassay, and fluorescence immunosensors. However, these methods suffer from disadvantages such as the significant rate of false-positive and false-negative results due to antibody cross-reactivity with nontarget food components in the complex food matrix and epitope degradation during food processing. Hence, different types of fluorescence-based immunoassays are suitable for standardization and quantification of allergens in fresh foods. In addition, we summarize new fluorescence-based quantitative platforms, including fluorescence genosensors, fluorescence cell sensors, and fluorescence aptamer sensors. With the advantages of high sensitivity and simple operation, fluorescence biosensors will have great potential in the future and could provide portable methods for multiallergen real-time detection in complex food systems.
Collapse
Affiliation(s)
- Linglin Fu
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, People's Republic of China
| | - Yifan Qian
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, People's Republic of China
| | - Jinru Zhou
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, People's Republic of China
| | - Lei Zheng
- School of Food Science and Engineering, Hefei University of Technology, Hefei, People's Republic of China
| | - Yanbo Wang
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, People's Republic of China
| |
Collapse
|
3
|
Liu S, Lin C, Diao X, Meng L, Lu H. Interactions between tetracycline and extracellular polymeric substances in anammox granular sludge. BIORESOURCE TECHNOLOGY 2019; 293:122069. [PMID: 31518816 DOI: 10.1016/j.biortech.2019.122069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/19/2019] [Accepted: 08/24/2019] [Indexed: 06/10/2023]
Abstract
The effects of antibiotics on extracellular polymeric substances (EPS) using tetracycline as the model chemical were analyzed in terms of molecular property and structure. Results showed that three components, tryptophan, tryptophan type-proteins and polysaccharides in EPS of granular sludge from anaerobic ammonium oxidation (anammox) reactor can interacted with tetracycline, detected by the static quenching via the endogenous fluorescence quenching and transient fluorescence spectroscopy. Thermodynamic experiment confirmed that their interaction was dominated by the hydrophobic force. Combined with the synchronous fluorescence spectroscopy, it was found that tetracycline facilitated the extension degree of peptide chains in tryptophan type-proteins, leading to the enhancement of hydrodynamic diameter of the macromolecules in EPS when binding with tetracycline. EPS in AnGS demonstrated the resistance ability to tetracycline by converting from gel to sol state in rheological term. With the increase of tetracycline concentration, the stability of elastic structures in EPS declined, influencing the AnGS stability.
Collapse
Affiliation(s)
- Song Liu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, PR China; Shenzhen Research Institute of Sun Yat-sen University, Shenzhen, PR China; School of Urban and Rural Construction, Zhongkai University of Agriculture and Engineering, Guangzhou, PR China
| | - Chong Lin
- School of Urban and Rural Construction, Zhongkai University of Agriculture and Engineering, Guangzhou, PR China
| | - Xingxing Diao
- Shenzhen Lisai Industrial Development Co LtD, Shenzhen, PR China
| | - Liao Meng
- Shenzhen Xiaping Solid Waste Landfill Site, Shenzhen, PR China
| | - Hui Lu
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, PR China; Shenzhen Research Institute of Sun Yat-sen University, Shenzhen, PR China.
| |
Collapse
|
4
|
Chen SJ, Sinsuebphon N, Rudkouskaya A, Barroso M, Intes X, Michalet X. In vitro and in vivo phasor analysis of stoichiometry and pharmacokinetics using short-lifetime near-infrared dyes and time-gated imaging. JOURNAL OF BIOPHOTONICS 2019; 12:e201800185. [PMID: 30421551 PMCID: PMC6559731 DOI: 10.1002/jbio.201800185] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/08/2018] [Accepted: 11/11/2018] [Indexed: 05/22/2023]
Abstract
We introduce a simple new approach for time-resolved multiplexed analysis of complex systems using near-infrared (NIR) dyes, applicable to in vitro and in vivo studies. We show that fast and precise in vitro quantification of NIR fluorophores' short (subnanosecond) lifetime and stoichiometry can be done using phasor analysis, a computationally efficient and user-friendly representation of complex fluorescence intensity decays obtained with pulsed laser excitation and time-gated camera imaging. We apply this approach to the study of binding equilibria by Förster resonant energy transfer using two different model systems: primary/secondary antibody binding in vitro and ligand/receptor binding in cell cultures. We then extend it to dynamic imaging of the pharmacokinetics of transferrin engagement with the transferrin receptor in live mice, elucidating the kinetics of differential transferrin accumulation in specific organs, straightforwardly differentiating specific from nonspecific binding. Our method, implemented in a freely-available software, has the advantage of time-resolved NIR imaging, including better tissue penetration and background-free imaging, but simplifies and considerably speeds up data processing and interpretation, while remaining quantitative. These advances make this method attractive and of broad applicability for in vitro and in vivo molecular imaging and could be extended to applications as diverse as image-guided surgery or optical tomography.
Collapse
Affiliation(s)
- Sez-Jade Chen
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Nattawut Sinsuebphon
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Alena Rudkouskaya
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Margarida Barroso
- Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York
| | - Xavier Intes
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Xavier Michalet
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California
- Correspondence Xavier Michalet, Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095.
| |
Collapse
|
5
|
Goo BMSS, Sanstrum BJ, Holden DZY, Yu Y, James NG. Arc/Arg3.1 has an activity-regulated interaction with PICK1 that results in altered spatial dynamics. Sci Rep 2018; 8:14675. [PMID: 30279480 PMCID: PMC6168463 DOI: 10.1038/s41598-018-32821-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/25/2018] [Indexed: 01/28/2023] Open
Abstract
Activity-regulated cytoskeleton-associated protein (Arc; also known as Arg3.1) is an immediate early gene product that is transcribed in dendritic spines and, to date, has been best characterized as a positive regulator of AMPAR endocytosis during long-term depression (LTD) through interaction with endocytic proteins. Here, we show that protein interacting with C terminal kinase 1 (PICK1), a protein known to bind to the GluA2 subunit of AMPARs and associated with AMPAR trafficking, was pulled-down from brain homogenates and synaptosomes when using Arc as immobilized bait. Fluctuation and FLIM-FRET-Phasor analysis revealed direct interaction between these proteins when co-expressed that was increased under depolarizing conditions in live cells. At the plasma membrane, Arc-mCherry oligomerization was found to be concentration dependent. Additionally, co-expression of Arc-mCherry and EGFP-PICK1 followed by depolarizing conditions resulted in significant increases in the number and size of puncta containing both proteins. Furthermore, we identified the Arc binding region to be the first 126 amino acids of the PICK1 BAR domain. Overall, our data support a novel interaction and model where PICK1 mediates Arc regulation of AMPARs particularly under depolarizing conditions.
Collapse
Affiliation(s)
- Brandee M S S Goo
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | - Bethany J Sanstrum
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | - Diana Z Y Holden
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA
| | | | - Nicholas G James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, 651 Ilalo St., BSB 222, University of Hawaii, Honolulu, HI, 96813, USA.
| |
Collapse
|
6
|
Blaffert J, Haeri HH, Blech M, Hinderberger D, Garidel P. Spectroscopic methods for assessing the molecular origins of macroscopic solution properties of highly concentrated liquid protein solutions. Anal Biochem 2018; 561-562:70-88. [PMID: 30243977 DOI: 10.1016/j.ab.2018.09.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 09/08/2018] [Accepted: 09/17/2018] [Indexed: 01/14/2023]
Abstract
In cases of subcutaneous injection of therapeutic monoclonal antibodies, high protein concentrations (>50 mg/ml) are often required. During the development of these high concentration liquid formulations (HCLF), challenges such as aggregation, gelation, opalescence, phase separation, and high solution viscosities are more prone compared to low concentrated protein formulations. These properties can impair manufacturing processes, as well as protein stability and shelf life. To avoid such unfavourable solution properties, a detailed understanding about the nature of these properties and their driving forces are required. However, the fundamental mechanisms that lead to macroscopic solution properties, as above mentioned, are complex and not fully understood, yet. Established analytical methods for assessing the colloidal stability, i.e. the ability of a native protein to remain dispersed in solution, are restricted to dilute conditions and provide parameters such as the second osmotic virial coefficient, B22, and the diffusion interaction coefficient, kD. These parameters are routinely applied for qualitative estimations and identifications of proteins with challenging solution behaviours, such as high viscosities and aggregation, although the assays are prepared for low protein concentration conditions, typically between 0.1 and 20 mg/ml ("ideal" solution conditions). Quantitative analysis of samples of high protein concentration is difficult and it is hard to obtain information about the driving forces of such solution properties and corresponding protein-protein self-interactions. An advantage of using specific spectroscopic methods is the potential of directly analysing highly concentrated protein solutions at different solution conditions. This allows for collecting/gaining valuable information about the fundamental mechanisms of solution properties of the high protein concentration regime. In addition, the derived parameters might be more predictive as compared to the parameters originating from assays which are optimized for the low protein concentration range. The provided information includes structural data, molecular dynamics at various timescales and protein-solvent interactions, which can be obtained at molecular resolution. Herein, we provide an overview about spectroscopic techniques for analysing the origins of macroscopic solution behaviours in general, with a specific focus on pharmaceutically relevant high protein concentration and formulation conditions.
Collapse
Affiliation(s)
- Jacob Blaffert
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Haleh Hashemi Haeri
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Michaela Blech
- Boehringer Ingelheim Pharma GmbH & Co. KG, Protein Science, Birkerndorfer Str. 65, 88397, Biberach/Riß, Germany
| | - Dariush Hinderberger
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany
| | - Patrick Garidel
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120, Halle/Saale, Germany; Boehringer Ingelheim Pharma GmbH & Co. KG, Protein Science, Birkerndorfer Str. 65, 88397, Biberach/Riß, Germany.
| |
Collapse
|
7
|
Petersen KJ, Peterson KC, Muretta JM, Higgins SE, Gillispie GD, Thomas DD. Fluorescence lifetime plate reader: resolution and precision meet high-throughput. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:113101. [PMID: 25430092 PMCID: PMC4242087 DOI: 10.1063/1.4900727] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We describe a nanosecond time-resolved fluorescence spectrometer that acquires fluorescence decay waveforms from each well of a 384-well microplate in 3 min with signal-to-noise exceeding 400 using direct waveform recording. The instrument combines high-energy pulsed laser sources (5-10 kHz repetition rate) with a photomultiplier and high-speed digitizer (1 GHz) to record a fluorescence decay waveform after each pulse. Waveforms acquired from rhodamine or 5-((2-aminoethyl)amino) naphthalene-1-sulfonic acid dyes in a 384-well plate gave lifetime measurements 5- to 25-fold more precise than the simultaneous intensity measurements. Lifetimes as short as 0.04 ns were acquired by interleaving with an effective sample rate of 5 GHz. Lifetime measurements resolved mixtures of single-exponential dyes with better than 1% accuracy. The fluorescence lifetime plate reader enables multiple-well fluorescence lifetime measurements with an acquisition time of 0.5 s per well, suitable for high-throughput fluorescence lifetime screening applications.
Collapse
Affiliation(s)
- Karl J Petersen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Kurt C Peterson
- Fluorescence Innovations, Inc., Minneapolis, Minnesota 55455, USA
| | - Joseph M Muretta
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Sutton E Higgins
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Gregory D Gillispie
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| |
Collapse
|
8
|
Montecinos-Franjola F, James NG, Concha-Marambio L, Brunet JE, Lagos R, Monasterio O, Jameson DM. Single tryptophan mutants of FtsZ: nucleotide binding/exchange and conformational transitions. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2014; 1844:1193-200. [PMID: 24704635 DOI: 10.1016/j.bbapap.2014.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 03/24/2014] [Accepted: 03/26/2014] [Indexed: 11/27/2022]
Abstract
Cell division protein FtsZ cooperatively self-assembles into straight filaments when bound to GTP. A set of conformational changes that are linked to FtsZ GTPase activity are involved in the transition from straight to curved filaments that eventually disassemble. In this work, we characterized the fluorescence of single Trp mutants as a reporter of the predicted conformational changes between the GDP- and GTP-states of Escherichia coli FtsZ. Steady-state fluorescence characterization showed the Trp senses different environments and displays low solvent accessibility. Time-resolved fluorescence data indicated that the main conformational changes in FtsZ occur at the interaction surface between the N and C domains, but also minor rearrangements were detected in the bulk of the N domain. Surprisingly, despite its location near the bottom protofilament interface at the C domain, the Trp 275 fluorescence lifetime did not report changes between the GDP and GTP states. The equilibrium unfolding of FtsZ features an intermediate that is stabilized by the nucleotide bound in the N-domain as well as by quaternary protein-protein interactions. In this context, we characterized the unfolding of the Trp mutants using time-resolved fluorescence and phasor plot analysis. A novel picture of the structural transition from the native state in the absence of denaturant, to the solvent-exposed unfolded state is presented. Taken together our results show that conformational changes between the GDP and GTP states of FtsZ, such as those observed in FtsZ unfolding, are restricted to the interaction surface between the N and C domains.
Collapse
Affiliation(s)
- Felipe Montecinos-Franjola
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Nicholas G James
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu 96813, HI, USA.
| | - Luis Concha-Marambio
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Juan E Brunet
- Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso 2373223, Chile.
| | - Rosalba Lagos
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - Octavio Monasterio
- Laboratorio de Biología Estructural y Molecular, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago 7800024, Chile.
| | - David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu 96813, HI, USA.
| |
Collapse
|
9
|
Yan W, Peng X, Qi J, Gao J, Fan S, Wang Q, Qu J, Niu H. Dynamic fluorescence lifetime imaging based on acousto-optic deflectors. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:116004. [PMID: 25375349 DOI: 10.1117/1.jbo.19.11.116004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/13/2014] [Indexed: 06/04/2023]
Abstract
We report a dynamic fluorescence lifetime imaging (D-FLIM) system that is based on a pair of acousto-optic deflectors for the random regions of interest (ROI) study in the sample. The two-dimensional acousto-optic deflector devices are used to rapidly scan the femtosecond excitation laser beam across the sample, providing specific random access to the ROI. Our experimental results using standard fluorescent dyes in live cancer cells demonstrate that the D-FLIM system can dynamically monitor the changing process of the microenvironment in the ROI in live biological samples.
Collapse
|
10
|
|