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Díaz-García C, Renart ML, Poveda JA, Giudici AM, González-Ros JM, Prieto M, Coutinho A. Probing the Structural Dynamics of the Activation Gate of KcsA Using Homo-FRET Measurements. Int J Mol Sci 2021; 22:ijms222111954. [PMID: 34769384 PMCID: PMC8584343 DOI: 10.3390/ijms222111954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/18/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
The allosteric coupling between activation and inactivation processes is a common feature observed in K+ channels. Particularly, in the prokaryotic KcsA channel the K+ conduction process is controlled by the inner gate, which is activated by acidic pH, and by the selectivity filter (SF) or outer gate, which can adopt non-conductive or conductive states. In a previous study, a single tryptophan mutant channel (W67 KcsA) enabled us to investigate the SF dynamics using time-resolved homo-Förster Resonance Energy Transfer (homo-FRET) measurements. Here, the conformational changes of both gates were simultaneously monitored after labelling the G116C position with tetramethylrhodamine (TMR) within a W67 KcsA background. At a high degree of protein labeling, fluorescence anisotropy measurements showed that the pH-induced KcsA gating elicited a variation in the homo-FRET efficiency among the conjugated TMR dyes (TMR homo-FRET), while the conformation of the SF was simultaneously tracked (W67 homo-FRET). The dependence of the activation pKa of the inner gate with the ion occupancy of the SF unequivocally confirmed the allosteric communication between the two gates of KcsA. This simple TMR homo-FRET based ratiometric assay can be easily extended to study the conformational dynamics associated with the gating of other ion channels and their modulation.
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Affiliation(s)
- Clara Díaz-García
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Maria Lourdes Renart
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
- Correspondence: (M.L.R.); (A.C.)
| | - José Antonio Poveda
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Ana Marcela Giudici
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - José M. González-Ros
- Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche, Universidad Miguel Hernández, 03202 Elche, Spain; (J.A.P.); (A.M.G.); (J.M.G.-R.)
| | - Manuel Prieto
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Ana Coutinho
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (C.D.-G.); (M.P.)
- Associate Laboratory i4HB, Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
- Correspondence: (M.L.R.); (A.C.)
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2
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Lerner E, Barth A, Hendrix J, Ambrose B, Birkedal V, Blanchard SC, Börner R, Sung Chung H, Cordes T, Craggs TD, Deniz AA, Diao J, Fei J, Gonzalez RL, Gopich IV, Ha T, Hanke CA, Haran G, Hatzakis NS, Hohng S, Hong SC, Hugel T, Ingargiola A, Joo C, Kapanidis AN, Kim HD, Laurence T, Lee NK, Lee TH, Lemke EA, Margeat E, Michaelis J, Michalet X, Myong S, Nettels D, Peulen TO, Ploetz E, Razvag Y, Robb NC, Schuler B, Soleimaninejad H, Tang C, Vafabakhsh R, Lamb DC, Seidel CAM, Weiss S. FRET-based dynamic structural biology: Challenges, perspectives and an appeal for open-science practices. eLife 2021; 10:e60416. [PMID: 33779550 PMCID: PMC8007216 DOI: 10.7554/elife.60416] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 02/09/2021] [Indexed: 12/18/2022] Open
Abstract
Single-molecule FRET (smFRET) has become a mainstream technique for studying biomolecular structural dynamics. The rapid and wide adoption of smFRET experiments by an ever-increasing number of groups has generated significant progress in sample preparation, measurement procedures, data analysis, algorithms and documentation. Several labs that employ smFRET approaches have joined forces to inform the smFRET community about streamlining how to perform experiments and analyze results for obtaining quantitative information on biomolecular structure and dynamics. The recent efforts include blind tests to assess the accuracy and the precision of smFRET experiments among different labs using various procedures. These multi-lab studies have led to the development of smFRET procedures and documentation, which are important when submitting entries into the archiving system for integrative structure models, PDB-Dev. This position paper describes the current 'state of the art' from different perspectives, points to unresolved methodological issues for quantitative structural studies, provides a set of 'soft recommendations' about which an emerging consensus exists, and lists openly available resources for newcomers and seasoned practitioners. To make further progress, we strongly encourage 'open science' practices.
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Affiliation(s)
- Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, and The Center for Nanoscience and Nanotechnology, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Anders Barth
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-UniversitätDüsseldorfGermany
| | - Jelle Hendrix
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and Biomedical Research Institute (BIOMED), Hasselt UniversityDiepenbeekBelgium
| | - Benjamin Ambrose
- Department of Chemistry, University of SheffieldSheffieldUnited Kingdom
| | - Victoria Birkedal
- Department of Chemistry and iNANO center, Aarhus UniversityAarhusDenmark
| | - Scott C Blanchard
- Department of Structural Biology, St. Jude Children's Research HospitalMemphisUnited States
| | - Richard Börner
- Laserinstitut HS Mittweida, University of Applied Science MittweidaMittweidaGermany
| | - Hoi Sung Chung
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Thorben Cordes
- Physical and Synthetic Biology, Faculty of Biology, Ludwig-Maximilians-Universität MünchenPlanegg-MartinsriedGermany
| | - Timothy D Craggs
- Department of Chemistry, University of SheffieldSheffieldUnited Kingdom
| | - Ashok A Deniz
- Department of Integrative Structural and Computational Biology, The Scripps Research InstituteLa JollaUnited States
| | - Jiajie Diao
- Department of Cancer Biology, University of Cincinnati School of MedicineCincinnatiUnited States
| | - Jingyi Fei
- Department of Biochemistry and Molecular Biology and The Institute for Biophysical Dynamics, University of ChicagoChicagoUnited States
| | - Ruben L Gonzalez
- Department of Chemistry, Columbia UniversityNew YorkUnited States
| | - Irina V Gopich
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Howard Hughes Medical InstituteBaltimoreUnited States
| | - Christian A Hanke
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-UniversitätDüsseldorfGermany
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of ScienceRehovotIsrael
| | - Nikos S Hatzakis
- Department of Chemistry & Nanoscience Centre, University of CopenhagenCopenhagenDenmark
- Denmark Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences, University of CopenhagenCopenhagenDenmark
| | - Sungchul Hohng
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National UniversitySeoulRepublic of Korea
| | - Seok-Cheol Hong
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science and Department of Physics, Korea UniversitySeoulRepublic of Korea
| | - Thorsten Hugel
- Institute of Physical Chemistry and Signalling Research Centres BIOSS and CIBSS, University of FreiburgFreiburgGermany
| | - Antonino Ingargiola
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los AngelesLos AngelesUnited States
| | - Chirlmin Joo
- Department of BioNanoScience, Kavli Institute of Nanoscience, Delft University of TechnologyDelftNetherlands
| | - Achillefs N Kapanidis
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of OxfordOxfordUnited Kingdom
| | - Harold D Kim
- School of Physics, Georgia Institute of TechnologyAtlantaUnited States
| | - Ted Laurence
- Physical and Life Sciences Directorate, Lawrence Livermore National LaboratoryLivermoreUnited States
| | - Nam Ki Lee
- School of Chemistry, Seoul National UniversitySeoulRepublic of Korea
| | - Tae-Hee Lee
- Department of Chemistry, Pennsylvania State UniversityUniversity ParkUnited States
| | - Edward A Lemke
- Departments of Biology and Chemistry, Johannes Gutenberg UniversityMainzGermany
- Institute of Molecular Biology (IMB)MainzGermany
| | - Emmanuel Margeat
- Centre de Biologie Structurale (CBS), CNRS, INSERM, Universitié de MontpellierMontpellierFrance
| | | | - Xavier Michalet
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los AngelesLos AngelesUnited States
| | - Sua Myong
- Department of Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Daniel Nettels
- Department of Biochemistry and Department of Physics, University of ZurichZurichSwitzerland
| | - Thomas-Otavio Peulen
- Department of Bioengineering and Therapeutic Sciences, University of California, San FranciscoSan FranciscoUnited States
| | - Evelyn Ploetz
- Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), Center for Integrated Protein Science Munich (CIPSM) and Nanosystems Initiative Munich (NIM), Ludwig-Maximilians-UniversitätMünchenGermany
| | - Yair Razvag
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, and The Center for Nanoscience and Nanotechnology, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of JerusalemJerusalemIsrael
| | - Nicole C Robb
- Warwick Medical School, University of WarwickCoventryUnited Kingdom
| | - Benjamin Schuler
- Department of Biochemistry and Department of Physics, University of ZurichZurichSwitzerland
| | - Hamid Soleimaninejad
- Biological Optical Microscopy Platform (BOMP), University of MelbourneParkvilleAustralia
| | - Chun Tang
- College of Chemistry and Molecular Engineering, PKU-Tsinghua Center for Life Sciences, Beijing National Laboratory for Molecular Sciences, Peking UniversityBeijingChina
| | - Reza Vafabakhsh
- Department of Molecular Biosciences, Northwestern UniversityEvanstonUnited States
| | - Don C Lamb
- Physical Chemistry, Department of Chemistry, Center for Nanoscience (CeNS), Center for Integrated Protein Science Munich (CIPSM) and Nanosystems Initiative Munich (NIM), Ludwig-Maximilians-UniversitätMünchenGermany
| | - Claus AM Seidel
- Lehrstuhl für Molekulare Physikalische Chemie, Heinrich-Heine-UniversitätDüsseldorfGermany
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, and Department of Physiology, University of California, Los AngelesLos AngelesUnited States
- Department of Physiology, CaliforniaNanoSystems Institute, University of California, Los AngelesLos AngelesUnited States
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Single-molecule localization microscopy and tracking with red-shifted states of conventional BODIPY conjugates in living cells. Nat Commun 2019; 10:3400. [PMID: 31363088 PMCID: PMC6667493 DOI: 10.1038/s41467-019-11384-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/11/2019] [Indexed: 11/09/2022] Open
Abstract
Single-molecule localization microscopy (SMLM) is a rapidly evolving technique to resolve subcellular structures and single-molecule dynamics at the nanoscale. Here, we employ conventional BODIPY conjugates for live-cell SMLM via their previously reported red-shifted ground-state dimers (DII), which transiently form through bi-molecular encounters and emit bright single-molecule fluorescence. We employ the versatility of DII-state SMLM to resolve the nanoscopic spatial regulation and dynamics of single fatty acid analogs (FAas) and lipid droplets (LDs) in living yeast and mammalian cells with two colors. In fed cells, FAas localize to the endoplasmic reticulum and LDs of ~125 nm diameter. Upon fasting, however, FAas form dense, non-LD clusters of ~100 nm diameter at the plasma membrane and transition from free diffusion to confined immobilization. Our reported SMLM capability of conventional BODIPY conjugates is further demonstrated by imaging lysosomes in mammalian cells and enables simple and versatile live-cell imaging of sub-cellular structures at the nanoscale. Single-molecule localization microscopy (SMLM) requires the use of fluorophores with specific sets of properties. Here the authors employ conventional BODIPY dyes as SMLM fluorophores by making use of rarely reported red-shifted ground state BODIPY dimers to image fatty acids, lipid droplets and lysosomes at single-molecule resolution.
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4
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Conformational plasticity in the KcsA potassium channel pore helix revealed by homo-FRET studies. Sci Rep 2019; 9:6215. [PMID: 30996281 PMCID: PMC6470172 DOI: 10.1038/s41598-019-42405-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 03/29/2019] [Indexed: 11/24/2022] Open
Abstract
Potassium channels selectivity filter (SF) conformation is modulated by several factors, including ion-protein and protein-protein interactions. Here, we investigate the SF dynamics of a single Trp mutant of the potassium channel KcsA (W67) using polarized time-resolved fluorescence measurements. For the first time, an analytical framework is reported to analyze the homo-Förster resonance energy transfer (homo-FRET) within a symmetric tetrameric protein with a square geometry. We found that in the closed state (pH 7), the W67-W67 intersubunit distances become shorter as the average ion occupancy of the SF increases according to cation type and concentration. The hypothesis that the inactivated SF at pH 4 is structurally similar to its collapsed state, detected at low K+, pH 7, was ruled out, emphasizing the critical role played by the S2 binding site in the inactivation process of KcsA. This homo-FRET approach provides complementary information to X-ray crystallography in which the protein conformational dynamics is usually compromised.
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5
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De Vetta M, González L, Corral I. The Role of Electronic Triplet States and High‐Lying Singlet States in the Deactivation Mechanism of the Parent BODIPY: An ADC(2) and CASPT2 Study. CHEMPHOTOCHEM 2018. [DOI: 10.1002/cptc.201800169] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Martina De Vetta
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of Vienna Währinger Str. 17, A- 1090 Wien Austria
- Departamento de QuímicaUniversidad Autónoma de Madrid C/ Francisco Tomás y Valiente 7 28049 Cantoblanco Madrid Spain
| | - Leticia González
- Institute of Theoretical ChemistryFaculty of ChemistryUniversity of Vienna Währinger Str. 17, A- 1090 Wien Austria
| | - Inés Corral
- Departamento de QuímicaUniversidad Autónoma de Madrid C/ Francisco Tomás y Valiente 7 28049 Cantoblanco Madrid Spain
- IADCHEM. Institute for Advanced Research in ChemistryUniversidad Autónoma de Madrid C/ Francisco Tomás y Valiente 7 28049 Cantoblanco Madrid Spain
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6
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Kyrychenko A. Using fluorescence for studies of biological membranes: a review. Methods Appl Fluoresc 2015; 3:042003. [DOI: 10.1088/2050-6120/3/4/042003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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7
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Maximum entropy analysis of data simulations and practical aspects of time-resolved fluorescence measurements in the study of molecular interactions. J Mol Struct 2014. [DOI: 10.1016/j.molstruc.2013.12.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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8
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Pochorovski I, Knehans T, Nettels D, Müller AM, Schweizer WB, Caflisch A, Schuler B, Diederich F. Experimental and computational study of BODIPY dye-labeled cavitand dynamics. J Am Chem Soc 2014; 136:2441-9. [PMID: 24490940 DOI: 10.1021/ja4104292] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Understanding the distance distribution and dynamics between moieties attached to the walls of a resorcin[4]arene cavitand, which is switchable between an expanded kite and a contracted vase form, might enable the use of this molecular system for the study of fundamental distance-dependent interactions. Toward this goal, a combined experimental and molecular dynamics (MD) simulation study on donor/acceptor borondipyrromethene (BODIPY) dye-labeled cavitands present in the vase and kite forms was performed. Direct comparison between anisotropy decays calculated from MD simulations with experimental fluorescence anisotropy data showed excellent agreement, indicating that the simulations provide an accurate representation of the dynamics of the system. Distance distributions between the BODIPY dyes were established by comparing time-resolved Förster resonance energy transfer experiments and MD simulations. Fluorescence intensity decay curves emulated on the basis of the MD trajectories showed good agreement with the experimental data, suggesting that the simulations present an accurate picture of the distance distributions and dynamics in this molecular system and provide an important tool for understanding the behavior of extended molecular systems and designing future applications.
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Affiliation(s)
- Igor Pochorovski
- Laboratorium für Organische Chemie, ETH Zürich , Hönggerberg, HCI, 8093 Zürich, Switzerland
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9
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Heisig F, Gollos S, Freudenthal SJ, El-Tayeb A, Iqbal J, Müller CE. Synthesis of BODIPY derivatives substituted with various bioconjugatable linker groups: a construction kit for fluorescent labeling of receptor ligands. J Fluoresc 2013; 24:213-30. [PMID: 24052460 DOI: 10.1007/s10895-013-1289-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2013] [Accepted: 08/09/2013] [Indexed: 12/15/2022]
Abstract
The goal of the present study was to design small, functionalized green-emitting BODIPY dyes, which can readily be coupled to target molecules such as receptor ligands, or even be integrated into their pharmacophores. A simple two-step one-pot procedure starting from 2,4-dimethylpyrrole and ω-bromoalkylcarboxylic acid chlorides was used to obtain new ω-bromoalkyl-substituted BODIPY fluorophores (1a-1f) connected via alkyl spacers of different length to the 8-position of the fluorescent dye. The addition of radical inhibitors reduced the amount of side products. The ω-bromoalkyl-substituted BODIPYs were further converted to introduce various functional groups: iodo-substituted dyes were obtained by Finkelstein reaction in excellent yields; microwave-assisted reaction with methanolic ammonia led to fast and clean conversion to the amino-substituted dyes; a hydroxyl-substituted derivative was prepared by reaction with sodium ethylate, and thiol-substituted BODIPYs were obtained by reaction of 1a-1f with potassium thioacetate followed by alkaline cleavage of the thioesters. Water-soluble derivatives were prepared by introducing sulfonate groups into the 2- and 6-position of the BODIPY core. The synthesized BODIPY derivatives showed high fluorescent yields and appeared to be stable under basic, reducing and oxidative conditions. As a proof of concept, 2-thioadenosine was alkylated with bromoethyl-BODIPY 1b. The resulting fluorescent 2-substituted adenosine derivative 15 displayed selectivity for the A3 adenosine receptor (ARs) over the other AR subtypes, showed agonistic activity, and may thus become a useful tool for studying A3ARs, or a lead structure for further optimization. The new functionalized dyes may be widely used for fluorescent labeling allowing the investigation of biological targets and processes.
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Affiliation(s)
- Fabian Heisig
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, University Bonn, 53121, Bonn, Germany
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10
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Cunha Dias de Rezende L, Menezes Vaidergorn M, Biazzotto Moraes JC, da Silva Emery F. Synthesis, photophysical properties and solvatochromism of meso-substituted tetramethyl BODIPY dyes. J Fluoresc 2013; 24:257-66. [PMID: 24008989 DOI: 10.1007/s10895-013-1293-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 08/21/2013] [Indexed: 11/26/2022]
Abstract
The 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene fluorescent dyes (BODIPYs) were first synthesized almost 50 years ago; however, the exploration of their technological application has only begun in the last 20 years. These dyes possess interesting photophysical properties, increasing interest in their application as fluorescent markers and/or dyes. Herein, we report the synthesis of tetramethyl BODIPY and four meso-substituted dyes (2-thienyl, 4-pyridinyl, 4-fluorophenyl and 4-nitrophenyl derivatives). Their photophysical characterization (absorption spectra, emission spectra, fluorescence quantum yields and time-resolved fluorescence) and solvatochromic behavior were studied. Absorption and emission were barely affected by substituents, with a slightly higher stokes shift observed in the substituted dyes. Substitutions could be associated with a shorter fluorescence lifetime and lower quantum yields. Good correlations were observed between the Catalán solvent descriptors and the photophysical parameters. Also, better correlation was observed between the solvent polarizability descriptor (SP) and photophysical parameters. Overall, only slight solvatochromism was observed. The 4-pyridinyl derivative was the subject of a relatively significant solvatochromism regarding the wavelengths of the emission spectra, with the observation of a bathochromically shifted emission in methanol. The fluorescence quantum yield of the 4-nitrophenyl substituted BODIPY was approximately 30 times higher in hexane, which may be of interest for practical applications.
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Affiliation(s)
- Lucas Cunha Dias de Rezende
- Faculty of Pharmaceutical Sciences at Ribeirao Preto, University of São Paulo, Ribeirão Preto, 14040-903, Brazil
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11
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Briggs EA, Besley NA, Robinson D. QM/MM excited state molecular dynamics and fluorescence spectroscopy of BODIPY. J Phys Chem A 2013; 117:2644-50. [PMID: 23461546 DOI: 10.1021/jp312229b] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Absorption and emission spectra arising from the lowest energy transition in BODIPY have been simulated in the gas phase and water using a quantum mechanics/molecular mechanics (QM/MM) approach. Kohn-Sham density functional theory (DFT) is used to calculate both ground (So) and first excited (S1) states using the maximum overlap method to obtain the S1 state. This approach gives ground and excited state structures in good agreement with structures found using multiconfigurational perturbation theory (CASPT2). Application of a post-self-consistent field spin-purification relationship also yields transition energies in agreement with CASPT2 and available experimental data. Spectral bands were simulated using many structures taken from ab initio molecular dynamics simulations of the ground and first excited states. In these simulations, DFT is used for BODIPY, and in the condensed phase simulations the water molecules are treated classically. The resulting spectra show a blue shift of 0.3 eV in both absorption and emission bands in water compared to the gas phase. A Stokes shift of about 0.1 eV is predicted, and the width of the emission band in solution is significantly broader than the absorption band. These results are consistent with experimental data for BODIPY and closely related dyes, and demonstrate how both absorption and emission spectra in solution can be simulated using a quantum mechanical treatment of the electronic structure of the solute.
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Affiliation(s)
- Edward A Briggs
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, United Kingdom
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12
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Jun T, Kim K, Lee KM, Benniston AC, Churchill DG. Meso-thienyl and furyl rotor effects in BF2-chelated dipyrrin dyes: solution spectroscopic studies and X-ray structural packing analysis of isomer and congener effects. J COORD CHEM 2012. [DOI: 10.1080/00958972.2012.740023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Taehong Jun
- a Department of Chemistry , Korea Advanced Institute of Science and Technology 373-1 Guseong-dong , Yuseong-gu , Daejeon 305-701 , Republic of Korea
| | - Kibong Kim
- a Department of Chemistry , Korea Advanced Institute of Science and Technology 373-1 Guseong-dong , Yuseong-gu , Daejeon 305-701 , Republic of Korea
| | - Kang Mun Lee
- a Department of Chemistry , Korea Advanced Institute of Science and Technology 373-1 Guseong-dong , Yuseong-gu , Daejeon 305-701 , Republic of Korea
| | - Andrew C. Benniston
- b Molecular Photonics Laboratory , School of Chemistry, Newcastle University , Newcastle-upon-Tyne, NE1 7RU , UK
| | - David G. Churchill
- a Department of Chemistry , Korea Advanced Institute of Science and Technology 373-1 Guseong-dong , Yuseong-gu , Daejeon 305-701 , Republic of Korea
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13
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Berezin MB, Antina EV, Dudina NA, Bushmarinov IS, Antipin MY, Antina LA, Guseva GB. Synthesis, structure and fluorescence of a zinc(ii) chelate complex with bis(2,4,7,8,9-pentamethyldipyrrolylmethen-3-yl)methane. MENDELEEV COMMUNICATIONS 2011. [DOI: 10.1016/j.mencom.2011.04.020] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Abraham BG, Tkachenko NV, Santala V, Lemmetyinen H, Karp M. Bidirectional Fluorescence Resonance Energy Transfer (FRET) in Mutated and Chemically Modified Yellow Fluorescent Protein (YFP). Bioconjug Chem 2011; 22:227-34. [DOI: 10.1021/bc100372u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bobin George Abraham
- Department of Chemistry and Bioengineering, Tampere University of Technology, 541, 33101 Tampere, Finland
| | - Nikolai V. Tkachenko
- Department of Chemistry and Bioengineering, Tampere University of Technology, 541, 33101 Tampere, Finland
| | - Ville Santala
- Department of Chemistry and Bioengineering, Tampere University of Technology, 541, 33101 Tampere, Finland
| | - Helge Lemmetyinen
- Department of Chemistry and Bioengineering, Tampere University of Technology, 541, 33101 Tampere, Finland
| | - Matti Karp
- Department of Chemistry and Bioengineering, Tampere University of Technology, 541, 33101 Tampere, Finland
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Histone H2B ubiquitylation disrupts local and higher-order chromatin compaction. Nat Chem Biol 2011; 7:113-9. [PMID: 21196936 PMCID: PMC3078768 DOI: 10.1038/nchembio.501] [Citation(s) in RCA: 337] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/10/2010] [Indexed: 11/25/2022]
Abstract
Regulation of chromatin structure involves histone post-translational modifications which can modulate intrinsic properties of the chromatin fiber to change the chromatin state. We used chemically defined nucleosome arrays to demonstrate that H2B ubiquitylation (uH2B), a modification associated with transcription, interferes with chromatin compaction and leads to an open and biochemically accessible fiber conformation. Importantly, these effects were specific for ubiquitin, as compaction of chromatin modified with a similar ubiquitin-sized protein, Hub1, was only weakly affected. Applying a fluorescence based method we found that uH2B acts through a mechanism distinct from H4 tail acetylation (acH4), a modification known to disrupt chromatin folding. Finally, incorporation of both uH2B and acH4 in nucleosomes resulted in synergistic inhibition of higher order chromatin structure formation, possibly a result of their distinct mode of action.
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16
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Mansoor SE, Dewitt MA, Farrens DL. Distance mapping in proteins using fluorescence spectroscopy: the tryptophan-induced quenching (TrIQ) method. Biochemistry 2010; 49:9722-31. [PMID: 20886836 DOI: 10.1021/bi100907m] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studying the interplay between protein structure and function remains a daunting task. Especially lacking are methods for measuring structural changes in real time. Here we report our most recent improvements to a method that can be used to address such challenges. This method, which we now call tryptophan-induced quenching (TrIQ), provides a straightforward, sensitive, and inexpensive way to address questions of conformational dynamics and short-range protein interactions. Importantly, TrIQ only occurs over relatively short distances (∼5-15 Å), making it complementary to traditional fluorescence resonance energy transfer (FRET) methods that occur over distances too large for precise studies of protein structure. As implied in the name, TrIQ measures the efficient quenching induced in some fluorophores by tryptophan (Trp). We present here our analysis of the TrIQ effect for five different fluorophores that span a range of sizes and spectral properties. Each probe was attached to four different cysteine residues on T4 lysozyme, and the extent of TrIQ caused by a nearby Trp was measured. Our results show that, at least for smaller probes, the extent of TrIQ is distance dependent. Moreover, we also demonstrate how TrIQ data can be analyzed to determine the fraction of fluorophores involved in a static, nonfluorescent complex with Trp. Based on this analysis, our study shows that each fluorophore has a different TrIQ profile, or "sphere of quenching", which correlates with its size, rotational flexibility, and the length of attachment linker. This TrIQ-based "sphere of quenching" is unique to every Trp-probe pair and reflects the distance within which one can expect to see the TrIQ effect. Thus,TrIQ provides a straightforward, readily accessible approach for mapping distances within proteins and monitoring conformational changes using fluorescence spectroscopy.
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Affiliation(s)
- Steven E Mansoor
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239-3098, United States
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17
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Jiao L, Yu C, Liu M, Wu Y, Cong K, Meng T, Wang Y, Hao E. Synthesis and Functionalization of Asymmetrical Benzo-Fused BODIPY Dyes. J Org Chem 2010; 75:6035-8. [PMID: 20690775 DOI: 10.1021/jo101164a] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lijuan Jiao
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Changjiang Yu
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Mingming Liu
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Yangchun Wu
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Kebing Cong
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Ting Meng
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Yuqing Wang
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
| | - Erhong Hao
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu, 241000, China
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18
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Opanasyuk O, Johansson LBÅ. Extended Förster theory: a quantitative approach to the determination of inter-chromophore distances in biomacromolecules. Phys Chem Chem Phys 2010; 12:7758-67. [DOI: 10.1039/b924113b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Jiao L, Yu C, Uppal T, Liu M, Li Y, Zhou Y, Hao E, Hu X, Vicente MGH. Long wavelength red fluorescent dyes from 3,5-diiodo-BODIPYs. Org Biomol Chem 2010; 8:2517-9. [DOI: 10.1039/c001068e] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Gretskaya NM, Mikhalyov II. Some patterns in dimer II formation in BODIPY-FL-labeled lipids. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009. [DOI: 10.1134/s1068162009060132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Gretskaya NM, Mikhalyov II. BODIPY-labeled ganglioside probes for membrane and biological studies. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 35:701-8. [DOI: 10.1134/s106816200905015x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Jiao L, Yu C, Li J, Wang Z, Wu M, Hao E. β-Formyl-BODIPYs from the Vilsmeier−Haack Reaction. J Org Chem 2009; 74:7525-8. [DOI: 10.1021/jo901407h] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Lijuan Jiao
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
| | - Changjiang Yu
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
| | - Jilong Li
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
| | - Zhaoyun Wang
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
| | - Min Wu
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
| | - Erhong Hao
- Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Material Science, and Anhui Key Laboratory of Molecular Based Materials, Anhui Normal University, Wuhu 241000, China
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23
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EDMAN PETER, HÅKANSSON PÄR, WESTLUND PEROLOF, JOHANSSON LENNARTBÅ. Extended Förster theory of donor-donor energy migration in bifluorophoric macromolecules. Part I. A new approach to quantitative analyses of the time-resolved fluorescence anisotropy. Mol Phys 2009. [DOI: 10.1080/00268970009483358] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- PETER EDMAN
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - PÄR HÅKANSSON
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - PER-OLOF WESTLUND
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
| | - LENNART B.-Å. JOHANSSON
- a Department of Chemistry, Biophysical Chemistry , Umeå University , S-901 87 , Umeå , Sweden
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24
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Opanasyuk O, Ryderfors L, Mukhtar E, Johansson LBÅ. Two-photon excited fluorescence depolarisation and electronic energy migration within donor–donor pairs. Phys Chem Chem Phys 2009; 11:7152-60. [DOI: 10.1039/b900650h] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Noothi SK, Kombrabail M, Kundu TK, Krishnamoorthy G, Rao BJ. Enhanced DNA dynamics due to cationic reagents, topological states of dsDNA and high mobility group box 1 as probed by PicoGreen. FEBS J 2008; 276:541-51. [DOI: 10.1111/j.1742-4658.2008.06802.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Abstract
Submolecular details of Azotobacter vinelandii apoflavodoxin (apoFD) (un)folding are revealed by time-resolved fluorescence anisotropy using wild-type protein and variants lacking one or two of apoFD's three tryptophans. ApoFD equilibrium (un)folding by guanidine hydrochloride follows a three-state model: native <--> unfolded <--> intermediate. In native protein, W128 is a sink for Förster resonance energy transfer (FRET). Consequently, unidirectional FRET with a 50-ps transfer correlation time occurs from W167 to W128. FRET from W74 to W167 is much slower (6.9 ns). In the intermediate, W128 and W167 have native-like geometry because the 50-ps transfer time is observed. However, non-native structure exists between W74 and W167 because instead of 6.9 ns the transfer correlation time is 2.0 ns. In unfolded apoFD this 2.0-ns transfer correlation time is also detected. This decrease in transfer correlation time is a result of W74 and W167 becoming solvent accessible and randomly oriented toward one another. Apparently W74 and W167 are near-natively separated in the folding intermediate and in unfolded apoFD. Both tryptophans may actually be slightly closer in space than in the native state, even though apoFD's radius increases substantially upon unfolding. In unfolded apoFD the 50-ps transfer time observed for native and intermediate folding states becomes 200 ps as W128 and W167 are marginally further separated than in the native state. Apparently, apoFD's unfolded state is not a featureless statistical coil but contains well-defined substructures. The approach presented is a powerful tool to study protein folding.
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27
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Norlin N, Håkansson P, Westlund PO, Johansson LBÅ. Extended Förster theory for determining intraprotein distances : Part III. Partial donor–donor energy migration among reorienting fluorophores. Phys Chem Chem Phys 2008; 10:6962-70. [DOI: 10.1039/b810661d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Loudet A, Burgess K. BODIPY dyes and their derivatives: syntheses and spectroscopic properties. Chem Rev 2007; 107:4891-932. [PMID: 17924696 DOI: 10.1021/cr078381n] [Citation(s) in RCA: 3515] [Impact Index Per Article: 206.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aurore Loudet
- Department of Chemistry, Texas A & M University, PO Box 30012, College Station, Texas 77842, USA
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29
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Wood TE, Thompson A. Advances in the chemistry of dipyrrins and their complexes. Chem Rev 2007; 107:1831-61. [PMID: 17430001 DOI: 10.1021/cr050052c] [Citation(s) in RCA: 500] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tabitha E Wood
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, B3H 4J3, Canada
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30
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Isaksson M, Hägglöf P, Håkansson P, Ny T, Johansson LBA. Extended Förster theory for determining intraprotein distances: 2. An accurate analysis of fluorescence depolarisation experiments. Phys Chem Chem Phys 2007; 9:3914-22. [PMID: 17637983 DOI: 10.1039/b701591g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The extended Förster theory (EFT) is for the first time applied to the quantitative determination of the intramolecular distances in proteins. It is shown how the EFT (J. Chem. Phys., 1996, 105, 10896) can be adapted to the analyses of fluorescence depolarisation experiments based on the time-correlated single photon counting technique (TCSPC). The protein system studied was the latent form of plasminogen activator inhibitor type I (PAI-1), which was mutated and labelled by the thiol reactive BODIPY(R) derivative {N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl iodoacetamide}. The energy migration occurs within pairs of photophysically identical donor groups that undergo reorientational motions on the timescales of energy migration and fluorescence relaxation. Unlike all models currently used for analysing fluorescence TCSPC data, the EFT explicitly accounts for the time-dependent reorientations that influence the rate of electronic energy transfer/migration in a complex manner. The complexity is related to the "kappa(2) problem", which has been discussed for years. The EFT brings the analyses of DDEM data to the same level of molecular description as in ESR and NMR spectroscopy, i.e. it yields microscopic information about the reorientation correlation times, the order parameters, as well as inter-chromophoric distances.
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Affiliation(s)
- Mikael Isaksson
- Department of Chemistry, Biophysical Chemistry, University of Umeå, S-901 87 Umeå, Sweden
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31
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Zou P, Surendhran K, Mchaourab HS. Distance measurements by fluorescence energy homotransfer: evaluation in T4 lysozyme and correlation with dipolar coupling between spin labels. Biophys J 2006; 92:L27-9. [PMID: 17142264 PMCID: PMC1783887 DOI: 10.1529/biophysj.106.098913] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We demonstrate the feasibility and practical limitations of using steady-state anisotropy to determine distances from fluorescence homotransfer in the context of a protein of known crystal structure. Eight double mutants of T4 lysozyme spanning the distance range between 20 A and 50 A were labeled with a methanethiosulfonate derivative of fluorescein. The measured distances in liquid solution are in agreement with those determined from dipolar coupling between spin labels in the frozen state. They can be interpreted in the context of the crystal structure after accounting for the probe linking arm. Overall, the results establish the necessary calibration for this spectroscopic ruler. The measurement of similar distance trends using independent probes sets the stage for the complementary use of homotransfer and dipolar coupling in the determination of static structures and detection of conformational changes.
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32
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Olofsson M, Kalinin S, Zdunek J, Oliveberg M, Johansson LBA. Tryptophan-BODIPY: a versatile donor-acceptor pair for probing generic changes of intraprotein distances. Phys Chem Chem Phys 2006; 8:3130-40. [PMID: 16804615 DOI: 10.1039/b601313a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We demonstrate that Tryptophan (Trp) and N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl iodoacetamide (BODIPY) is a suitable donor-acceptor (D-A) pair for intraprotein distance measurements, applicable to the study of protein folding. The suitability of the Trp-BODIPY electronic energy transfer is exemplified on the extensively-characterised two-state protein, S6, from Thermus thermophilus. This protein has proved to be useful for the elucidation of folding cooperativity and nucleation, as well as the changes upon induction of structural transitions. For a comprehensive structural coverage, BODIPY molecules were anchored by Cys insertions at four different positions on the S6 surface. Trp residues at position 33 or 62 acted as donors of electronic energy to the BODIPY groups. None of the D-A pairs show any detectable difference in the folding kinetics (or protein stability), which supports the notion that the two-state transition of S6 is a highly concerted process. Similar results are obtained for mutants affecting the N- and C-terminus. The kinetic analyses indicate that changes of the transition state occur through local unfolding of the native state, rather than by a decrease of the folding cooperativity. The distances obtained from the analysis of the time-resolved fluorescence experiments in the native state were compared to those calculated from X-ray structure. As an additional measure, molecular dynamics simulations of the different protein constructs were performed to account for variability in the BODIPY location on the protein surface. The agreement between fluorescence and X-ray data is quite convincing, and shows that energy transfer measurements between Trp and BODIPY can probe distances between ca. 17 to 34 A, with an error better than 10%.
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Affiliation(s)
- Maria Olofsson
- Biophysical Chemistry and Biochemistry, Department of Chemistry, Umeå University, S-901 87 Umeå, Sweden
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33
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Boldyrev IA, Molotkovsky JG. A synthesis and properties of new 4,4-difluoro-3a,4a-diaza-s-indacene (BODIPY)-labeled lipids. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2006. [DOI: 10.1134/s1068162006010080] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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34
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Hall MJ, McDonnell SO, Killoran J, O'Shea DF. A modular synthesis of unsymmetrical tetraarylazadipyrromethenes. J Org Chem 2005; 70:5571-8. [PMID: 15989339 DOI: 10.1021/jo050696k] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A stepwise route to unsymmetrical tetraarylazadipyrromethenes by a condensation of 2,4-diaryl-5-nitroso-pyrroles with 2,4-diarylpyrroles is described. This modular building-block approach allows for the introduction of up to four different aryl substituents on the azadipyrromethene and is tolerant of a varied substituent set. An efficient synthesis of the 2,4-diarylpyrroles building blocks from 1,3-diaryl-4-nitro-butan-1-ones by nitro hydrolysis to a keto-aldehyde and subsequent ammonia condensation reaction has been achieved. The facile conversion of 2,4-diarylpyrroles into their alpha-nitroso analogues by their reaction with sodium nitrite generated the second building block required for the synthesis.
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Affiliation(s)
- Michael J Hall
- Centre for Synthesis and Chemical Biology, Conway Institute, Department of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
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35
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Boldyrev IA, Molotkovskiĭ IG. [A synthesis of new rigid fluorescent bichromophoric probes for studying mechanisms of donor-donor energy migration]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2005; 31:331-4. [PMID: 16004393 DOI: 10.1007/s11171-005-0041-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Three new fluorescent probes were synthesized for improving the method of studying donor-donor energy migration (DDEM). Each probe has two identical fluorescent 7-diethylaminocoumarin-3-carbonyl groups attached to a rigid bisteroid dodecacyclic spacer through additional inserts. In two probes, the inserts are beta-Ala and L-Ser residues, which provide for a different nearest environment of the fluorophores. The third probe has identical beta-Ala inserts. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.
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36
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Lobov S, Wilczynska M, Bergström F, Johansson LBA, Ny T. Structural Bases of the Redox-dependent Conformational Switch in the Serpin PAI-2. J Mol Biol 2004; 344:1359-68. [PMID: 15561148 DOI: 10.1016/j.jmb.2004.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 10/04/2004] [Accepted: 10/06/2004] [Indexed: 11/16/2022]
Abstract
Depending on the redox-status, the serpin plasminogen activator inhibitor type 2 (PAI-2) can exist in either a stable monomeric or polymerogenic form. The latter form, which spontaneously forms loop-sheet polymers, has an open beta-sheet A and is stabilized by a disulfide bond between C79 (in the CD-loop) and C161 (at the bottom of PAI-2). Reduction of this bond results in a closing of the beta-sheet A and converts PAI-2 to a stable monomeric form. Here we show that the stable monomeric and polymerogenic forms of PAI-2 are fully interconvertible, depending on redox-status of the environment. Our intramolecular distance measurements indicate that the CD-loop folds mainly on one side of the stable monomeric form of the inhibitor. However, the loop can translocate about 54A to the bottom of PAI-2 so that the C79-C161 disulfide bond can form under oxidizing conditions. We show also that the redox-active C79 can form a disulfide-link to the matrix protein vitronectin, suggesting that vitronectin can stabilize active PAI-2 in extracellular compartments. PAI-2 is therefore a rare example of a redox-sensitive protein for which the activity and polymerization ability are regulated by reversible disulfide bond formation leading to major translocation of a loop and significant conformational changes in the molecule.
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Affiliation(s)
- Sergei Lobov
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
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37
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Benninger RKP, Önfelt B, Neil MAA, Davis DM, French PMW. Fluorescence imaging of two-photon linear dichroism: cholesterol depletion disrupts molecular orientation in cell membranes. Biophys J 2004; 88:609-22. [PMID: 15520272 PMCID: PMC1305038 DOI: 10.1529/biophysj.104.050096] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The plasma membrane of cells is an ordered environment, giving rise to anisotropic orientation and restricted motion of molecules and proteins residing in the membrane. At the same time as being an organized matrix of defined structure, the cell membrane is heterogeneous and dynamic. Here we present a method where we use fluorescence imaging of linear dichroism to measure the orientation of molecules relative to the cell membrane. By detecting linear dichroism as well as fluorescence anisotropy, the orientation parameters are separated from dynamic properties such as rotational diffusion and homo energy transfer (energy migration). The sensitivity of the technique is enhanced by using two-photon excitation for higher photo-selection compared to single photon excitation. We show here that we can accurately image lipid organization in whole cell membranes and in delicate structures such as membrane nanotubes connecting two cells. The speed of our wide-field imaging system makes it possible to image changes in orientation and anisotropy occurring on a subsecond timescale. This is demonstrated by time-lapse studies showing that cholesterol depletion rapidly disrupts the orientation of a fluorophore located within the hydrophobic region of the cell membrane but not of a surface bound probe. This is consistent with cholesterol having an important role in stabilizing and ordering the lipid tails within the plasma membrane.
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Affiliation(s)
- Richard K. P. Benninger
- Department of Physics and Department of Biological Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Björn Önfelt
- Department of Physics and Department of Biological Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Mark A. A. Neil
- Department of Physics and Department of Biological Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daniel M. Davis
- Department of Physics and Department of Biological Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Paul M. W. French
- Department of Physics and Department of Biological Sciences, Imperial College London, London SW7 2AZ, United Kingdom
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38
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Isaksson M, Kalinin S, Lobov S, Wang S, Ny T, Johansson LBÅ. Partial donor–donor energy migration (PDDEM): A novel fluorescence method for internal protein distance measurements. Phys Chem Chem Phys 2004. [DOI: 10.1039/b403264k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Hägglöf P, Bergström F, Wilczynska M, Johansson LBA, Ny T. The Reactive-center Loop of Active PAI-1 is Folded Close to the Protein Core and can be Partially Inserted. J Mol Biol 2004; 335:823-32. [PMID: 14687577 DOI: 10.1016/j.jmb.2003.11.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasminogen activator inhibitor 1 (PAI-1) is the main inhibitor of plasminogen activators and plays an important role in many pathophysiological processes. Like other members of the serpin family, PAI-1 has a reactive center consisting of a mobile loop (RCL) with P1 and P1' residues acting as a "bait" for cognate protease. In contrast to the other serpins, PAI-1 loses activity by spontaneous conversion to an inactive latent form. This involves full insertion of the RCL into beta-sheet A. To search for molecular determinants that could be responsible for conversion of PAI-1 to the latent form, we studied the conformation of the RCL in active PAI-1 in solution. Intramolecular distance measurements by donor-donor energy migration and probe quenching methods reveal that the RCL is located much closer to the core of PAI-1 than has been suggested by the recently resolved X-ray structures of stable PAI-1 mutants. Disulfide bonds can be formed in double-cysteine mutants with substitutions at positions P11 or P13 of the RCL and neighboring residues in beta-sheet A. This suggests that the RCL may be preinserted up to residue P13 in active PAI-1, and possibly even to residue P11. We propose that the close proximity of the RCL to the protein core, and the ability of the loop to preinsert into beta-sheet A is a possible reason for PAI-1 being able to convert spontaneously to its latent form.
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Affiliation(s)
- Peter Hägglöf
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
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Dahim M, Mizuno NK, Li XM, Momsen WE, Momsen MM, Brockman HL. Physical and photophysical characterization of a BODIPY phosphatidylcholine as a membrane probe. Biophys J 2002; 83:1511-24. [PMID: 12202376 PMCID: PMC1302249 DOI: 10.1016/s0006-3495(02)73921-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Lipids containing the dimethyl BODIPY fluorophore are used in cell biology because their fluorescence properties change with fluorophore concentration (C.-S. Chen, O. C. Martin, and R. E. Pagano. 1997. Biophys J. 72:37-50). The miscibility and steady-state fluorescence behavior of one such lipid, 1-palmitoyl-2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-sn-glycero-3-phosphocholine (PBPC), have been characterized in mixtures with 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC). PBPC packs similarly to phosphatidylcholines having a cis-unsaturated acyl chain and mixes nearly ideally with SOPC, apparently without fluorophore-fluorophore aggregation. Increasing PBPC mole fraction from 0.0 to 1.0 in SOPC membranes changes the emission characteristics of the probe in a continuous manner. Analysis of these changes shows that emission from the excited dimethyl BODIPY monomer self quenches with a critical radius of 25.9 A. Fluorophores sufficiently close (< or =13.7 A) at the time of excitation can form an excited dimer, emission from which depends strongly on total lipid packing density. Overall, the data show that PBPC is a reasonable physical substitute for other phosphatidylcholines in fluid membranes. Knowledge of PBPC fluorescence in lipid monolayers has been exploited to determine the two-dimensional concentration of SOPC in unilamellar, bilayer membranes.
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Affiliation(s)
- Mohammed Dahim
- The Hormel Institute, University of Minnesota, Austin, Minnesota 55912 USA
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Abstract
Fluorescence resonance energy transfer (FRET) provides a unique means of measuring interatomic distances in biological molecules in real time. Recent advances have been made in the application of this technique to studies of conformational changes in proteins. New ways of introducing fluorescence probes into proteins, newly developed fluorescence probes, and progress in the technologies for fluorescence signal detection have greatly expanded the range of applications of FRET. In particular, studies of conformational changes in proteins at a single molecule level and in the native in vivo context of a living cell are now possible.
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Affiliation(s)
- Tomasz Heyduk
- E.A. Doisy Department of Biochemistry and Molecular Biology, St Louis University School of Medicine, 1402 South Grand Blvd, St Louis, MO 63104, USA.
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Kalinin SV, Molotkovsky JG, Johansson LBA. Partial donor-donor energy migration (PDDEM) as a fluorescence spectroscopic tool for measuring distances in biomacromolecules. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2002; 58:1087-1097. [PMID: 11942395 DOI: 10.1016/s1386-1425(01)00613-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A theoretical model is presented, tested and applied for determining the rates of energy migration and distances within pairs of chemically identical fluorophores, so-called donors (D), which are exposed to different physical properties. The model is a general extension of the recently developed donor-donor energy migration (DDEM) model [J. Chem. Soc., Faraday Trans. 92 (1996)1563; J. Chem. Phys. 105 (1996) 10896] that applies to examining structure-function of biomacromolecules, such as proteins. Most fluorescent groups of the same kind incorporated at different positions (alpha and beta) in a macromolecule exhibit shifts of the absorption and/or emission spectra, as well as different relaxation rates of the photophysics. As a consequence, the energy migration between the D(alpha) and D(beta) groups will be partially reversible. We refer to this case, as the partial donor-donor energy migration (PDDEM). The models of PPDEM presented can be used for analysing time-resolved fluorescence relaxation, as well as fluorescence depolarisation experiments. To explore the limitations of the PDDEM model, we have generated and re-analysed synthetic data that mimic time-correlated single photon counting (TCSPC) experiments. It was found that slow and fast rates of energy migration are most accurately recovered from the fluorescence relaxation and the depolarisation experiments, respectively. At comparable transfer and fluorescence rates, both kinds of experiments are equally useful. Real experiments on PDDEM were performed on an asymmetrically quenched bichromophoric molecule (1,32-dihydroxy-dotriacontane-bis-(Rhodamine 101) ester), that spans across the lipid bilayer of a vesicle. The depolarisation data were analysed by the PDDEM model and provide a distance between Rhodamine 101 groups, which agrees with independent studies.
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Mikhalyov I, Gretskaya N, Bergström F, Johansson LBÅ. Electronic ground and excited state properties of dipyrrometheneboron difluoride (BODIPY): Dimers with application to biosciences. Phys Chem Chem Phys 2002. [DOI: 10.1039/b206357n] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Engelborghs Y. The analysis of time resolved protein fluorescence in multi-tryptophan proteins. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2001; 57:2255-2270. [PMID: 11603842 DOI: 10.1016/s1386-1425(01)00485-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In the last decades, considerable progress has been made in the analysis of the fluorescence decay of proteins with more than one tryptophan. The construction of single tryptophan containing proteins has shown that the lifetimes of the wild type proteins are often the linear combinations of the family lifetimes of the contributing tryptophan residues. Additivity is not followed when energy transfer takes place among tryptophan residues or when the structure of the remaining protein is altered upon the modification. Progress has also been made in the interpretation of the value of the lifetime and the linkage with the immediate environment. Probably all the irreversible processes leading to return to the ground state have been catalogued and their rate constants are documented. Also, the process of electron transfer to the peptide carbonyl is becoming more and more documented and is linked to the rotameric state of tryptophan. Reversible excited state processes are also being considered, including reversible interconversions between rotamers. Interesting information about tryptophan and its environment comes also from anisotropy measurements for proteins in the native, the denatured and the molten globule states. Alterations of protein fluorescence due to the effects of ligand binding or side chain modifications can be analyzed via the ratio of the quantum yields of the modified protein and the reference state. Using the ratio of quantum yields and the (amplitude weighted) average lifetime, three factors can be identified: (1) a change in the apparent radiative rate constant reflecting either static quenching or an intrinsic change in the radiative properties; (2) a change in dynamic quenching; and (3) a change in the balance of the populations of the microstates or local static quenching.
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Affiliation(s)
- Y Engelborghs
- Laboratory of Biomolecular Dynamics, University of Leuven, Belgium.
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Gautier I, Tramier M, Durieux C, Coppey J, Pansu RB, Nicolas JC, Kemnitz K, Coppey-Moisan M. Homo-FRET microscopy in living cells to measure monomer-dimer transition of GFP-tagged proteins. Biophys J 2001; 80:3000-8. [PMID: 11371472 PMCID: PMC1301483 DOI: 10.1016/s0006-3495(01)76265-0] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Fluorescence anisotropy decay microscopy was used to determine, in individual living cells, the spatial monomer-dimer distribution of proteins, as exemplified by herpes simplex virus thymidine kinase (TK) fused to green fluorescent protein (GFP). Accordingly, the fluorescence anisotropy dynamics of two fusion proteins (TK27GFP and TK366GFP) was recorded in the confocal mode by ultra-sensitive time-correlated single-photon counting. This provided a measurement of the rotational time of these proteins, which, by comparing with GFP, allowed the determination of their oligomeric state in both the cytoplasm and the nucleus. It also revealed energy homo-transfer within aggregates that TK366GFP progressively formed. Using a symmetric dimer model, structural parameters were estimated; the mutual orientation of the transition dipoles of the two GFP chromophores, calculated from the residual anisotropy, was 44.6 +/- 1.6 degrees, and the upper intermolecular limit between the two fluorescent tags, calculated from the energy transfer rate, was 70 A. Acquisition of the fluorescence steady-state intensity, lifetime, and anisotropy decay in the same cells, at different times after transfection, indicated that TK366GFP was initially in a monomeric state and then formed dimers that grew into aggregates. Picosecond time-resolved fluorescence anisotropy microscopy opens a promising avenue for obtaining structural information on proteins in individual living cells, even when expression levels are very low.
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Affiliation(s)
- I Gautier
- Institut Jacques Monod, Centre National de la Recherche Scientifique, Université P6/P7, 75251 Paris, France
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Fa M, Bergström F, Hägglöf P, Wilczynska M, Johansson LB, Ny T. The structure of a serpin-protease complex revealed by intramolecular distance measurements using donor-donor energy migration and mapping of interaction sites. Structure 2000; 8:397-405. [PMID: 10801484 DOI: 10.1016/s0969-2126(00)00121-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND The inhibitors that belong to the serpin family are widely distributed regulatory molecules that include most protease inhibitors found in blood. It is generally thought that serpin inhibition involves reactive-centre cleavage, loop insertion and protease translocation, but different models of the serpin-protease complex have been proposed. In the absence of a spatial structure of a serpin-protease complex, a detailed understanding of serpin inhibition and the character of the virtually irreversible complex have remained controversial. RESULTS We used a recently developed method for making precise distance measurements, based on donor-donor energy migration (DDEM), to accurately triangulate the position of the protease urokinase-type plasminogen activator (uPA) in complex with the serpin plasminogen activator inhibitor type 1 (PAI-1). The distances from residue 344 (P3) in the reactive-centre loop of PAI-1 to residues 185, 266, 313 and 347 (P1') were determined. Modelling of the complex using this distance information unequivocally placed residue 344 in a position at the distal end from the initial docking site with the reactive-centre loop fully inserted into beta sheet A. To validate the model, seven single cysteine substitution mutants of PAI-1 were used to map sites of protease-inhibitor interaction by fluorescence depolarisation measurements of fluorophores attached to these residues and cross-linking using a sulphydryl-specific cross-linker. CONCLUSIONS The data clearly demonstrate that serpin inhibition involves reactive-centre cleavage followed by full-loop insertion whereby the covalently linked protease is translocated from one pole of the inhibitor to the opposite one.
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Affiliation(s)
- M Fa
- Department of Medical Biosciences, Medical Biochemistry, Umeâ University, Umeâ, S-90187, Sweden
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