1
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Jones BJ, Greene BL. Singlet oxygen-mediated photochemical cross-linking of an engineered fluorescent flavoprotein iLOV. J Biol Chem 2024:107845. [PMID: 39357827 DOI: 10.1016/j.jbc.2024.107845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 08/30/2024] [Accepted: 09/19/2024] [Indexed: 10/04/2024] Open
Abstract
Genetically-encoded photoactive proteins are integral tools in modern biochemical and molecular biological research. Within this tool box, truncated variants of the phototropin 2 light-oxygen-voltage (LOV) flavoprotein have been developed to photochemically generate singlet oxygen (1O2) in vitro and in vivo, yet the effect of 1O2 on these genetically encoded photosensitizers remains underexplored. In this study, we demonstrate that the "improved" LOV (iLOV) flavoprotein is capable of photochemical 1O2 generation. Once generated, 1O2 induces protein oligomerization via covalent cross-linking. The molecular targets of protein oligomerization by cross-linking are not endogenous tryptophans or tyrosines, but rather primarily histidines. Substitution of surface-exposed histidines for serine or glycine residues effectively eliminates protein cross-linking. When used in biochemical applications, such protein-protein cross-links may interfere with native biological responses to 1O2, which can be ameliorated by substitution of the surface exposed histidines of iLOV or other 1O2-generating flavoproteins.
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Affiliation(s)
- Benjamin J Jones
- Department of Chemistry and Biochemistry the University of California Santa Barbara, Santa Barbara, California, 93106
| | - Brandon L Greene
- Department of Chemistry and Biochemistry the University of California Santa Barbara, Santa Barbara, California, 93106; Biomolecular Science and Engineering Program, the University of California Santa Barbara, Santa Barbara, California, 93106.
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2
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Gotthard G, Mous S, Weinert T, Maia RNA, James D, Dworkowski F, Gashi D, Furrer A, Ozerov D, Panepucci E, Wang M, Schertler GFX, Heberle J, Standfuss J, Nogly P. Capturing the blue-light activated state of the Phot-LOV1 domain from Chlamydomonas reinhardtii using time-resolved serial synchrotron crystallography. IUCRJ 2024; 11:792-808. [PMID: 39037420 PMCID: PMC11364019 DOI: 10.1107/s2052252524005608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 06/11/2024] [Indexed: 07/23/2024]
Abstract
Light-oxygen-voltage (LOV) domains are small photosensory flavoprotein modules that allow the conversion of external stimuli (sunlight) into intracellular signals responsible for various cell behaviors (e.g. phototropism and chloroplast relocation). This ability relies on the light-induced formation of a covalent thioether adduct between a flavin chromophore and a reactive cysteine from the protein environment, which triggers a cascade of structural changes that result in the activation of a serine/threonine (Ser/Thr) kinase. Recent developments in time-resolved crystallography may allow the activation cascade of the LOV domain to be observed in real time, which has been elusive. In this study, we report a robust protocol for the production and stable delivery of microcrystals of the LOV domain of phototropin Phot-1 from Chlamydomonas reinhardtii (CrPhotLOV1) with a high-viscosity injector for time-resolved serial synchrotron crystallography (TR-SSX). The detailed process covers all aspects, from sample optimization to data collection, which may serve as a guide for soluble protein preparation for TR-SSX. In addition, we show that the crystals obtained preserve the photoreactivity using infrared spectroscopy. Furthermore, the results of the TR-SSX experiment provide high-resolution insights into structural alterations of CrPhotLOV1 from Δt = 2.5 ms up to Δt = 95 ms post-photoactivation, including resolving the geometry of the thioether adduct and the C-terminal region implicated in the signal transduction process.
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Affiliation(s)
- Guillaume Gotthard
- Institute of Molecular Biology and Biophysics, Department of BiologyETH Zurich8093ZürichSwitzerland
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Sandra Mous
- Institute of Molecular Biology and Biophysics, Department of BiologyETH Zurich8093ZürichSwitzerland
| | - Tobias Weinert
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Raiza Nara Antonelli Maia
- Experimental Molecular Biophysics, Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Daniel James
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Florian Dworkowski
- Macromolecular Crystallography, Swiss Light SourcePaul Scherrer Institute5232Villigen PSISwitzerland
| | - Dardan Gashi
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
- Laboratory of Femtochemistry, Photon Science DivisionPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Antonia Furrer
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Dmitry Ozerov
- Science ITPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Ezequiel Panepucci
- Laboratory for Macromolecules and Bioimaging, Photon Science DivisionPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Meitian Wang
- Laboratory for Macromolecules and Bioimaging, Photon Science DivisionPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Gebhard F. X. Schertler
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
- Department of BiologyETH Zürich8093ZürichSwitzerland
| | - Joachim Heberle
- Experimental Molecular Biophysics, Department of PhysicsFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Joerg Standfuss
- Laboratory of Biomolecular Research, Division of Biology and ChemistryPaul Scherrer Institute5232Villigen PSISwitzerland
| | - Przemyslaw Nogly
- Institute of Molecular Biology and Biophysics, Department of BiologyETH Zurich8093ZürichSwitzerland
- Dioscuri Center For Structural Dynamics of Receptors, Faculty of Biochemistry, Biophysics and BiotechnologyJagiellonian University in Kraków30-387KrakówPoland
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3
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Kabir M, Ghosh P, Gozem S. Electronic Structure Methods for Simulating Flavin's Spectroscopy and Photophysics: Comparison of Multi-reference, TD-DFT, and Single-Reference Wave Function Methods. J Phys Chem B 2024; 128:7545-7557. [PMID: 39074870 PMCID: PMC11317985 DOI: 10.1021/acs.jpcb.4c03748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/14/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024]
Abstract
The use of flavins and flavoproteins in photocatalytic, sensing, and biotechnological applications has led to a growing interest in computationally modeling the excited-state electronic structure and photophysics of flavin. However, there is limited consensus regarding which computational methods are appropriate for modeling flavin's photophysics. We compare the energies of low-lying excited states of flavin computed with time-dependent density functional theory (TD-DFT), equation-of-motion coupled cluster (EOM-EE-CCSD), scaled opposite-spin configuration interaction [SOS-CIS(D)], multiconfiguration pair-density functional theory (MC-PDFT), and several multireference perturbation theory (MR-PT2) methods. In the first part, we focus on excitation energies of the first singlet excited state (S1) of five different redox and protonation states of flavin, with the goal of finding a suitable active space for MR-PT2 calculations. In the second part, we construct two sets of one-dimensional potential energy surfaces connecting the S0 and S1 equilibrium geometries (S0-S1 path) and the S1 (π,π*) and S2 (n,π*) equilibrium geometries (S1-S2 path). The first path therefore follows a Franck-Condon active mode of flavin while the second path maps crossings points between low-lying singlet and triplet states in flavin. We discuss the similarities and differences in the TD-DFT, EOM-EE-CCSD, SOS-CIS(D), MC-PDFT and MR-PT2 energy profiles along these paths. We find that (TD-)DFT methods are suitable for applications such as simulating the spectra of flavins but are inconsistent with several other methods when used for some geometry optimizations and when describing the energetics of dark (n,π*) states. MR-PT2 methods show promise for the simulation of flavin's low-lying excited states, but the selection of orbitals for the active space and the number of roots used for state averaging must be done carefully to avoid artifacts. Some properties, such as the intersystem crossing geometry and energy between the S1 (π,π*) and T2 (n,π*) states, may require additional benchmarking before they can be determined quantitatively.
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Affiliation(s)
- Mohammad
Pabel Kabir
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Paulami Ghosh
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
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4
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Anderson NT, Xie JS, Chacko AN, Liu VL, Fan KC, Mukherjee A. Rational Design of a Circularly Permuted Flavin-Based Fluorescent Protein. Chembiochem 2024; 25:e202300814. [PMID: 38356332 PMCID: PMC11065581 DOI: 10.1002/cbic.202300814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/12/2024] [Accepted: 02/14/2024] [Indexed: 02/16/2024]
Abstract
Flavin-based fluorescent proteins are oxygen-independent reporters that hold great promise for imaging anaerobic and hypoxic biological systems. In this study, we explored the feasibility of applying circular permutation, a valuable method for the creation of fluorescent sensors, to flavin-based fluorescent proteins. We used rational design and structural data to identify a suitable location for circular permutation in iLOV, a flavin-based reporter derived from A. thaliana. However, relocating the N- and C-termini to this position resulted in a significant reduction in fluorescence. This loss of fluorescence was reversible, however, by fusing dimerizing coiled coils at the new N- and C-termini to compensate for the increase in local chain entropy. Additionally, by inserting protease cleavage sites in circularly permuted iLOV, we developed two protease sensors and demonstrated their application in mammalian cells. In summary, our work establishes the first approach to engineer circularly permuted FbFPs optimized for high fluorescence and further showcases the utility of circularly permuted FbFPs to serve as a scaffold for sensor engineering.
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Affiliation(s)
| | - Jason S. Xie
- Department of Molecular, Cellular, and Developmental Biology
| | | | - Vannie L. Liu
- Department of Molecular, Cellular, and Developmental Biology
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5
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Elahi Y, Baker MAB. Light Control in Microbial Systems. Int J Mol Sci 2024; 25:4001. [PMID: 38612810 PMCID: PMC11011852 DOI: 10.3390/ijms25074001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Light is a key environmental component influencing many biological processes, particularly in prokaryotes such as archaea and bacteria. Light control techniques have revolutionized precise manipulation at molecular and cellular levels in recent years. Bacteria, with adaptability and genetic tractability, are promising candidates for light control studies. This review investigates the mechanisms underlying light activation in bacteria and discusses recent advancements focusing on light control methods and techniques for controlling bacteria. We delve into the mechanisms by which bacteria sense and transduce light signals, including engineered photoreceptors and light-sensitive actuators, and various strategies employed to modulate gene expression, protein function, and bacterial motility. Furthermore, we highlight recent developments in light-integrated methods of controlling microbial responses, such as upconversion nanoparticles and optical tweezers, which can enhance the spatial and temporal control of bacteria and open new horizons for biomedical applications.
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6
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Tchagang CF, Mah TF, Campbell-Valois FX. Anaerobic fluorescent reporters for live imaging of Pseudomonas aeruginosa. Front Microbiol 2023; 14:1245755. [PMID: 37928662 PMCID: PMC10623331 DOI: 10.3389/fmicb.2023.1245755] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
Pseudomonas aeruginosa thrives in the airways of individuals with cystic fibrosis, in part by forming robust biofilms that are resistant to immune clearance or antibiotic treatment. In the cystic fibrosis lung, the thickened mucus layers create an oxygen gradient, often culminating with the formation of anoxic pockets. In this environment, P. aeruginosa can use nitrate instead of oxygen to grow. Current fluorescent reporters for studying P. aeruginosa are limited to the GFP and related analogs. However, these reporters require oxygen for the maturation of their chromophore, making them unsuitable for the study of anaerobically grown P. aeruginosa. To overcome this limitation, we evaluated seven alternative fluorescent proteins, including iLOV, phiLOV2.1, evoglow-Bs2, LucY, UnaG, Fluorescence-Activating and Absorption-Shifting Tag (FAST), and iRFP670, which have been reported to emit light under oxygen-limiting conditions. We generated a series of plasmids encoding these proteins and validated their fluorescence using plate reader assays and confocal microscopy. Six of these proteins successfully labeled P. aeruginosa in anoxia. In particular, phiLOV2.1 and FAST provided superior fluorescence stability and enabled dual-color imaging of both planktonic and biofilm cultures. This study provides a set of fluorescent reporters for monitoring P. aeruginosa under low-oxygen conditions. These reporters will facilitate studies of P. aeruginosa in biofilms or other contexts relevant to its pathogenesis, such as those found in cystic fibrosis airways. Due to the broad host range of our expression vector, the phiLOV2.1 and FAST-based reporters may be applicable to the study of other Gram-negative bacteria that inhabit similar low-oxygen niches.
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Affiliation(s)
- Caetanie F. Tchagang
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON, Canada
- Host-Microbe Interactions Laboratory, Center for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Thien-Fah Mah
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON, Canada
| | - François-Xavier Campbell-Valois
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
- Centre for Infection, Immunity, and Inflammation, University of Ottawa, Ottawa, ON, Canada
- Host-Microbe Interactions Laboratory, Center for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, Canada
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7
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Marchetti M, Ronda L, Cozzi M, Bettati S, Bruno S. Genetically Encoded Biosensors for the Fluorescence Detection of O 2 and Reactive O 2 Species. SENSORS (BASEL, SWITZERLAND) 2023; 23:8517. [PMID: 37896609 PMCID: PMC10611200 DOI: 10.3390/s23208517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/07/2023] [Accepted: 10/14/2023] [Indexed: 10/29/2023]
Abstract
The intracellular concentrations of oxygen and reactive oxygen species (ROS) in living cells represent critical information for investigating physiological and pathological conditions. Real-time measurement often relies on genetically encoded proteins that are responsive to fluctuations in either oxygen or ROS concentrations. The direct binding or chemical reactions that occur in their presence either directly alter the fluorescence properties of the binding protein or alter the fluorescence properties of fusion partners, mostly consisting of variants of the green fluorescent protein. Oxygen sensing takes advantage of several mechanisms, including (i) the oxygen-dependent hydroxylation of a domain of the hypoxia-inducible factor-1, which, in turn, promotes its cellular degradation along with fluorescent fusion partners; (ii) the naturally oxygen-dependent maturation of the fluorophore of green fluorescent protein variants; and (iii) direct oxygen binding by proteins, including heme proteins, expressed in fusion with fluorescent partners, resulting in changes in fluorescence due to conformational alterations or fluorescence resonance energy transfer. ROS encompass a group of highly reactive chemicals that can interconvert through various chemical reactions within biological systems, posing challenges for their selective detection through genetically encoded sensors. However, their general reactivity, and particularly that of the relatively stable oxygen peroxide, can be exploited for ROS sensing through different mechanisms, including (i) the ROS-induced formation of disulfide bonds in engineered fluorescent proteins or fusion partners of fluorescent proteins, ultimately leading to fluorescence changes; and (ii) conformational changes of naturally occurring ROS-sensing domains, affecting the fluorescence properties of fusion partners. In this review, we will offer an overview of these genetically encoded biosensors.
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Affiliation(s)
- Marialaura Marchetti
- Department of Medicine and Surgery, University of Parma, 43125 Parma, Italy; (M.M.); (L.R.); (M.C.)
| | - Luca Ronda
- Department of Medicine and Surgery, University of Parma, 43125 Parma, Italy; (M.M.); (L.R.); (M.C.)
- Institute of Biophysics, Italian National Research Council (CNR), 56124 Pisa, Italy
| | - Monica Cozzi
- Department of Medicine and Surgery, University of Parma, 43125 Parma, Italy; (M.M.); (L.R.); (M.C.)
| | - Stefano Bettati
- Department of Medicine and Surgery, University of Parma, 43125 Parma, Italy; (M.M.); (L.R.); (M.C.)
- Institute of Biophysics, Italian National Research Council (CNR), 56124 Pisa, Italy
| | - Stefano Bruno
- Department of Food and Drug, University of Parma, 43124 Parma, Italy;
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8
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Chen Y, Hu R, Li K, Zhang Y, Fu L, Zhang J, Si T. Deep Mutational Scanning of an Oxygen-Independent Fluorescent Protein CreiLOV for Comprehensive Profiling of Mutational and Epistatic Effects. ACS Synth Biol 2023; 12:1461-1473. [PMID: 37066862 PMCID: PMC10204710 DOI: 10.1021/acssynbio.2c00662] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Indexed: 04/18/2023]
Abstract
Oxygen-independent, flavin mononucleotide-based fluorescent proteins (FbFPs) are promising alternatives to green fluorescent protein in anaerobic contexts. Deep mutational scanning performs systematic profiling of protein sequence-function relationships but has not been applied to FbFPs. Focusing on CreiLOV from Chlamydomonas reinhardtii, we created and analyzed two comprehensive mutant collections: (1) single-residue, site-saturation mutagenesis libraries covering all 118 residues; and (2) a full combinatorial metagenesis library among 20 mutations at 15 residues, where mutation and residue selection was based on single-site mutagenesis results. Notably, the second type of library is indispensable to study higher-order epistasis but underrepresented in the literature. Using optimized FACS-seq assays, 2,185 (>92.5%) out of 2,360 possible single-site mutants and 165,428 (>89.7%) out of 184,320 possible combinatorial mutants were reliably assigned with fitness values. We constructed statistical and machine-learning models to analyze the CreiLOV data set, enabling accurate fitness prediction of higher-order mutants using lower-order mutagenesis data. In addition, we successfully isolated CreiLOV variants with improved fluorescence quantum yield and thermostability. This work provides new empirical data and design rules to engineer combinatorial protein variants.
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Affiliation(s)
- Yongcan Chen
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ruyun Hu
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Keyi Li
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yating Zhang
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Lihao Fu
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianzhi Zhang
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Tong Si
- CAS
Key Laboratory for Quantitative Engineering Biology, Shenzhen Institute
of Synthetic Biology, Shenzhen Institute
of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- BGI-Shenzhen, Shenzhen 518083, China
- University
of Chinese Academy of Sciences, Beijing 100049, China
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9
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Panda R, Panda PK, Krishnamoorthy J, Kar RK. Network analysis of chromophore binding site in LOV domain. Comput Biol Med 2023; 161:106996. [PMID: 37201443 DOI: 10.1016/j.compbiomed.2023.106996] [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: 12/08/2022] [Revised: 03/16/2023] [Accepted: 05/01/2023] [Indexed: 05/20/2023]
Abstract
Photoreceptor proteins are versatile toolbox for developing biosensors for optogenetic applications. These molecular tools get activated upon illumination of blue light, which in turn offers a non-invasive method for gaining high spatiotemporal resolution and precise control of cellular signal transduction. The Light-Oxygen-Voltage (LOV) domain family of proteins is a well-recognized system for constructing optogenetic devices. Translation of these proteins into efficient cellular sensors is possible by tuning their photochemistry lifetime. However, the bottleneck is the need for more understanding of the relationship between the protein environment and photocycle kinetics. Significantly, the effect of the local environment also modulates the electronic structure of chromophore, which perturbs the electrostatic and hydrophobic interaction within the binding site. This work highlights the critical factors hidden in the protein networks, linking with their experimental photocycle kinetics. It presents an opportunity to quantitatively examine the alternation in chromophore's equilibrium geometry and identify details which have substantial implications in designing synthetic LOV constructs with desirable photocycle efficiency.
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Affiliation(s)
- Rishab Panda
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Pritam K Panda
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20, Uppsala, Sweden; Division of Immunology and Chronic Disease, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Rajiv K Kar
- Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
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10
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Mishra A, Sharma A, Kateriya S. Effect of tryptophan mutation on the structure of LOV1 domain of phototropin1 protein of Ostreococcus tauri: A combined molecular dynamics simulation and biophysical approach. Biochim Biophys Acta Gen Subj 2023; 1867:130304. [PMID: 36627087 DOI: 10.1016/j.bbagen.2023.130304] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 12/13/2022] [Accepted: 01/04/2023] [Indexed: 01/08/2023]
Abstract
BACKGROUND Light, oxygen and voltage (LOV) proteins detect blue light by formation of a covalent 'photoadduct' between the flavin chromophore and the neighboring conserved cysteine residue. LOV proteins devoid of this conserved photoactive cysteine are unable to form this 'photoadduct' upon light illumination, but they can still elicit functional response via the formation of neutral flavin radical. Recently, tryptophan residue has been shown to be the primary electron donors to the flavin excited state. METHODS Photoactive cysteine (Cys42) and tryptophan (Trp68) residues in the LOV1 domain of phototropin1 of Ostreococcus tauri (OtLOV1) was mutated to alanine and threonine respectively. Effect of these mutations have been studied using molecular dynamics simulation and spectroscopic techniques. RESULTS Molecular dynamics simulation indicated that W68T did not affect the structure of OtLOV1 protein, but C42A leads to some structural changes. An increase in the fluorescence lifetime and quantum yield values was observed for the Trp68 mutant. CONCLUSIONS An increase in the fluorescence lifetime and quantum yield of Trp68 mutant compared to the wild type protein suggests that Trp68 residue participates in quenching of the flavin excited state followed by photoexcitation. GENERAL SIGNIFICANCE Enhanced photo-physical properties of Trp68 OtLOV1 mutant might enable its use for the optogenetic and microscopic applications.
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Affiliation(s)
- Ayushi Mishra
- Laboratory of Optobiotechnology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India
| | - Amit Sharma
- Multidisciplinary Centre for Advanced Research and Studies, Jamia Millia Islamia, New Delhi 110025, India
| | - Suneel Kateriya
- Laboratory of Optobiotechnology, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
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11
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Kabir MP, Ouedraogo D, Orozco-Gonzalez Y, Gadda G, Gozem S. Alternative Strategy for Spectral Tuning of Flavin-Binding Fluorescent Proteins. J Phys Chem B 2023; 127:1301-1311. [PMID: 36740810 PMCID: PMC9940217 DOI: 10.1021/acs.jpcb.2c06475] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
iLOV is an engineered flavin-binding fluorescent protein (FbFP) with applications for in vivo cellular imaging. To expand the range of applications of FbFPs for multicolor imaging and FRET-based biosensing, it is desirable to understand how to modify their absorption and emission wavelengths (i.e., through spectral tuning). There is particular interest in developing FbFPs that absorb and emit light at longer wavelengths, which has proven challenging thus far. Existing spectral tuning strategies that do not involve chemical modification of the flavin cofactor have focused on placing positively charged amino acids near flavin's C4a and N5 atoms. Guided by previously reported electrostatic spectral tunning maps (ESTMs) of the flavin cofactor and by quantum mechanical/molecular mechanical (QM/MM) calculations reported in this work, we suggest an alternative strategy: placing a negatively charged amino acid near flavin's N1 atom. We predict that a single-point mutant, iLOV-Q430E, has a slightly red-shifted absorption and fluorescence maximum wavelength relative to iLOV. To validate our theoretical prediction, we experimentally expressed and purified iLOV-Q430E and measured its spectral properties. We found that the Q430E mutation results in a slight change in absorption and a 4-8 nm red shift in the fluorescence relative to iLOV, in good agreement with the computational predictions. Molecular dynamics simulations showed that the carboxylate side chain of the glutamate in iLOV-Q430E points away from the flavin cofactor, which leads to a future expectation that further red shifting may be achieved by bringing the side chain closer to the cofactor.
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12
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Fine spectral tuning of a flavin-binding fluorescent protein for multicolor imaging. J Biol Chem 2023; 299:102977. [PMID: 36738792 PMCID: PMC10023982 DOI: 10.1016/j.jbc.2023.102977] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/20/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
Flavin-binding fluorescent proteins are promising genetically encoded tags for microscopy. However, spectral properties of their chromophores (riboflavin, flavin mononucleotide, and flavin adenine dinucleotide) are notoriously similar even between different protein families, which limits applications of flavoproteins in multicolor imaging. Here, we present a palette of 22 finely tuned fluorescent tags based on the thermostable LOV domain from Chloroflexus aggregans. We performed site saturation mutagenesis of three amino acid positions in the flavin-binding pocket, including the photoactive cysteine, to obtain variants with fluorescence emission maxima uniformly covering the wavelength range from 486 to 512 nm. We demonstrate three-color imaging based on spectral separation and two-color fluorescence lifetime imaging of bacteria, as well as two-color imaging of mammalian cells (HEK293T), using the proteins from the palette. These results highlight the possibility of fine spectral tuning of flavoproteins and pave the way for further applications of flavin-binding fluorescent proteins in fluorescence microscopy.
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13
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Bitzenhofer NL, Hilgers F, Bosio GN, Torra J, Casini G, Beinlich FRM, Knieps-Grünhagen E, Gordeliy V, Jaeger KE, Nonell S, Krauss U, Gensch T, Drepper T. Development and Characterization of Flavin-Binding Fluorescent Proteins, Part II: Advanced Characterization. Methods Mol Biol 2023; 2564:143-183. [PMID: 36107341 DOI: 10.1007/978-1-0716-2667-2_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Flavin-based fluorescent proteins (FbFPs), a class of small fluorescent proteins derived from light-oxygen-voltage (LOV) domains, bind ubiquitous endogenous flavins as chromophores. Due to their unique properties, they can be used as versatile in vivo reporter proteins under aerobic and anaerobic conditions. This chapter presents methodologies for in-depth characterization of the biochemical, spectroscopic, photophysical, and photochemical properties of FbFPs.
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Affiliation(s)
- Nora Lisa Bitzenhofer
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Fabienne Hilgers
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Gabriela N Bosio
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Joaquim Torra
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Giorgia Casini
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Felix R M Beinlich
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Esther Knieps-Grünhagen
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Valentin Gordeliy
- Institute of Bio-and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain.
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.
- Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Thomas Gensch
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.
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14
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Łabuz J, Sztatelman O, Hermanowicz P. Molecular insights into the phototropin control of chloroplast movements. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6034-6051. [PMID: 35781490 DOI: 10.1093/jxb/erac271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 06/22/2022] [Indexed: 06/15/2023]
Abstract
Chloroplast movements are controlled by ultraviolet/blue light through phototropins. In Arabidopsis thaliana, chloroplast accumulation at low light intensities and chloroplast avoidance at high light intensities are observed. These responses are controlled by two homologous photoreceptors, the phototropins phot1 and phot2. Whereas chloroplast accumulation is triggered by both phototropins in a partially redundant manner, sustained chloroplast avoidance is elicited only by phot2. Phot1 is able to trigger only a small, transient chloroplast avoidance, followed by the accumulation phase. The source of this functional difference is not fully understood at either the photoreceptor or the signalling pathway levels. In this article, we review current understanding of phototropin functioning and try to dissect the differences that result in signalling to elicit two distinct chloroplast responses. First, we focus on phototropin structure and photochemical and biochemical activity. Next, we analyse phototropin expression and localization patterns. We also summarize known photoreceptor systems controlling chloroplast movements. Finally, we focus on the role of environmental stimuli in controlling phototropin activity. All these aspects impact the signalling to trigger chloroplast movements and raise outstanding questions about the mechanism involved.
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Affiliation(s)
- Justyna Łabuz
- Laboratory of Photobiology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa, Kraków, Poland
| | - Olga Sztatelman
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego, Warszawa, Poland
| | - Paweł Hermanowicz
- Laboratory of Photobiology, Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa, Kraków, Poland
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15
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Liang GT, Lai C, Yue Z, Zhang H, Li D, Chen Z, Lu X, Tao L, Subach FV, Piatkevich KD. Enhanced small green fluorescent proteins as a multisensing platform for biosensor development. Front Bioeng Biotechnol 2022; 10:1039317. [PMID: 36324888 PMCID: PMC9618808 DOI: 10.3389/fbioe.2022.1039317] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 09/30/2022] [Indexed: 12/02/2022] Open
Abstract
Engineered light, oxygen, and voltage (LOV)-based proteins are able to fluoresce without oxygen requirement due to the autocatalytic incorporation of exogenous flavin as a chromophore thus allowing for live cell imaging under hypoxic and anaerobic conditions. They were also discovered to have high sensitivity to transition metal ions and physiological flavin derivatives. These properties make flavin-binding fluorescent proteins (FPs) a perspective platform for biosensor development. However, brightness of currently available flavin-binding FPs is limited compared to GFP-like FPs creating a need for their further enhancement and optimization. In this study, we applied a directed molecular evolution approach to develop a pair of flavin-binding FPs, named miniGFP1 and miniGFP2. The miniGFP proteins are characterized by cyan-green fluorescence with excitation/emission maxima at 450/499 nm and a molecular size of ∼13 kDa. We carried out systematic benchmarking of miniGFPs in Escherichia coli and cultured mammalian cells against spectrally similar FPs including GFP-like FP, bilirubin-binding FP, and bright flavin-binding FPs. The miniGFPs proteins exhibited improved photochemical properties compared to other flavin-binding FPs enabling long-term live cell imaging. We demonstrated the utility of miniGFPs for live cell imaging in bacterial culture under anaerobic conditions and in CHO cells under hypoxia. The miniGFPs’ fluorescence was highly sensitive to Cu(II) ions in solution with Kd values of 67 and 68 nM for miniGFP1 and miniGFP2, respectively. We also observed fluorescence quenching of miniGFPs by the reduced form of Cu(I) suggesting its potential application as an optical indicator for Cu(I) and Cu(II). In addition, miniGFPs showed the ability to selectively bind exogenous flavin mononucleotide demonstrating a potential for utilization as a selective fluorescent flavin indicator. Altogether, miniGFPs can serve as a multisensing platform for fluorescence biosensor development for in vitro and in-cell applications.
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Affiliation(s)
- Guo-Teng Liang
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | - Cuixin Lai
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Zejun Yue
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
- School of Basic Medical Sciences, Xi’an Jiao Tong University, Xi’an, Shaanxi, China
| | - Hanbin Zhang
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Danyang Li
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Instrumentation and Service Center for Molecular Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Xingyu Lu
- Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, School of Science, Instrumentation and Service Center for Molecular Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Liang Tao
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
| | - Fedor V. Subach
- Complex of NBICS Technologies, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Kiryl D. Piatkevich
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- Institute of Basic Medical Sciences, Westlake Institute for Advanced Study, Hangzhou, Zhejiang, China
- *Correspondence: Kiryl D. Piatkevich,
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16
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Wehler P, Armbruster D, Günter A, Schleicher E, Di Ventura B, Öztürk MA. Experimental Characterization of In Silico Red-Shift-Predicted iLOV L470T/Q489K and iLOV V392K/F410V/A426S Mutants. ACS OMEGA 2022; 7:19555-19560. [PMID: 35722011 PMCID: PMC9202016 DOI: 10.1021/acsomega.2c01283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/28/2022] [Indexed: 06/15/2023]
Abstract
iLOV is a flavin mononucleotide-binding fluorescent protein used for in vivo cellular imaging similar to the green fluorescent protein. To expand the range of applications of iLOV, spectrally tuned red-shifted variants are desirable to reduce phototoxicity and allow for better tissue penetration. In this report, we experimentally tested two iLOV mutants, iLOVL470T/Q489K and iLOVV392K/F410V/A426S, which were previously computationally proposed by (KhrenovaJ. Phys. Chem. B2017, 121 ( (43), ), pp 10018-10025) to have red-shifted excitation and emission spectra. While iLOVL470T/Q489K is about 20% brighter compared to the WT in vitro, it exhibits a blue shift in contrast to quantum mechanics/molecular mechanics (QM/MM) predictions. Additional optical characterization of an iLOVV392K mutant revealed that V392 is essential for cofactor binding and, accordingly, variants with V392K mutation are unable to bind to FMN. iLOVL470T/Q489K and iLOVV392K/F410V/A426S are expressed at low levels and have no detectable fluorescence in living cells, preventing their utilization in imaging applications.
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Affiliation(s)
- Pierre Wehler
- Institute
of Biology II, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Centers
for Biological Signalling Studies BIOSS and CIBSS, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Daniel Armbruster
- Institute
of Biology II, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Centers
for Biological Signalling Studies BIOSS and CIBSS, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Andreas Günter
- Institute
of Physical Chemistry, University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Erik Schleicher
- Institute
of Physical Chemistry, University of Freiburg, Albertstr. 21, 79104 Freiburg, Germany
| | - Barbara Di Ventura
- Institute
of Biology II, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Centers
for Biological Signalling Studies BIOSS and CIBSS, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
| | - Mehmet Ali Öztürk
- Institute
of Biology II, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
- Centers
for Biological Signalling Studies BIOSS and CIBSS, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany
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17
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Raman V, Rojas CM, Vasudevan B, Dunning K, Kolape J, Oh S, Yun J, Yang L, Li G, Pant BD, Jiang Q, Mysore KS. Agrobacterium expressing a type III secretion system delivers Pseudomonas effectors into plant cells to enhance transformation. Nat Commun 2022; 13:2581. [PMID: 35546550 PMCID: PMC9095702 DOI: 10.1038/s41467-022-30180-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/20/2022] [Indexed: 01/07/2023] Open
Abstract
Agrobacterium-mediated plant transformation (AMT) is the basis of modern-day plant biotechnology. One major drawback of this technology is the recalcitrance of many plant species/varieties to Agrobacterium infection, most likely caused by elicitation of plant defense responses. Here, we develop a strategy to increase AMT by engineering Agrobacterium tumefaciens to express a type III secretion system (T3SS) from Pseudomonas syringae and individually deliver the P. syringae effectors AvrPto, AvrPtoB, or HopAO1 to suppress host defense responses. Using the engineered Agrobacterium, we demonstrate increase in AMT of wheat, alfalfa and switchgrass by ~250%-400%. We also show that engineered A. tumefaciens expressing a T3SS can deliver a plant protein, histone H2A-1, to enhance AMT. This strategy is of great significance to both basic research and agricultural biotechnology for transient and stable transformation of recalcitrant plant species/varieties and to deliver proteins into plant cells in a non-transgenic manner.
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Affiliation(s)
- Vidhyavathi Raman
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Plant and Microbial Biology, University of Minnesota, St. Paul, MN, 55108, USA
| | - Clemencia M Rojas
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR, 72701, USA
| | | | - Kevin Dunning
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | | | - Sunhee Oh
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Jianfei Yun
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Lishan Yang
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Guangming Li
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
| | - Bikram D Pant
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA
| | | | - Kirankumar S Mysore
- Noble Research Institute, LLC, Ardmore, OK, 73401, USA.
- Institute for Agricultural Biosciences, Oklahoma State University, Ardmore, OK, 73401, USA.
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, OK, 74078, USA.
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18
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Babakhanova S, Jung EE, Namikawa K, Zhang H, Wang Y, Subach OM, Korzhenevskiy DA, Rakitina TV, Xiao X, Wang W, Shi J, Drobizhev M, Park D, Eisenhard L, Tang H, Köster RW, Subach FV, Boyden ES, Piatkevich KD. Rapid directed molecular evolution of fluorescent proteins in mammalian cells. Protein Sci 2022; 31:728-751. [PMID: 34913537 PMCID: PMC8862398 DOI: 10.1002/pro.4261] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 11/24/2021] [Accepted: 12/14/2021] [Indexed: 12/31/2022]
Abstract
In vivo imaging of model organisms is heavily reliant on fluorescent proteins with high intracellular brightness. Here we describe a practical method for rapid optimization of fluorescent proteins via directed molecular evolution in cultured mammalian cells. Using this method, we were able to perform screening of large gene libraries containing up to 2 × 107 independent random genes of fluorescent proteins expressed in HEK cells, completing one iteration of directed evolution in a course of 8 days. We employed this approach to develop a set of green and near-infrared fluorescent proteins with enhanced intracellular brightness. The developed near-infrared fluorescent proteins demonstrated high performance for fluorescent labeling of neurons in culture and in vivo in model organisms such as Caenorhabditis elegans, Drosophila, zebrafish, and mice. Spectral properties of the optimized near-infrared fluorescent proteins enabled crosstalk-free multicolor imaging in combination with common green and red fluorescent proteins, as well as dual-color near-infrared fluorescence imaging. The described method has a great potential to be adopted by protein engineers due to its simplicity and practicality. We also believe that the new enhanced fluorescent proteins will find wide application for in vivo multicolor imaging of small model organisms.
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19
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Oliveira Paiva AM, Friggen AH, Douwes R, Wittekoek B, Smits WK. Practical observations on the use of fluorescent reporter systems in Clostridioides difficile. Antonie van Leeuwenhoek 2022; 115:297-323. [PMID: 35039954 DOI: 10.1007/s10482-021-01691-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/19/2021] [Indexed: 12/18/2022]
Abstract
Fluorescence microscopy is a valuable tool to study a broad variety of bacterial cell components and dynamics thereof. For Clostridioides difficile, the fluorescent proteins CFPopt, mCherryOpt and phiLOV2.1, and the self-labelling tags SNAPCd and HaloTag, hereafter collectively referred as fluorescent systems, have been described to explore different cellular pathways. In this study, we sought to characterize previously used fluorescent systems in C. difficile cells. We performed single cell analyses using fluorescence microscopy of exponentially growing C. difficile cells harbouring different fluorescent systems, either expressing these separately in the cytosol or fused to the C-terminus of HupA, under defined conditions. We show that the intrinsic fluorescence of C. difficile cells increases during growth, independent of sigB or spo0A. However, when C. difficile cells are exposed to environmental oxygen autofluorescence is enhanced. Cytosolic overexpression of the different fluorescent systems alone, using the same expression signals, showed heterogeneous expression of the fluorescent systems. High levels of mCherryOpt were toxic for C. difficile cells limiting the applicability of this fluorophore as a transcriptional reporter. When fused to HupA, a C. difficile histone-like protein, the fluorescent systems behaved similarly and did not affect the HupA overproduction phenotype. The present study compares several commonly used fluorescent systems for application as transcriptional or translational reporters in microscopy and summarizes the limitations and key challenges for live-cell imaging of C. difficile. Due to independence of molecular oxygen and fluorescent signal, SNAPCd appears the most suitable candidate for live-cell imaging in C. difficile to date.
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Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands.,Center for Microbial Cell Biology, Leiden, The Netherlands.,Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198, Gif-sur-Yvette, France
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands.,Center for Microbial Cell Biology, Leiden, The Netherlands
| | - Roxanne Douwes
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Bert Wittekoek
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands. .,Center for Microbial Cell Biology, Leiden, The Netherlands.
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20
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Beaujean P, Champagne B, Grimme S, de Wergifosse M. All-Atom Quantum Mechanical Calculation of the Second-Harmonic Generation of Fluorescent Proteins. J Phys Chem Lett 2021; 12:9684-9690. [PMID: 34590850 DOI: 10.1021/acs.jpclett.1c02911] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fluorescent proteins (FPs) are biotags of choice for second-harmonic imaging microscopy (SHIM). Because of their large size, computing their second-harmonic generation (SHG) response represents a great challenge for quantum chemistry. In this contribution, we propose a new all-atom quantum mechanics methodology to compute SHG of large systems. This is now possible because of two recent implementations: the tight-binding GFN2-xTB method to optimize geometries and a related version of the simplified time-dependent density functional theory (sTD-DFT-xTB) to evaluate quadratic response functions. In addition, a new dual-threshold configuration selection scheme is introduced to reduce the computational costs while retaining overall similar accuracy. This methodology was tested to evaluate the SHG of the proteins iLOV and bacteriorhodopsin (bR). In the case of bR, quantitative agreement with respect to experiment was reached for the out-of-resonance low-energy part of the βHRS frequency dispersion. This work paves the way toward an accurate prediction of the SHG of large structures-a requirement for the design of new and improved SHIM biotags.
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Affiliation(s)
- Pierre Beaujean
- Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Benoît Champagne
- Laboratory of Theoretical Chemistry, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium
| | - Stefan Grimme
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Berings. 4, D-53115 Bonn, Germany
| | - Marc de Wergifosse
- Mulliken Center for Theoretical Chemistry, Institut für Physikalische und Theoretische Chemie, Universität Bonn, Berings. 4, D-53115 Bonn, Germany
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21
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Joseph RC, Kelley SQ, Kim NM, Sandoval NR. Metabolic Engineering and the Synthetic Biology Toolbox for
Clostridium. Metab Eng 2021. [DOI: 10.1002/9783527823468.ch16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Yee EF, Oldemeyer S, Böhm E, Ganguly A, York DM, Kottke T, Crane BR. Peripheral Methionine Residues Impact Flavin Photoreduction and Protonation in an Engineered LOV Domain Light Sensor. Biochemistry 2021; 60:1148-1164. [PMID: 33787242 PMCID: PMC8107827 DOI: 10.1021/acs.biochem.1c00064] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Proton-coupled electron transfer reactions play critical roles in many aspects of sensory phototransduction. In the case of flavoprotein light sensors, reductive quenching of flavin excited states initiates chemical and conformational changes that ultimately transmit light signals to downstream targets. These reactions generally require neighboring aromatic residues and proton-donating side chains for rapid and coordinated electron and proton transfer to flavin. Although photoreduction of flavoproteins can produce either the anionic (ASQ) or neutral semiquinone (NSQ), the factors that favor one over the other are not well understood. Here we employ a biologically active variant of the light-oxygen-voltage (LOV) domain protein VVD devoid of the adduct-forming Cys residue (VVD-III) to probe the mechanism of flavin photoreduction and protonation. A series of isosteric and conservative residue replacements studied by rate measurements, fluorescence quantum yields, FTIR difference spectroscopy, and molecular dynamics simulations indicate that tyrosine residues facilitate charge recombination reactions that limit sustained flavin reduction, whereas methionine residues facilitate radical propagation and quenching and also gate solvent access for flavin protonation. Replacement of a single surface Met residue with Leu favors formation of the ASQ over the NSQ and desensitizes photoreduction to oxidants. In contrast, increasing site hydrophilicity by Gln substitution promotes rapid NSQ formation and weakens the influence of the redox environment. Overall, the photoreactivity of VVD-III can be understood in terms of redundant electron donors, internal hole quenching, and coupled proton transfer reactions that all depend upon protein conformation, dynamics, and solvent penetration.
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Affiliation(s)
- Estella F. Yee
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Sabine Oldemeyer
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Elena Böhm
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Abir Ganguly
- Laboratory for Biomolecular Simulation Research, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Darrin M. York
- Laboratory for Biomolecular Simulation Research, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Tilman Kottke
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, 33615 Bielefeld, Germany
| | - Brian R. Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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23
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Röllen K, Granzin J, Remeeva A, Davari MD, Gensch T, Nazarenko VV, Kovalev K, Bogorodskiy A, Borshchevskiy V, Hemmer S, Schwaneberg U, Gordeliy V, Jaeger KE, Batra-Safferling R, Gushchin I, Krauss U. The molecular basis of spectral tuning in blue- and red-shifted flavin-binding fluorescent proteins. J Biol Chem 2021; 296:100662. [PMID: 33862085 PMCID: PMC8131319 DOI: 10.1016/j.jbc.2021.100662] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 01/09/2023] Open
Abstract
Photoactive biological systems modify the optical properties of their chromophores, known as spectral tuning. Determining the molecular origin of spectral tuning is instrumental for understanding the function and developing applications of these biomolecules. Spectral tuning in flavin-binding fluorescent proteins (FbFPs), an emerging class of fluorescent reporters, is limited by their dependency on protein-bound flavins, whose structure and hence electronic properties cannot be altered by mutation. A blue-shifted variant of the plant-derived improved light, oxygen, voltage FbFP has been created by introducing a lysine within the flavin-binding pocket, but the molecular basis of this shift remains unconfirmed. We here structurally characterize the blue-shifted improved light, oxygen, voltage variant and construct a new blue-shifted CagFbFP protein by introducing an analogous mutation. X-ray structures of both proteins reveal displacement of the lysine away from the chromophore and opening up of the structure as instrumental for the blue shift. Site saturation mutagenesis and high-throughput screening yielded a red-shifted variant, and structural analysis revealed that the lysine side chain of the blue-shifted variant is stabilized close to the flavin by a secondary mutation, accounting for the red shift. Thus, a single additional mutation in a blue-shifted variant is sufficient to generate a red-shifted FbFP. Using spectroscopy, X-ray crystallography, and quantum mechanics molecular mechanics calculations, we provide a firm structural and functional understanding of spectral tuning in FbFPs. We also show that the identified blue- and red-shifted variants allow for two-color microscopy based on spectral separation. In summary, the generated blue- and red-shifted variants represent promising new tools for application in life sciences.
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Affiliation(s)
- Katrin Röllen
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Joachim Granzin
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Mehdi D Davari
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Thomas Gensch
- IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Vera V Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Kirill Kovalev
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia; Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France; Institute of Crystallography, RWTH Aachen University, Aachen, Germany
| | - Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Valentin Borshchevskiy
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Stefanie Hemmer
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany; DWI-Leibniz Institute for Interactive Materials, Aachen, Germany
| | - Valentin Gordeliy
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia; Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France
| | - Karl-Erich Jaeger
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Renu Batra-Safferling
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia.
| | - Ulrich Krauss
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
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Remeeva A, Nazarenko VV, Kovalev K, Goncharov IM, Yudenko A, Astashkin R, Gordeliy V, Gushchin I. Insights into the mechanisms of light-oxygen-voltage domain color tuning from a set of high-resolution X-ray structures. Proteins 2021; 89:1005-1016. [PMID: 33774867 DOI: 10.1002/prot.26078] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 03/16/2021] [Indexed: 01/01/2023]
Abstract
Light-oxygen-voltage (LOV) domains are widespread photosensory modules that can be used in fluorescence microscopy, optogenetics and controlled production of reactive oxygen species. All of the currently known LOV domains have absorption maxima in the range of ~440 to ~450 nm, and it is not clear whether they can be shifted significantly using mutations. Here, we have generated a panel of LOV domain variants by mutating the key chromophore-proximal glutamine aminoacid of a thermostable flavin based fluorescent protein CagFbFP (Gln148) to asparagine, aspartate, glutamate, histidine, lysine and arginine. Absorption spectra of all of the mutants are blue-shifted, with the maximal shift of 8 nm observed for the Q148H variant. While CagFbFP and its Q148N/D/E variants are not sensitive to pH, Q148H/K/R reveal a moderate red shift induced byacidic pH. To gain further insight, we determined high resolution crystal structures of all of the mutants studied at the resolutions from 1.07 Å for Q148D to 1.63 Å for Q148R. Whereas in some of the variants, the aminoacid 148 remains in the vicinity of the flavin, in Q148K, Q148R and partially Q148D, the C-terminus of the protein unlatches and the side chain of the residue 148 is reoriented away from the chromophore. Our results explain the absence of color shifts from replacing Gln148 with charged aminoacids and pave the way for rational design of color-shifted flavin based fluorescent proteins.
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Affiliation(s)
- Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Vera V Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Kirill Kovalev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institute of Crystallography, RWTH Aachen University, Aachen, Germany
| | - Ivan M Goncharov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Anna Yudenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Roman Astashkin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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25
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Cardoso
Ramos F, Cupellini L, Mennucci B. Computational Investigation of Structural and Spectroscopic Properties of LOV-Based Proteins with Improved Fluorescence. J Phys Chem B 2021; 125:1768-1777. [PMID: 33566620 PMCID: PMC7917436 DOI: 10.1021/acs.jpcb.0c10834] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/27/2021] [Indexed: 01/22/2023]
Abstract
Flavin-based fluorescent proteins are a class of fluorescent reporters derived from light, oxygen, and voltage (LOV) sensing proteins. Through mutagenesis, natural LOV proteins have been engineered to obtain improved fluorescence properties. In this study, we combined extended classical Molecular Dynamics simulations and multiscale Quantum Mechanics/Molecular Mechanics methods to clarify the relationship between structural and dynamic changes induced by specific mutations and the spectroscopic response. To reach this goal we compared two LOV variants, one obtained by the single mutation needed to photochemically inactivate the natural system, and the other (iLOV) obtained through additional mutations and characterized by a significantly improved fluorescence. Our simulations confirmed the "flipping and crowding" effect induced in iLOV by the additional mutations and revealed its mechanism of action. We also showed that these mutations, and the resulting differences in the composition and flexibility of the binding pockets, are not reflected in significant shifts of the excitation and emission energies, in agreement with the similarity of the spectra measured for the two systems. However, a small but consistent reduction was found in the Stokes shift of iLOV, suggesting a reduction of the intermolecular reorganization experienced by the chromophore after excitation, which could slow down its internal conversion to the ground state and improve the fluorescence.
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Affiliation(s)
- Felipe Cardoso
Ramos
- Dipartimento di Chimica e
Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa, I-56124, Italy
| | - Lorenzo Cupellini
- Dipartimento di Chimica e
Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa, I-56124, Italy
| | - Benedetta Mennucci
- Dipartimento di Chimica e
Chimica Industriale, University of Pisa, Via G. Moruzzi 13, Pisa, I-56124, Italy
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26
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Yudenko A, Smolentseva A, Maslov I, Semenov O, Goncharov IM, Nazarenko VV, Maliar NL, Borshchevskiy V, Gordeliy V, Remeeva A, Gushchin I. Rational Design of a Split Flavin-Based Fluorescent Reporter. ACS Synth Biol 2021; 10:72-83. [PMID: 33325704 DOI: 10.1021/acssynbio.0c00454] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Protein-fragment complementation assays are used ubiquitously for probing protein-protein interactions. Most commonly, the reporter protein is split in two parts, which are then fused to the proteins of interest and can reassemble and provide a readout if the proteins of interest interact with each other. The currently known split fluorescent proteins either can be used only in aerobic conditions and assemble irreversibly, or require addition of exogenous chromophores, which complicates the design of experiments. In recent years, light-oxygen-voltage (LOV) domains of several photoreceptor proteins have been developed into flavin-based fluorescent proteins (FbFPs) that, under some circumstances, can outperform commonly used fluorescent proteins such as GFP. Here, we show that CagFbFP, a small thermostable FbFP based on a LOV domain-containing protein from Chloroflexus aggregans, can serve as a split fluorescent reporter. We use the available genetic and structural information to identify three loops between the conserved secondary structure elements, Aβ-Bβ, Eα-Fα, and Hβ-Iβ, that tolerate insertion of flexible poly-Gly/Ser segments and eventually splitting. We demonstrate that the designed split pairs, when fused to interacting proteins, are fluorescent in vivo in E. coli and human cells and have low background fluorescence. Our results enable probing protein-protein interactions in anaerobic conditions without using exogenous fluorophores and provide a basis for further development of LOV and PAS (Per-Arnt-Sim) domain-based fluorescent reporters and optogenetic tools.
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Affiliation(s)
- Anna Yudenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Anastasia Smolentseva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Oleg Semenov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Ivan M. Goncharov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Vera V. Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Nina L. Maliar
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, 38044 Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52425 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny 141701, Russia
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27
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Anderson NT, Weyant KB, Mukherjee A. Characterization of flavin binding in oxygen-independent fluorescent reporters. AIChE J 2020; 66. [PMID: 34305141 DOI: 10.1002/aic.17083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Fluorescent proteins based on light, oxygen, and voltage (LOV) sensing photoreceptors are among the few reporter gene technologies available for studying living systems in oxygen-free environments that render reporters based on the green fluorescent protein nonfluorescent. LOV reporters develop fluorescence by binding flavin mononucleotide (FMN), which they endogenously obtain from cells. As FMN is essential to cell physiology as well as for determining fluorescence in LOV proteins, it is important to be able to study and characterize flavin binding in LOV reporters. To this end, we report a method for reversibly separating FMN from two commonly used LOV reporters to prepare stable and soluble apoproteins. Using fluorescence titration, we measured the equilibrium dissociation constant for binding with all three cellular flavins: FMN, flavin adenine dinucleotide, and riboflavin. Finally, we exploit the riboflavin affinity of apo LOV reporters, identified in this work, to develop a fluorescence turn-on biosensor for vitamin B2.
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Affiliation(s)
- Nolan T. Anderson
- Department of Chemical Engineering University of California Santa Barbara California 93106 USA
| | - Kevin B. Weyant
- Smith School of Chemical & Biomolecular Engineering Cornell University Ithaca New York 14853 USA
| | - Arnab Mukherjee
- Department of Chemical Engineering University of California Santa Barbara California 93106 USA
- Department of Chemistry University of California Santa Barbara California 93106 USA
- Neuroscience Research Institute University of California Santa Barbara California 93106 USA
- Center for Bioengineering University of California Santa Barbara California 93106 USA
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28
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Verchot J, Herath V, Urrutia CD, Gayral M, Lyle K, Shires MK, Ong K, Byrne D. Development of a Reverse Genetic System for Studying Rose Rosette Virus in Whole Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:1209-1221. [PMID: 32815767 DOI: 10.1094/mpmi-04-20-0094-r] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rose rosette virus (RRV) is a negative-sense RNA virus with a seven-segmented genome that is enclosed by a double membrane. We constructed an unconventional minireplicon system encoding the antigenomic (ag)RNA1 (encoding the viral RNA-dependent RNA polymerase [RdRp]), agRNA3 (encoding the nucleocapsid protein [N]), and a modified agRNA5 containing the coding sequence for the iLOV protein in place of the P5 open reading frame (R5-iLOV). iLOV expression from the R5-iLOV template was amplified by activities of the RdRp and N proteins in Nicotiana benthamiana leaves. A mutation was introduced into the RdRp catalytic domain and iLOV expression was eliminated, indicating RNA1-encoded polymerase activity drives iLOV expression from the R5-iLOV template. Fluorescence from the replicon was highest at 3 days postinoculation (dpi) and declined at 7 and 13 dpi. Addition of the tomato bushy stunt virus (TBSV) P19 silencing-suppressor protein prolonged expression until 7 dpi. A full-length infectious clone system was constructed of seven binary plasmids encoding each of the seven genome segments. Agro-delivery of constructs encoding RRV RNAs 1 through 4 or RNAs 1 through 7 to N. benthamiana plants produced systemic infection. Finally, agro-delivery of the full-length RRV infectious clone including all segments produced systemic infection within 60 dpi. This advance opens new opportunities for studying RRV infection biology.
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Affiliation(s)
- Jeanmarie Verchot
- Texas A&M Agrilife Center in Dallas, 17360 Coit Rd, Dallas, TX, U.S.A
- Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, U.S.A
| | - Venura Herath
- Texas A&M Agrilife Center in Dallas, 17360 Coit Rd, Dallas, TX, U.S.A
- Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, U.S.A
- Department of Agricultural Biology, Faculty of Agriculture, University of Peradeniya, 20400, Sri Lanka
| | - Cesar D Urrutia
- Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, U.S.A
| | - Mathieu Gayral
- Texas A&M Agrilife Center in Dallas, 17360 Coit Rd, Dallas, TX, U.S.A
| | - Kelsey Lyle
- Department of Biological Sciences, The University of Texas at Dallas, Dallas, TX, U.S.A
| | - Madalyn K Shires
- Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, U.S.A
| | - Kevin Ong
- Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX, U.S.A
| | - David Byrne
- Department of Horticulture Sciences, Texas A&M University, College Station, TX, U.S.A
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29
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Aissa HB, Gautier A. Engineering Glowing Chemogenetic Hybrids for Spying on Cells. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000340] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Hela Ben Aissa
- École normale supérieure PSL University CNRS, Laboratoire des biomolécules, LBM Sorbonne Université 75005 Paris France
| | - Arnaud Gautier
- École normale supérieure PSL University CNRS, Laboratoire des biomolécules, LBM Sorbonne Université 75005 Paris France
- Institut Universitaire de France Paris France
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Domain Organization in Plant Blue-Light Receptor Phototropin2 of Arabidopsis thaliana Studied by Small-Angle X-ray Scattering. Int J Mol Sci 2020; 21:ijms21186638. [PMID: 32927860 PMCID: PMC7555306 DOI: 10.3390/ijms21186638] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 01/10/2023] Open
Abstract
Phototropin2 (phot2) is a blue-light (BL) receptor protein that regulates the BL-dependent activities of plants for efficient photosynthesis. Phot2 is composed of two light-oxygen-voltage sensing domains (LOV1 and LOV2) to absorb BL, and a kinase domain. Photo-activated LOV domains, especially LOV2, play a major role in photo-dependent increase in the phosphorylation activity of the kinase domain. The atomic details of the overall structure of phot2 and the intramolecular mechanism to convert BL energy to a phosphorylation signal remain unknown. We performed structural studies on the LOV fragments LOV1, LOV2, LOV2-linker, and LOV2-kinase, and full-length phot2, using small-angle X-ray scattering (SAXS). The aim of the study was to understand structural changes under BL irradiation and discuss the molecular mechanism that enhance the phosphorylation activity under BL. SAXS is a suitable technique for visualizing molecular structures of proteins in solution at low resolution and is advantageous for monitoring their structural changes in the presence of external physical and/or chemical stimuli. Structural parameters and molecular models of the recombinant specimens were obtained from SAXS profiles in the dark, under BL irradiation, and after dark reversion. LOV1, LOV2, and LOV2-linker fragments displayed minimal structural changes. However, BL-induced rearrangements of functional domains were noted for LOV2-kinase and full-length phot2. Based on the molecular model together with the absorption measurements and biochemical assays, we discuss the intramolecular interactions and domain motions necessary for BL-enhanced phosphorylation activity of phot2.
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31
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Pletneva NV, Goryacheva EA, Artemyev IV, Arkhipova SF, Pletnev VZ. Fluorescent Tags in Biology: Three-Dimensional Structure. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2020. [DOI: 10.1134/s1068162020040160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Ko S, Jeon H, Yoon S, Kyung M, Yun H, Na JH, Jung ST. Discovery of Novel Pseudomonas putida Flavin-Binding Fluorescent Protein Variants with Significantly Improved Quantum Yield. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5873-5879. [PMID: 32367716 DOI: 10.1021/acs.jafc.0c00121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Oxygen-independent, flavin-binding fluorescent proteins (FbFPs) are emerging as alternatives to green fluorescent protein (GFP), which has limited applicability in studying anaerobic microorganisms, such as human gastrointestinal bacteria, which grow in oxygen-deficient environments. However, the utility of these FbFPs has been compromised because of their poor fluorescence emission. To overcome this limitation, we have employed a high-throughput library screening strategy and engineered an FbFP derived from Pseudomonas putida (SB2) for enhanced quantum yield. Of the resulting SB2 variants, KOFP-7 exhibited a significantly improved quantum yield (0.61) compared to other reported engineered FbFPs, which was even higher than that of enhanced GFP (EGFP, 0.60), with significantly enhanced tolerance against a strong reducing agent.
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Affiliation(s)
- Sanghwan Ko
- Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul 02841, Korea
- Department of Applied Chemistry, Kookmin University, Seoul 02707, Korea
| | - Hyunwoo Jeon
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Sanghan Yoon
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Munsu Kyung
- Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul 02841, Korea
| | - Hyungdon Yun
- Department of Bioscience and Biotechnology, Konkuk University, Seoul 05029, Korea
| | - Jung-Hyun Na
- Department of Pharmaceutical Engineering, Sangji University, Wonju 26339, Korea
| | - Sang Taek Jung
- Department of Biomedical Sciences, Graduate School of Medicine, Korea University, Seoul 02841, Korea
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33
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Effects of Proline Substitutions on the Thermostable LOV Domain from Chloroflexus aggregans. CRYSTALS 2020. [DOI: 10.3390/cryst10040256] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Light-oxygen-voltage (LOV) domains are ubiquitous photosensory modules found in proteins from bacteria, archaea and eukaryotes. Engineered versions of LOV domains have found widespread use in fluorescence microscopy and optogenetics, with improved versions being continuously developed. Many of the engineering efforts focused on the thermal stabilization of LOV domains. Recently, we described a naturally thermostable LOV domain from Chloroflexus aggregans. Here we show that the discovered protein can be further stabilized using proline substitution. We tested the effects of three mutations, and found that the melting temperature of the A95P mutant is raised by approximately 2 °C, whereas mutations A56P and A58P are neutral. To further evaluate the effects of mutations, we crystallized the variants A56P and A95P, while the variant A58P did not crystallize. The obtained crystal structures do not reveal any alterations in the proteins other than the introduced mutations. Molecular dynamics simulations showed that mutation A58P alters the structure of the respective loop (Aβ-Bβ), but does not change the general structure of the protein. We conclude that proline substitution is a viable strategy for the stabilization of the Chloroflexus aggregans LOV domain. Since the sequences and structures of the LOV domains are overall well-conserved, the effects of the reported mutations may be transferable to other proteins belonging to this family.
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34
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Ozbakir HF, Anderson NT, Fan KC, Mukherjee A. Beyond the Green Fluorescent Protein: Biomolecular Reporters for Anaerobic and Deep-Tissue Imaging. Bioconjug Chem 2020; 31:293-302. [PMID: 31794658 PMCID: PMC7033020 DOI: 10.1021/acs.bioconjchem.9b00688] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fluorescence imaging represents cornerstone technology for studying biological function at the cellular and molecular levels. The technology's centerpiece is a prolific collection of genetic reporters based on the green fluorescent protein (GFP) and related analogs. More than two decades of protein engineering have endowed the GFP repertoire with an incredible assortment of fluorescent proteins, allowing scientists immense latitude in choosing reporters tailored to various cellular and environmental contexts. Nevertheless, GFP and derivative reporters have specific limitations that hinder their unrestricted use for molecular imaging. These challenges have inspired the development of new reporter proteins and imaging mechanisms. Here, we review how these developments are expanding the frontiers of reporter gene techniques to enable nondestructive studies of cell function in anaerobic environments and deep inside intact animals-two important biological contexts that are fundamentally incompatible with the use of GFP-based reporters.
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Affiliation(s)
- Harun F. Ozbakir
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Nolan T. Anderson
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Kang-Ching Fan
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Arnab Mukherjee
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Department of Chemistry, University of California, Santa Barbara, California 93106, United States
- Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
- Center for Bioengineering, University of California, Santa Barbara, California 93106, United States
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35
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Zou W, Le K, Zastrow ML. Live‐Cell Copper‐Induced Fluorescence Quenching of the Flavin‐Binding Fluorescent Protein CreiLOV. Chembiochem 2020; 21:1356-1363. [DOI: 10.1002/cbic.201900669] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Wenping Zou
- Department of ChemistryUniversity of Houston 3585 Cullen Boulevard Houston TX 77204 USA
| | - Khoa Le
- Department of ChemistryUniversity of Houston 3585 Cullen Boulevard Houston TX 77204 USA
| | - Melissa L. Zastrow
- Department of ChemistryUniversity of Houston 3585 Cullen Boulevard Houston TX 77204 USA
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Ko S, Hwang B, Na JH, Lee J, Jung ST. Engineered Arabidopsis Blue Light Receptor LOV Domain Variants with Improved Quantum Yield, Brightness, and Thermostability. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:12037-12043. [PMID: 31581772 DOI: 10.1021/acs.jafc.9b05473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Despite remarkable contribution of green fluorescent protein and its variants for better understanding of various biological functions, its application for anaerobic microorganisms has been limited because molecular oxygen is essential for chromophore formation. To overcome the limitation, we engineered a plant-derived light, oxygen, or voltage (LOV) domain containing flavin mononucleotide for enhanced spectral properties. The resulting LOV variants exhibited improved fluorescence intensity (20 and 70% higher for SH3 and 70% for BR1, respectively) compared to iLOV, an LOV variant isolated in a previous study, and the quantum yields of the LOV variants (0.40 for SH3 and 0.45 for BR1) were also improved relative to that of iLOV (Q = 0.37). In addition to fluorescence intensity, the identified mutations of SH3 enabled an improved thermostability of the protein. The engineered LOV variants with enhanced spectral properties could provide a valuable tool for fluorescent molecular probes under anaerobic conditions.
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Affiliation(s)
- Sanghwan Ko
- Department of Biomedical Sciences, Graduate School of Medicine , Korea University , Seoul 02841 , Republic of Korea
- Department of Applied Chemistry , Kookmin University , Seoul 02707 , Republic of Korea
| | - Bora Hwang
- Department of Applied Chemistry , Kookmin University , Seoul 02707 , Republic of Korea
| | - Jung-Hyun Na
- Department of Applied Chemistry , Kookmin University , Seoul 02707 , Republic of Korea
- Division of Discovery and Optimization, New Drug Development Center , Osong Medical Innovation Foundation , Cheongju , Chungcheongbuk-do 28160 , Republic of Korea
| | - Jisun Lee
- Department of Biomedical Sciences, Graduate School of Medicine , Korea University , Seoul 02841 , Republic of Korea
| | - Sang Taek Jung
- Department of Biomedical Sciences, Graduate School of Medicine , Korea University , Seoul 02841 , Republic of Korea
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Zhao H, Zhang Y, Pan M, Song Y, Bai L, Miao Y, Huang Y, Zhu X, Song CP. Dynamic imaging of cellular pH and redox homeostasis with a genetically encoded dual-functional biosensor, pHaROS, in yeast. J Biol Chem 2019; 294:15768-15780. [PMID: 31488545 PMCID: PMC6816096 DOI: 10.1074/jbc.ra119.007557] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 08/25/2019] [Indexed: 11/06/2022] Open
Abstract
Intracellular pH and redox states are critical for multiple processes and partly determine cell behavior. Here, we developed a genetically encoded dual-function probe, named p H and redox-sensitive fluorescent protein (pHaROS), for simultaneous real-time detection of changes in redox potential and pH in living cells. pHaROS consists of the Arabidopsis flavin mononucleotide-binding fluorescent protein iLOV and an mKATE variant, mBeRFP. Using pHaROS in Saccharomyces cerevisiae cells, we confirmed that H2O2 raises the overall redox potential of the cell and found that this increase is accompanied by a decrease in cytosolic pH. Furthermore, we observed spatiotemporal pH and redox homeostasis within the nucleus at various stages of the cell cycle in budding yeast (Saccharomyces cerevisiae) during cellular development and responses to oxidative stress. Importantly, we could tailor pHaROS to specific applications, including measurements in different organelles and cell types and the GSH/GSSG ratio, highlighting pHaROS's high flexibility and versatility. In summary, we have developed pHaROS as a dual-function probe that can be used for simultaneously measuring cellular pH and redox potential, representing a very promising tool for determining the cross-talk between intracellular redox- and pH-signaling processes in yeast and mammalian U87 cell.
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Affiliation(s)
- Hang Zhao
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Yu Zhang
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Mingming Pan
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Yichen Song
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Ling Bai
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Yuchen Miao
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Yanqin Huang
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Xiaohong Zhu
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
| | - Chun-Peng Song
- Department of Biology, Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Henan University, Kaifeng, China 475001
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Cheng C, Lin M, Jiang W, Zhao J, Li W, Yang ST. Development of an in vivo fluorescence based gene expression reporter system for Clostridium tyrobutyricum. J Biotechnol 2019; 305:18-22. [PMID: 31472166 DOI: 10.1016/j.jbiotec.2019.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/01/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022]
Abstract
C. tyrobutyricum, an acidogenic Clostridium, has aroused increasing interest due to its potential to produce biofuel efficiently. However, construction of recombinant C. tyrobutyricum for enhanced biofuel production has been impeded by the limited genetic engineering tools. In this study, a flavin mononucleotide (FMN)-dependent fluorescent protein Bs2-based gene expression reporter system was developed to monitor transformation and explore in vivo strength and regulation of various promoters in C. tyrobutyricum and C. acetobutylicum. Unlike green fluorescent protein (GFP) and its variants, Bs2 can emit green light without oxygen, which makes it extremely suitable for promoter screening and transformation confirmation in organisms grown anaerobically. The expression levels of bs2 under thiolase promoters from C. tyrobutyricum and C. acetobutylicum were measured and compared based on fluorescence intensities. The capacities of the two promoters in driving secondary alcohol dehydrogenase (adh) gene for isopropanol production in C. tyrobutyricum were distinguished, confirming that this reporter system is a convenient, effective and reliable tool for promoter strength assay and real time monitoring in C. tyrobutyricum, while demonstrating the feasibility of producing isopropanol in C. tyrobutyricum for the first time.
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Affiliation(s)
- Chi Cheng
- School of Bioengineering, Dalian University of Technology, Dalian 116024, China; William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 Woodruff Ave., Columbus, OH 43210, USA
| | - Meng Lin
- Bioprocessing Innovative Company, 4734 Bridle Path Ct., Dublin, OH 43017, USA
| | - Wenyan Jiang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 Woodruff Ave., Columbus, OH 43210, USA
| | - Jingbo Zhao
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 Woodruff Ave., Columbus, OH 43210, USA
| | - Weiming Li
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 Woodruff Ave., Columbus, OH 43210, USA; School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shang-Tian Yang
- William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 151 Woodruff Ave., Columbus, OH 43210, USA.
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Meteleshko YI, Nemukhin AV, Khrenova MG. Molecular Modeling of Photophysical Properties of Components of Förster Resonance Energy Transfer Pairs Containing Flavin-Based Fluorescent Proteins and Their Analogs. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2019. [DOI: 10.1134/s1990793119030205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Split-miniSOG for Spatially Detecting Intracellular Protein-Protein Interactions by Correlated Light and Electron Microscopy. Cell Chem Biol 2019; 26:1407-1416.e5. [PMID: 31378710 DOI: 10.1016/j.chembiol.2019.07.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 03/18/2019] [Accepted: 07/17/2019] [Indexed: 01/07/2023]
Abstract
A protein-fragment complementation assay (PCA) for detecting and localizing intracellular protein-protein interactions (PPIs) was built by bisection of miniSOG, a fluorescent flavoprotein derived from the light, oxygen, voltage (LOV)-2 domain of Arabidopsis phototropin. When brought together by interacting proteins, the fragments reconstitute a functional reporter that permits tagged protein complexes to be visualized by fluorescence light microscopy (LM), and then by standard as well as "multicolor" electron microscopy (EM) via the photooxidation of 3-3'-diaminobenzidine and its derivatives.
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41
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Westberg M, Etzerodt M, Ogilby PR. Rational design of genetically encoded singlet oxygen photosensitizing proteins. Curr Opin Struct Biol 2019; 57:56-62. [DOI: 10.1016/j.sbi.2019.01.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/14/2019] [Accepted: 01/29/2019] [Indexed: 01/29/2023]
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42
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Gotthard G, Aumonier S, De Sanctis D, Leonard G, von Stetten D, Royant A. Specific radiation damage is a lesser concern at room temperature. IUCRJ 2019; 6:665-680. [PMID: 31316810 PMCID: PMC6608634 DOI: 10.1107/s205225251900616x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/02/2019] [Indexed: 05/22/2023]
Abstract
Carrying out macromolecular crystallography (MX) experiments at cryogenic temperatures significantly slows the rate of global radiation damage, thus facilitating the solution of high-resolution crystal structures of macromolecules. However, cryo-MX experiments suffer from the early onset of so-called specific radiation damage that affects certain amino-acid residues and, in particular, the active sites of many proteins. Here, a series of MX experiments are described which suggest that specific and global radiation damage are much less decoupled at room temperature than they are at cryogenic temperatures. The results reported here demonstrate the interest in reviving the practice of collecting MX diffraction data at room temperature and allow structural biologists to favourably envisage the development of time-resolved MX experiments at synchrotron sources.
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Affiliation(s)
| | - Sylvain Aumonier
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | - Gordon Leonard
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | | | - Antoine Royant
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
- Université Grenoble Alpes, CNRS, CEA, IBS (Institut de Biologie Structurale), F-38000 Grenoble, France
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Nemukhin AV, Grigorenko BL, Khrenova MG, Krylov AI. Computational Challenges in Modeling of Representative Bioimaging Proteins: GFP-Like Proteins, Flavoproteins, and Phytochromes. J Phys Chem B 2019; 123:6133-6149. [DOI: 10.1021/acs.jpcb.9b00591] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Alexander V. Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 119334, Russia
| | - Bella L. Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow 119334, Russia
| | - Maria G. Khrenova
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Federal Research Center of Biotechnology, Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow 119071, Russian
| | - Anna I. Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, United States
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Abstract
ABSTRACT
The spatial dimensions of host cells and bacterial microbes are perfectly suited to being studied by microscopy techniques. Therefore, cellular imaging has been instrumental in uncovering many paradigms of the intracellular lifestyle of microbes. Initially, microscopy was used as a qualitative, descriptive tool. However, with the onset of specific markers and the power of computer-assisted image analysis, imaging can now be used to gather quantitative data on biological processes. This makes imaging a driving force for the study of cellular phenomena. One particular imaging modality stands out, which is based on the physical principles of fluorescence. Fluorescence is highly specific and therefore can be exploited to label biomolecules of choice. It is also very sensitive, making it possible to follow individual molecules with this approach. Also, microscopy hardware has played an important role in putting microscopy in the spotlight for host-pathogen investigations. For example, microscopes have been automated for microscopy-based screenings. A new generation of microscopes and molecular probes are being used to image events below the resolution limit of light. Finally, workflows are being developed to link light microscopy with electron microscopy methods via correlative light electron microscopy. We are witnessing a golden age of cellular imaging in cellular microbiology.
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45
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Orozco-Gonzalez Y, Kabir MP, Gozem S. Electrostatic Spectral Tuning Maps for Biological Chromophores. J Phys Chem B 2019; 123:4813-4824. [DOI: 10.1021/acs.jpcb.9b00489] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Mohammad Pabel Kabir
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
| | - Samer Gozem
- Department of Chemistry, Georgia State University, Atlanta, Georgia 30302, United States
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46
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Patel S, Wall DM, Castillo A, McCormick BA. Caspase-3 cleavage of Salmonella type III secreted effector protein SifA is required for localization of functional domains and bacterial dissemination. Gut Microbes 2019; 10:172-187. [PMID: 30727836 PMCID: PMC6546311 DOI: 10.1080/19490976.2018.1506668] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
SifA is a bi-functional Type III Secretion System (T3SS) effector protein that plays an important role in Salmonella virulence. The N-terminal domain of SifA binds SifA-Kinesin-Interacting-Protein (SKIP), and via an interaction with kinesin, forms tubular membrane extensions called Sif filaments (Sifs) that emanate from the Salmonella Containing Vacuole (SCV). The C-terminal domain of SifA harbors a WxxxE motif that functions to mimic active host cell GTPases. Taken together, SifA functions in inducing endosomal tubulation in order to maintain the integrity of the SCV and promote bacterial dissemination. Since SifA performs multiple, unrelated functions, the objective of this study was to determine how each functional domain of SifA becomes processed. Our work demonstrates that a linker region containing a caspase-3 cleavage motif separates the two functional domains of SifA. To test the hypothesis that processing of SifA by caspase-3 at this particular site is required for function and proper localization of the effector protein domains, we developed two tracking methods to analyze the intracellular localization of SifA. We first adapted a fluorescent tag called phiLOV that allowed for type-III secretion system (T3SS) mediated delivery of SifA and observation of its intracellular colocalization with caspase-3. Additionally, we created a dual-tagging strategy that permitted tracking of each of the SifA functional domains following caspase-3 cleavage to different subcellular locations. The results of this study reveal that caspase-3 cleavage of SifA is required for the proper localization of functional domains and bacterial dissemination. Considering the importance of these events in Salmonella pathogenesis, we conclude that caspase-3 cleavage of effector proteins is a more broadly applicable effector processing mechanism utilized by Salmonella to invade and persist during infection.
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Affiliation(s)
- Samir Patel
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA,CONTACT Beth McCormick Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street AS8-2011, Worcester, MA 01605, USA
| | - Daniel M. Wall
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Antonio Castillo
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Beth A. McCormick
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
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47
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Kabir MP, Orozco-Gonzalez Y, Gozem S. Electronic spectra of flavin in different redox and protonation states: a computational perspective on the effect of the electrostatic environment. Phys Chem Chem Phys 2019; 21:16526-16537. [DOI: 10.1039/c9cp02230a] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This study discusses how UV/vis absorption spectra of flavin in different redox and protonation states are shifted by the nearby electrostatic microenvironment.
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Affiliation(s)
| | | | - Samer Gozem
- Department of Chemistry
- Georgia State University
- Atlanta
- USA
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48
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Nazarenko VV, Remeeva A, Yudenko A, Kovalev K, Dubenko A, Goncharov IM, Kuzmichev P, Rogachev AV, Buslaev P, Borshchevskiy V, Mishin A, Dhoke GV, Schwaneberg U, Davari MD, Jaeger KE, Krauss U, Gordeliy V, Gushchin I. A thermostable flavin-based fluorescent protein from Chloroflexus aggregans: a framework for ultra-high resolution structural studies. Photochem Photobiol Sci 2019; 18:1793-1805. [DOI: 10.1039/c9pp00067d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A new thermostable fluorescent protein is shown to be a promising model for ultra-high resolution structural studies of LOV domains and for application as a fluorescent reporter.
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49
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Meteleshko YI, Nemukhin AV, Khrenova MG. Novel flavin-based fluorescent proteins with red-shifted emission bands: a computational study. Photochem Photobiol Sci 2018; 18:177-189. [PMID: 30403258 DOI: 10.1039/c8pp00361k] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The iLOV protein is a promising member of the class of flavin mononucleotide (FMN) based fluorescent proteins (FbFPs). It is becoming a popular tool for bioanalytical applications and bioimaging as a competitor of the well-known green fluorescent protein and its analogues. The main limitation of FbFPs is that all the members have close values of their absorption and emission band maxima. Therefore the upcoming challenge is to introduce novel variants of FbFPs to extend their color palette. We report the results of computational studies of iLOV variants, introducing point mutations and chromophore analogues. We found that point mutations of the apoprotein and substitution of FMN with either 8-amino-FMN or 8-methylamino-FMN lead to the red shift of emission bands up to 100 nm. Substitution with 1-deaza-FMN and the point mutations of the apoprotein result in a set of novel fluorescent proteins with emission bands in the "transparent" window where light readily penetrates through mammalian tissues. Newly suggested FbFPs can be used for multicolor imaging and also as components of FRET pairs.
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Affiliation(s)
- Yulia I Meteleshko
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation.
| | - Alexander V Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation. and Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygina 4, Moscow, 119334, Russian Federation
| | - Maria G Khrenova
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow, 119991, Russian Federation. and Federal Research Center of Biotechnology, Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskiy Prospect 33, 119071 Moscow, Russian Federation
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50
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Charubin K, Bennett RK, Fast AG, Papoutsakis ET. Engineering Clostridium organisms as microbial cell-factories: challenges & opportunities. Metab Eng 2018; 50:173-191. [DOI: 10.1016/j.ymben.2018.07.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 11/25/2022]
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