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Tavares D, van der Meer JR. Subcellular Localization Defects Characterize Ribose-Binding Mutant Proteins with New Ligand Properties in Escherichia coli. Appl Environ Microbiol 2022; 88:e0211721. [PMID: 34757821 PMCID: PMC8788693 DOI: 10.1128/aem.02117-21] [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: 10/27/2021] [Accepted: 11/04/2021] [Indexed: 11/20/2022] Open
Abstract
Periplasmic binding proteins have been previously proclaimed as a general scaffold to design sensor proteins with new recognition specificities for nonnatural compounds. Such proteins can be integrated in bacterial bioreporter chassis with hybrid chemoreceptors to produce a concentration-dependent signal after ligand binding to the sensor cell. However, computationally designed new ligand-binding properties ignore the more general properties of periplasmic binding proteins, such as their periplasmic translocation, dynamic transition of open and closed forms, and interactions with membrane receptors. In order to better understand the roles of such general properties in periplasmic signaling behavior, we studied the subcellular localization of ribose-binding protein (RbsB) in Escherichia coli in comparison to a recently evolved set of mutants designed to bind 1,3-cyclohexanediol. As proxies for localization, we calibrated and deployed C-terminal end mCherry fluorescent protein fusions. Whereas RbsB-mCherry coherently localized to the periplasmic space and accumulated in (periplasmic) polar regions depending on chemoreceptor availability, mutant RbsB-mCherry expression resulted in high fluorescence cell-to-cell variability. This resulted in higher proportions of cells devoid of clear polar foci and of cells with multiple fluorescent foci elsewhere, suggesting poorer translocation, periplasmic autoaggregation, and mislocalization. Analysis of RbsB mutants and mutant libraries at different stages of directed evolution suggested overall improvement to more RbsB-wild-type-like characteristics, which was corroborated by structure predictions. Our results show that defects in periplasmic localization of mutant RbsB proteins partly explain their poor sensing performance. Future efforts should be directed to predicting or selecting secondary mutations outside computationally designed binding pockets, taking folding, translocation, and receptor interactions into account. IMPORTANCE Biosensor engineering relies on transcription factors or signaling proteins to provide the actual sensory functions for the target chemicals. Since for many compounds there are no natural sensory proteins, there is a general interest in methods that could unlock routes to obtaining new ligand-binding properties. Bacterial periplasmic binding proteins (PBPs) form an interesting family of proteins to explore for this purpose, because there is a large natural variety suggesting evolutionary trajectories to bind new ligands. PBPs are conserved and amenable to accurate computational binding pocket predictions. However, studying ribose-binding protein in Escherichia coli, we discovered that designed variants have defects in their proper localization in the cell, which can impair appropriate sensor signaling. This indicates that functional sensing capacity of PBPs cannot be obtained solely through computational design of the ligand-binding pocket but must take other properties of the protein into account, which are currently very difficult to predict.
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Affiliation(s)
- Diogo Tavares
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Jan R. van der Meer
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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2
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Periplasmic-binding protein-based biosensors and bioanalytical assay platforms: Advances, considerations, and strategies for optimal utility. TALANTA OPEN 2021. [DOI: 10.1016/j.talo.2021.100038] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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3
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Tavares D, van der Meer JR. Ribose-Binding Protein Mutants With Improved Interaction Towards the Non-natural Ligand 1,3-Cyclohexanediol. Front Bioeng Biotechnol 2021; 9:705534. [PMID: 34368100 PMCID: PMC8343135 DOI: 10.3389/fbioe.2021.705534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/29/2021] [Indexed: 01/08/2023] Open
Abstract
Bioreporters consist of genetically modified living organisms that respond to the presence of target chemical compounds by production of an easily measurable signal. The central element in a bioreporter is a sensory protein or aptamer, which, upon ligand binding, modifies expression of the reporter signal protein. A variety of naturally occurring or modified versions of sensory elements has been exploited, but it has proven to be challenging to generate elements that recognize non-natural ligands. Bacterial periplasmic binding proteins have been proposed as a general scaffold to design receptor proteins for non-natural ligands, but despite various efforts, with only limited success. Here, we show how combinations of randomized mutagenesis and reporter screening improved the performance of a set of mutants in the ribose binding protein (RbsB) of Escherichia coli, which had been designed based on computational simulations to bind the non-natural ligand 1,3-cyclohexanediol (13CHD). Randomized mutant libraries were constructed that used the initially designed mutants as scaffolds, which were cloned in an appropriate E. coli bioreporter system and screened for improved induction of the GFPmut2 reporter fluorescence in presence of 1,3-cyclohexanediol. Multiple rounds of library screening, sorting, renewed mutagenesis and screening resulted in 4.5-fold improvement of the response to 1,3-cyclohexanediol and a lower detection limit of 0.25 mM. All observed mutations except one were located outside the direct ligand-binding pocket, suggesting they were compensatory and helping protein folding or functional behavior other than interaction with the ligand. Our results thus demonstrate that combinations of ligand-binding-pocket redesign and randomized mutagenesis can indeed lead to the selection and recovery of periplasmic-binding protein mutants with non-natural compound recognition. However, current lack of understanding of the intermolecular movement and ligand-binding in periplasmic binding proteins such as RbsB are limiting the rational production of further and better sensory mutants.
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Affiliation(s)
- Diogo Tavares
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
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4
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Bearham J, Krutrök N, Lindberg B, Woodall M, Astrand A, Taylor JD, Biggart M, Vasiljevs S, Tarran R, Baines DL. A modified fluorescent sensor for reporting glucose concentration in the airway lumen. PLoS One 2021; 16:e0254248. [PMID: 34242292 PMCID: PMC8270177 DOI: 10.1371/journal.pone.0254248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/23/2021] [Indexed: 11/19/2022] Open
Abstract
We have modified the periplasmic Escherichia coli glucose/galactose binding protein (GBP) and labelled with environmentally sensitive fluorophores to further explore its potential as a sensor for the evaluation of glucose concentration in airway surface liquid (ASL). We identified E149C/A213R GBP labelled with N,N'-Dimethyl-N-(iodoacetyl)-N'-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)ethylenediamine (IANBD, emission wavelength maximum 536nm) with a Kd for D-glucose of 1.02mM and a fluorescence dynamic range of 5.8. This sensor was specific for D-glucose and exhibited fluorescence stability in experiments for several hours. The use of E149C/A213R GBP-IANBD in the ASL of airway cells grown at air-liquid-interface (ALI) detected an increase in glucose concentration 10 minutes after raising basolateral glucose from 5 to 15mM. This sensor also reported a greater change in ASL glucose concentration in response to increased basolateral glucose in H441 airway cells compared to human bronchial epithelial cells (HBEC) and there was less variability with HBEC data than that of H441 indicating that HBEC more effectively regulate glucose movement into the ASL. The sensor detected glucose in bronchoalveolar lavage fluid (BALf) from diabetic db/db mice but not normoglycaemic wildtype mice, indicating limited sensitivity of the sensor at glucose concentrations <50μM. Using nasal inhalation of the sensor and spectral unmixing to generate images, E149C/A213R GBP-IANBD fluorescence was detected in luminal regions of cryosections of the murine distal lung that was greater in db/db than wildtype mice. In conclusion, this sensor provides a useful tool for further development to measure luminal glucose concentration in models of lung/airway to explore how this may change in disease.
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Affiliation(s)
- Jade Bearham
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Nina Krutrök
- Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Botilda Lindberg
- Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Maximillian Woodall
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Annika Astrand
- Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - John D. Taylor
- Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Matthew Biggart
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Stanislavs Vasiljevs
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
| | - Robert Tarran
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Deborah L. Baines
- Institute for Infection and Immunity, St George’s University of London, London, United Kingdom
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5
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Yang M, Tang Y, Weng J, Liu Z, Wang W. The Role of Calcium in Regulating the Conformational Dynamics of d-Galactose/d-Glucose-Binding Protein Revealed by Markov State Model Analysis. J Chem Inf Model 2021; 61:891-900. [PMID: 33445873 DOI: 10.1021/acs.jcim.0c01119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The d-glucose/d-galactose-binding protein (GGBP) from Escherichia coli is a substrate-binding protein (SBP) associated with sugar transport and chemotaxis. It is also a calcium-binding protein, which makes it unique in the SBP family. However, the functional importance of Ca2+ binding is not fully understood. Here, the calcium-dependent properties of GGBP were explored by all-atom molecular dynamics simulations and Markov state model (MSM) analysis as well as single-molecule Förster resonance energy transfer (smFRET) measurements. In agreement with previous experimental studies, we observed the structure stabilization effect of Ca2+ binding on the C-terminal domain of GGBP, especially the Ca2+-binding site. Interestingly, the MSMs of calcium-depleted GGBP and calcium-bound GGBP (GGBP/Ca2+) demonstrate that Ca2+ greatly stabilizes the open conformation, and smFRET measurements confirmed this result. Further analysis reveals that Ca2+ binding disturbs the local hydrogen bonding interactions and the conformational dynamics of the hinge region, thereby weakening the long-range interdomain correlations to favor the open conformation. These results suggest an active regulatory role of Ca2+ binding in GGBP, which finely tunes the conformational distribution. The work sheds new light on the study of calcium-binding proteins in prokaryotes.
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Affiliation(s)
- Maohua Yang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Yegen Tang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Jingwei Weng
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
| | - Zhijun Liu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
| | - Wenning Wang
- Department of Chemistry, Multiscale Research Institute of Complex Systems and Institute of Biomedical Sciences, Fudan University, Shanghai 200438, China
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6
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Single-Molecule Studies on a FRET Biosensor: Lessons from a Comparison of Fluorescent Protein Equipped versus Dye-Labeled Species. Molecules 2018; 23:molecules23123105. [PMID: 30486450 PMCID: PMC6320824 DOI: 10.3390/molecules23123105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/23/2018] [Accepted: 11/24/2018] [Indexed: 11/16/2022] Open
Abstract
Bacterial periplasmic binding proteins (PBPs) undergo a pronounced ligand-induced conformational change which can be employed to monitor ligand concentrations. The most common strategy to take advantage of this conformational change for a biosensor design is to use a Förster resonance energy transfer (FRET) signal. This can be achieved by attaching either two fluorescent proteins (FPs) or two organic fluorescent dyes of different colors to the PBPs in order to obtain an optical readout signal which is closely related to the ligand concentration. In this study we compare a FP-equipped and a dye-labeled version of the glucose/galactose binding protein MglB at the single-molecule level. The comparison demonstrates that changes in the FRET signal upon glucose binding are more pronounced for the FP-equipped sensor construct as compared to the dye-labeled analog. Moreover, the FP-equipped sensor showed a strong increase of the FRET signal under crowding conditions whereas the dye-labeled sensor was not influenced by crowding. The choice of a labeling scheme should therefore be made depending on the application of a FRET-based sensor.
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Hu H, Wei Y, Wang D, Su N, Chen X, Zhao Y, Liu G, Yang Y. Glucose monitoring in living cells with single fluorescent protein-based sensors. RSC Adv 2018; 8:2485-2489. [PMID: 35541484 PMCID: PMC9077360 DOI: 10.1039/c7ra11347a] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 12/23/2017] [Indexed: 11/26/2022] Open
Abstract
Glucose is the main source of energy and carbon in organisms and plays a central role in metabolism and cellular homeostasis. However, the sensitive fluctuation of glucose in living cells is difficult to monitor. Thus, we developed a series of ratiometric, highly responsive, single fluorescent protein-based glucose sensors of wide dynamic range by combining a circularly permuted yellow fluorescent protein with a bacterial periplasmic glucose/galactose-binding protein. We used these sensors to monitor glucose transport in living Escherichia coli cells, and found that the cells take up glucose within 10 min to maintain physiological glucose levels, and observed the differences in glucose uptake and glucose metabolism between wild-type and Mlc knockout cells. These sensors can be specific and simple tools for glucose detection in vitro and non-invasive tools for real-time monitoring of glucose metabolism in vivo. Glucose is the main source of energy and carbon in organisms and plays a central role in metabolism and cellular homeostasis.![]()
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Affiliation(s)
- Hanyang Hu
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Yufeng Wei
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Daocheng Wang
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Ni Su
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Xianjun Chen
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Yuzheng Zhao
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
| | - Guixia Liu
- Shanghai Key Laboratory of New Drug Design
- School of Pharmacy
- East China University of Science and Technology
- Shanghai 200237
- China
| | - Yi Yang
- Synthetic Biology and Biotechnology Laboratory
- State Key Laboratory of Bioreactor Engineering
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology
- East China University of Science and Technology
- Shanghai 200237
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8
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Li D, Su J, Yang J, Yu S, Zhang J, Xu K, Yu H. Optical surface plasmon resonance sensor modified by mutant glucose/galactose-binding protein for affinity detection of glucose molecules. BIOMEDICAL OPTICS EXPRESS 2017; 8:5206-5217. [PMID: 29188114 PMCID: PMC5695964 DOI: 10.1364/boe.8.005206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/18/2017] [Accepted: 10/18/2017] [Indexed: 06/07/2023]
Abstract
Transdermal extraction of interstitial fluid (ISF) offers an attractive method for minimally invasive blood glucose monitoring. However, only a minute volume of ISF could be transdermally extracted, which is required to be diluted to form a manipulable volume of fluid for easy collection, transportation, and glucose detection. Therefore, a high-resolution glucose detection method is required for detecting glucose concentration in diluted ISF. In this paper, an optical surface plasmon resonance (SPR) sensor modified by the glucose/galactose-binding (GGB) protein which has good affinity to glucose molecules was presented for specific and sensitive glucose detection. The GGB protein was mutated at different sites for thiol coupling with the SPR surface and adjusting the affinity between glucose molecules and GGB protein. And the immobilization process of the GGB protein onto the surface of SPR sensor was optimized. Then, the stability of the SPR sensor modified with GGB protein was tested immediately and two weeks after immobilization. The coefficient of variation for glucose concentration measurement was less than 4.5%. By further mutation of the GGB protein at the A213S and L238S sites, the measurement range of the SPR sensor was adjusted to 0.1-100 mg/dL, which matches the glucose concentration range of 5-10 times diluted ISF (3-100 mg/dL). These results suggest that the SPR biosensor immobilized with GGB protein has the potential for continuous glucose monitoring by integrating into the microfluidic ISF extraction chip.
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Affiliation(s)
- Dachao Li
- School of Precision Instrument and Opto-Electronics Engineering at Tianjin University, Tianjin 300072, China
| | - Jie Su
- School of Precision Instrument and Opto-Electronics Engineering at Tianjin University, Tianjin 300072, China
| | - Jia Yang
- Tianjin Institute of Metrological Supervision and Testing, Tianjin 300192, China
| | - Songlin Yu
- Tianjin Institute of Metrological Supervision and Testing, Tianjin 300192, China
| | - Jingxin Zhang
- School of Precision Instrument and Opto-Electronics Engineering at Tianjin University, Tianjin 300072, China
| | - Kexin Xu
- School of Precision Instrument and Opto-Electronics Engineering at Tianjin University, Tianjin 300072, China
| | - Haixia Yu
- School of Precision Instrument and Opto-Electronics Engineering at Tianjin University, Tianjin 300072, China
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9
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An Enhanced Platform to Analyse Low-Affinity Amyloid β Protein by Integration of Electrical Detection and Preconcentrator. Sci Rep 2017; 7:14303. [PMID: 29084978 PMCID: PMC5662786 DOI: 10.1038/s41598-017-14338-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 10/09/2017] [Indexed: 11/09/2022] Open
Abstract
Sensitivity and limit of detection (LOD) enhancement are essential criteria for the development of ultrasensitive molecular sensors. Although various sensor types have been investigated to enhance sensitivity and LOD, analyte detection and its quantification are still challenging, particularly for protein-protein interactions with low association constants. To solve this problem, here, we used ion concentration polarization (ICP)-based preconcentration to increase the local concentration of analytes in a microfluidic platform for LOD improvement. This was the first demonstration of a microfluidic device with an integrated ICP preconcentrator and interdigitated microelectrode (IME) sensor to detect small changes in surface binding between antigens and antibodies. We detected the amyloid beta (Aβ) protein, an Alzheimer's disease marker, with low binding affinity to its antibodies by adopting ICP preconcentration phenomena. We demonstrated that a combination of ICP preconcentrator and IME sensor increased the LOD by 13.8-fold to femtomolar level (8.15 fM), which corresponds to a significant advance for clinical applications.
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10
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Siska EK, Weisman I, Romano J, Ivics Z, Izsvák Z, Barkai U, Petrakis S, Koliakos G. Generation of an immortalized mesenchymal stem cell line producing a secreted biosensor protein for glucose monitoring. PLoS One 2017; 12:e0185498. [PMID: 28949988 PMCID: PMC5614622 DOI: 10.1371/journal.pone.0185498] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/13/2017] [Indexed: 01/19/2023] Open
Abstract
Diabetes is a chronic disease characterized by high levels of blood glucose. Diabetic patients should normalize these levels in order to avoid short and long term clinical complications. Presently, blood glucose monitoring is dependent on frequent finger pricking and enzyme based systems that analyze the drawn blood. Continuous blood glucose monitors are already on market but suffer from technical problems, inaccuracy and short operation time. A novel approach for continuous glucose monitoring is the development of implantable cell-based biosensors that emit light signals corresponding to glucose concentrations. Such devices use genetically modified cells expressing chimeric genes with glucose binding properties. MSCs are good candidates as carrier cells, as they can be genetically engineered and expanded into large numbers. They also possess immunomodulatory properties that, by reducing local inflammation, may assist long operation time. Here, we generated a novel immortalized human MSC line co-expressing hTERT and a secreted glucose biosensor transgene using the Sleeping Beauty transposon technology. Genetically modified hMSCs retained their mesenchymal characteristics. Stable transgene expression was validated biochemically. Increased activity of hTERT was accompanied by elevated and constant level of stem cell pluripotency markers and subsequently, by MSC immortalization. Furthermore, these cells efficiently suppressed PBMC proliferation in MLR transwell assays, indicating that they possess immunomodulatory properties. Finally, biosensor protein produced by MSCs was used to quantify glucose in cell-free assays. Our results indicate that our immortalized MSCs are suitable for measuring glucose concentrations in a physiological range. Thus, they are appropriate for incorporation into a cell-based, immune-privileged, glucose-monitoring medical device.
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Affiliation(s)
- Evangelia K. Siska
- School of Medicine, Faculty of Life Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Biohellenika SA Biotechnology Company, Thessaloniki, Greece
| | | | - Jacob Romano
- GluSense Ltd, Rabin Science Parkm, Rehovot, Israel
| | | | - Zsuzsanna Izsvák
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Uriel Barkai
- GluSense Ltd, Rabin Science Parkm, Rehovot, Israel
| | - Spyros Petrakis
- Biohellenika SA Biotechnology Company, Thessaloniki, Greece
- * E-mail:
| | - George Koliakos
- School of Medicine, Faculty of Life Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
- Biohellenika SA Biotechnology Company, Thessaloniki, Greece
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11
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Fonin AV, Golikova AD, Zvereva IA, D'Auria S, Staiano M, Uversky VN, Kuznetsova IM, Turoverov KK. Osmolyte-Like Stabilizing Effects of Low GdnHCl Concentrations on d-Glucose/d-Galactose-Binding Protein. Int J Mol Sci 2017; 18:E2008. [PMID: 28925982 PMCID: PMC5618657 DOI: 10.3390/ijms18092008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/14/2017] [Accepted: 09/16/2017] [Indexed: 11/16/2022] Open
Abstract
The ability of d-glucose/d-galactose-binding protein (GGBP) to reversibly interact with its ligands, glucose and galactose, makes this protein an attractive candidate for sensing elements of glucose biosensors. This potential is largely responsible for attracting researchers to study the conformational properties of this protein. Previously, we showed that an increase in the fluorescence intensity of the fluorescent dye 6-bromoacetyl-2-dimetylaminonaphtalene (BADAN) is linked to the holo-form of the GGBP/H152C mutant in solutions containing sub-denaturing concentrations of guanidine hydrochloride (GdnHCl). It was hypothesized that low GdnHCl concentrations might lead to compaction of the protein, thereby facilitating ligand binding. In this work, we utilize BADAN fluorescence spectroscopy, intrinsic protein UV fluorescence spectroscopy, and isothermal titration calorimetry (ITC) to show that the sub-denaturing GdnHCl concentrations possess osmolyte-like stabilizing effects on the structural dynamics, conformational stability, and functional activity of GGBP/H152C and the wild type of this protein (wtGGBP). Our data are consistent with the model where low GdnHCl concentrations promote a shift in the dynamic distribution of the protein molecules toward a conformational ensemble enriched in molecules with a tighter structure and a more closed conformation. This promotes the increase in the configurational complementarity between the protein and glucose molecules that leads to the increase in glucose affinity in both GGBP/H152C and wtGGBP.
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Affiliation(s)
- Alexander V Fonin
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
| | - Alexandra D Golikova
- Saint Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia.
| | - Irina A Zvereva
- Saint Petersburg State University, Universitetskaya nab. 7/9, 199034 St. Petersburg, Russia.
| | - Sabato D'Auria
- CNR, Institute of Food Science, via Roma 64, 83100 Avellino, Italy.
| | - Maria Staiano
- CNR, Institute of Food Science, via Roma 64, 83100 Avellino, Italy.
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, 12901 Bruce B. Downs Blvd., Tampa, FL 33612, USA.
| | - Irina M Kuznetsova
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
| | - Konstantin K Turoverov
- Institute of Cytology of the Russian Academy of Sciences, Laboratory of Structural Dynamics, Stability and Folding of Proteins, Tikhoretsky av. 4, 194064 St. Petersburg, Russia.
- Department of Biophysics, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya av. 29, 195251 St. Petersburg, Russia.
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12
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Tiangco C, Andar A, Quarterman J, Ge X, Sevilla F, Rao G, Stinchcomb A, Bunge A, Tolosa L. Measuring transdermal glucose levels in neonates by passive diffusion: an in vitro porcine skin model. Anal Bioanal Chem 2017; 409:3475-3482. [PMID: 28283718 DOI: 10.1007/s00216-017-0289-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/01/2017] [Accepted: 02/28/2017] [Indexed: 11/30/2022]
Abstract
Current glucose monitoring techniques for neonates rely heavily on blood glucose monitors which require intermittent blood collection through skin-penetrating pricks on the heel or fingers. This procedure is painful and often not clinically conducive, which presents a need for a noninvasive method for monitoring glucose in neonates. Our motivation for this study was to develop an in vitro method for measuring passive diffusion of glucose in premature neonatal skin using a porcine skin model. Such a model will allow us to initially test new devices for noninvasive glucose monitoring without having to do in vivo testing of newborns. The in vitro model is demonstrated by comparing uncompromised and tape-stripped skin in an in-line flow-through diffusion apparatus with glucose concentrations that mimic the hypo-, normo-, and hyper-glycemic conditions in the neonate (2.0, 5.0, and 20 mM, respectively). Transepidermal water loss (TEWL) of the tape-stripped skin was approximately 20 g m-2 h-1, which closely mimics TEWL for neonatal skin at about 190 days post-conceptional age. The tape-stripped skin showed a >15-fold increase in glucose diffusion compared to the uncompromised skin. The very small concentrations of collected glucose were measured with a highly selective and highly sensitive fluorescent glucose biosensor based on the glucose binding protein (GBP). The demonstrated method of glucose determination is noninvasive and painless, which makes it especially desirable for glucose testing in neonates and children. This study is an important step towards an in vitro model for noninvasive real-time glucose monitoring that may be easily transferred to the clinic for glucose monitoring in neonates. Graphical Abstract Glucose diffusion through model skin was measured using an in-line flow-through diffusion apparatus with glucose solutions mimicking hypo-, normo- and hyperglycemia in the neonate. Phosphate buffered saline was added to the top chamber and the glucose that diffused through the model skin into the buffer was measured using a fluorescent glucose binding protein biosensor.
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Affiliation(s)
- Cristina Tiangco
- Center for Advanced Sensor Technologycsm, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, USA.,The Graduate School, University of Santo Tomas, España Boulevard, 1015, Manila, Philippines
| | - Abhay Andar
- Center for Advanced Sensor Technologycsm, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, USA.,Department of Pharmaceutical Sciences, University of Maryland, 20 North Pine Street, Baltimore, MD, 21201, USA
| | - Juliana Quarterman
- Department of Pharmaceutical Sciences, University of Maryland, 20 North Pine Street, Baltimore, MD, 21201, USA
| | - Xudong Ge
- Center for Advanced Sensor Technologycsm, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, USA
| | - Fortunato Sevilla
- The Graduate School, University of Santo Tomas, España Boulevard, 1015, Manila, Philippines
| | - Govind Rao
- Center for Advanced Sensor Technologycsm, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, USA
| | - Audra Stinchcomb
- Department of Pharmaceutical Sciences, University of Maryland, 20 North Pine Street, Baltimore, MD, 21201, USA
| | - Annette Bunge
- Chemical and Biological Engineering Department, Colorado School of Mines, 1500 Illinois Street, Golden, CO, 80401, USA
| | - Leah Tolosa
- Center for Advanced Sensor Technologycsm, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD, 21250, USA.
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13
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The role of water molecules in stereoselectivity of glucose/galactose-binding protein. Sci Rep 2016; 6:36807. [PMID: 27827455 PMCID: PMC5101532 DOI: 10.1038/srep36807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 10/21/2016] [Indexed: 11/22/2022] Open
Abstract
Using molecular dynamics (MD) simulation methods, we attempted to explain the experimental results on ligand specificity of glucose/galactose-binding protein (GGBP) to β-D-glucose and β-D-galactose. For the simulation, a three-dimensional structure of GGBP was prepared, and homology modeling was performed to generate variant structures of GGBP with mutations at Asp14. Then, docking was carried out to find a reasonable β-D-glucose and β-D-galactose binding conformations with GGBP. Subsequent molecular dynamics simulations of β-D-glucose–GGBP and β-D-galactose–GGBP complexes and estimation of the orientation and stability of water molecules at the binding site revealed how water molecules influence ligand specificity. In our simulation, water molecules mediated interactions of β-D-glucose or β-D-galactose with residue 14 of GGBP. In this mechanism, the Phe16Ala mutant leaves both sugar molecules free to move, and the specific role of water molecules were eliminated, while the wild type, Asp14Asn mutant, and Asp14Glu mutant make hydrogen bond interactions with β-D-glucose more favorable. Our results demonstrate that bound water molecules at the binding site of GGBP are related to localized conformational change, contributing to ligand specificity of GGBP for β-D-glucose over β-D-galactose.
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14
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Stepanenko OV, Fonin AV, Stepanenko OV, Staiano M, D'Auria S, Kuznetsova IM, Turoverov KK. Tryptophan residue of the D-galactose/D-glucose-binding protein from E. Coli localized in its active center does not contribute to the change in intrinsic fluorescence upon glucose binding. J Fluoresc 2014; 25:87-94. [PMID: 25501855 DOI: 10.1007/s10895-014-1483-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 11/25/2014] [Indexed: 11/24/2022]
Abstract
Changes of the characteristics of intrinsic tryptophan fluorescence of the wild type of D-galactose/D-glucose-binding protein from Escherichia coli (GGBPwt) induced by D-glucose binding were examined by the intrinsic UV-fluorescence of proteins, circular dyhroism in the near-UV region, and acrylamide-induced fluorescence quenching. The analysis of the different characteristics of GGBPwt and its mutant form GGBP-W183A together with the analysis of the microenvironment of tryptophan residues of GGBPwt revealed that Trp 183, which is directly involved in sugar binding, has the least influence on the provoked by D-glucose blue shift and increase in the intensity of protein intrinsic fluorescence in comparison with other tryptophan residues of GGBP.
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Affiliation(s)
- Olga V Stepanenko
- Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky ave., 4, 194064, St. Petersburg, Russia
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15
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Joel S, Turner KB, Daunert S. Glucose recognition proteins for glucose sensing at physiological concentrations and temperatures. ACS Chem Biol 2014; 9:1595-602. [PMID: 24841549 PMCID: PMC4215909 DOI: 10.1021/cb500132g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 05/19/2014] [Indexed: 11/30/2022]
Abstract
Advancements in biotechnology have allowed for the preparation of designer proteins with a wide spectrum of unprecedented chemical and physical properties. A variety of chemical and genetic methods can be employed to tailor the protein's properties, including its stability and various functions. Herein, we demonstrate the production of semisynthetic glucose recognition proteins (GRPs) prepared by truncating galactose/glucose binding protein (GBP) of E. coli and expanding the genetic code via global incorporation of unnatural amino acids into the structure of GBP and its fragments. The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins. The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability. These modifications enabled the utilization of the protein for the detection of glucose within physiological concentrations (mM) and temperatures ranging from hypothermia to hyperthermia. This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring.
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Affiliation(s)
- Smita Joel
- Department
of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, 1011 NW 15th Street, Miami, Florida 33136, United
States
| | - Kendrick B. Turner
- Department
of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, 1011 NW 15th Street, Miami, Florida 33136, United
States
| | - Sylvia Daunert
- Department
of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, 1011 NW 15th Street, Miami, Florida 33136, United
States
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16
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Fonin AV, Stepanenko OV, Povarova OI, Volova CA, Philippova EM, Bublikov GS, Kuznetsova IM, Demchenko AP, Turoverov KK. Spectral characteristics of the mutant form GGBP/H152C of D-glucose/D-galactose-binding protein labeled with fluorescent dye BADAN: influence of external factors. PeerJ 2014; 2:e275. [PMID: 24711960 PMCID: PMC3970809 DOI: 10.7717/peerj.275] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/26/2014] [Indexed: 11/22/2022] Open
Abstract
The mutant form GGBP/H152C of the D-glucose/D-galactose-binding protein with the solvatochromic dye BADAN linked to cysteine residue Cys 152 can be used as a potential base for a sensitive element of glucose biosensor system. We investigated the influence of various external factors on the physical-chemical properties of GGBP/H152C-BADAN and its complex with glucose. The high affinity (Kd = 8.5 µM) and high binding rate of glucose make GGBP/H152C-BADAN a good candidate to determine the sugar content in biological fluids extracted using transdermal techniques. It was shown that changes in the ionic strength and pH of solution within the physiological range did not have a significant influence on the fluorescent characteristics of GGBP/H152C-BADAN. The mutant form GGBP/H152C has relatively low resistance to denaturation action of GdnHCl and urea. This result emphasizes the need to find more stable proteins for the creation of a sensitive element for a glucose biosensor system.
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Affiliation(s)
- Alexander V Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia
| | - Olga V Stepanenko
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia
| | - Olga I Povarova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia
| | - Catherine A Volova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia ; Department of Biology, St. Petersburg State University , St. Petersburg , Russia
| | - Elizaveta M Philippova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia ; Department of Physical Electronics, St. Petersburg State Polytechnical University , St. Petersburg , Russia
| | - Grigory S Bublikov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia ; Department of Biophysics, St. Petersburg State Polytechnical University , St. Petersburg , Russia
| | - Alexander P Demchenko
- Laboratory of Nanobiotechnologies, Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine , Kiev , Ukraine
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Science , St. Petersburg , Russia ; Department of Biophysics, St. Petersburg State Polytechnical University , St. Petersburg , Russia
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17
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Paek SH, Park JN, Kim DH, Kim HS, Ha UH, Seo SK, Paek SH. Semi-continuous, label-free immunosensing approach for Ca2+-based conformation change of a calcium-binding protein. Analyst 2014; 139:3781-9. [DOI: 10.1039/c4an00343h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Label-free immunosensing based on the conformational change of CBP depending on analyte concentration was explored for semi-continuous analysis of Ca2+.
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Affiliation(s)
- Sung-Ho Paek
- Department of Bio-Microsystem Technology
- Korea University
- Seoul 136-701, Korea
| | - Ji-Na Park
- Department of Bio-Microsystem Technology
- Korea University
- Seoul 136-701, Korea
| | - Dong-Hyung Kim
- Department of Bio-Microsystem Technology
- Korea University
- Seoul 136-701, Korea
| | - Hee-Soo Kim
- Department of Bio-Microsystem Technology
- Korea University
- Seoul 136-701, Korea
| | - Un-Hwan Ha
- Department of Biotechnology and Bioinformatics
- Korea University
- Sejong 339-700, Korea
| | - Sung-Kyu Seo
- Department of Electronics & Information Engineering
- Korea University
- Sejong 339-700, Korea
| | - Se-Hwan Paek
- Department of Bio-Microsystem Technology
- Korea University
- Seoul 136-701, Korea
- Department of Biotechnology and Bioinformatics
- Korea University
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18
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Gifford R. Continuous glucose monitoring: 40 years, what we've learned and what's next. Chemphyschem 2013; 14:2032-44. [PMID: 23649735 DOI: 10.1002/cphc.201300172] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Indexed: 01/05/2023]
Abstract
After 40 years of research and development, today continuous glucose monitoring (CGM) is demonstrating the benefit it provides for millions with diabetes. To provide in vivo accuracy, new permselective membranes and mediated systems have been developed to prevent enzyme saturation and to minimize interference signals. Early in vivo implanted sensor research clearly showed that the foreign body response was a more difficult issue to overcome. Understanding the biological interface and circumventing the inflammatory response continue to drive development of a CGM sensor with accuracy and reliability performance suitable in a closed-loop artificial pancreas. Along with biocompatible polymer development, other complimentary algorithm and data analysis techniques have improved the performance of commercial systems significantly. For example, the mean average relative difference of Dexcom's CGM system improved from 26 to 14% and its use-life was extended from 3 to 7 d. Significant gains in usability, including size, flexibility, insertion, calibration, and data interface, have been incorporated into new generations of commercial CGM systems. Besides Medtronic, Dexcom, and Abbott, other major players are also investing in CGM. Becton Dickinson is conducting clinical trials with an optical galactose glucose binding system. Development of fully implanted sensor systems fulfills the desire for a discreet, reliable CGM system. Research continues to find innovative ways to help make living with diabetes easier and more normal, and new segments are being pursued (intensive care unit, surgery, behavior modification) in which CGM is being utilized.
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Affiliation(s)
- Raeann Gifford
- Life Science, Acreo Swedish ICT AB, Box 787 SE-601 17 Norrköping, Sweden.
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19
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Ausili A, Staiano M, Dattelbaum J, Varriale A, Capo A, D'Auria S. Periplasmic Binding Proteins in Thermophiles: Characterization and Potential Application of an Arginine-Binding Protein from Thermotoga maritima: A Brief Thermo-Story. Life (Basel) 2013; 3:149-60. [PMID: 25371336 PMCID: PMC4187188 DOI: 10.3390/life3010149] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/11/2013] [Accepted: 01/29/2013] [Indexed: 01/26/2023] Open
Abstract
Arginine-binding protein from the extremophile Thermotoga maritima is a 27.7 kDa protein possessing the typical two-domain structure of the periplasmic binding proteins family. The protein is characterized by a very high specificity and affinity to bind to arginine, also at high temperatures. Due to its features, this protein could be taken into account as a potential candidate for the design of a biosensor for arginine. It is important to investigate the stability of proteins when they are used for biotechnological applications. In this article, we review the structural and functional features of an arginine-binding protein from the extremophile Thermotoga maritima with a particular eye on its potential biotechnological applications.
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Affiliation(s)
- Alessio Ausili
- Laboratory for Molecular Sensing, Institute of Protein Biochemistry, CNR, Via Pietro Castellino, 111, Napoli, 80131, Italy.
| | - Maria Staiano
- Laboratory for Molecular Sensing, Institute of Protein Biochemistry, CNR, Via Pietro Castellino, 111, Napoli, 80131, Italy.
| | | | - Antonio Varriale
- Laboratory for Molecular Sensing, Institute of Protein Biochemistry, CNR, Via Pietro Castellino, 111, Napoli, 80131, Italy.
| | - Alessandro Capo
- Laboratory for Molecular Sensing, Institute of Protein Biochemistry, CNR, Via Pietro Castellino, 111, Napoli, 80131, Italy.
| | - Sabato D'Auria
- Laboratory for Molecular Sensing, Institute of Protein Biochemistry, CNR, Via Pietro Castellino, 111, Napoli, 80131, Italy.
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20
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Huang X, Leduc C, Ravussin Y, Li S, Davis E, Song B, Wang Q, Accili D, Leibel R, Lin Q. Continuous monitoring of glucose in subcutaneous tissue using microfabricated differential affinity sensors. J Diabetes Sci Technol 2012; 6:1436-44. [PMID: 23294791 PMCID: PMC3570886 DOI: 10.1177/193229681200600625] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE We describe miniaturized differential glucose sensors based on affinity binding between glucose and a synthetic polymer. The sensors possess excellent resistance to environmental disturbances and can potentially allow wireless measurements of glucose concentrations within interstitial fluid in subcutaneous tissue for long-term, stable continuous glucose monitoring (CGM). METHODS The sensors are constructed using microelectromechanical systems (MEMS) technology and exploit poly(N-hydroxy-ethyl acrylamide-ran-3-acrylamidophenylboronic acid) (PHEAA-ran-PAAPBA), a glucose-binding polymer with excellent specificity, reversibility, and stability. Two sensing approaches have been investigated, which respectively, use a pair of magnetically actuated diaphragms and perforated electrodes to differentially measure the glucose-binding-induced changes in the viscosity and permittivity of the PHEAA-ran-PAAPBA solution with respect to a reference, glucose-unresponsive polymer solution. RESULTS In vivo characterization of the MEMS affinity sensors were performed by controlling blood glucose concentrations of laboratory mice by exogenous glucose and insulin administration. The sensors experienced an 8-30 min initialization period after implantation and then closely tracked commercial capillary glucose meter readings with time lags ranging from 0-15 min during rapid glucose concentration changes. Clarke error grid plots obtained from sensor calibration suggest that, for the viscometric and dielectric sensors, respectively, approximately 95% (in the hyperglycemic range) and 84% (ranging from hypoglycemic to hyperglycemic glucose concentrations) of measurement points were clinically accurate, while 5% and 16% of the points were clinically acceptable. CONCLUSIONS The miniaturized MEMS sensors explore differential measurements of affinity glucose recognition. In vivo testing demonstrated excellent accuracy and stability, suggesting that the devices hold the potential to enable long-term and reliable CGM in clinical applications.
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Affiliation(s)
- Xian Huang
- Department of Mechanical Engineering, Columbia University, New York, NY 10027, USA.
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21
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Ferrero VEV, Di Nardo G, Catucci G, Sadeghi SJ, Gilardi G. Fluorescence detection of ligand binding to labeled cytochrome P450BM3. Dalton Trans 2012; 41:2018-25. [DOI: 10.1039/c1dt11437a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Stepanenko OV, Fonin AV, Stepanenko OV, Morozova KS, Verkhusha VV, Kuznetsova IM, Turoverov KK, Staiano M, D’Auria S. New Insight in Protein–Ligand Interactions. 2. Stability and Properties of Two Mutant Forms of the d-Galactose/d-Glucose-Binding Protein from E. coli. J Phys Chem B 2011; 115:9022-32. [DOI: 10.1021/jp204555h] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Olga V. Stepanenko
- Laboratory of Protein structure, stability and folding of proteins, Institute of Cytology RAS, 194064 St. Petersburg, Russia
| | - Alexander V. Fonin
- Laboratory of Protein structure, stability and folding of proteins, Institute of Cytology RAS, 194064 St. Petersburg, Russia
| | - Olesya V. Stepanenko
- Laboratory of Protein structure, stability and folding of proteins, Institute of Cytology RAS, 194064 St. Petersburg, Russia
| | - Kateryna S. Morozova
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Vladislav V. Verkhusha
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Irina M. Kuznetsova
- Laboratory of Protein structure, stability and folding of proteins, Institute of Cytology RAS, 194064 St. Petersburg, Russia
| | - Konstantin K. Turoverov
- Laboratory of Protein structure, stability and folding of proteins, Institute of Cytology RAS, 194064 St. Petersburg, Russia
| | - Maria Staiano
- Laboratory for Molecular Sensing, IBP-CNR, 111 80131 Naples, Italy
| | - Sabato D’Auria
- Laboratory for Molecular Sensing, IBP-CNR, 111 80131 Naples, Italy
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23
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Cashman DJ, Mamonov AB, Bhatt D, Zuckerman DM. Thermal motions of the E. coli glucose-galactose binding protein studied using well-sampled, semi-atomistic simulations. Curr Top Med Chem 2011; 11:211-20. [PMID: 20939787 DOI: 10.2174/156802611794863607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 04/14/2010] [Indexed: 11/22/2022]
Abstract
The E. coli glucose-galactose chemosensory receptor is a 309 residue, 32 kDa protein consisting of two distinct structural domains. We used two computational methods to examine the protein's thermal fluctuations, including both the large-scale interdomain movements that contribute to the receptor's mechanism of action, as well as smaller-scale motions. We primarily employ extremely fast, "semi-atomistic" Library-Based Monte Carlo (LBMC) simulations, which include all backbone atoms but "implicit" side chains. Our results were compared with previous experiments and all-atom molecular dynamics (MD) simulation. Both LBMC and MD simulations were performed using both the apo and glucose-bound form of the protein, with LBMC exhibiting significantly larger fluctuations. The LBMC simulations are in general agreement with the disulfide trapping experiments of Careaga & Falke (J. Mol. Biol., 1992, Vol. 226, 1219-35), which indicate that distant residues in the crystal structure (i.e. beta carbons separated by 10 to 20 angstroms) form spontaneous transient contacts in solution. Our simulations illustrate several possible "mechanisms" (configurational pathways) for these fluctuations. We also observe several discrepancies between our calculations and experimental rate constants. Nevertheless, we believe that our semi-atomistic approach could be used to study fluctuations in other proteins, perhaps for ensemble docking or other analyses of protein flexibility in virtual screening studies.
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Affiliation(s)
- D J Cashman
- Department of Computational and Systems Biology, School of Medicine, University of Pittsburgh, PA, USA
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24
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Weidemaier K, Lastovich A, Keith S, Pitner JB, Sistare M, Jacobson R, Kurisko D. Multi-day pre-clinical demonstration of glucose/galactose binding protein-based fiber optic sensor. Biosens Bioelectron 2011; 26:4117-23. [PMID: 21549586 DOI: 10.1016/j.bios.2011.04.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 04/04/2011] [Accepted: 04/05/2011] [Indexed: 11/27/2022]
Abstract
We report here the first pre-clinical demonstration of continuous glucose tracking by fluorophore-labeled and genetically engineered glucose/galactose binding protein (GGBP). Acrylodan-labeled GGBP was immobilized in a hydrogel matrix at the tip of a small diameter optical fiber contained in a stainless steel needle. The fiber optic biosensors were inserted subcutaneously into Yucatan and Yorkshire swine, and the sensor response to changing glucose levels was monitored at intervals over a 7-day period. Sensor mean percent error on day 7 was 16.4±5.0% using a single daily reference blood glucose value to calibrate the sensor. The GGBP sensor's susceptibility to common interferents was tested in a well-plate system using human sera. No significant interference was observed from the tested interferents except for tetracycline at the drug's maximum plasma concentration. The robust performance of the GGBP-based fiber optic sensor in swine models and resistance to interferents indicates the potential of this technology for continuous glucose monitoring in humans.
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25
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Jeffery CJ. Engineering periplasmic ligand binding proteins as glucose nanosensors. NANO REVIEWS 2011; 2:NANO-2-5743. [PMID: 22110874 PMCID: PMC3215197 DOI: 10.3402/nano.v2i0.5743] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 12/02/2010] [Accepted: 12/02/2010] [Indexed: 12/21/2022]
Abstract
Diabetes affects over 100 million people worldwide. Better methods for monitoring blood glucose levels are needed for improving disease management. Several labs have previously made glucose nanosensors by modifying members of the periplasmic ligand binding protein superfamily. This minireview summarizes recent developments in constructing new versions of these proteins that are responsive within the physiological range of blood glucose levels, employ new reporter groups, and/or are more robust. These experiments are important steps in the development of novel proteins that have the characteristics needed for an implantable glucose nanosensor for diabetes management: specificity for glucose, rapid response, sensitivity within the physiological range of glucose concentrations, reproducibility, and robustness.
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Affiliation(s)
- Constance J Jeffery
- Department of Biological Sciences, Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
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26
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Yoon H, Ahn JH, Barone PW, Yum K, Sharma R, Boghossian AA, Han JH, Strano MS. Periplasmic Binding Proteins as Optical Modulators of Single-Walled Carbon Nanotube Fluorescence: Amplifying a Nanoscale Actuator. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006167] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Yoon H, Ahn JH, Barone PW, Yum K, Sharma R, Boghossian AA, Han JH, Strano MS. Periplasmic Binding Proteins as Optical Modulators of Single-Walled Carbon Nanotube Fluorescence: Amplifying a Nanoscale Actuator. Angew Chem Int Ed Engl 2011; 50:1828-31. [DOI: 10.1002/anie.201006167] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 12/13/2010] [Indexed: 02/05/2023]
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28
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Development of a galactose biosensor with galactose oxidase-immobilized epidermis of Solanum lycopersicum: Potential point-of-care testing for citrin deficiency in high-prevalence areas. Clin Chim Acta 2011; 412:391-2. [DOI: 10.1016/j.cca.2010.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 10/08/2010] [Accepted: 10/08/2010] [Indexed: 11/22/2022]
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29
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Loving GS, Sainlos M, Imperiali B. Monitoring protein interactions and dynamics with solvatochromic fluorophores. Trends Biotechnol 2010; 28:73-83. [PMID: 19962774 PMCID: PMC2818466 DOI: 10.1016/j.tibtech.2009.11.002] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 11/03/2009] [Accepted: 11/05/2009] [Indexed: 10/20/2022]
Abstract
Solvatochromic fluorophores possess emission properties that are sensitive to the nature of the local microenvironment. These dyes have been exploited in applications ranging from the study of protein structural dynamics to the detection of protein-binding interactions. Although the solvatochromic indole fluorophore of tryptophan has been utilized extensively for in vitro studies to advance our understanding of basic protein biochemistry, the emergence of new extrinsic synthetic dyes with improved properties, in conjunction with recent developments in site-selective methods to incorporate these chemical tools into proteins, now open the way for studies in more complex systems. Herein, we discuss recent technological advancements and their application in the design of powerful reporters, which serve critical roles in modern cell biology and assay development.
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Affiliation(s)
- Galen S Loving
- Department of Chemistry and Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, USA
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30
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Tolosa L. On the design of low-cost fluorescent protein biosensors. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2009; 116:143-57. [PMID: 19347267 DOI: 10.1007/10_2008_39] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
Abstract
There is a large body of knowledge on proteins and their ligands that is available to the sensor researcher for the successful design of fluorescent biosensors. Chemically synthesized receptors rarely match the sensitivity and selectivity of proteins.Additionally, proteins are easily produced and manipulated through recombinant protein techniques. Although limitations exist in the prediction of signal response of proteins labeled with fluorescent probes, thoughtful experimentation can lead to useful, highly responsive fluorescent protein assays. Conversion of these assays into sensor devices may require additional manipulation of the fluorescence properties of the labeled proteins. We have shown that this can be achieved by a second fluorophore serving as a reference for ratiometric measurements. The choice of reference is contingent on the low-cost, miniaturized design of the device. Accordingly, the reference fluorophore is excitable with the same LED as the signal transducing probe and has a fluorescence decay lifetime that is orders of magnitude longer.Alternating illumination with intensity modulated light at two frequencies allows for ratiometric sensing without the need for bulky filter wheels while collecting the signals over a wide range of emission wavelengths. The result is a simple optoelectronics design that is cost-effective and small enough to be portable.In summary, the process of designing protein-based fluorescent biosensors for practical applications requires the systematic collaboration of a cross-disciplinary group of molecular biologists, chemists and engineers.
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Affiliation(s)
- Leah Tolosa
- Center for Advanced Sensor Technology, University of Maryland Baltimore County, Baltimore, MD21050, USA
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Thomas GE, Bone S, Drago G. Determination of Protein Denaturation and Glass Transition Temperatures Using High-Frequency Time Domain Reflectometry. J Phys Chem B 2008; 112:15903-6. [DOI: 10.1021/jp806775w] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gareth E. Thomas
- Institute for Bioelectronic and Molecular Microsystems, Bangor University, Dean Street, Bangor LL571UT, Gwynedd, U. K., and Applied Enzyme Technology, Monmouth House, Mamhilad Park, Pontypool, NP4 0HZ, U.K
| | - Stephen Bone
- Institute for Bioelectronic and Molecular Microsystems, Bangor University, Dean Street, Bangor LL571UT, Gwynedd, U. K., and Applied Enzyme Technology, Monmouth House, Mamhilad Park, Pontypool, NP4 0HZ, U.K
| | - Guido Drago
- Institute for Bioelectronic and Molecular Microsystems, Bangor University, Dean Street, Bangor LL571UT, Gwynedd, U. K., and Applied Enzyme Technology, Monmouth House, Mamhilad Park, Pontypool, NP4 0HZ, U.K
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Schneider S, Sandalova T, Schneider G, Sprenger GA, Samland AK. Replacement of a phenylalanine by a tyrosine in the active site confers fructose-6-phosphate aldolase activity to the transaldolase of Escherichia coli and human origin. J Biol Chem 2008; 283:30064-72. [PMID: 18687684 PMCID: PMC2662071 DOI: 10.1074/jbc.m803184200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Revised: 06/18/2008] [Indexed: 01/04/2023] Open
Abstract
Based on a structure-assisted sequence alignment we designed 11 focused libraries at residues in the active site of transaldolase B from Escherichia coli and screened them for their ability to synthesize fructose 6-phosphate from dihydroxyacetone and glyceraldehyde 3-phosphate using a newly developed color assay. We found one positive variant exhibiting a replacement of Phe(178) to Tyr. This mutant variant is able not only to transfer a dihydroxyacetone moiety from a ketose donor, fructose 6-phosphate, onto an aldehyde acceptor, erythrose 4-phosphate (14 units/mg), but to use it as a substrate directly in an aldolase reaction (7 units/mg). With a single amino acid replacement the fructose-6-phosphate aldolase activity was increased considerably (>70-fold compared with wild-type). Structural studies of the wild-type and mutant protein suggest that this is due to a different H-bond pattern in the active site leading to a destabilization of the Schiff base intermediate. Furthermore, we show that a homologous replacement has a similar effect in the human transaldolase Taldo1 (aldolase activity, 14 units/mg). We also demonstrate that both enzymes TalB and Taldo1 are recognized by the same polyclonal antibody.
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Affiliation(s)
- Sarah Schneider
- Institute of Microbiology, Universität Stuttgart, 70550 Stuttgart, Germany
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