36 results on '"Martine Monette"'
Search Results
2. Overcoming challenges in 67Zn NMR: a new strategy of signal enhancement for MOF characterization
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Wanli Zhang, Alia Hassan, Jochem Struppe, Martine Monette, Ivan Hung, Zhehong Gan, Vinicius Martins, Victor Terskikh, and Yining Huang
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Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Combining a cryogenic MAS probe and high magnetic field results in remarkable signal enhancement, permitting MOF characterization by 67Zn 3QMAS NMR at natural abundance.
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- 2023
3. Solid-state 17O NMR study of α-<scp>d</scp>-glucose: exploring new frontiers in isotopic labeling, sensitivity enhancement, and NMR crystallography
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Jiahui Shen, Victor Terskikh, Jochem Struppe, Alia Hassan, Martine Monette, Ivan Hung, Zhehong Gan, Andreas Brinkmann, and Gang Wu
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General Chemistry - Abstract
We report the first “total synthesis” of 17O-labeled d-glucose and its solid-state 17O NMR characterization with unprecedented sensitivity and resolution.
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- 2022
4. Racing toward Fast and Effective 17O Isotopic Labeling and Nuclear Magnetic Resonance Spectroscopy of N-Formyl-MLF-OH and Associated Building Blocks
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Jochem Struppe, Job Boekhoven, Serge Nader, Martine Monette, Shane Pawsey, Vladimir K. Michaelis, Michelle Ha, and Sheref S. Mansy
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chemistry.chemical_classification ,Materials science ,010405 organic chemistry ,Hydrogen bond ,Biomolecule ,Nuclear magnetic resonance spectroscopy ,Tripeptide ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Surfaces, Coatings and Films ,Isotopic labeling ,Protein structure ,chemistry ,Materials Chemistry ,Molecule ,Physical and Theoretical Chemistry ,Spectroscopy - Abstract
Solid-state 1H, 13C, and 15N nuclear magnetic resonance (NMR) spectroscopy has been an essential analytical method in studying complex molecules and biomolecules for decades. While oxygen-17 (17O) NMR is an ideal and robust candidate to study hydrogen bonding within secondary and tertiary protein structures for example, it continues to elude many. We discuss an improved multiple-turnover labeling procedure to develop a fast and cost-effective method to 17O label fluoroenylmethyloxycarbonyl (Fmoc)-protected amino acid building blocks. This approach allows for inexpensive ($0.25 USD/mg) insertion of 17O labels, an important barrier to overcome for future biomolecular studies. The 17O NMR results of these building blocks and a site-specific strategy for labeled N-acetyl-MLF-OH and N-formyl-MLF-OH tripeptides are presented. We showcase growth in NMR development for maximizing sensitivity gains using emerging sensitivity enhancement techniques including population transfer, high-field dynamic nuclear polarization, and cross-polarization magic-angle spinning cryoprobes.
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- 2021
5. Expanding current applications and permitting the analysis of larger intact samples by means of a 7 mm CMP–NMR probe
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Thomas Frei, Henry J. Stronks, Michael Fey, Monica Bastawrous, Martine Monette, Wolfgang Bermel, Rajshree Ghosh Biswas, Myrna J. Simpson, Ivan Kovacevic, Stephan Graf, Sebastian Wegner, Peter De Castro, Jochem Struppe, Rainer Kuemmerle, Paris Ning, Daniel Schmidig, Amy Jenne, André J. Simpson, Daniel Lane, Falko Busse, Till Kuehn, and Ronald Soong
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Magnetic Resonance Spectroscopy ,Materials science ,Sample (material) ,Analytical chemistry ,010501 environmental sciences ,010402 general chemistry ,Magnetic Resonance Imaging ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,Volume (thermodynamics) ,Solubilization ,Cytidine Monophosphate ,Electrochemistry ,Environmental Chemistry ,Sample preparation ,Biomass ,POMEGRANATE SEED ,Spectroscopy ,0105 earth and related environmental sciences - Abstract
Comprehensive multiphase NMR combines the ability to study and differentiate all phases (solids, gels, and liquids) using a single NMR probe. The general goal of CMP-NMR is to study intact environmental and biological samples to better understand conformation, organization, association, and transfer between and across phases/interfaces that may be lost with conventional sample preparation such as drying or solubilization. To date, all CMP-NMR studies have used 4 mm probes and rotors. Here, a larger 7 mm probehead is introduced which provides ∼3 times the volume and ∼2.4 times the signal over a 4 mm version. This offers two main advantages: (1) the additional biomass reduces experiment time, making 13C detection at natural abundance more feasible; (2) it allows the analysis of larger samples that cannot fit within a 4 mm rotor. Chicken heart tissue and Hyalella azteca (freshwater shrimp) are used to demonstrate that phase-based spectral editing works with 7 mm rotors and that the additional biomass from the larger volumes allows detection with 13C at natural abundance. Additionally, a whole pomegranate seed berry (aril) and an intact softgel capsule of hydroxyzine hydrochloride are used to demonstrate the analysis of samples too large to fit inside a conventional 4 mm CMP probe. The 7 mm version introduced here extends the range of applications and sample types that can be studied and is recommended when 4 mm CMP probes cannot provide adequate signal-to-noise (S/N), or intact samples are simply too big for 4 mm rotors.
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- 2021
6. Comprehensive Multiphase NMR—A Powerful Tool to Understand and Monitor Molecular Processes during Biofuel Production
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Stephan Graf, Myrna J. Simpson, Peter De Castro, Thomas Frei, Henry J. Stronks, Ivan Kovacevic, Martine Monette, Falko Busse, Michael Fey, André J. Simpson, Daniel Schmidig, Jochem Struppe, Paris Ning, Daniel Lane, Ronald Soong, and Sebastian Wegner
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biology ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,biology.organism_classification ,7. Clean energy ,01 natural sciences ,0104 chemical sciences ,Sustainable energy ,Algae fuel ,Algae ,Biofuel ,Environmental Chemistry ,Production (economics) ,Environmental science ,Biochemical engineering ,0210 nano-technology - Abstract
Considered as a promising source of sustainable energy, biofuel produced from algae holds many advantages. However, to truly understand the production process and assess the potential for further o...
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- 2020
7. Solid-state
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Jiahui, Shen, Victor, Terskikh, Jochem, Struppe, Alia, Hassan, Martine, Monette, Ivan, Hung, Zhehong, Gan, Andreas, Brinkmann, and Gang, Wu
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We report synthesis and solid-state
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- 2021
8. Racing toward Fast and Effective
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Michelle, Ha, Serge, Nader, Shane, Pawsey, Jochem, Struppe, Martine, Monette, Sheref S, Mansy, Job, Boekhoven, and Vladimir K, Michaelis
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Magnetic Resonance Spectroscopy ,Isotope Labeling ,Proteins ,Amino Acids ,Nuclear Magnetic Resonance, Biomolecular - Abstract
Solid-state
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- 2021
9. Comprehensive Multiphase NMR Probehead with Reduced Radiofrequency Heating Improves the Analysis of Living Organisms and Heat-Sensitive Samples
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Till Kuehn, Ronald Soong, Michael Fey, Paris Ning, Ivan Kovacevic, Sebastian Wegner, Falko Busse, Rajshree Ghosh Biswas, Myrna J. Simpson, Daniel Schmidig, Martine Monette, André J. Simpson, Jochem Struppe, Thomas Frei, Henry J. Stronks, Stephan Graf, Peter De Castro, and Daniel Lane
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Hot Temperature ,Magnetic Resonance Spectroscopy ,Chemistry ,Radio Waves ,Sample (material) ,Analytical chemistry ,Ionic bonding ,Solenoid ,010501 environmental sciences ,010402 general chemistry ,01 natural sciences ,Magnetic Resonance Imaging ,6. Clean water ,0104 chemical sciences ,Analytical Chemistry ,Heating ,Chemical species ,Soil water ,Dielectric heating ,Radiofrequency heating ,Decoupling (electronics) ,0105 earth and related environmental sciences - Abstract
Comprehensive multiphase (CMP) NMR, first described in 2012, combines all of the hardware components necessary to analyze all phases (solid, gel, and solution) in samples in their natural state. In combination with spectral editing experiments, it can fully differentiate phases and study the transfer of chemical species across and between phases, providing unprecedented molecular-level information in unaltered natural systems. However, many natural samples, such as swollen soils, plants, and small organisms, contain water, salts, and ionic compounds, making them electrically lossy and susceptible to RF heating, especially when using high-strength RF fields required to select the solid domains. While dedicated reduced-heating probes have been developed for solid-state NMR, to date, all CMP-NMR probes have been based on solenoid designs, which can lead to problematic sample heating. Here, a new prototype CMP probe was developed, incorporating a loop gap resonator (LGR) for decoupling. Temperature increases are monitored in salt solutions analogous to those in small aquatic organisms and then tested in vivo on Hyalella azteca (freshwater shrimp). In the standard CMP probe (solenoid), 80% of organisms died within 4 h under high-power decoupling, while in the LGR design, all organisms survived the entire test period of 12 h. The LGR design reduced heating by a factor of ∼3, which allowed 100 kHz decoupling to be applied to salty samples with generally ≤10 °C sample heating. In addition to expanding the potential for in vivo research, the ability to apply uncompromised high-power decoupling could be beneficial for multiphase samples containing true crystalline solids that require the strongest possible decoupling fields for optimal detection.
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- 2021
10. Assessing the potential of quantitative 2D HSQC NMR in 13C enriched living organisms
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Hermann Heumann, Thomas E. Skinner, Wolfgang Bermel, Naum I. Gershenzon, André J. Simpson, Rudraksha Dutta Majumdar, Myrna J. Simpson, Yalda Liaghati Mobarhan, Ronald Soong, Martine Monette, Daniel Lane, and Sebastian Schmidt
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010405 organic chemistry ,Chemistry ,Metabolite ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Water flea ,chemistry.chemical_compound ,13. Climate action ,In vivo ,Biological system ,Flux (metabolism) ,Two-dimensional nuclear magnetic resonance spectroscopy ,Quantitative analysis (chemistry) ,Spectroscopy ,Heteronuclear single quantum coherence spectroscopy - Abstract
In vivo Nuclear Magnetic Resonance (NMR) spectroscopy has great potential to interpret the biochemical response of organisms to their environment, thus making it an essential tool in understanding toxic mechanisms. However, magnetic susceptibility distortions lead to 1D NMR spectra of living organisms with lines that are too broad to identify and quantify metabolites, necessitating the use of 2D 1H-13C Heteronuclear Single Quantum Coherence (HSQC) as a primary tool. While quantitative 2D HSQC is well established, to our knowledge it has yet to be applied in vivo. This study represents a simple pilot study that compares two of the most popular quantitative 2D HSQC approaches to determine if quantitative results can be directly obtained in vivo in isotopically enriched Daphnia magna (water flea). The results show the perfect-HSQC experiment performs very well in vivo, but the decoupling scheme used is critical for accurate quantitation. An improved decoupling approach derived using optimal control theory is presented here that improves the accuracy of metabolite concentrations that can be extracted in vivo down to micromolar concentrations. When combined with 2D Electronic Reference To access In vivo Concentrations (ERETIC) protocols, the protocol allows for the direct extraction of in vivo metabolite concentrations without the use of internal standards that can be detrimental to living organisms. Extracting absolute metabolic concentrations in vivo is an important first step and should, for example, be important for the parameterization as well as the validation of metabolic flux models in the future.
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- 2019
11. Real-time monitoring of the aggregation of Alzheimer's amyloid-β via1H magic angle spinning NMR spectroscopy
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Martine Monette, Sarah J. Cox, Jing Wang, Kyle J. Korshavn, Jia Bai, Ayyalusamy Ramamoorthy, and Tomoya Yamamoto
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0301 basic medicine ,chemistry.chemical_classification ,Proton ,Metals and Alloys ,S amyloid ,Peptide ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Jian wang ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,03 medical and health sciences ,chemistry.chemical_compound ,Crystallography ,030104 developmental biology ,Monomer ,chemistry ,Amyloid aggregation ,Materials Chemistry ,Ceramics and Composites ,Magic angle spinning - Abstract
Proton magic-angle-spinning NMR used for real-time analysis of amyloid aggregation reveals that mechanical rotation of Aβ1–40 monomers increases the rate of formation of aggregates, and that the increasing lag-time with peptide concentration suggests the formation of growth-incompetent species. EGCG's ability to shift off-pathway aggregation is also demonstrated.
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- 2018
12. Assessing the potential of quantitative 2D HSQC NMR in
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Daniel, Lane, Thomas E, Skinner, Naum I, Gershenzon, Wolfgang, Bermel, Ronald, Soong, Rudraksha, Dutta Majumdar, Yalda, Liaghati Mobarhan, Sebastian, Schmidt, Hermann, Heumann, Martine, Monette, Myrna J, Simpson, and André J, Simpson
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Carbon Isotopes ,Magnetic Resonance Spectroscopy ,Daphnia ,Animals ,Metabolomics ,Pilot Projects - Abstract
In vivo Nuclear Magnetic Resonance (NMR) spectroscopy has great potential to interpret the biochemical response of organisms to their environment, thus making it an essential tool in understanding toxic mechanisms. However, magnetic susceptibility distortions lead to 1D NMR spectra of living organisms with lines that are too broad to identify and quantify metabolites, necessitating the use of 2D
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- 2018
13. Real-time monitoring of the aggregation of Alzheimer's amyloid-β via
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Jian, Wang, Tomoya, Yamamoto, Jia, Bai, Sarah J, Cox, Kyle J, Korshavn, Martine, Monette, and Ayyalusamy, Ramamoorthy
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Article - Abstract
Proton magic-angle-spinning NMR used for real-time analysis of amyloid aggregation reveals that the mechanical rotation of Aβ(1–40) monomers increases the rate of formation of aggregates, and that the increasing lag-time with peptide concentration suggests the formation of growth-incompetent species. EGCG’s ability to shift off-pathway aggregation is also demonstrated.
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- 2018
14. Comprehensive multiphase NMR: a promising technology to study plants in their native state
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Sridevi Krishnamurthy, Michael Fey, Martine Monette, Werner E. Maas, Ronald Soong, Blythe Fortier-McGill, Heather L. Wheeler, André J. Simpson, Adolfo Botana, Denis Courtier-Murias, Malcolm M. Campbell, Howard Hutchins, Rajeev Kumar, and Henry J. Stronks
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biology ,Starch ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,Cell wall ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Nucleic acid ,Native state ,Lignin ,Organic chemistry ,Arabidopsis thaliana ,Molecule ,General Materials Science - Abstract
Nuclear magnetic resonance (NMR) spectroscopy is arguably one the most powerful tools to study the interactions and molecular structure within plants. Traditionally, however, NMR has developed as two separate fields, one dealing with liquids and the other dealing with solids. Plants in their native state contain components that are soluble, swollen, and true solids. Here, a new form of NMR spectroscopy, developed in 2012, termed comprehensive multiphase (CMP)-NMR is applied for plant analysis. The technology composes all aspects of solution, gel, and solid-state NMR into a single NMR probe such that all components in all phases in native unaltered samples can be studied and differentiated in situ. The technology is evaluated using wild-type Arabidopsis thaliana and the cellulose-deficient mutant ectopic lignification1 (eli1) as examples. Using CMP-NMR to study intact samples eliminated the bias introduced by extraction methods and enabled the acquisition of a more complete structural and metabolic profile; thus, CMP-NMR revealed molecular differences between wild type (WT) and eli1 that could be overlooked by conventional methods. Methanol, fatty acids and/or lipids, glutamine, phenylalanine, starch, and nucleic acids were more abundant in eli1 than in WT. Pentaglycine was present in A. thaliana seedlings and more abundant in eli1 than in WT. Copyright © 2015 John Wiley & Sons, Ltd.
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- 2015
15. Comprehensive Multiphase NMR Spectroscopy of Intact 13C-Labeled Seeds
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Michael Fey, Howard Hutchins, Henry J. Stronks, Leayen Lam, Heather L. Wheeler, Jochem Struppe, A. Gorissen, André J. Simpson, Myrna J. Simpson, Ronald Soong, Andre Sutrisno, Ries de Visser, Rajeev Kumar, Brian Andrew, Werner E. Maas, Martine Monette, Alan Hume, Malcolm M. Campbell, and Sridevi Krishnamurthy
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In situ ,Chemical engineering ,Chemistry ,Phase (matter) ,Solid-state ,food and beverages ,Molecule ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Food chemistry ,Organic component ,General Agricultural and Biological Sciences ,Endosperm - Abstract
Seeds are complex entities composed of liquids, gels, and solids. NMR spectroscopy is a powerful tool for studying molecular structure but has evolved into two fields, solution and solid state. Comprehensive multiphase (CMP) NMR spectroscopy is capable of liquid-, gel-, and solid-state experiments for studying intact samples where all organic components are studied and differentiated in situ. Herein, intact 13C-labeled seeds were studied by a variety of 1D/2D 1H/13C experiments. In the mobile phase, an assortment of metabolites in a single 13C-labeled wheat seed were identified; the gel phase was dominated by triacylglycerides; the semisolid phase was composed largely of carbohydrate biopolymers, and the solid phase was greatly influenced by starchy endosperm signals. Subsequently, the seeds were compared and relative similarities and differences between seed types discussed. This study represents the first application of CMP-NMR to food chemistry and demonstrates its general utility and feasibility for s...
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- 2013
16. Rapid parameter optimization of low signal-to-noise samples in NMR spectroscopy using rapid CPMG pulsing during acquisition: application to recycle delays
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Ronald Soong, Myrna J. Simpson, André J. Simpson, Henry J. Stronks, Hussain Masoom, Rajeev Kumar, Denis Courtier-Murias, Martine Monette, Werner E. Maas, Michael Fey, and Hashim Farooq
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Pulse (signal processing) ,Chemistry ,Range (statistics) ,Analytical chemistry ,General Materials Science ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Focus (optics) ,Biological system ,Signal ,Intensity (heat transfer) ,Excitation ,Mixing (physics) - Abstract
A method is presented that combines Carr–Purcell–Meiboom–Gill (CPMG) during acquisition with either selective or nonselective excitation to produce a considerable intensity enhancement and a simultaneous loss in chemical shift information. A range of parameters can theoretically be optimized very rapidly on the basis of the signal from the entire sample (hard excitation) or spectral subregion (soft excitation) and should prove useful for biological, environmental, and polymer samples that often exhibit highly dispersed and broad spectral profiles. To demonstrate the concept, we focus on the application of our method to T1 determination, specifically for the slowest relaxing components in a sample, which ultimately determines the optimal recycle delay in quantitative NMR. The traditional inversion recovery (IR) pulse program is combined with a CPMG sequence during acquisition. The slowest relaxing components are selected with a shaped pulse, and then, low-power CPMG echoes are applied during acquisition with intervals shorter than chemical shift evolution (RCPMG) thus producing a single peak with an SNR commensurate with the sum of the signal integrals in the selected region. A traditional 13C IR experiment is compared with the selective 13C IR-RCPMG sequence and yields the same T1 values for samples of lysozyme and riverine dissolved organic matter within error. For lysozyme, the RCPMG approach is ~70 times faster, and in the case of dissolved organic matter is over 600 times faster. This approach can be adapted for the optimization of a host of parameters where chemical shift information is not necessary, such as cross-polarization/mixing times and pulse lengths. Copyright © 2013 John Wiley & Sons, Ltd.
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- 2013
17. Rapid estimation of nuclear magnetic resonance experiment time in low-concentration environmental samples
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Werner E. Maas, Denis Courtier-Murias, Henry J. Stronks, Martine Monette, Rajeev Kumar, Myrna J. Simpson, André J. Simpson, Hussain Masoom, Ronald Soong, and Hashim Farooq
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Air Pollutants ,Geologic Sediments ,Magnetic Resonance Spectroscopy ,Chemistry ,Health, Toxicology and Mutagenesis ,Chemical shift ,Sample (material) ,Analytical chemistry ,Nuclear magnetic resonance spectroscopy ,Soil ,Nuclear magnetic resonance ,Signal-to-noise ratio ,Models, Chemical ,Dispersion (optics) ,Soil Pollutants ,Environmental Chemistry ,Spike (software development) ,Spectroscopy ,Intensity (heat transfer) ,Environmental Monitoring - Abstract
Nuclear magnetic resonance (NMR) spectroscopy is an essential tool for studying environmental samples but is often hindered by low sensitivity, especially for the direct detection of nuclei such as13C. In very heterogeneous samples with NMR nuclei at low abundance, such as soils, sediments, and air particulates, it can take days to acquire a conventional13C spectrum. The present study describes a prescreening method that permits the rapid prediction of experimental run time in natural samples. The approach focuses the NMR chemical shift dispersion into a single spike, and, even in samples with extremely low carbon content, the spike can be observed in two to three minutes, or less. The intensity of the spike is directly proportional to the total concentration of nuclei of interest in the sample. Consequently, the spike intensity can be used as a powerful prescreening method that answers two key questions: (1) Will this sample produce a conventional NMR spectrum? (2) How much instrument time is required to record a spectrum with a specific signal-to-noise (S/N) ratio? The approach identifies samples to avoid (or pretreat) and permits additional NMR experiments to be performed on samples producing high-quality NMR data. Applications in solid- and liquid-state13C NMR are demonstrated, and it is shown that the technique is applicable to a range of nuclei. Environ. Toxicol. Chem. 2013;32:129–136. © 2012 SETAC
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- 2012
18. Comprehensive multiphase NMR applied to a living organism
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Sebastian Schmidt, Henry J. Stronks, André J. Simpson, Blythe Fortier-McGill, Martine Monette, Hermann Heumann, Werner E. Maas, Warren P. Norwood, Michael Fey, Yalda Liaghati Mobarhan, and Ronald Soong
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Chemistry ,010401 analytical chemistry ,Molecular binding ,Nanotechnology ,General Chemistry ,010402 general chemistry ,Biological system ,01 natural sciences ,Organism ,0104 chemical sciences - Abstract
Comprehensive Multiphase NMR provides an overview as to all components (liquids, gels, solids) in a living organism., Comprehensive multiphase (CMP) NMR is a novel technology that integrates all the hardware from solution-, gel- and solid-state into a single NMR probe, permitting all phases to be studied in intact samples. Here comprehensive multiphase (CMP) NMR is used to study all components in a living organism for the first time. This work describes 4 new scientific accomplishments summarized as: (1) CMP-NMR is applied to a living animal, (2) an effective method to deliver oxygen to the organisms is described which permits longer studies essential for in-depth NMR analysis in general, (3) a range of spectral editing approaches are applied to fully differentiate the various phases solutions (metabolites) through to solids (shell) (4) 13C isotopic labelling and multidimensional NMR are combined to provide detailed assignment of metabolites and structural components in vivo. While not explicitly studied here the multiphase capabilities of the technique offer future possibilities to study kinetic transfer between phases (e.g. nutrient assimilation, contaminant sequestration), molecular binding at interfaces (e.g. drug or contaminant binding) and bonding across and between phases (e.g. muscle to bone) in vivo. Future work will need to focus on decreasing the spinning speed to reduce organism stress during analysis.
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- 2016
19. Soil Organic Matter in Its Native State: Unravelling the Most Complex Biomaterial on Earth
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Brian P. Kelleher, Myrna J. Simpson, Denis Courtier-Murias, Michael Fey, André J. Simpson, Hussain Masoom, Hashim Farooq, Ronald Soong, Werner E. Maas, Chao Zhang, Martine Monette, Henry J. Stronks, and Rajeev Kumar
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Magnetic Resonance Spectroscopy ,Carbohydrates ,Biomass ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Lignin ,chemistry.chemical_compound ,Soil ,Native state ,Environmental Chemistry ,Organic matter ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Aqueous solution ,Soil organic matter ,Water ,Agriculture ,04 agricultural and veterinary sciences ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,15. Life on land ,Lipids ,chemistry ,Environmental chemistry ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Hydrophobic and Hydrophilic Interactions ,Macromolecule - Abstract
Since the isolation of soil organic matter in 1786, tens of thousands of publications have searched for its structure. Nuclear magnetic resonance (NMR) spectroscopy has played a critical role in defining soil organic matter but traditional approaches remove key information such as the distribution of components at the soil-water interface and conformational information. Here a novel form of NMR with capabilities to study all physical phases termed Comprehensive Multiphase NMR, is applied to analyze soil in its natural swollen-state. The key structural components in soil organic matter are identified to be largely composed of macromolecular inputs from degrading biomass. Polar lipid heads and carbohydrates dominate the soil-water interface while lignin and microbes are arranged in a more hydrophobic interior. Lignin domains cannot be penetrated by aqueous solvents even at extreme pH indicating they are the most hydrophobic environment in soil and are ideal for sequestering hydrophobic contaminants. Here, for the first time, a complete range of physical states of a whole soil can be studied. This provides a more detailed understanding of soil organic matter at the molecular level itself key to develop the most efficient soil remediation and agricultural techniques, and better predict carbon sequestration and climate change.
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- 2016
20. Comprehensive multiphase NMR spectroscopy: Basic experimental approaches to differentiate phases in heterogeneous samples
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Werner E. Maas, Hussain Masoom, Sridevi Krishnamurthy, Rajeev Kumar, Denis Courtier-Murias, James G. Longstaffe, Michael Fey, Hashim Farooq, Howard Hutchins, Alan Hume, André J. Simpson, Jochem Struppe, Ronald Soong, Henry J. Stronks, Myrna J. Simpson, Brian Andrew, Adolfo Botana, and Martine Monette
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Nuclear and High Energy Physics ,Phase transition ,Magnetic Resonance Spectroscopy ,Chemistry ,Sample (material) ,Kinetics ,Biophysics ,Analytical chemistry ,Equipment Design ,Nuclear magnetic resonance spectroscopy ,Complex Mixtures ,Condensed Matter Physics ,Biochemistry ,Phase Transition ,Spectral line ,Specimen Handling ,Equipment Failure Analysis ,Phase (matter) ,Magic angle spinning ,Native state ,Biological system - Abstract
Heterogeneous samples, such as soils, sediments, plants, tissues, foods and organisms, often contain liquid-, gel- and solid-like phases and it is the synergism between these phases that determine their environmental and biological properties. Studying each phase separately can perturb the sample, removing important structural information such as chemical interactions at the gel-solid interface, kinetics across boundaries and conformation in the natural state. In order to overcome these limitations a Comprehensive Multiphase-Nuclear Magnetic Resonance (CMP-NMR) probe has been developed, and is introduced here, that permits all bonds in all phases to be studied and differentiated in whole unaltered natural samples. The CMP-NMR probe is built with high power circuitry, Magic Angle Spinning (MAS), is fitted with a lock channel, pulse field gradients, and is fully susceptibility matched. Consequently, this novel NMR probe has to cover all HR-MAS aspects without compromising power handling to permit the full range of solution-, gel- and solid-state experiments available today. Using this technology, both structures and interactions can be studied independently in each phase as well as transfer/interactions between phases within a heterogeneous sample. This paper outlines some basic experimental approaches using a model heterogeneous multiphase sample containing liquid-, gel- and solid-like components in water, yielding separate (1)H and (13)C spectra for the different phases. In addition, (19)F performance is also addressed. To illustrate the capability of (19)F NMR soil samples, containing two different contaminants, are used, demonstrating a preliminary, but real-world application of this technology. This novel NMR approach possesses a great potential for the in situ study of natural samples in their native state.
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- 2012
21. From Spill to Sequestration: The Molecular Journey of Contamination via Comprehensive Multiphase NMR
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Hussain Masoom, André J. Simpson, Michael Fey, Martine Monette, Ronald Soong, Werner E. Maas, Henry J. Stronks, Rajeev Kumar, Denis Courtier-Murias, and Myrna J. Simpson
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Magnetic Resonance Spectroscopy ,010501 environmental sciences ,010402 general chemistry ,complex mixtures ,01 natural sciences ,Lignin ,chemistry.chemical_compound ,Soil ,Phenols ,Phase (matter) ,Environmental Chemistry ,Soil Pollutants ,Soil Microbiology ,0105 earth and related environmental sciences ,Fluorocarbons ,Water ,Sorption ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Fluorine ,Contamination ,6. Clean water ,0104 chemical sciences ,Fluorobenzenes ,Kinetics ,chemistry ,Environmental chemistry ,Perfluorooctanoic acid ,Caprylates ,Soil microbiology ,Gels ,Hydrophobic and Hydrophilic Interactions - Abstract
Comprehensive multiphase NMR is a novel NMR technique that permits all components (solutions, gels, and solids) to be studied in unaltered natural samples. In this study a wide range of CMP-NMR interaction and editing-based experiments are combined to follow contaminants (pentafluorophenol (PFP) and perfluorooctanoic acid (PFOA)) from the solution state (after a spill) through the gel-state and finally into the true solid-state (sequestered) in an intact water-swollen soil. Kinetics experiments monitoring each phase illustrate PFOA rapidly transfers from solution to the solid phase while for PFP the process is slower with longer residence times in the solution and gel phase. Interaction-based experiments reveal that PFOA enters the soil via its hydrophobic tails and selectively binds to soil microbial protein. PFP sorption shows less specificity exhibiting interactions with a range of gel and solid soil components with a preference toward aromatics (mainly lignin). The results indicate that in addition to more traditional measurements such as Koc, other factors including the influence of the contaminant on the soil-water interface, specific biological interactions, soil composition (content of lignin, protein, etc.) and physical accessibility/swellability of soil organic components will likely be central to better explaining and predicting the true behavior of contaminants in soil.
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- 2015
22. High-resolution NMR characterization of low abundance oligomers of amyloid-β without purification
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Martine Monette, Meagan A. Cauble, Jeffrey R. Brender, E. Neil G. Marsh, Mark M. Banaszak Holl, Subramanian Vivekanandan, Samuel A. Kotler, Patrick Walsh, Janarthanan Krishnamoorthy, Kazutoshi Yamamoto, Ayyalusamy Ramamoorthy, and Yuta Suzuki
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Amyloid ,Macromolecular Substances ,Protein Conformation ,Population ,Peptide ,Fibril ,Oligomer ,Protein Aggregation, Pathological ,Article ,Isotopic labeling ,chemistry.chemical_compound ,Protein structure ,Alzheimer Disease ,Magic angle spinning ,Humans ,Amino Acid Sequence ,education ,Nuclear Magnetic Resonance, Biomolecular ,chemistry.chemical_classification ,education.field_of_study ,Multidisciplinary ,Amyloid beta-Peptides ,Peptide Fragments ,Monomer ,chemistry ,Biochemistry ,Biophysics - Abstract
Alzheimer’s disease is characterized by the misfolding and self-assembly of the amyloidogenic protein amyloid-β (Aβ). The aggregation of Aβ leads to diverse oligomeric states, each of which may be potential targets for intervention. Obtaining insight into Aβ oligomers at the atomic level has been a major challenge to most techniques. Here, we use magic angle spinning recoupling 1H-1H NMR experiments to overcome many of these limitations. Using 1H-1H dipolar couplings as a NMR spectral filter to remove both high and low molecular weight species, we provide atomic-level characterization of a non-fibrillar aggregation product of the Aβ1-40 peptide using non-frozen samples without isotopic labeling. Importantly, this spectral filter allows the detection of the specific oligomer signal without a separate purification procedure. In comparison to other solid-state NMR techniques, the experiment is extraordinarily selective and sensitive. A resolved 2D spectra could be acquired of a small population of oligomers (6 micrograms, 7% of the total) amongst a much larger population of monomers and fibers (93% of the total). By coupling real-time 1H-1H NMR experiments with other biophysical measurements, we show that a stable, primarily disordered Aβ1-40 oligomer 5–15 nm in diameter can form and coexist in parallel with the well-known cross-β-sheet fibrils.
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- 2015
23. Characterization of environmental samples in their natural state using comprehensive multiphase NMR
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Martine Monette, Blythe Fortier-McGill, Hussain Masoom, Ronald Soong, Andre J. Simpson, Denis Courtier-Murias, KL Colson, and Y Liaghati Mobarhan
- Subjects
Pharmacology ,Engineering ,business.industry ,Organic Chemistry ,Pharmaceutical Science ,Analytical Chemistry ,Characterization (materials science) ,Complementary and alternative medicine ,Chemical engineering ,Drug Discovery ,Molecular Medicine ,Biochemical engineering ,business ,Natural state - Published
- 2015
24. Comprehensive multiphase NMR: a promising technology to study plants in their native state
- Author
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Heather L, Wheeler, Ronald, Soong, Denis, Courtier-Murias, Adolfo, Botana, Blythe, Fortier-Mcgill, Werner E, Maas, Michael, Fey, Howard, Hutchins, Sridevi, Krishnamurthy, Rajeev, Kumar, Martine, Monette, Henry J, Stronks, Malcolm M, Campbell, and Andre, Simpson
- Subjects
Magnetic Resonance Spectroscopy ,Glutamine ,Methanol ,Phenylalanine ,Fatty Acids ,Arabidopsis ,Water ,Starch ,Genes, Plant ,Plants, Genetically Modified ,Cell Wall ,Seedlings ,Nucleic Acids ,Plant Cells ,Metabolome ,Cellulose ,Gene Deletion - Abstract
Nuclear magnetic resonance (NMR) spectroscopy is arguably one the most powerful tools to study the interactions and molecular structure within plants. Traditionally, however, NMR has developed as two separate fields, one dealing with liquids and the other dealing with solids. Plants in their native state contain components that are soluble, swollen, and true solids. Here, a new form of NMR spectroscopy, developed in 2012, termed comprehensive multiphase (CMP)-NMR is applied for plant analysis. The technology composes all aspects of solution, gel, and solid-state NMR into a single NMR probe such that all components in all phases in native unaltered samples can be studied and differentiated in situ. The technology is evaluated using wild-type Arabidopsis thaliana and the cellulose-deficient mutant ectopic lignification1 (eli1) as examples. Using CMP-NMR to study intact samples eliminated the bias introduced by extraction methods and enabled the acquisition of a more complete structural and metabolic profile; thus, CMP-NMR revealed molecular differences between wild type (WT) and eli1 that could be overlooked by conventional methods. Methanol, fatty acids and/or lipids, glutamine, phenylalanine, starch, and nucleic acids were more abundant in eli1 than in WT. Pentaglycine was present in A. thaliana seedlings and more abundant in eli1 than in WT.
- Published
- 2014
25. Aspects of the hydrolysis of formamide: revisitation of the water reaction and determination of the solvent deuterium kinetic isotope effect in base
- Author
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R S Brown, F Sauriol, H Slebocka-Tilk, and Martine Monette
- Subjects
Formamide ,chemistry.chemical_classification ,Base (chemistry) ,Organic Chemistry ,Inorganic chemistry ,General Chemistry ,Kinetic energy ,Catalysis ,Solvent ,chemistry.chemical_compound ,Hydrolysis ,chemistry ,Deuterium ,Kinetic isotope effect ,Acid–base reaction - Abstract
A study of the hydrolysis of formamide is reported with the aims of isolating the water reaction for hydrolysis from the acid and base hydrolysis terms and determining the solvent deuterium kinetic isotope effect (dkie) on base-catalyzed hydrolysis. Respective activation parameters (ΔHand ΔS) of (17.0 ± 0.4) kcal mol1and (18.8 ± 1.3) cal mol1K1for the acid reaction and (17.9 ± 0.2) kcal mol1and (11.1 ± 0.5) cal mol1K1for the base reaction were determined from Eyring plots of the second-order rate constants over the range of 27120°C. Kinetic studies at the minima of the pH/rate profiles in the pH range from 5.6 to 6.2 in MES buffers at 56°C, and in the pH range of 4.256.87 in acetate and phosphate buffers at 120°C are reported. At 56°C the available data fit the expression k56obs= 0.00303[H3O+] + 0.032[HO] + (3.6 ± 0.1) × 109, while at 120°C the data fit k120obs= (0.15 ± 0.02)[H3O+] + (3.20 ± 0.24)[HO] + (1.09 ± 0.29) × 106. Preliminary experimental estimates of Ea(ln A) of 22.5 kcal mol1(15.03) for the water rate constant (kw) are calculated from an Arrhenius plot of the 56 and 120°C data giving an estimated kwof 1.1 × 1010s1(t1/2= 199 years) at 25°C. Solvent dkie values of kOH/kOD= 1.15 and 0.77 ± 0.06 were determined at [OL] = 0.075 and 1.47 M, respectively. The inverse value is determined under conditions where the the first step of the reaction dominates and is analyzed in terms of a rate-limiting attack of OL.Key words: formamide, activation parameters, water reaction, acid and base hydrolysis, solvent kinetic isotope effect.
- Published
- 2002
26. 14N Quadrupolar, 14N and 15N Chemical Shift, and 14N−H Dipolar Tensors of Sulfamic Acid
- Author
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Young Sik Kye, Michelle Grandin, Glenn H. Penner, Gerard S. Harbison, and Martine Monette
- Subjects
Coupling constant ,Chemistry ,Molecular physics ,Surfaces, Coatings and Films ,Dipole ,Nuclear magnetic resonance ,Residual dipolar coupling ,Ab initio quantum chemistry methods ,Quadrupole ,Materials Chemistry ,Tensor ,Physical and Theoretical Chemistry ,Anisotropy ,Single crystal - Abstract
A 14N solid-state NMR single crystal study was used to determine the 14N quadrupolar, chemical shift, and 14N−1H dipolar tensors of sulfamic acid. The quadrupolar tensor is nearly axially symmetric, with the quasi-unique axis aligned 3° away from the N−S bond. The quadrupole coupling constant of 0.794 MHz is substantially less than the gas-phase value (1.6682 MHz); ab initio calculations show that the difference can be attributed almost entirely to the significantly shorter N−S bond in the solid state. The single crystal study, together with 15N CP/MAS and CP/static experiments, yields an isotropic chemical shift that lies close to its solution value, and a chemical shielding anisotropy of about −80 ppm, and the dipolar couplings are about 10% smaller than computed from the neutron structure, probably because of vibrational averaging. All three tensors are almost collinear. HF, MP2, CI, and DFT(B3LYP) calculations of the nitrogen quadrupole coupling constant and shielding are also reported.
- Published
- 2002
27. Structure of a malaria parasite antigenic determinant displayed on filamentous bacteriophage determined by NMR spectroscopy: Implications for the structure of continuous peptide epitopes of proteins
- Author
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Stanley J. Opella, Judith Greenwood, Richard N. Perham, Anne E. Willis, and Martine Monette
- Subjects
Antigenicity ,Magnetic Resonance Spectroscopy ,Phage display ,Protein Conformation ,Molecular Sequence Data ,Plasmodium falciparum ,Biology ,Biochemistry ,Article ,Epitope ,Epitopes ,Protein structure ,Animals ,Bacteriophages ,Amino Acid Sequence ,Antigens ,Molecular Biology ,Peptide sequence ,Micelles ,Virion ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,Molecular biology ,Malaria ,Circumsporozoite protein ,Filamentous bacteriophage ,Peptides - Abstract
The NANP repeating sequence of the circumsporozoite protein of Plasmodium falciparum was displayed on the surface of fd filamentous bacteriophage as a 12-residue insert (NANP)(3) in the N-terminal region of the major coat protein (pVIII). The structure of the epitope determined by multidimensional solution NMR spectroscopy of the modified pVIII protein in lipid micelles was shown to be a twofold repeat of an extended and non-hydrogen-bonded loop based on the sequence NPNA, demonstrating that the repeating sequence is NPNA, not NANP. Further, high resolution solid-state NMR spectra of intact hybrid virions containing the modified pVIII proteins demonstrate that the peptides displayed on the surface of the virion adopt a single, stable conformation; this is consistent with their pronounced immunogenicity as well as their ability to mimic the antigenicity of their native parent proteins.
- Published
- 2001
28. Comprehensive multiphase NMR spectroscopy of intact ¹³C-labeled seeds
- Author
-
Leayen, Lam, Ronald, Soong, Andre, Sutrisno, Ries, de Visser, Myrna J, Simpson, Heather L, Wheeler, Malcolm, Campbell, Werner E, Maas, Michael, Fey, Antonie, Gorissen, Howard, Hutchins, Brian, Andrew, Jochem, Struppe, Sridevi, Krishnamurthy, Rajeev, Kumar, Martine, Monette, Henry J, Stronks, Alan, Hume, and André J, Simpson
- Subjects
Carbon Isotopes ,Magnetic Resonance Spectroscopy ,Isotope Labeling ,Seeds ,Brassica ,Zea mays ,Triticum ,Glycerides - Abstract
Seeds are complex entities composed of liquids, gels, and solids. NMR spectroscopy is a powerful tool for studying molecular structure but has evolved into two fields, solution and solid state. Comprehensive multiphase (CMP) NMR spectroscopy is capable of liquid-, gel-, and solid-state experiments for studying intact samples where all organic components are studied and differentiated in situ. Herein, intact (13)C-labeled seeds were studied by a variety of 1D/2D (1)H/(13)C experiments. In the mobile phase, an assortment of metabolites in a single (13)C-labeled wheat seed were identified; the gel phase was dominated by triacylglycerides; the semisolid phase was composed largely of carbohydrate biopolymers, and the solid phase was greatly influenced by starchy endosperm signals. Subsequently, the seeds were compared and relative similarities and differences between seed types discussed. This study represents the first application of CMP-NMR to food chemistry and demonstrates its general utility and feasibility for studying intact heterogeneous samples.
- Published
- 2013
29. In-situ molecular-level elucidation of organofluorine binding sites in a whole peat soil
- Author
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André J. Simpson, Jochem Struppe, Mehran Alaee, Sridevi Krishnamurthy, Henry J. Stronks, Werner E. Maas, Michael Fey, Myrna J. Simpson, Ronald Soong, Rajeev Kumar, Denis Courtier-Murias, James G. Longstaffe, Howard Hutchins, and Martine Monette
- Subjects
Fluorine Radioisotopes ,Fluorocarbons ,Binding Sites ,Magnetic Resonance Spectroscopy ,Chemistry ,Fluorine Compounds ,Biogeochemistry ,Chemical modification ,Sorption ,General Chemistry ,Fractionation ,Lignin ,chemistry.chemical_compound ,Soil ,Environmental chemistry ,Albumins ,Soil water ,Magic angle spinning ,Environmental Chemistry ,Ecotoxicity ,Caprylates ,Xenobiotic ,Humic Substances - Abstract
The chemical nature of xenobiotic binding sites in soils is of vital importance to environmental biogeochemistry. Interactions between xenobiotics and the naturally occurring organic constituents of soils are strongly correlated to environmental persistence, bioaccessibility, and ecotoxicity. Nevertheless, because of the complex structural and chemical heterogeneity of soils, studies of these interactions are most commonly performed indirectly, using correlative methods, fractionation, or chemical modification. Here we identify the organic components of an unmodified peat soil where some organofluorine xenobiotic compounds interact using direct molecular-level methods. Using (19)F→(1)H cross-polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy, the (19)F nuclei of organofluorine compounds are used to induce observable transverse magnetization in the (1)H nuclei of organic components of the soil with which they interact after sorption. The observed (19)F→(1)H CP-MAS spectra and dynamics are compared to those produced using model soil organic compounds, lignin and albumin. It is found that lignin-like components can account for the interactions observed in this soil for heptafluoronaphthol (HFNap) while protein structures can account for the interactions observed for perfluorooctanoic acid (PFOA). This study employs novel comprehensive multi-phase (CMP) NMR technology that permits the application of solution-, gel-, and solid-state NMR experiments on intact soil samples in their swollen state.
- Published
- 2012
30. Rapid parameter optimization of low signal-to-noise samples in NMR spectroscopy using rapid CPMG pulsing during acquisition: application to recycle delays
- Author
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Hashim, Farooq, Denis, Courtier-Murias, Ronald, Soong, Hussain, Masoom, Werner, Maas, Michael, Fey, Rajeev, Kumar, Martine, Monette, Henry, Stronks, Myrna J, Simpson, and André J, Simpson
- Subjects
Time Factors ,Polymers ,Equipment Reuse ,Muramidase ,Organic Chemicals ,Nuclear Magnetic Resonance, Biomolecular - Abstract
A method is presented that combines Carr-Purcell-Meiboom-Gill (CPMG) during acquisition with either selective or nonselective excitation to produce a considerable intensity enhancement and a simultaneous loss in chemical shift information. A range of parameters can theoretically be optimized very rapidly on the basis of the signal from the entire sample (hard excitation) or spectral subregion (soft excitation) and should prove useful for biological, environmental, and polymer samples that often exhibit highly dispersed and broad spectral profiles. To demonstrate the concept, we focus on the application of our method to T(1) determination, specifically for the slowest relaxing components in a sample, which ultimately determines the optimal recycle delay in quantitative NMR. The traditional inversion recovery (IR) pulse program is combined with a CPMG sequence during acquisition. The slowest relaxing components are selected with a shaped pulse, and then, low-power CPMG echoes are applied during acquisition with intervals shorter than chemical shift evolution (RCPMG) thus producing a single peak with an SNR commensurate with the sum of the signal integrals in the selected region. A traditional (13)C IR experiment is compared with the selective (13)C IR-RCPMG sequence and yields the same T(1) values for samples of lysozyme and riverine dissolved organic matter within error. For lysozyme, the RCPMG approach is ~70 times faster, and in the case of dissolved organic matter is over 600 times faster. This approach can be adapted for the optimization of a host of parameters where chemical shift information is not necessary, such as cross-polarization/mixing times and pulse lengths.
- Published
- 2012
31. NMR assignment of an intrinsically disordered protein under physiological conditions: the 18.5 kDa isoform of murine myelin basic protein
- Author
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George Harauz, Valerie J. Robertson, Martine Monette, and David S. Libich
- Subjects
Gene isoform ,Calmodulin ,Nerve Tissue Proteins ,Intrinsically disordered proteins ,Biochemistry ,Protein Structure, Secondary ,law.invention ,Mice ,Protein structure ,Structural Biology ,law ,Animals ,Protein Isoforms ,Nuclear Magnetic Resonance, Biomolecular ,biology ,Molecular Structure ,Chemistry ,Myelin Basic Protein ,Recombinant Proteins ,Myelin basic protein ,Molecular Weight ,biology.protein ,Recombinant DNA ,Two-dimensional nuclear magnetic resonance spectroscopy ,Transcription Factors - Abstract
We report the NMR assignment of 18.5 kDa recombinant murine myelin basic protein (MBP) in 100 mM KCl as a prerequisite to structural analyses of its Ca2+-dependent interaction with calmodulin.
- Published
- 2007
32. Characterisation of oil contaminated soils by comprehensive multiphase NMR spectroscopy
- Author
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Brian Andrew, Michael Fey, Howard Hutchins, Rajeev Kumar, Hashim Farooq, Werner E. Maas, Henry J. Stronks, Myrna J. Simspon, Martine Monette, Jochem Struppe, Sridevi Krishnamurthy, André J. Simpson, and Denis Courtier-Murias
- Subjects
Geochemistry and Petrology ,Chemistry (miscellaneous) ,Chemistry ,Environmental chemistry ,Soil water ,Fluorescence spectrometry ,Environmental Chemistry ,Soil chemistry ,Soil classification ,Context (language use) ,Soil contamination ,Groundwater ,Asphaltene - Abstract
Environmental context Novel technology is used to examine oil contaminated soil to better understand this longstanding problem. The data indicate that oil forms a non-discriminant layer over all the soil components, which in their natural state would be exposed to water, and that it retains certain polar compounds while contributing other oil contaminants to the surrounding porewater and groundwater. Such molecular level information helps to better understand the reoccurrence of hydrophobicity in remediated soil, and could lead to novel clean-up methods. Abstract Comprehensive multiphase (CMP) NMR spectroscopy is a novel NMR technology introduced in 2012. CMP NMR spectroscopy permits the analysis of solid, gel and liquid phases in unaltered natural samples. Here the technology is applied to control and oil contaminated soils to understand the molecular processes that give rise to non-wettable soils. 13C solid-state NMR spectroscopy is found to be excellent for studying the bulk rigid components of the soils whereas 1H solution and gel-state NMR provide a complimentary overview to subtleties occurring at the soil–water interface. Considered holistically the NMR data support the finding that the oil forms a non-discriminant layer over all the soil components, which in the natural state, would be exposed to water. Specifically, the oil was found to preferentially coat aliphatics and carbohydrates that normally stick out at the soil–water interface. In addition, it was shown that the oil forms a barrier that keeps small polar molecules such as formic acid inside the soil. At the soil–water interface selective oil components, such as asphaltenes, were found to exhibit unrestricted diffusion, suggesting that these components could leach into surrounding groundwater.
- Published
- 2015
33. Environmental Comprehensive Multiphase NMR
- Author
-
Michael Fey, Ronald Soong, Andre Sutrisno, Martine Monette, Jochem Struppe, Myrna J. Simpson, Hussain Masoom, Werner Maas, Howard Hutchins, Leayen Lam, Henry J. Stronks, James G. Longstaffe, Sridevi Krishnamurthy, Denis Courtier-Murias, Brian Andrew, Hashim Farooq, Rajeev Kumar, and André J. Simpson
- Subjects
carbohydrates (lipids) ,Chemical physics ,Chemistry ,Environmental remediation ,Phase (matter) ,Soil water ,Analytical chemistry ,Biomass ,Degradation (geology) ,Nuclear magnetic resonance spectroscopy ,Spectroscopy ,Heterogeneous catalysis - Abstract
Comprehensive multiphase (CMP)-NMR spectroscopy provides the ability to study all bonds in all phases in natural, unaltered samples. CMP-NMR probes comprise a lock, magic-angle gradients, magic-angle spinning, are fully susceptibility matched and use high-power circuitry to permit the full range of solution-, gel-, and solid-state NMR experiments. As such, it represents a key step forward in environmental research, where, for example, the overall properties of a soil are of environmental relevance and understanding complex associations, aggregations, interactions, and reactions in situ are the key to unravel its environmental properties. CMP-NMR spectroscopy allows the transfer, kinetics, degradation, and interactions of contaminants between phases to be elucidated and monitored in real time. Materials with complex multiphase structure such as plants, air particles, sediments, soils and tissues are ideally suited to CMP-NMR analysis. Processes that convert one phase into another, for example, the conversion of biomass to bioethanol, can also be probed in detail by CMP-NMR spectroscopy. CMP-NMR spectroscopy will likely find widespread application not only in environmental research but also in fields such as medicine, biochemistry, biology, heterogeneous catalysis, or any other area that deal with samples containing more than one phase. Keywords: environmental NMR spectroscopy; comprehensive multiphase NMR; structure; contaminant interactions; environmental sequestration and remediation
- Published
- 1996
34. Initial characterization of a peptide epitope displayed on the surface of fd bacteriophage by solution and solid-state NMR spectroscopy
- Author
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Stanley J. Opella, Martine Monette, Richard N. Perhamp, Anne E. Wills, Judith Greenwood, and Holly Gratkowski
- Subjects
Bacteriophage ,Crystallography ,Linear epitope ,Solid-state nuclear magnetic resonance ,biology ,Tetrapeptide ,Chemistry ,Biophysics ,Context (language use) ,Nuclear magnetic resonance spectroscopy ,biology.organism_classification ,Filamentous bacteriophage fd ,Epitope - Abstract
Publisher Summary This chapter describes spectroscopic methods and preliminary results from structural studies of the epitope (NANP) 3 displayed close to the N-terminus of the major coat protein in hybrid phage. The main antigenic determinant of the circumsporozoite (CS) protein contains several repetitions of the tetrapeptide NANP, and proteins containing several units of this epitope are used to raise a high titer of antibodies. When the epitope is displayed on the surface of the filamentous bacteriophage fd, an even higher immunogenic response is observed. The chapter describes the use of multidimensional solution nuclear magnetic resonance (NMR) to study the three-dimensional structure of the epitope in isolated coat proteins solubilized in micelles. The solid-state NMR is applied to intact phage particles. The spontaneous orientation of the virion in the presence of strong magnetic fields enables the epitope to be characterized on the surface of the bacteriophage. The results obtained by solution and solid-state NMR spectroscopy show that the epitope is folded in the context of the phage coat protein and its structure in micelles, and in the virion, particles can be determined by NMR spectroscopy.
- Published
- 1996
35. Letter to the Editor: Backbone resonance assignments of the 18.5 kDa isoform of murine myelin basic protein (MBP)
- Author
-
Martine Monette, George Harauz, Valerie J. Robertson, and David S. Libich
- Subjects
Gene isoform ,biology ,Chemistry ,Biochemistry ,Oligodendrocyte ,Myelin basic protein ,law.invention ,Myelin ,medicine.anatomical_structure ,law ,Cytoplasm ,medicine ,biology.protein ,Recombinant DNA ,Two-dimensional nuclear magnetic resonance spectroscopy ,Protein secondary structure ,Spectroscopy - Abstract
Myelin basic protein (MBP) is a family of developmentally-regulated and translocatable isoforms involved in formation of the myelin sheath of the central nervous system (Campagnoni and Skoff, 2001). The 18.5 kDa isoform of MBP is the most common in adult humans and exists as a series of highly post-translationally modified charge isomers (Kim et al., 2003). The in vivo environment of this isoform is the major dense line of myelin, where it maintains the cytoplasmic leaflets of the oligodendrocyte membrane in close apposition. Deiminated MBP is a candidate autoantigen in multiple sclerosis. Other MBP isoforms potentially have roles in signalling pathways during myelin development, yet our understanding of these phenomena is limited by the lack of detailed structural knowledge. All MBP isoforms are ‘intrinsically unstructured’ to facilitate their interactions with diverse ligands (Hill et al., 2002). The protein is primarily a flexible coil in aqueous solution, but attains ordered secondary structure in the presence of detergents and lipids, as well as in organic solvents such as trifluorethanol (TFE) (Liebes et al., 1975). Recently, site-directed spin labelling and electron paramagnetic resonance experiments on a recombinant form of the 18.5 kDa isoform of murine MBP (rmMBP, 176 residues, Mr 19421.5 Da) in protein-vesicle pellets have defined how different regions of the protein interact with myelin-like membranes (Bates et al., 2004). We have turned to solution NMR in order to define its tertiary struc∗To whom correspondence should be addressed. E-mail: gharauz@uoguelph.ca. ture, and present here the first NMR assignment of the backbone of uniformly 13C15N-labelled rmMBP.
- Published
- 2004
36. Effect of cholesterol on the polymorphism of dipalmitoylphosphatidylcholine/melittin complexes: an NMR study
- Author
-
Martine Monette, Marie-Rose Van Calsteren, and Michel Lafleur
- Subjects
Hot Temperature ,Magnetic Resonance Spectroscopy ,Polymorphism, Genetic ,1,2-Dipalmitoylphosphatidylcholine ,Chemistry ,Stereochemistry ,Vesicle ,Bilayer ,Lipid Bilayers ,technology, industry, and agriculture ,Biophysics ,Cell Biology ,Thermotropism ,complex mixtures ,Biochemistry ,Melitten ,Sterol ,Melittin ,chemistry.chemical_compound ,Cholesterol ,Polymorphism (biophysics) ,Dipalmitoylphosphatidylcholine ,lipids (amino acids, peptides, and proteins) ,Lipid bilayer - Abstract
In order to get insights into the effects of cholesterol on protein activity, the lytic power of melittin on 1,2-dipalmitoyl-sn-glycero-3- phosphocholine (DPPC)/ cholesterol mixtures was studied using solid-state deuterium and phosphorus-31 nuclear magnetic resonance spectroscopy (2H and 31P-NMR). After incubation, melittin disrupts pure DPPC vesicles, leading to the formation of small lipid/peptide complexes below the phase transition temperature ( T m , whereas large bilayer assemblies are reformed above T m ; the transition between these two species is thermally reversible. This study reveals that cholesterol modifies this thermal behavior and that this modulation of the lytic power of melittin is indirect, since it is essentially related to the original effect of the sterol on the thermotropism of pure lipid bilayers. It is known that melittin does not lyse gel phase DPPC bilayers spontaneously. Our study shows that the addition of large amounts of sterol (30 mol%) does not promote the spontaneous lysis at 26°C, despite the increased fluidity of the lipid system. The lysis takes place around 32°C, regardless of the cholesterol concentration. This study also shows that high concentrations of cholesterol ( ≧ 30% ) in DPPC bilayer inhibit the lysis. It is proposed that the tight lipid packing due to high cholesterol concentrations prevents the penetration of melittin into the bilayer. When melittin interacts with cholesterol-rich bilayers (30 mol%), the lysis is only partial, and leads to the formation of small cholesterol-depleted particles. Finally, DPPC which bears deuteriated acyl chains was used to determine the infuence of melittin on the orientational order of the lipid chains in the large assemblies. The quadrupolar splittings obtained in the presence of melittin are not considerably different than those obtained in the absence of melittin.
- Published
- 1993
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