Orientation and Conformation of Met-enkephalin in a Liquid Crystal As Studied by Magic-Angle- and Near-Magic-Angle-Spinning Two-Dimensional NMR Spectroscopy

We recently introduced a technique, termed SAD-REDOR, for recoupling residual dipolar couplings in a single-domain polymer-stabilized liquid crystal (PSLC) undergoing magic-angle spinning (MAS). The experiment was demonstrated with 1H–15N dipolar couplings in a small molecule. Here, we show the applicability of the technique to a strongly aligned protein and we describe a novel two-dimensional experiment to generate in-phase and anti-phase (IPAP) doublets in the 1H dimension of an HSQC NMR spectrum. This pulse sequence, SAD-IPAP, was tested on a sample of 15N-labeled ubiquitin (5 mmol/L) in a polyacrylamide-stabilized Pf1 phage liquid crystal (20 mg/mL). 15N–1H residual dipolar couplings (RDCs) were measured with the SAD-IPAP pulse sequence at spinning speeds of 1000 and 1250 Hz. RDSs were also measured using the conventional HSQC-IPAP method in a sample of 15N-ubiquitin dissolved in a solution of Pf1 phage (1 mg/mL). The resulting RDCs were fitted to the solution structure of ubiquitin to estimate the alignment tensor and to determine the accuracy of the measured couplings. The results highlight the benefits of SAD-REDOR for the measurement of RDCs in strongly aligned macromolecules.Key words: residual dipolar couplings (RDCs), polymer-stabilized liquid crystals (PSLCs), rotational echo double resonance (REDOR) recoupling, magic-angle spinning (MAS), ubiquitin, biomolecular nuclear magnetic resonance (NMR), proteins.

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Applications of high resolution magic angle spinning NMR spectroscopy in tumor metabonomics research

Academic Journal of Second Military Medical University ◽

10.3724/sp.j.1008.2012.01024 ◽

2013 ◽

Vol 32 (9) ◽

pp. 1024-1027

Author(s):

Yu LI ◽

Jing-xia ZHAO ◽

Gen-jin YANG ◽

Wei ZHANG ◽

Zi-yang LOU

Keyword(s):

Nmr Spectroscopy ◽

High Resolution ◽

Magic Angle Spinning ◽

Magic Angle ◽

Angle Spinning

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Wideline 2H -NMR Spectroscopy and Imaging of Solids

Zeitschrift für Naturforschung A ◽

10.1515/zna-1994-1-206 ◽

1994 ◽

Vol 49 (1-2) ◽

pp. 19-26 ◽

Cited By ~ 4

Author(s):

B. Blümich

Keyword(s):

Nmr Spectroscopy ◽

Excitation Power ◽

Magic Angle Spinning ◽

Magic Angle ◽

2H Nmr ◽

Stochastic Excitation ◽

2H Nmr Spectroscopy ◽

Spatially Inhomogeneous ◽

Recent Developments ◽

Angle Spinning

Abstract Recent developments, focussing on reduction of the rf excitation power by stochastic excitation, on improvements in sensitivity and excitation bandwidth by magic angle spinning, and on combining wideline spectroscopy with spatial resolution for investigations o f spatially inhomogeneous objects are reviewed.

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Sampling Method Affects HR-MAS NMR Spectra of Healthy Caprine Brain Biopsies

Metabolites ◽

10.3390/metabo11010038 ◽

2021 ◽

Vol 11 (1) ◽

pp. 38

Author(s):

Annakatrin Häni ◽

Gaëlle Diserens ◽

Anna Oevermann ◽

Peter Vermathen ◽

Christina Precht

Keyword(s):

Nmr Spectroscopy ◽

Sampling Method ◽

Magic Angle Spinning ◽

Mas Nmr ◽

Magic Angle ◽

1H Nuclear Magnetic Resonance ◽

Rapid Changes ◽

Tissue Degradation ◽

Angle Spinning

The metabolic profiling of tissue biopsies using high-resolution–magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy may be influenced by experimental factors such as the sampling method. Therefore, we compared the effects of two different sampling methods on the metabolome of brain tissue obtained from the brainstem and thalamus of healthy goats by 1H HR-MAS NMR spectroscopy—in vivo-harvested biopsy by a minimally invasive stereotactic approach compared with postmortem-harvested sample by dissection with a scalpel. Lactate and creatine were elevated, and choline-containing compounds were altered in the postmortem compared to the in vivo-harvested samples, demonstrating rapid changes most likely due to sample ischemia. In addition, in the brainstem samples acetate and inositols, and in the thalamus samples ƴ-aminobutyric acid, were relatively increased postmortem, demonstrating regional differences in tissue degradation. In conclusion, in vivo-harvested brain biopsies show different metabolic alterations compared to postmortem-harvested samples, reflecting less tissue degradation. Sampling method and brain region should be taken into account in the analysis of metabolic profiles. To be as close as possible to the actual situation in the living individual, it is desirable to use brain samples obtained by stereotactic biopsy whenever possible.

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