The effect of glassing solvent deuteration and Gd3+ doping on 13C DNP at 5 T

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 38855-38860 ◽  
Author(s):  
Andhika Kiswandhi ◽  
Bimala Lama ◽  
Peter Niedbalski ◽  
Mudrekh Goderya ◽  
Joanna Long ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dynamic Nuclear Polarization ◽  
Sodium Acetate ◽  
Nuclear Polarization ◽  
Nuclear Magnetic

We report the influence of glassing solvent deuteration and Gd3+ doping on 13C dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) performed on [1-13C] sodium acetate at B0 = 5 T and 1.2 K.

scholarly journals Solid-State <sup>1</sup>H Spin Polarimetry by <sup>13</sup>CH<sub>3</sub> Nuclear Magnetic Resonance

2021 ◽  
Author(s):  
Stuart J. Elliott ◽  
Quentin Stern ◽  
Sami Jannin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Solid State ◽  
Magnetic Resonance ◽  
Microwave Irradiation ◽  
Dynamic Nuclear Polarization ◽  
Thermal Equilibrium ◽  
Sodium Acetate ◽  
Nuclear Polarization ◽  
Nuclear Magnetic ◽  
Dissolution Dynamic Nuclear Polarization

Abstract. Dissolution-dynamic nuclear polarization is emerging as a promising means to prepare proton polarizations approaching unity. At present, 1H polarization quantification remains fastidious due to the requirement of measuring thermal equilibrium signals. Lineshape polarimetry of solid-state nuclear magnetic resonance spectra is used to determine a number of useful properties regarding the spin system under investigation. In the case of highly polarized nuclear spins, such as those prepared under the conditions of dissolution-dynamic nuclear polarization experiments, the absolute polarization of a particular isotopic species within the sample can be directly inferred from the characteristics of the corresponding resonance lineshape. In situations where direct measurements of polarization are complicated by deleterious phenomena, indirect estimates of polarization using coupled heteronuclear spins prove informative. We present a simple analysis of the 13C spectral lineshape asymmetry of [2-13C]sodium acetate based on relative peak intensities, which can be used to indirectly evaluate the proton polarization of the methyl group moiety, and very likely the entire sample in the case of rapid and homogeneous 1H-1H spin diffusion. 1H polarizations greater than ~10–25 % (depending on the sign of the microwave irradiation) were found to be linearly proportional to the 13C peak asymmetry, which responds differently to positive or negative microwave irradiation. These results suggest that, as a dopant, [2-13C]sodium acetate could be used to indirectly gauge 1H polarizations in standard sample formulations, which is potentially advantageous for: samples polarized in commercial dissolution-dynamic nuclear polarization devices that lack 1H radiofrequency hardware, measurements which are deleteriously influenced by radiation damping or complicated by the presence of large background signals, and situations where the acquisition of a thermal equilibrium spectrum is not feasible.

scholarly journals Competing transfer pathways in direct and indirect dynamic nuclear polarization magic anglespinning nuclear magnetic resonance experiments on HIV-1 capsid assemblies: implications for sensitivity and resolution

2021 ◽  
Vol 2 (1) ◽  
pp. 239-249
Author(s):  
Ivan V. Sergeyev ◽  
Caitlin M. Quinn ◽  
Jochem Struppe ◽  
Angela M. Gronenborn ◽  
Tatyana Polenova
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Dynamic Nuclear Polarization ◽  
Nuclear Polarization ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Large Signal ◽  
Experimental Conditions ◽  
Hiv 1 ◽  
Nuclear Magnetic

Abstract. Dynamic nuclear polarization (DNP)-enhanced magic angle spinning (MAS) nuclear magnetic resonance (NMR) of biological systems is a rapidly growing field. Large signal enhancements make the technique particularly attractive for signal-limited cases, such as studies of complex biological assemblies or at natural isotopic abundance. However, spectral resolution is considerably reduced compared to ambient-temperature non-DNP spectra. Herein, we report a systematic investigation into sensitivity and resolution of 1D and 2D 13C-detected DNP MAS NMR experiments on HIV-1 CA capsid protein tubular assemblies. We show that the magnitude and sign of signal enhancement as well as the homogeneous line width are strongly dependent on the biradical concentration, the dominant polarization transfer pathway, and the enhancement buildup time. Our findings provide guidance for optimal choice of sample preparation and experimental conditions in DNP experiments.

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