Barnes, Alexander, Nicholas Alaniva, Edward P. Saliba, Erika L. Sesti, and Patrick T. Judge. “Electron Decoupling with Chirped Microwave Pulses for Rapid Signal Acquisition and Electron Saturation Recovery.” Angewandte Chemie, March 28, 2019.
Dynamic nuclear polarization (DNP) increases NMR sensitivity by transferring polarization from electron to nuclear spins. Here we demonstrate that electron decoupling enables improved observation of DNP-enhanced 13C spins in direct dipolar contact with electron spins, thereby leading to an optimal delay between transients largely governed by relatively fast electron relaxation. Signal acquisition constitutes 12% of the total experimental time, significantly increasing signal-to-noise per unit time. We report the first measurement of electron longitudinal relaxation (T1e) during magicangle spinning (MAS) NMR through observation of DNP-enhanced NMR (T1e = 40 ± 6 ms, 40 mM trityl 4.0 kHz MAS, 4.3 K). With a 5 ms DNP period, electron decoupling results in a 195% increase in signal intensity. Chirped microwave pulses and MAS at 4.3 K are achieved with a custom spectrometer. MAS at 4.3 K, DNP, electron decoupling, and short recycle delays improves the sensitivity of 13C in the vicinity of the polarizing agent. This is the first demonstration of recovery times between MAS-NMR transients being governed by short electron T1 and fast DNP transfer.
Electron decoupling with cross polarization and dynamic nuclear polarization below 6 K #DNPNMR
From The DNP-NMR Blog:
Electron decoupling with cross polarization and dynamic nuclear polarization below 6 K #DNPNMR
Sesti, Erika L., Edward P. Saliba, Nicholas Alaniva, and Alexander B. Barnes. “Electron Decoupling with Cross Polarization and Dynamic Nuclear Polarization below 6 K.” Journal of Magnetic Resonance 295 (October 2018): 1–5.
https://doi.org/10.1016/j.jmr.2018.07.016.
Multiple frequency saturation pulses reduce CEST acquisition time for quantifying conformational exchange in biomolecules
Multiple frequency saturation pulses reduce CEST acquisition time for quantifying conformational exchange in biomolecules
Abstract
Exchange between conformational states is required for biomolecular catalysis, allostery, and folding. A variety of NMR experiments have been developed to quantify motional regimes ranging from nanoseconds to seconds. In this work, we describe an approach to speed up the acquisition of chemical exchange saturation transfer (CEST) experiments that are commonly used to probe millisecond to second conformational exchange in...
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05-24-2018 12:57 AM
Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization #DNPNMR
From The DNP-NMR Blog:
Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization #DNPNMR
Scott, F.J., et al., Frequency-agile gyrotron for electron decoupling and pulsed dynamic nuclear polarization. J Magn Reson, 2018. 289: p. 45-54.
https://www.ncbi.nlm.nih.gov/pubmed/29471275
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04-27-2018 10:26 PM
Electron Decoupling with Dynamic Nuclear Polarization in Rotating Solids #DNPNMR
From The DNP-NMR Blog:
Electron Decoupling with Dynamic Nuclear Polarization in Rotating Solids #DNPNMR
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Saliba, E.P., et al., Electron Decoupling with Dynamic Nuclear Polarization in Rotating Solids. J Am Chem Soc, 2017. 139(18): p. 6310-6313.
https://www.ncbi.nlm.nih.gov/pubmed/28429936
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08-11-2017 08:52 PM
Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy
Spin-Label CW Microwave Power Saturation and Rapid Passage with Triangular Non-Adiabatic Rapid Sweep (NARS) and Adiabatic Rapid Passage (ARP) EPR Spectroscopy
Publication date: Available online 11 April 2015
Source:Journal of Magnetic Resonance</br>
Author(s): Aaron W. Kittell , James S. Hyde</br>
Non-adiabatic rapid passage (NARS) electron paramagnetic resonance (EPR) spectroscopy was introduced by Kittell, A.W., Camenisch, T.G., Ratke, J.J. Sidabras, J.W., Hyde, J.S., 2011 as a general purpose technique to collect the pure absorption response. The technique has...
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04-12-2015 02:40 AM
Phase cycling with a 240 GHz, free electron laser-powered electron paramagnetic resonance spectrometer
From the The DNP-NMR Blog:
Phase cycling with a 240 GHz, free electron laser-powered electron paramagnetic resonance spectrometer
This is not an article directly related to DNP spectroscopy. However, it shows the tremendous progress made in the development of high-frequency, high-power sources that can be utilized for high-field EPR and eventually DNP experiments.
<div>Edwards, D.T., et al., Phase cycling with a 240 GHz, free electron laser-powered electron paramagnetic resonance spectrometer. Phys. Chem. Chem. Phys., 2013.
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04-15-2013 08:52 AM
[NMR paper] Gated electron transfers and electron pathways in azurin: a NMR dynamic study at mult
Gated electron transfers and electron pathways in azurin: a NMR dynamic study at multiple fields and temperatures.
Related Articles Gated electron transfers and electron pathways in azurin: a NMR dynamic study at multiple fields and temperatures.
J Mol Biol. 2004 Oct 1;342(5):1599-611
Authors: Zhuravleva AV, Korzhnev DM, Kupce E, Arseniev AS, Billeter M, Orekhov VY
Dynamic properties of electron transfer pathways in a small blue copper cupredoxin are explored using an extensive 15N NMR relaxation study of reduced Pseudomonas aeruginosa azurin...
Electron Decoupling with Chirped Microwave Pulses for Rapid Signal Acquisition and Electron Saturation Recovery #DNPNMR
Linear Mode
