Multiple-bond carbonâ??carbon homonuclear mixing is a hurdle in extensively deuterated proteins and under fast MAS due to the absence of an effective proton dipolar-coupling network. Such conditions are now commonly employed in solid-state NMR spectroscopy. Here, we introduce an isotropic homonuclear 13Câ??13C through-bond mixing sequence, MOCCA, for the solid state. Even though applied under MAS, this scheme performs without rotor synchronization and thus does not pose the usual hurdles in terms of power dissipation for fast spinning. We compare its performance with existing homonuclear 13Câ??13C mixing schemes using a perdeuterated and partially proton-backexchanged protein. Based on the analysis of side chain carbonâ??carbon correlations, we show that particularly MOCCA with standard 180-degree pulses and delays leading to non-rotor-synchronized spacing performs exceptionally well. This method provides high magnetization transfer efficiency for multiple-bond transfer in the aliphatic region compared with other tested mixing sequences. In addition, we show that this sequence can also be tailor-made for recoupling within a selected spectral region using band-selective pulses.
[NMR paper] A new broadband homonuclear mixing pulse for NMR with low applied power.
A new broadband homonuclear mixing pulse for NMR with low applied power.
A new broadband homonuclear mixing pulse for NMR with low applied power.
J Chem Phys. 2014 Jul 14;141(2):024201
Authors: Coote P, Leigh KE, Yu TY, Khaneja N, Wagner G, Arthanari H
Abstract
Broadband homonuclear mixing pulses with low radiofrequency power are essential for NMR spectroscopy of proteins and small molecules, especially for emerging applications in high field NMR. We have analytically designed a mixing pulse with high bandwidth-to-power ratio,...
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07-17-2014 12:17 PM
Aliphatic chain length by isotropic mixing (ALCHIM): determining composition of complex lipid samples by 1H NMR spectroscopy
Aliphatic chain length by isotropic mixing (ALCHIM): determining composition of complex lipid samples by 1H NMR spectroscopy
Abstract
Quantifying the amounts and types of lipids present in mixtures is important in fields as diverse as medicine, food science, and biochemistry. Nuclear magnetic resonance (NMR) spectroscopy can quantify the total amounts of saturated and unsaturated fatty acids in mixtures, but identifying the length of saturated fatty acid or the position of unsaturation by NMR is a daunting challenge. We have developed an NMR...
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06-19-2014 10:21 PM
[NMR paper] Improved NMR experiments with (13)C-isotropic mixing for assignment of aromatic and aliphatic side chains in labeled proteins.
Improved NMR experiments with (13)C-isotropic mixing for assignment of aromatic and aliphatic side chains in labeled proteins.
http://www.bionmr.com//www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--production.springer.de-OnlineResources-Logos-springerlink.gif Related Articles Improved NMR experiments with (13)C-isotropic mixing for assignment of aromatic and aliphatic side chains in labeled proteins.
J Biomol NMR. 2014 Jan 4;
Authors: Kovacs H, Gossert A
Abstract
Three improved (13)C-spinlock experiments for side chain assignments of...
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01-07-2014 11:16 PM
[NMR paper] Efficient CO-CA transfer in highly deuterated proteins by band-selective homonuclear cross-polarization
Efficient CO-CA transfer in highly deuterated proteins by band-selective homonuclear cross-polarization
Available online 14 March 2013
Publication year: 2013
Source:Journal of Magnetic Resonance</br>
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Robust and efficient band-selective magnetization transfer between CO and CA spins can be achieved in highly deuterated solid proteins by dipolar-based homonuclear cross polarization. The approach is designed for moderate magic-angle spinning rates and high external magnetic fields where the isotropic chemical shift difference of CO and CA considerably exceeds the...
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03-16-2013 02:22 AM
[Question from NMRWiki Q&A forum] Pulse sequence for homonuclear correlation with SPC5 mixing period
Pulse sequence for homonuclear correlation with SPC5 mixing period
Hi,I'm looking for a pulse program suitable for Bruker Avance llI (topspin 2.1) which is 2D homonuclear correlation with a mixing period of the symmetry based pulse scheme - the SPC5 scheme. I took the basic PDSD experiment and just replaced the mixing period with the appropriate pulses of the SPC5 scheme but it didn't work. Does someone has a ready-to-run pulse scheme out there? Basically for 13C-13C correlation, the program starts with a 90 pulse on 1H, followed by CP from 1H to 13C, t1 evolution, 90 pulse on 13C, mixing...
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09-27-2012 03:49 PM
Estimating side-chain order in methyl-protonated, perdeuterated proteins via multiple-quantum relaxation violated coherence transfer NMR spectroscopy
Estimating side-chain order in methyl-protonated, perdeuterated proteins via multiple-quantum relaxation violated coherence transfer NMR spectroscopy
Abstract Relaxation violated coherence transfer NMR spectroscopy (Tugarinov et al. in J Am Chem Soc 129:1743â??1750, 2007) is an established experimental tool for quantitative estimation of the amplitudes of side-chain motions in methyl-protonated, highly deuterated proteins. Relaxation violated coherence transfer experiments monitor the build-up of methyl proton multiple-quantum coherences that can be created in magnetically equivalent...
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02-11-2012 10:31 AM
Homonuclear Mixing Sequences for Perdeuterated Proteins
Homonuclear Mixing Sequences for Perdeuterated Proteins
Publication year: 2010
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 26 October 2010</br>
Kuo-Ying, Huang , Ansgar B., Siemer , Ann E., McDermott</br>
We test the performance of several 13C homonuclear mixing sequences on perdeuterated microcrystalline ubiquitin. All sequences were applied without 1H decoupling and at relatively low MAS frequencies. We found that RFDR gave the highest overall transfer efficiency and that DREAM performs surprisingly well under these conditions being twice...
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10-27-2010 08:51 AM
Broadband homonuclear TOCSY with amplitude and phase-modulated RF mixing schemes
Broadband homonuclear TOCSY with amplitude and phase-modulated RF mixing schemes
Anika Kirschstein, Christian Herbst, Kerstin Riedel, Michela Carella, Jörg Leppert, Oliver Ohlenschläger, Matthias Görlach and Ramadurai Ramachandran
Journal of Biomolecular NMR; 2008; 40(4); pp 227-237
Abstract:
We have explored the design of broadband scalar coupling mediated 13C–13C and cross-relaxation suppressed 1H–1H TOCSY sequences employing phase/amplitude modulated inversion pulses. Considering a variety of supercycles, pulsewidths and a RF field strength of 10 kHz, the Fourier coefficients...