In this work, we present a new ultrafast method for acquiring dynamic 2D EXchange SpectroscopY (EXSY) within a single acquisition. This technique reconstructs two-dimensional EXSY spectra from one-dimensional spectra based on the phase accrual during echo times. The Ultrafast-EXSY acquisition overcomes long acquisition times typically needed to acquire 2D NMR data by utilizing sparsity and phase dependence to dramatically undersample in the indirect time dimension. This allows for the acquisition of the 2D spectrum within a single shot. We have validated this method in simulations and hyperpolarized enzyme assay experiments separating the dehydration of pyruvate and lactate-to-pyruvate conversion. In a renal cell carcinoma cell (RCC) line, bidirectional exchange was observed. This new technique revealed decreased conversion of lactate-to-pyruvate with high expression of monocarboxylate transporter 4 (MCT4), known to correlate with aggressive cancer phenotypes. We also showed feasibility of this technique in vivo in a RCC model where bidirectional exchange was observed for pyruvate-lactate, pyruvate-alanine, and pyruvate-hydrate and were resolved in time. Broadly, the technique is well suited to investigate the dynamics of multiple exchange pathways and applicable to hyperpolarized substrates where chemical exchange has shown great promise across a range of disciplines.
Imaging metabolism with hyperpolarized (13)c-labeled cell substrates
From The DNP-NMR Blog:
Imaging metabolism with hyperpolarized (13)c-labeled cell substrates
Brindle, K.M., Imaging metabolism with hyperpolarized (13)c-labeled cell substrates. J Am Chem Soc, 2015. 137(20): p. 6418-27.
http://www.ncbi.nlm.nih.gov/pubmed/25950268
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06-15-2015 02:45 PM
[NMR paper] H/D exchange of a 15N labelled Tau fragment as measured by a simple Relax-EXSY experiment
H/D exchange of a 15N labelled Tau fragment as measured by a simple Relax-EXSY experiment
Publication date: December 2014
Source:Journal of Magnetic Resonance, Volume 249</br>
Author(s): Juan Lopez , Puneet Ahuja , Isabelle Landrieu , François-Xavier Cantrelle , Isabelle Huvent , Guy Lippens</br>
We present an equilibrium H/D exchange experiment to measure the exchange rates of labile amide protons in intrinsically unfolded proteins. By measuring the contribution of the H/D exchange to the apparent T 1 relaxation rates in solvents of different D2O content, we...
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11-14-2014 08:33 AM
Optimal variable flip angle schemes for dynamic acquisition of exchanging hyperpolarized substrates
From The DNP-NMR Blog:
Optimal variable flip angle schemes for dynamic acquisition of exchanging hyperpolarized substrates
Xing, Y., et al., Optimal variable flip angle schemes for dynamic acquisition of exchanging hyperpolarized substrates. J. Magn. Reson., 2013. 234(0): p. 75-81.
http://dx.doi.org/10.1016/j.jmr.2013.06.003
Longitudinal exchange: an alternative strategy towards quantification of dynamics parameters in ZZ exchange spectroscopy
Longitudinal exchange: an alternative strategy towards quantification of dynamics parameters in ZZ exchange spectroscopy
Abstract Longitudinal exchange experiments facilitate the quantification of the rates of interconversion between the exchanging species, along with their longitudinal relaxation rates, by analyzing the time-dependence of direct correlation and exchange cross peaks. Here we present a simple and robust alternative to this strategy, which is based on the combination of two complementary experiments, one with and one without resolving exchange cross peaks. We show that...
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09-30-2011 08:01 PM
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Solution NMR of Polypeptides Hyperpolarized by Dynamic Nuclear Polarization.
Anal Chem. 2011 Jun 7;
Authors: Ragavan M, Chen HY, Sekar G, Hilty C
Hyperpolarization of nuclear spins through techniques such as Dynamic Nuclear Polarization (DNP) can greatly increase the signal to noise ratio in NMR measurements, thus eliminating the need for signal averaging. This enables the study of many dynamic processes which would otherwise not be amenable to study by NMR spectroscopy....
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06-10-2011 11:52 AM
[NMR paper] Ultrafast 2D NMR spectroscopy using a continuous spatial encoding of the spin interac
Ultrafast 2D NMR spectroscopy using a continuous spatial encoding of the spin interactions.
Related Articles Ultrafast 2D NMR spectroscopy using a continuous spatial encoding of the spin interactions.
J Magn Reson. 2004 Nov;171(1):163-70
Authors: Shrot Y, Shapira B, Frydman L
A new protocol for acquiring multidimensional NMR spectra within a single scan is introduced and illustrated. The approach relies on applying a pair of frequency-chirped excitation and storage pulses in combination with echoing magnetic field gradients, in order to impart...
Dynamic UltraFast 2D EXchange SpectroscopY (UF-EXSY) of hyperpolarized substrates
Linear Mode
