For the past decade chemical exchange saturation transfer (CEST) experiments have been successfully applied to study exchange processes in biomolecules involving sparsely populated, transiently formed conformers. Initial implementations focused on extensive sampling of the CEST frequency domain, requiring significant measurement times. Here we show that the lengthy sampling schemes often used are not optimal and that reduced frequency sampling schedules can be developed without a priori knowledge of the exchange parameters, that only depend on the chosen B1 field, and, to a lesser extent, on the intrinsic transverse relaxation rates of ground state spins. The reduced sampling approach described here can be used synergistically with other methods for reducing measurement times such as those that excite multiple frequencies in the CEST dimension simultaneously, or make use of non-uniform sampling of indirectly detected time domains, to further decrease measurement times. The proposed approach is validated by analysis of simulated and experimental datasets.
Exchangeable deuterons introduce artifacts in amide 15 N CEST experiments used to study protein conformational exchange
Exchangeable deuterons introduce artifacts in amide 15 N CEST experiments used to study protein conformational exchange
Abstract
Protein molecules sample different conformations in solution and characterizing these conformations is crucial to understanding protein function. 15N CEST experiments are now routinely used to study slow conformational exchange of protein molecules between a ā??visibleā?? major state and ā??invisibleā?? minor states. These experiments have also been adapted to measure the solvent exchange rates of amide protons by exploiting...
[NMR paper] Residue Selective 15N CEST and CPMG Experiments for Studies of Millisecond Timescale Protein Dynamics
Residue Selective 15N CEST and CPMG Experiments for Studies of Millisecond Timescale Protein Dynamics
Publication date: Available online 1 June 2018
Source:Journal of Magnetic Resonance</br>
Author(s): Xiaogang Niu, Jienv Ding, Wenbo Zhang, Qianwen Li, Yunfei Hu, Changwen Jin</br>
Proteins are intrinsically dynamic molecules and undergo exchanges among multiple conformations to perform biological functions. The CPMG relaxation dispersion and CEST experiments are two important solution NMR techniques for characterizing the conformational exchange processes...
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06-03-2018 01:00 AM
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
A new class of CEST experiment based on selecting different magnetization components at the start and end of the CEST relaxation element: an application to 1 H CEST
A new class of CEST experiment based on selecting different magnetization components at the start and end of the CEST relaxation element: an application to 1 H CEST
Abstract
Chemical exchange saturation transfer (CEST) experiments are becoming increasingly popular for investigating biomolecular exchange dynamics with rates on the order of approximately 50ā??500Ā*sā??1 and a rich toolkit of different methods has emerged over the past few years. Typically, experiments are based on the evolution of longitudinal magnetization, or in some cases two-spin...
Triple resonance-based 13 C Ī± and 13 C Ī² CEST experiments for studies of ms timescale dynamics in proteins
Triple resonance-based 13 C Ī± and 13 C Ī² CEST experiments for studies of ms timescale dynamics in proteins
Abstract
A pair of triple resonance based CEST pulse schemes are presented for measuring 13CĪ± and 13CĪ² chemical shifts of sparsely populated and transiently formed conformers that are invisible to traditional NMR experiments. CEST profiles containing dips at resonance positions of 13CĪ± or 13CĪ² spins of major (ground) and minor (excited) conformers are obtained in a pseudo 3rd dimension that is generated by quantifying modulations of cross...
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10-28-2014 02:42 PM
[NMR paper] Optimizing ssNMR experiments for dilute proteins in heterogeneous mixtures at high magnetic fields.
Optimizing ssNMR experiments for dilute proteins in heterogeneous mixtures at high magnetic fields.
Related Articles Optimizing ssNMR experiments for dilute proteins in heterogeneous mixtures at high magnetic fields.
Magn Reson Chem. 2007 Dec;45 Suppl 1:S209-20
Authors: McNeill SA, Gor'kov PL, Struppe J, Brey WW, Long JR
Abstract
Solid-state NMR spectroscopy at high magnetic fields is proving to be an effective technique in structural biology, particularly for proteins which are not amenable to traditional X-ray and solution NMR...
Optimizing frequency sampling in CEST experiments
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