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
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 order, during a fixed CEST relaxation delay, with the same class of magnetization prepared at the start and selected at end of the CEST period. Here we present a pair of TROSY-based pulse schemes for recording amide and methyl 1H CEST profiles where longitudinal magnetization at the start evolves to produce two-spin order that is then selected at the completion of the CEST element. This selection process subtracts out contributions from 1Hā??1H cross-relaxation on the fly that would otherwise complicate analysis of the data. It also obviates the need to record spin-state selective CEST profiles as an alternative to eliminating NOE effects, leading to significant improvements in sensitivity. The utility of the approach is demonstrated on a sample of a cavity mutant of T4 lysozyme that undergoes chemical exchange between conformations where the cavity is free and occupied.
Longitudinal relaxation optimized amide 1 H-CEST experiments for studying slow chemical exchange processes in fully protonated proteins
Longitudinal relaxation optimized amide 1 H-CEST experiments for studying slow chemical exchange processes in fully protonated proteins
Abstract
Chemical Exchange Saturation Transfer (CEST) experiments are increasingly used to study slow timescale exchange processes in biomolecules. Although 15N- and 13C-CEST have been the approaches of choice, the development of spin state selective 1H-CEST pulse sequences that separate the effects of chemical and dipolar exchange significantly increases the utility of 1H-based experiments. Pulse schemes have been...
Evaluating the influence of initial magnetization conditions on extracted exchange parameters in NMR relaxation experiments: applications to CPMG and CEST
Evaluating the influence of initial magnetization conditions on extracted exchange parameters in NMR relaxation experiments: applications to CPMG and CEST
Abstract
Transient excursions of native protein states to functionally relevant higher energy conformations often occur on the Ī¼sā??ms timescale. NMR spectroscopy has emerged as an important tool to probe such processes using techniques such as Carrā??Purcellā??Meiboomā??Gill (CPMG) relaxation dispersion and Chemical Exchange Saturation Transfer (CEST). The extraction of kinetic and...
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07-30-2016 04:57 AM
[NMR paper] Transfer Rate Edited Experiment for the Selective Detection of Chemical Exchange via Saturaion Transfer (TRE-CEST)
Transfer Rate Edited Experiment for the Selective Detection of Chemical Exchange via Saturaion Transfer (TRE-CEST)
Publication date: Available online 7 May 2015
Source:Journal of Magnetic Resonance</br>
Author(s): Joshua I. Friedman , Ding Xia , Ravinder R. Regatte , Alexej Jerschow</br>
Chemical Exchange Saturation Transfer (CEST) magnetic resonance experiments have become valuable tools in magnetic resonance for the detection of low concentration solutes with far greater sensitivity than direct detection methods. Accurate measures of rates of chemical exchange...
13 C Ī± CEST experiment on uniformly 13 C-labeled proteins
13 C Ī± CEST experiment on uniformly 13 C-labeled proteins
Abstract
A new HSQC-based 13CĪ± CEST pulse scheme is proposed, which is suitable for uniformly 13C- or 13C, 15N-labeled samples in either water or heavy water. Except for Thr and Ser residues, the sensitivity of this scheme for uniformly labeled samples is similar to that of the previous scheme for selectively 13CĪ±-labeled samples with 100Ā*% isotope enrichment. The experiment is demonstrated on an acyl carrier protein domain. Our 13CĪ± CEST data reveal that the minor state of the acyl...
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12-03-2014 04:05 PM
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
A 2D 13C-CEST experiment for studying slowly exchanging protein systems using methyl probes: an application to protein folding
A 2D 13C-CEST experiment for studying slowly exchanging protein systems using methyl probes: an application to protein folding
Abstract A 2D 13C Chemical Exchange Saturation Transfer (CEST) experiment is presented for studying slowly exchanging protein systems using methyl groups as probes. The utility of the method is first established through studies of protein L, a small protein, for which chemical exchange on the millisecond time-scale is not observed. Subsequently the approach is applied to a folding exchange reaction of a G48M mutant Fyn SH3 domain, for which only cross-peaks...
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
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