T₂ relaxation measurement with solvent suppression and implications to solvent suppression in general

Abstract

A number of suppression pulse sequences including Excitation Sculpting and WATERGATE were incorporated into the standard Carr-Purcell-Meiboom-Gill (CPMG) program for T 2 measurement and experimentally evaluated. The chosen suppression schemes were of varying complexity encompassing pulse program elements, such as presaturation, gradients, and selective pulses, which are typically utilized for solvent suppression. The quality of the spectral data and the accuracy of T 2 measurements of the investigated suppression schemes were evaluated using three aqueous samples with increasing proton content in the water solvent,

Synthetic ligands for PreQ1 riboswitches provide structural and mechanistic insights into targeting RNA tertiary structure

“…2A). In addition to WaterLOGSY experiments, we evaluated the behavior of 1 in Carr-Purcell-Meiboom-Gill (CPMG) 1 H NMR experiments, which can be used to observe alterations in T 2 relaxation times of small molecules that bind large molecules in solution (with binding shortening relaxation time) 45,46 . Here, 1 was subjected to a CPMG pulse sequence in the absence and presence of both the Bs and Tt aptamers used in the WaterLOGSY experiments.…”

“…The spectra of the sample with and without RNA were aligned and scaled so that the peak heights of the internal standard N -methyl- l -valine were equivalent. Significantly attenuated ligand peaks (≥ 20%) in the presence of RNA were considered indicative of small molecule binding 45 .…”

A Small-Molecule Microarray Approach for the Identification of E2 Enzyme Inhibitors in Ubiquitin-Like Conjugation Pathways

“…We performed ligand-observed CPMG (LO-CPMG) T 2 relaxation NMR experiments to confirm that 2 binds directly to Ubc9. 14,15 Spectra were normalized to an internal negative control ( N -methyl- l -valine), which does not bind to Ubc9. In this experiment, substantial (>20%) decreases in peak intensities for protons of 2 were observed in the presence of Ubc9, indicating direct binding to the protein ( Fig.…”

17β-estradiol (E2) in membranes: Orientation and dynamic properties

“…All 1D proton and 2D 1 H- 13 C HSQC experiments were performed at 38°C on a Bruker AVANCE II 700 MHz NMR spectrometer. Water suppression was achieved by using excitation sculpting (19) for the 1D and WATERGATE (20, 21) for the 2D experiments.…”