Ultrafast diffusion exchange nuclear magnetic resonance

Abstract

The exchange of molecules between different physical or chemical environments due to diffusion or chemical transformations has a crucial role in a plethora of fundamental processes such as breathing, protein folding, chemical reactions and catalysis. Here, we introduce a method for a single-scan, ultrafast NMR analysis of molecular exchange based on the diffusion coefficient contrast. The method shortens the experiment time by one to four orders of magnitude. Consequently, it opens the way for high sensitivity quantification of important transient physical and chemical exchange processes such as in cellular metabolism. As a proof of principle, we demonstrate that the method reveals the structure of aggregates formed by surfactants relevant to aerosol research.

Accelerating Restricted Diffusion NMR Studies with Time-Resolved and Ultrafast Methods

“… 18 , 19 The method was also adapted successfully to the Laplace NMR, 20 comprising relaxation and diffusion experiments, allowing single-scan measurements of conventional diffusion ordered spectroscopy (DOSY), 21 − 25 or even two-dimensional (2D) Laplace correlation maps like T 1 – T 2 26 − 28 and D – T 2 , 28 − 30 as well as diffusion exchange spectroscopy (DEXSY). 31 …”

Identification of extracellular nanoparticle subsets by nuclear magnetic resonance

“…The sensitivity and information content of the DOSY and Hyper-CEST analysis can be improved signicantly by optimizing and standardizing the sample preparation, its concentrations and volumes, and by using higher magnetic elds and more efficient detection techniques. 53,54 Furthermore, the Hyper-CEST method could be made more specic by functionalizing cages with antibodies against exosomal surface markers, e.g. like translating the approach that has been done for CD14 to exosome-related targets such as CD81 or CD63.…”

“…Another potential approach to improve the sensitivity is to use more efficient methods to collect diffusion data. 53,54 For our proof-of-concept study, we tested several EV isolation methods: sequential ultracentrifugation, ltration, and size exclusion chromatography with Exo-spin™ columns. Because 6 Western blot of EKC and RCC EV samples, isolated by sequential ultracentrifugation (UCF) or by using Exo-spin columns (see Materials and methods), with antibodies against common EV markers ALIX, TSG101, CD81, and CD9.…”

Ultrafast Laplace NMR to study metal–ligand interactions in reversible polarisation transfer from parahydrogen

“…2 Consequently, ultrafast LNMR has been used to study molecular dynamics in a range of chemical systems including porous materials, 17,20 cellular metabolites, 21 and surfactant aggregates. 22 Nevertheless, these measurements can be limited by the low sensitivity of MR which is derived from perturbations of very small population differences across closely spaced nuclear spin energy levels. In fact, an astonishingly low number of nuclear spins (only 1 of every 32,000 1 H spins at 9.4 T) contribute to the MR signals detected using ultrafast LNMR and more traditional NMR methods.…”