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Title: Quantitative chemical exchange saturation transfer with hyperpolarized nuclei (qHyper-CEST): Sensing xenon-host exchange dynamics and binding affinities by NMR

The reversible binding of xenon to host molecules has found numerous applications in nuclear magnetic resonance studies. Quantitative characterization of the Xe exchange dynamics is important to understand and optimize the physico-chemical behavior of such Xe hosts, but is often challenging to achieve at low host concentrations. We have investigated a sensitive quantification technique based on chemical exchange saturation transfer with hyperpolarized nuclei, qHyper-CEST. Using simulated signals we demonstrated that qHyper-CEST yielded accurate and precise results and was robust in the presence of large amounts of noise (10%). This is of particular importance for samples with completely unknown exchange rates. Using these findings we experimentally determined the following exchange parameters for the Xe host cryptophane-A monoacid in dimethyl sulfoxide in one type of experiment: the ratio of bound and free Xe, the Xe exchange rate, the resonance frequencies of free and bound Xe, the Xe host occupancy, and the Xe binding constant. Taken together, qHyper-CEST facilitates sensitive quantification of the Xe exchange dynamics and binding to hydrophobic cavities and has the potential to analyze many different host systems or binding sites. This makes qHyper-CEST an indispensable tool for the efficient design of highly specific biosensors.
Authors:
; ;  [1]
  1. ERC Project BiosensorImaging, Leibniz-Institut für Molekulare Pharmakologie (FMP), 13125 Berlin (Germany)
Publication Date:
OSTI Identifier:
22415374
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AFFINITY; CONCENTRATION RATIO; DMSO; MOLECULES; NUCLEAR MAGNETIC RESONANCE; NUCLEI; SATURATION; SIMULATION; XENON