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Diffusion rate measurement for excited state with methyl ¹H TQ-CPMG

Files

You can get the example files from the GitHub ChemEx page.

This example demonstrates the use of CPMG experiment to measure diffusion rate constant of the excited state. In order to achieve such purpose an additional pair of gradients should be placed around the CPMG element, such idea has been successfully applied in the modified version of methyl ¹H TQ-CPMG experiment.1 In order to take into account the additional pair of gradients, a separate module (cpmg_ch3_1h_tq_diff) is required to fit datasets from this experiment.

In this example methyl ¹H TQ-CPMG datasets with different strengths of additional gradients are measured to obtain diffusion rate constant of the excited state. Note that those parameters about gradients around the CPMG element should be specified in experiment files, such as the strength and duration.

Footnotes​

  1. T. Yuwen, A. Sekhar, A. Baldwin, P. Vallurupalli, and L. E. Kay. Measuring Diffusion Constants of Invisible Protein Conformers by Triple-Quantum ¹H CPMG Relaxation Dispersion. Angew. Chem. Int. Ed. 57, 16777-16780 (2018). https://doi.org/10.1002/anie.201810868 ↩