The transverse relaxation rates R (2) = 1/T (2) of protons can be determined by spin-echo sequences with multiple refocusing pulses using moderate radio-frequency field strengths and properly chosen inter-pulse delays so as to suppress echo modulations due to homonuclear scalar couplings. Combination with 2D heteronuclear correlation spectroscopy (HSQC) allows one to measure R (2) of arbitrary protons attached to nitrogen-15 or carbon-13 nuclei. Decays of six amide protons in the protein Ubiquitin that is nitrogen-15 enriched (but not deuterated) were measured at different temperatures.
Andrea Capozzi, Jean-Noël Hyacinthe, Thanh Phong Kevin Lê
David Lyndon Emsley, Jean-Philippe Ansermet, Michael Allan Hope, Federico De Biasi, Saumya Badoni, Aaron James Rossini, Dominik Józef Kubicki, Jonas Milani, Moreno Lelli, Gabriele Stevanato, Aditya Mishra, Claudia Esther Avalos
Mayeul Sylvain Chipaux, Hoda Shirzad