Transverse Relaxation of Scalar Coupled Protons in Magnetic Resonance of Non-Deuterated Proteins
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.
Keywords: Quenching Echo Modulations ; High-Resolution Nmr ; Model-Free Approach ; Time-Scale ; Selective Excitation ; Correlation Spectroscopy ; Dispersion Experiments ; Radiofrequency Pulses ; Chemical-Exchange ; Single Scan
Record created on 2012-03-12, modified on 2016-08-09