Extensive 1H NMR resonance assignment of proteins using natural abundance gradient‐enhanced 13C−1H correlation spectroscopy

摘要

>The reliability and completeness of 1H NMR resonance assignment can be improved by the use of 13C−1H HSQC correlation spectra on unlabelled protein samples using pulsed field gradients. This technique is illustrated on a 5.2 mM sample of the 79 residue Desulfovibrio vulgaris ferrocytochrome c ₅₅₃. Protons attached to the same carbon can be unambiguously paired in a HSQC spectrum. Contrary to 1H, most amino acids exhibit characteristic 13C chemical shift ranges, which can be used for 13C assignment. This technique is especially useful for long side chain residues, such as Gln, Glu, Lys, Arg.