An accessible two-dimensional solution nuclear magnetic resonance experiment on human ubiquitin

Solution-state nuclear magnetic resonance (NMR) is an invaluable tool in structural and molecular biology research, but may be underutilized in undergraduate laboratories because instrumentation for performing structural studies of macromolecules in aqueous solutions is not yet widely available for use in undergraduate laboratories. We have implemented an experiment that is ideal for more commonly available 4.8-7.0 Tesla, double-channel NMR instruments that would not usually be used for biomolecular NMR work. We analyzed a commercially available, N-15-enriched human ubiquitin sample with a two-dimensional correlation experiment using indirect H-1 evolution and direct N-15 detection, which produced spectra with high resolution on a spectrometer operating at 7.0 Tesla (300 MHz H-1 resonance frequency). The simplicity of the experiment makes it possible to be configured by undergraduate students with minimal supervision from the instructor. Students gain experience in acquiring multidimensional biomolecular NMR experiments, confirm that ubiquitin is stably folded, and observe the correspondence between specific signals and individual amino acids in ubiquitin.