What is NMR?

Nuclear magnetic resonance (NMR) is a spectroscopic approach to observe local magnetic fields around certain nuclei being intrinsically magnetic. The NMR signals are generated by exciting nuclei with radio frequencies while being submitted to an external magnetic field. This is typically done in aqueous solution, but can also be performed with solid samples (see solid-state NMR).

More specifically, in structural biology, it is a method used for the determination of the three-dimensional molecular structure and dynamics of proteins and nucleic acids at atomic resolution. The results obtained from these measurements provide information about:

• How atoms are linked chemically (primary structure)
• How close atoms are positioned in space (secondary, tertiary structure)
• How rapidly they move with respect to each other

Among the techniques used to determine the structure of biomolecules at atomic resolution, NMR spectroscopy offers certain unique advantages, including (i) the possibility to study the dynamics of biomolecular folding and internal mobility over a wide range of timescales (from pico- to millisecond) and (ii) the capability to investigate intra- and intermolecular interactions under physiological conditions (Sugiki et al 2017).

Tutorial sections

• Instrumentation:
  • Overview of the instrumentation - to be familiar with the equipment in the laboratory
  • Software - pieces of software used by the instrument and for data analysis
• NMR experiment:
  • Sample requirements - how to prepare a good sample for NMR analysis
  • Running a basic 1D NMR experiment - first steps into data acquisition
  • 2D 15N-HSQC - bring the second dimension
• Data processing:
  • Basic processing of NMR data - initial data analysis and sample quality assessment

References for this tutorial

Demonstration data

If you would like to explore this tutorial with demonstration data, you can download these datasets:

• Ubiquitin dataset (ZIP file) for protein analysis. More experimental details and data organization on the GitHub page.
• RNA dataset (ZIP file) for RNA analysis. More experimental details and data organization on the GitHub page.

Websites

• Protein NMR | A Practical Guide
• eNMR
• University of Ottawa NMR Facility Blog
• UCSD Skaggs School of Pharmacy and Pharmaceutical Sciences NMR Facility blog

Software required

The instructions on how to install individual software programs on your personal computer are details on their respective websites.

• TopSpin
• CcpNmr Analysis
• nmrPipe
• ARIA

You also need to get the latest updates available from ccpNMR Analysis further down on their website.

Alternatively, the Structural Biology Platform has computers available where recent versions of these software programs are installed (TopSpin is only available on the computers controlling the spectrometers). Access to the computer room is controlled by access codes. Contact Normand Cyr in order to obtain a code.

Scientific literature

• Sattler M, et al (1999). Heteronuclear multidimensional NMR experiments for the structure determination of proteins in solution employing pulsed field gradients. Progress in Nuclear Magnetic Resonance Spectroscopy.