Instruments

The NMR facility maintains two spectrometers used for a variety of applications, including structure determination of small molecules or proteins, metabolomics, and binding studies using saturation transfer dispersion (STD).

MUSC 600MHz Spectrometer: A shielded 600MHz Bruker Avance II spectrometer incorporates the latest digital receiver technology for a significant improvement in NMR sensitivity and facilitates operations in a four-channel setup. Available Probes: 5mm triple resonance (TXI; H- C-N): single-axis gradient, ATM 5mm quadruple resonance (QXI; H-F-C, P) triple-axis gradients. Additionally a recent equipment grant award has allowed us to purchase a QCI-cryoprobe to further enhance the sensitivity of our system by 400%. The QCI probe is a proton-optimized quadruple resonance NMR inverse probe (QCI; H-F, C, N, P) a modification to the proton coil will allow us to tune to 19F thereby increasing application use with minimal sacrifice to sensitivity. The probe allows for decoupling on multiple nuclei such as 13C, 31P and 15N; and is equipped with cold preamplifiers for 1H, 13C and 31P.

MUSC 400MHz Spectrometer: A Bruker Nanobay- 400 (9.4 T), operating at 400MHz proton, provides a moderately high field multi-nuclear NMR capability to MUSC and the College of Charleston. The Bruker Nanobay- 400, a top-of-the-line spectrometer, is capable of running most contemporary homonuclear, heteronuclear one and two-dimensional pulse sequences, using pre- designed software. The spectrometer is equipped with a 5mm Multinuclear Broadband Fluorine Observe Plus (BBFOPLUS) probe, which allows for the routine acquisition of 1D and 2D 1H-1H correlations as well as 1D 31P and 2D 1H-31P correlations. Indirectly detected 1H-13C, 1H-15N and 1H-31P spectral correlations are also routinely obtained. Directly detected 13C spectra as well as other nuclei with resonances between 39-161 MHz are also accessible. Gradient versions of some 2-dimensional pulse sequences are present as is a deuterium gradient shimming module that provides automated shimming of off-axis shims using Real-Time control board capabilities. The availability of shaped pulses allow for very selective excitation of a selected resonance, which results in much improved water suppression in peptide NMR. Because of the magnetic field strength of the spectrometer, the practical peptide molecular weight limit for meaningful interpretation of 2D spectra is 3-4kDa.