With support from the Chemistry Research Instrumentation and Facilities (CRIF) and Major Research Instrumentation (MRI) Program, Edmund P. Day of Emory University will develop a Superconducting Quantum Interference Device (SQUID) Nuclear Quadrupole Double Resonance (NQDR) Spectrometer. This state-of-the-art spectrometer will have sufficient sensitivity to detect quadrupolar nuclei at the active sites of proteins. Day and colleagues will then exploit this new spectrometer in several metallo-enzyme and model metallo-enzyme studies. The new spectrometer will have the following capabilities: 1) a superconducting quantum interference device as a detector; 2) adiabatic fast passage detection of the longitudinal magnetization of the solvent protons; 3) a very low sample temperature; 4) a very low detection field; 5) rapid polarization of the proton magnetization; 6) two quenchable superconducting magnets; and 7) a mu-metal shield.
Nuclear Magnetic Resonance (NMR) spectroscopy is the most powerful tool available to chemists and biochemists for the elucidation of the structure of molecules. It is used to identify unknown substances, characterize specific arrangements of atoms within molecules, and to study the dynamics of interactions between molecules in solution. The significance of this new instrument is that it will directly study the isotopes that NMR spectroscopy can only study indirectly. In combination, then, SQUID NQDR and conventional NMR will cover essentially all of the elements in biology.