Q-band Upgrade to an X-band Pulsed EPR spectrometer

总结。

Summary. A continuous wave and pulsed electron paramagnetic (EPR) spectrometer operating at 34 GHz (Q-band) is requested by investigators at MIT Chemistry, Harvard Medical School, Harvard Chemistry and Brandeis Biochemistry. The instrument’s capabilities include pulsed ENDOR and ELDOR. The primary motivation for the Q-band instrument is the much improved sensitivity and resolution available at 34 GHz as compared to our current X-band (9 GHz) spectrometer. This improved sensitivity and resolution will permit us to address many problems which at the moment are beyond our scientific reach. The instrument will complement high-end X-ray crystallography, nuclear magnetic resonance (NMR), and cryoelectron microscope (cryoEM) capabilities in the Boston area to enable multidisciplinary structural biology and mechanistic biochemistry investigations of questions that are of great biological and medical importance. Research projects from six major user groups (Griffin, Nocera, Nolan, Pandelia, Raines, and Suess) and those from another three minor groups (Betley Keissling, and Wagner) are included in the proposal. The instrument will advance the following health-related research: 1) ENDOR and ESSEM studies of reactive intermediates in radical SAM enzymes, metalloenzymes involved in human immunity, and polynuclear Fe complexes that mimic the nitrogenase FeMo-cofactor; 2) pulsed EPR/DNP methods aimed at developing methods to dynamically polarize proteins at high fields and 3) DEER studies of membrane and soluble proteins, collagen, and polysaccharide secondary structure;. We anticipate that further projects targeting membrane proteins important for example in neurological disease and anesthesia; and viral and bacterial proteins important in infectious disease will appear during the lifetime of the spectrometer.