Acquisition of 500 MHz NMR Spectrometer for High Resolution Solution Studies

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Introduction For the ten research projects described here, the role of NMR spectroscopy ranges from an extremely useful complement to other spectroscopic and biochemical approaches to being the sine qua non for accomplishment of the project specific aims. In each case, however, a sophisticated, sensitive, high-field spectrometer is essential for the NMR components of the project. Such equipment is not available at the University of Illinois at Chicago (UIC) and this situation has led either to an interruption of on-going projects, to acquisition of data on a limited scale elsewhere, or to an external collaboration as a default. This is clearly unacceptable for a major Research I university such as UIC and must be urgently remedied. This proposal for a new 500MHz NMR spectrometer to be used for solution structural studies on proteins, peptides and complex natural products therefore represents part of a broader plan to address the major deficits in NMR spectroscopic facilities at UIC. The second part of the plan, to be dealt with separately, is to acquire additional NMR instrumentation equally-focussed to satisfy the needs of solids researchers. This two-pronged strategy was partly prompted by very sensible reviewers' comments on an earlier unsuccessful proposal to NSF-ARI for a 600MHz spectrometer. That single instrument proposal attempted to satisfy both solids and bio-macromolecule researchers. We think that the present bipartite, focussed-use strategy is both a more cost effective and efficient one. Proposed Instrumentation We are requesting 50% matching funds for the purchase of a narrow bore 500MHz NMR spectrometer optimized for solution structural studies on low concentrations of bio-macromolecules and complex plant-derived natural products. The spectrometer will consist of: 1. Basic two-RF channel (with lock) 500MHz spectrometer and standard bore ( 52mm) superconducting magnet with host computer and software, temperature control unit and vibration damping unit. 2. Additional two RF channels and 2H-decoupling hardware. 3. 5mm pulsed field gradient inverse triple resonance (13C and l5N) and inverse broadband (15N to 31P) probes. 5mm 19F-lH dual probe. 4. Additional temperature stabilization unit to give control of better than 0.1 C. Price quotes have been received from the two major vendors, Bruker and Varian. Although a detailed budget has been written for Bruker (p 31), the choice of instrument will be based principally on comparative performance, in addition to other considerations such as cost and future technical and equipment support. All available instruments will be evaluated. Research and Training to be Conducted The research to be conducted all relates to NMR solution structural studies on biomolecules. The studies fall into two main categories. (i) Structure elucidation of medium sized proteins, protein domains, and their complexes with DNA, with other protein domains and with peptide or polysaccharide ligands. Such studies benefit from the highestfield, most sensitive and experimentally-versatile spectrometer available. (ii) Structure elucidation of novel complex plant-derived natural products, which requires the sensitivity of a 500MHz spectrometer and the versatility of an instrument with up-to-date multi-channel pulse capabilities. Both graduate students and postdoctoral fellows will be trained in the theory and application of modern NMR spectroscopy by the core of six investigators with expertise in NMR spectroscopic methods. A joint bi-weekly NMR users research meeting is planned as a forum for dissemination of new methods and critical evaluation of acquired results. Activity resulting from funding State-of-the-art high field NMR instrumentation will have a profound and positive effect on structural research on campus. In addition to permitting the successful completion of on-going projects it will allow researchers who must now go elsewhere to carry out their studies on campus. This in turn will increase the local visibility of structurally-oriented research and help both in recruitment of structurally-oriented faculty, postdocs and students, and in fostering collaborations between faculty within the university.