In this award, funded by the Experimental Physical Chemistry Program of the Division of Chemistry, Professor Tatyana Polenova of the University of Delaware, together with her undergraduate and graduate student researchers, will develop methods of solid-state nuclear magnetic resonance spectroscopy to probe the chemical environment of Vanadium-51 in proteins and bioinorganic systems. The physical chemical research carried out here will benefit from the collaboration with a synthetic chemist -- Prof. Debbie Crans -- at Colorado State University. The majority of the work will focus on the vanadium haloperoxidase enzymes -- the most efficient halide oxidants known to date.
The ultimate goal of research like that of Prof. Polenova's group is to develop a better understanding of the role played by trace metals like Vanadium in biological systems. The nuclear magnetic resonance methods developed here will also likely be useful for studying the chemical environment of other Vanadium containing materials. Prof. Polenova's students receive excellent training in an interdisciplinary environment, and Prof. Polenova will continue to serve as a mentor to students from groups underrepresented in the sciences
The overall goal of this research is to elucidate the mechanisms of biological catalysis performed by an important and under-investigated family of enzymes, vanadium haloperoxidases, using solid-state nuclear magnetic resonance (NMR) spectroscopy and Density Functional Theory (DFT). This knowledge is important for development of vanadium enzymes with tuned halogenating and entirely novel activities, for biotechnological and synthetic applications. In a broader sense, this research will enhance our knowledge of the poorly understood biological role of vanadium. The scientific outcomes of this project are i) V-51 solid-state NMR investigations of R360A mutant of vanadium chloroperoxidase; ii) characterization of local environments of vanadium coordination complexes of unusual geometries and electronic structures; iii) characterization of vanadium sites in vanadium-substitited photocatalysts of mixed V(IV)/V(V) oxidation states; iv) development of NMR methodology for probing internuclear distances in vanadium-containing solids. The contributions to education, outreach and human resources development are: i) training and mentorship of a total of twenty-eight students at graduate, undergraduate, and postdoctoral levels in the PI and Co-PI laboratories; ii) training and mentorship of seven high-school summer students (six of these students were ACS-SEED scholars) in the PI laboratory; iii) training and mentorship of multiple undergraduate students in the REU, HURS, MARC, and IAEP programs by the Co-PI. The educational materials resulting from this project include one edited book (Ann E. McDermott and Tatyana Polenova (Editors) (2010) Solid-State NMR Studies of Biopolymers. John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom. ISBN: 978-0-470-72122-3) and two invited book chapters (i) Tatyana Polenova, Andrew S. Lipton, Paul D. Ellis (2012) Quadrupolar Metal Nuclides in Biological Materials. In "NMR of Quadrupolar Nuclei in Solid Materials", Eds. Sharon Ashbrook, Stephen Wimperis, Roderick Wasylishen, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom. ISBN: 978-0-470-97398-1). ii) Andrew S. Lipton, Tatyana Polenova, Paul D. Ellis (2010) Quadrupolar Metal Nuclides in Bioinorganic Chemistry: Solid-State NMR Studies. In "Solid-State NMR Studies of Biopolymers", Eds. Ann E. McDermott and Tatyana Polenova, John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom. ISBN: 978-0-470-72122-3) The NMR techniques developed in the course of this project are generally applicable to studies of diamagnetic vanadium sites in proteins, in bioinorganic and in technologically interesting inorganic materials. Thus we expect that our research will impact several fields, such as chemistry (physical, inorganic, and biochemistry), materials science, biotechnology and protein biophysics.
