Isolation and Purification of Vanadium Haloperoxidase Mutants for Characterization by 51V Solid-state NMR Spectroscopy

Abstract

Vanadium containing compounds have shown excellent potential in the treatment of diabetes, particularly as insulin enhancing compounds, as well as in the treatment of some forms of cancer. However, in order for these compounds to be useful in biomedical applications, the structures of their vanadium active sites and the mechanisms of their biochemical activity need to be determined. Vanadium haloperoxidases (VHPO) are a specific class of vanadium containing enzymes commonly found in marine algae, lichens and terrestrial fungi. These enzymes are the most efficient halide oxidants known to date. The focus of this project is to understand the catalytic mechanism of VHPO and their active site mutants by utilizing 51V solid-state NMR spectroscopy as a site-specific probe of the diamagnetic “spectroscopically silent” vanadium active sites. This knowledge is expected to be important in designing artificial vanadium enzymes with tuned halogenating activities. In this thesis, two VCPO active site mutants as well as the wild type protein have been successfully isolated and purified, and 51V solid-state NMR spectra have been acquired.