|
We exploit high-field NMR spectroscopy to elucidate the conformation of peptides and proteins in solution. A main emphasis of our effort is in deriving structures compatible with NMR constraints, such as experimental Overhauser connectivities, via interproton dipolar interactions, relaxation matrix analysis, distance-geometry computations and energy minimization/molecular dynamics simulations. The structures thus generated are analyzed vis-a-vis reported mutagenesis studies and compared with available X-ray crystallographic models. The dynamic behavior of the protein is experimentally characterized by means of magnetic relaxation, hydrogen isotope exchange and thermal stability profiles. These data, in turn, are correlated with the theoretical models, which thus provide valuable criteria for unveiling flexible regions of the polypeptide fold and to further refine the structure. The long-term goal of our project is to understand the biological function of proteins under physiological conditions, including accurate analysis of ligand-binding properties. This way, we hope to provide reliable criteria for tailored drug-protein interaction design. A main share of our effort focuses on domain substructures of blood coagulation proteins, the plasminogen system in particular. We are also investigating protein modules within cell matrix metalloproteinases, and proteins related to neurological function in the context of evolutionary relatedness. Another thrust of our effort is to develop robust algorithms for fast-throughput protein structural characterization requiring minimal NMR data. |
Department of Chemistry