The two main thrusts of this research program are to understand structure-function relationships that occur in metalloproteins and in biomembranes.
Metalloproteins are quite diverse in their functions, which range from electron or ligand transport to catalysis. Different metals, as well as the specifics of the interaction between the metal ions and their protein environments, contribute to this diversity. Structure-function relationships in metalloproteins are investigated using metal ions as endogenous spectroscopic probes of the sites of ligand binding and/or catalysis. Studies focus on determining metal ion coordination that are reduced by ligand or substrate binding, dimerization, or polyelectrolyte complexation. Links between overall protein conformation and metal coordination are considered, as well as the thermodynamic parameters governing the processes mentioned above.
Drugs and small molecules perturb the structure of biomembranes through interaction with phospholipids, membrane-bound enzymes, or both. However, the connection between structural perturbation and altered enzyme function is often unclear. Structure-function relationships in biomembranes are investigated by using fluorescence and electron paramagnetic resonance spectroscopies to quantitate drug-induced changes in biomembrane structure that are correlated with alteration in activity of membrane-bound enzymes. Often exogenous fluorescent probes or spin labels are used to quantitate structural change, but endogenous tryptophane fluorescence is also followed. A series of drugs with similar structure but varying hydrophobicity, charge, and/or steric determinants is used to help elucidate how such factors modulate drug binding and hence the associate change in biomembrane function.
