Dr. Larrabee is developing and using three different structural probe techniques to study the coupled binuclear copper sites in hemocyanin, tyrosinase and laccase. These probes are: 1) substitution of other metals for copper followed by uv/vis, CD and MCD spectral studies; 2) binding of exogenous ligands to the native and metal substituted proteins, followed by spectral studies, and 3) infrared spectroscopy of the internal vibrational modes of bound exogenous ligands. Coupled binuclear copper is found at the active site of a variety of proteins of living systems from fungi to humans. These proteins are involved in oxygen transport (hemocyanins) or in activation of dioxygen (tyrosine, laccase). Because of the large size and complexity of these proteins the exact structures of their active sites are unknown. Most of our knowledge of these structures has developed through the study of their spectroscopic properties.
