Post-Protein-Binding Reactivity and Modifications of the fac-Re(CO)(3)](+) Core

Abstract

The reactivity of the Re(CO)(3)(H2O)(2)](+) complex coordinated to the His15 residue of HEW lysozyme is described. In the fully metalated protein (Lys-1), the Re ion retains its reactivity only toward selected ligands, while others induce a ligand-mediated demetalation of the enzyme. It is further shown that some of the complexes that may be ``engineered'' on the lysozyme do not react with the free protein even if present in solution in excess. The formation of stable metal adducts starting from Lys-1 was confirmed by X-ray crystallography.