The bioinorganic chemistry of zinc: synthetic analogues of zinc enzymes that feature tripodal ligands

Zinc, as a constituent of more than 300 enzymes, plays essential roles in biological systems. The active sites of these enzymes feature a zinc center attached to the protein backbone by three or four amino acid residues, the nature of which influences the specific function of the enzyme. In order to understand why different zinc enzymes utilize different amino acid residues at the active site, it is necessary to understand how, and why, the chemistry of zinc is modulated by its coordination environment. Answers to these questions are being provided by a study of synthetic analogues of zinc enzymes, i.e. small molecules that resemble the enzyme active sites. This article provides an account of those studies that have specifically used tripodal ligands to mimic the active site protein residues in an effort to ascertain the bioinorganic chemistry of zinc.