Heavy metal complexes as tools and models in bioinorganic chemistry

Mercuric ion and its organic derivatives interact strongly with the soft sulfur- and nitrogen-containing ligands in proteins. Two aspects of this phenomenon have been investigated in this work. The first focuses on attempts to harness the strong bonding as the basis of a novel crosslinking protocol for the isolation of DNA-binding transcription factors. Details of the synthesis and characterization of a bimetallic reagent, which is composed of an organomercurial tethered by a flexible linker chain to an analog of the antitumor agent cis-diammine-dichloroplatinum(II), are given in Chapter 1. The second chapter gives details of preliminary investigations into the capacity of this reagent to mediate reversible DNA-protein crosslinking.;The interaction of mercuric ion with the metalloregulatory protein MerR is the focus of Chapters 3 & 4. This protein binds competitively to mercuric ion in the presence of a large excess of other thiol-containing ligands such as glutathione; furthermore, mercuric ion is bound in preference to other soft metal ions such as Zn(II) and Cd(II). Spectral comparisons of synthetic mercuric thiolate complexes with Hg(II)-MerR indicate that metal ion recognition by the protein is due to the unusual tendency of Hg(II) to form stable three-coordinate complexes with thiolate ligands. Chapter 3 describes the synthesis of a series of Hg(II) complexes with the stoichiometry (Hg(SR)...