title: Towards a custom chelator for mercury: evaluation of coordination environments by molecular modeling.
abstract: A chelator is a molecule which binds a metal or metalloid ion by two or more functional groups to form a stable ring complex known as a chelate. Despite the widespread clinical use of so-called chelation therapy to remove mercury, none of the drugs currently in use have been shown to chelate mercury. Mercury can adopt three common coordination environments: linear diagonal, trigonal planar, and tetrahedral. We have previously discussed some of the structural criteria for optimal binding of mercury in linear-diagonal coordination with thiolate donors (George et al. in Chem. Res. Toxicol. 17:999-1006, 2004). Here we employed density functional theory and X-ray absorption spectroscopy to evaluate the ideal chain length for simple alkane dithiolate chelators of Hg(2+). We have also extended our previous calculations of the optimum coordination geometries to the three-coordinate [Hg(SR)(3)](-) case. Finally, we propose a new chelator "tripod" molecule, benzene-1,3,5-triamidopropanethiolate, or "Trithiopod," which is expected to bind Hg(2+) in three-coordinate geometry with very high affinity.
authors.affiliation: Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, Canada.
authors.forename: Juxia
authors.initials: J
authors.lastname: Fu
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Hoffmeyer
authors.forename: M Jake
authors.initials: MJ
authors.lastname: Pushie
authors.forename: Satya P
authors.initials: SP
authors.lastname: Singh
authors.forename: Ingrid J
authors.initials: IJ
authors.lastname: Pickering
authors.forename: Graham N
authors.initials: GN
authors.lastname: George
mesh_terms: D000473:Alkanes / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D008628:Mercury / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009941:Organomercury Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000737:chemistry; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000473:Alkanes; D002614:Chelating Agents; D009941:Organomercury Compounds; D013438:Sulfhydryl Compounds; D008628:Mercury