Probing the Metal-Ion-Binding Strength of the Hydroxyl Group

Introduction How Is the Extent of a Weak Interaction Best Quantified? Metal-Ion Complexes with Phosph(on)ate Groups as Primary Binding Sites Extent of the Hydroxyl−M2+ Interaction in Complexes of Hydroxymethylphosphonate Metal-Ion−Glycerol 1-Phosphate Systems: A Decreasing Solvent Polarity Favors Hydroxyl−M2+ Interactions Some Generalizations Regarding Phosph(on)ate Ligands with a Weakly Coordinating Second Site Metal-Ion Complexes with Carboxylate Groups as Primary Binding Sites Extent of Chelate Formation in Complexes of Hydroxyacetate and Related Ligands at I = 0.1 M Construction of the Reference Lines for Several M2+−Carboxylate Systems. Extent of Chelate Formation in Metal-Ion Complexes Formed with Hydroxy Carboxylates and Related Ligands Extent of Chelate Formation in Complexes of Hydroxyacetate-Type Ligands at I = 2 M Effect of Chelate-Ring Enlargement on the Hydroxyl−Metal-Ion Interaction Decreasing Solvent Polarity Favors the Hydroxyl−Metal-Ion Interaction in Complexes of Hydroxyacetate and Related O Ligands But Inhibits Thioether Interactions Metal-Ion Complexes with Amino Groups as Primary Binding Sites Estimation of Straight-Line Parameters for Complexes Formed with RCH2−NH2 Ligands Extent of Hydroxyl Group−Metal-Ion Binding in Complexes of 2-Aminoethanol and Related Ligands Comparison of the Metal-Ion-Binding Properties of 2-Aminoethanol and Triethanolamine Imidazole Residue as a Primary Binding Site in Ligands Containing also a Hydroxyl Group Pyridyl Nitrogen Is an Ideal Primary Metal-Ion-Binding Site for a Hydroxyl−Metal-Ion Interaction Isomeric Quantification of Metal-Ion Binding with Ligands Offering Two Hydroxyl Groups Effect of the Primary Binding Site on the Extent of the Hydroxyl−Metal-Ion Interaction Extent of Hydroxyl−Metal-Ion Interactions in Complexes Having a Bidentate Primary Binding Site Metal-Ion Complexes of Ligands with Two or More Hydroxyl Groups and at Least Four Binding Sites Complexes of the Alkaline EarthIons with Bistris and Some Related Buffers: Reduced Solvent Polarity Favors Metal-Ion−Hydroxyl Group Interactions Complexes of Several 3d and Related Metal Ions with Bistris and Derivatives Quest for Selectivity in Metal-Ion Coordination Involving Hydroxyl Groups General Conclusion

Characterization of metal ion-nucleic acid interactions in solution

Metal ions are inextricably involved with nucleic acids due to their polyanionic nature. In order to understand the structure and function of RNAs and DNAs, one needs to have detailed pictures on the structural, thermodynamic, and kinetic properties of metal ion interactions with these biomacromolecules. In this review we first compile the physicochemical properties of metal ions found and used in combination with nucleic acids in solution. The main part then describes the various methods developed over the past decades to investigate metal ion binding by nucleic acids in solution. This includes for example hydrolytic and radical cleavage experiments, mutational approaches, as well as kinetic isotope effects. In addition, spectroscopic techniques like EPR, lanthanide(III) luminescence, IR and Raman as well as various NMR methods are summarized. Aside from gaining knowledge about the thermodynamic properties on the metal ion-nucleic acid interactions, especially NMR can be used to extract information on the kinetics of ligand exchange rates of the metal ions applied. The final section deals with the influence of anions, buffers, and the solvent permittivity on the binding equilibria between metal ions and nucleic acids. Little is known on some of these aspects, but it is clear that these three factors have a large influence on the interaction between metal ions and nucleic acids