title: First principle calculations of (113)Cd chemical shifts for proteins and model systems.
abstract: 113Cd isotropic NMR shieldings are calculated for a number of metal ion binding sites in proteins, using the GIAO-B3LYP and GIAO-HF methods with the uncontracted (19s15p9d4f) polarized basis set of Kellö and Sadlej on cadmium and 6-31G(d) on the ligands. The results compare favorably with experimental data, indicating that first principle calculations are a useful tool for structural interpretation of (113)Cd chemical shift data from metal ion containing proteins. The effect of different ligand types (thiolate, imidazole, water, and monodentate carboxylate), coordination number, and deviations of the coordination geometry from ideal structures is evaluated. In particular, the ligand type and coordination number are important factors, but also changes in cadmium-ligand bond lengths may cause significant changes of the chemical shift.
authors.affiliation: Quantum Protein Centre, Department of Physics, The Technical University of Denmark, Building 309, 2800 Lyngby, Denmark. lhemming@fysik.dtu.dk
authors.forename: Lars
authors.initials: L
authors.lastname: Hemmingsen
authors.forename: Lars
authors.initials: L
authors.lastname: Olsen
authors.forename: Jens
authors.initials: J
authors.lastname: Antony
authors.forename: Stephan P A
authors.initials: SP
authors.lastname: Sauer
mesh_terms: D001665:Binding Sites; D002104:Cadmium / Q000737:chemistry*; D002106:Cadmium Radioisotopes / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D007477:Ions; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D002106:Cadmium Radioisotopes; D007093:Imidazoles; D007477:Ions; D008024:Ligands; D009942:Organometallic Compounds; D011506:Proteins; D013438:Sulfhydryl Compounds; D002104:Cadmium; D014867:Water; C029899:imidazole