title: What factors influence the metal-proton spin-spin coupling constants in mercury- and cadmium-substutited rubredoxin?
abstract: The indirect metal-proton spin-spin coupling constants between protons in cysteine groups and the mercury or cadmium nucleus have been calculated for a small model of Me-rubredoxin complex (Me = Cd, Hg) by means of density functional theory with zeroth-order regular approximation Hamiltonian (DFT-ZORA). The calculated spin-spin coupling constants, in spite of the moderate size of the model system, are in good agreement with the values measured in NMR experiment, which are in the 0.29-0.56 Hz range for the Cd complex and in the 0.57-2.20 Hz range for the Hg complex. The robustness of the chosen method has been verified by calculations with a number of different exchange-correlation functionals and basis sets. Additionally, it has been shown that the short- and long-distance metal-proton coupling constants are affected mainly by the values of the metal-proton distance and the H-N-C-C dihedral angle.
authors.affiliation: Faculty of Chemistry, University of Warsaw , Pasteura 1, 02-093 Warszawa, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kauch
authors.forename: Magdalena
authors.initials: M
authors.lastname: Pecul