Competitive binding of amino-acids and nucleic acid constituents toward the nitrosyliron paramagnetic probe

The competitive binding of amino-acids and nucleic acid constituents with the FeI(NO)2 group has been studied. The Fermi contact interaction between the metal ion and the ligand nuclei has been investigated by means of isotopic substitution and computer simulation. Comparable binding powers have been shown by amino-acid and nucleic acids site, depending on pH. The availability of an ionized mercapto group in amino-acid side chains strongly modifies the co-ordination behaviour.