Formation of the proton, zinc(II) and cobalt(II) complexes of GlyCys and CysGly was studied by pH-metric, spectrophotometric and 1H-NMR methods. CysGly forms stable bis-complexes with both metal ions, with cysteine-like (S,N)-coordination. (S,O)-coordination is favoured, however, in the zinc(II) and cobalt(II) complexes of GlyCys. The binding mode is supported by the deprotonation micro-constants of the ligands and protonated complexes, and by the results of spectrophotometric and NMR studies. Amide deprotonation and coordination can not be observed below pH 10 in any of the systems studied.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry