Two-dimensional hyperfine sublevel correlation spectroscopy applied in the study of a Cu(super 2+)-[2-(alpha-hydroxyethyl)thiamin pyrophosphate]-[pentapeptide] system as a model of thiamin-dependent enzymes

The synthesis and characterization of a model for the active site of thiamin-dependent enzymes in solution is reported. The data showed that, in the ternary Cu(super 2+)-[pentapeptide]-[HETPP] system at physiological pH, the peptide backbone offers three coordination sites to the metal ion and the coordination sphere is completed by two additional phosphate oxygen and the nitrogen N(1') of the thiamine coenzymes.