Ligands which bind weakly to vancomycin: Studies by 13C NMR spectroscopy

C NMR chemical shifts of vancomycin have been used to obtain the association constants for a number of ligands which bind weakly to the antibiotic. The change in these C chemical shifts upon stepwise addition of ligands provides evidence that the ligands bind in a manner analogous to natural cell-wall precursor analogues. The binding constants obtained are in good agreement with those determined earlier by other methods. Where the ligands are amino acids (glycine or alanine), a potential alkylammonium to amide carbonyl interaction does not promote binding.