Binding of metal ions by Gamide and Ggly.

The affinity of, and the percentage absorbance change at 280 nm on, ferric or gallium ion binding to Gamide or Ggly were determined by fitting the mean data obtained in the absorbance experiments, described in the Fig 2 legend, to the models shown in Fig 1 with the program BioEqs. In the case of indium or ruthenium ions the corresponding values were obtained from fitting ferric ion titrations in the presence of various concentrations of indium or ruthenium ions, as described in the legends to Figs 3 and 4, respectively.