Investigation of deferiprone binding to different essential metal ions using microscale thermophoresis and electrospray ionization mass spectrometry

In this study, the microscale thermophoresis (MST) method was applied to investigate the interaction of deferiprone with biometals (Fe3+, Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Mg2+, and Ca2+). The MST results indicated significant interactions of deferiprone with Fe3+, Cu2+, Zn2+, Co2+, and Ni2+. The data fitted to the Hill model shows stoichiometry more than 1:1. No binding was observed for deferiprone with Mn2+, Mg2+, and Ca2+. Electrospray ionization mass spectrometry confirms the results obtained by MST indicating stable molecular ion peaks for the complexes of deferiprone with either Fe3+, Zn2+, Cu2+, Co2+, Ni2+, and Mn2+, but no binding was observed for deferiprone with either Ca2+ and Mg2+ under a gas phase state. MST shows a fast and simple approach to study the binding of deferiprone to different essential metal ions. Moreover, the complexes were stable for investigation by mass spectrometry under a soft ionization technique like used electrospray ionization, which aided to confirm binding stoichiometry.