Binding of platinum to human transferrin

Abstract

A complex of platinum and human transferrin has been formed by appropriately combining apotransferrin (metal free protein) and potassiumchloroplatinate (K₂PtCl₄). Atomic absorption spectroscopy indicated that both primary binding sites on the protein participated in the complex. Electron paramagnetic resonance (EPR) examination showed that the bound platinum was not paramagnetic, and thus it is highly probable that the Pt ion is in the +2 oxidation state. The results suggest a possible mechanism for physiological distribution of third-transition-series metal.