Iron(III) complexation of Desferrioxamine B encapsulated in apoferritin.
The dissociation of apoferritin into subunits at pH 2 followed by its reformation at pH 7.4 in presence of Desferrioxamine B (DFO) gives rise to a solution containing three DFO molecules trapped within the apoferritin (Apo-ferritin:DFO) and DFO molecules outside it. The untrapped DFO molecules in the solution were removed from Apo-ferritin:DFO by exhaustive dialysis until a negligible concentration was confirmed. The addition of Fe(III) to the dialyzed solution of Apo-ferritin:DFO resulted in the appearance of an orange-red color. The UV-Vis spectrum of this solution shows the characteristic absorption of the [DFOFe] complex centered at 425 nm. Following a similar procedure as for DFO, only one molecule of [DFOFe] was trapped in the apoferritin. The above results demonstrate the possibility of encapsulating a large molecule such as DFO in the apoferritin and, more interestingly, the ability of these DFO-encapsulated molecules to react with Fe(III) to give rise to an encapsulated [DFOFe] complex within the apoferritin.
Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain. josema@ugr.es
José M
JM
Domínguez-Vera
D000818:Animals; D001052:Apoferritins / Q000737:chemistry*; D003676:Deferoxamine / Q000737:chemistry*; D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry*; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007502:Iron Chelating Agents / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013154:Spleen / Q000737:chemistry
D005290:Ferric Compounds; D007502:Iron Chelating Agents; D001052:Apoferritins; D003676:Deferoxamine