title: Chemically and biologically harmless versus harmful ferritin/copper-metallothionein couples.
abstract: The simultaneous measurement of the decrease of available Fe(II) ions and the increase of available Fe(III) ions allowed the analysis of the ferroxidase activity of two distinct apoferritins. Although recombinant human apoferritin (HuFtH) rapidly oxidizes Fe(II) to Fe(III) , this iron is not properly stored in the ferritin cavity, as otherwise occurs in horse-spleen H/L-apoferritin (HsFt; H=heavy subunit, L=light subunit). Iron storage in these apoferritins was also studied in the presence of two copper-loaded mammalian metallothioneins (MT2 and MT3), a scenario that occurs in different brain-cell types. For HuFtH, unstored Fe(III) ions trigger the oxidation of Cu-MT2 with concomitant Cu(I) release. In contrast, there is no reaction with Cu-MT2 in the case of HsFt. Similarly, Cu-MT3 does not react during either HuFtH or HsFt iron reconstitution. Significantly, the combination of ferritin and metallothionein isoforms reported in glia and neuronal cells are precisely those combinations that avoid a harmful release of Fe(II) and Cu(I) ions.
authors.affiliation: Departamento de Química Inorgánica, Instituto de Biotecnología, Universidad de Granada, Fuentenueva s/n, 18071 Granada (Spain).
authors.forename: Fernando
authors.initials: F
authors.lastname: Carmona
authors.forename: Daniela
authors.initials: D
authors.lastname: Mendoza
authors.forename: Scheghajegh
authors.initials: S
authors.lastname: Kord
authors.forename: Michela
authors.initials: M
authors.lastname: Asperti
authors.forename: Paolo
authors.initials: P
authors.lastname: Arosio
authors.forename: Sílvia
authors.initials: S
authors.lastname: Atrian
authors.forename: Mercè
authors.initials: M
authors.lastname: Capdevila
authors.forename: Jose M
authors.initials: JM
authors.lastname: Dominguez-Vera
mesh_terms: D000818:Animals; D001052:Apoferritins / Q000378:metabolism*; D005290:Ferric Compounds / Q000032:analysis / Q000378:metabolism; D005293:Ferritins / Q000737:chemistry / Q000378:metabolism*; D005296:Ferrous Compounds / Q000032:analysis / Q000378:metabolism; D006736:Horses; D006801:Humans; D008668:Metallothionein / Q000032:analysis / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D011994:Recombinant Proteins; C007121:copper thionein; D005293:Ferritins; D001052:Apoferritins; D008668:Metallothionein
keywords: biological activity; ferritin; iron; metabolism; metalloenzymes