title: Independent metal-binding features of recombinant metallothioneins convergently draw a step gradation between Zn- and Cu-thioneins.
abstract: Data on the metal-binding behaviour of circa 20 recombinant metallothioneins (MTs) from evolutionary divergent organisms, gathered after years of systematic research, are here comprehensively analyzed. The consideration of four independent in vivo and in vitro metal-binding features reveals a gradation of the metal-binding character of the MTs considered that significantly coincides in a robust new classification: a stepwise gradation between Zn- and Cu-thioneins. The intermediate positions in this list are occupied by a group of polyvalent MTs, exhibiting a merging Zn-/Cu-thionein character that would suit general metal handling purposes. In contrast, the extreme positions are respectively occupied by those MTs that would have evolved to fulfil specialized Zn- or Cu-related physiological roles. Overall, the analyzed trends allow the proposal of a chemically- and biologically-sound new reflection on MT classification criteria.
authors.affiliation: Dept. de Química, Fac. de Ciències, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Roger
authors.initials: R
authors.lastname: Bofill
authors.forename: Mercè
authors.initials: M
authors.lastname: Capdevila
authors.forename: Sílvia
authors.initials: S
authors.lastname: Atrian
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008668:Metallothionein / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013054:Spectrophotometry, Atomic; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism
chemical_list: D020033:Protein Isoforms; D011994:Recombinant Proteins; D003300:Copper; D008668:Metallothionein; D015032:Zinc