Transfer of copper and zinc from ionic and metallothionein-bound forms to Cu, Zn--superoxide dismutase - PubMed (original) (raw)

Affiliations

Comparative Study

Transfer of copper and zinc from ionic and metallothionein-bound forms to Cu, Zn--superoxide dismutase

K T Suzuki et al. Res Commun Mol Pathol Pharmacol. 1995 Mar.

Abstract

Reactivity in transfer of copper (Cu) and zinc (Zn) to their binding sites of superoxide dismutase (SOD) was examined in vitro by the HPLC/atomic absorption spectrophotometry. Ionic Cu (cuprous and cupric ions) were incorporated more efficiently than the metal bound to metallothionein. Cu binds not only to the Cu-binding site but also to the Zn-binding site. Although Zn in the reaction medium and the metal bound to the Zn-binding site of SOD affected little the reactivity in binding of ionic Cu, they disturbed the reactivity of Cu bound to metallothionein to the Cu-binding site. Both ionic and metallothionein-bound Zn were transferred at a comparable efficiency to the Zn-binding site but not to the Cu-binding site. Co-existing ionic Cu but not metallothionein-bound Cu in the medium inhibited the binding of Zn to SOD. The results indicate that ionic Cu can be transferred to both Cu- and Zn-binding sites of SOD more efficiently than metallothionein-bound Cu, while both ionic and metallothionein-bound Zn are transferred only to Zn-binding site at a comparable efficiency.

PubMed Disclaimer

Similar articles

Cited by

Publication types

MeSH terms

Substances