Rapid binding of copper(I) to folded aporusticyanin

Abstract

Kinetics of copper uptake in both oxidation states by the folded and unfolded forms of the type 1 copper protein rusticyanin have been studied. The speed of the binding of copper(I) to the folded rusticyanin is fast, and of the same order of magnitude as copper(I) uptake by the unfolded form. Thus, the binding of copper can be subsequent to the protein folding, contrary to previous proposals. Implications for the mechanism of the formation of the active holoprotein in vivo are discussed. © 2005 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.