Escorting Metal Ions

Abstract

Within cells, many metal ions arc like double-edged swords. They are essential components of various enzymes, but they can wreak havoc if allowed to run loose. Presumably, cells avoid the toxic effects of metal ions they need by restricting the movement of the ions within them. Studies of copper transport suggest that several proteins play a role in delivering copper ions to specific sites. However, none of the fundamental chemistry of these processes, including the oxidation state and substitution mechanisms of copper, is understood. For the first time, researchers have evidence indicating that one of these transporters—operating in the deliver of copper to a protein involved in iron uptake-functions as a chaperone. handing over the metal ion to a specific acceptor while maintaining the Cu(I) oxidation state. The findings come from a collaboration among the research groups of chemistry professors Thomas V. O'Halloran. Northwestern University, Evanston, Ill.; and James E. Penner-Hahn, University of Michig...