Stoichiometry in zinc ion transfer from metallothionein to zinc finger peptides

Electrospray and nanospray ionizations are used to study the transfer of zinc ions between Zn-7-metallothionein and apo peptides that are models for several kinds of zinc finger proteins. A membrane experiment is reported here which demonstrates that interprotein contact is required for these transfers. Analysis on a quadrupole ion trap has allowed all reactants and all products to be monitored simultaneously. Evidence is provided for the preferential transfer of a single zinc ion from each Zn-7-metallothionein complex. (C) 2001 Elsevier Science B.V.