Neuronal growth inhibitory factor (GIF), a metallothionein-like protein (metallothionein-3), impairs the survival and neurite formation of cultured neurons. Native GIF contains 4 Cu(I) and three Zn(II) ions organized in homometallic metal-thiolate clusters. However, the cluster localization is not known. In this study, the metal-thiolate clusters formed with monovalent and divalent metal ions i...