This core will produce proteins that will be used for several different purposes: structure determination using both X-ray crystallography and NMR; metal binding analyses; analysis of posttranslational modification in response to metals; metal transport measurements using liposome reconstitution and for injection into animals to generate antibodies. The Protein Purification Core will purify proteins from large-scale cultures of bacteria; bacculovirus infected insect cells and yeast. While most members of the CEMH use protein expression in their laboratories, there are several reasons to centralize protein expression. First, the Core will centralize both expertise and reagents. The Core will contain a catalogue of bacterial expressions systems, permitting the production and purification of epitope tagged proteins (HIS, GST, Maltose, TAP) in large amounts. Second, the scale of the Core will be designed to accommodate the need to produce different levels of proteins from the relatively small amounts required for antibody production (mg) to metal binding assay (10 mg) to X-Ray crystallography (100's mg).