A novel technique for determining the stoichiometric ratio of metal to protein in metalloproteins after polyacrylamide gel electrophoresis is being developed. Native polyacrylamide gel electrophoresis was used for protein separation and provides thin samples necessary for ion beam analysis after drying. Particle induced X-ray emission (PIXE) spectroscopy is a non-destructive ion beam analysis technique excellently suited to determine the concentrations of heavy elements. Particle elastic scattering analysis (PESA) is a similar technique which measures the areal density of a thin target by quantifying the energy loss of the transmitted ions. A combination of PESA and PIXE has been developed to provide a quantitative technique for the determination of stoichiometric ratios in metalloproteins. Initial work has focused on Fe in myoglobin, while current work is focusing on the production of Cu-metallothionein from the CUP1-2 locus in Saccharomyces cerevisiae.

*This material is based upon work supported by the National Science Foundation under NSF-REU Grant No. 0452206