Location and Quantification of Metal Ions in Enzymes Combining Polyacrylamide Gel Electrophoresis and Particle-Induced X-Ray Emission

Abstract

A method is presented to identify and determine the relative amounts of protein-bound metal ions in situ. Proteins or their sub- units are separated by SDS-PAGE, the appropriately dried gel sections are directly scanned by a collimated proton beam of 3 MeV energy, and the characteristic X-rays produced are detected. The determination of Fe content of an iron-sulfur protein (HiPiP), as well as the Fe and Ni analysis of the hydrogenase from Thiocapsa roseopersicina, have shown the feasibility of this technique.

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