Analysis of metal-containing proteins by gel electrophoresis and synchrotron radiation X-ray fluorescence

For the analysis of metal-containing proteins, sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) has been combined with synchrotron radiation X-ray fluorescence (SRXRF). In a pilot study the applicability of this combined method was tested in the analysis of metalloaded apoazurin and of the selenoproteins in rat testis homogenate. It was shown that it can be applied in the determination of the major stable binding forms of trace elements. After further improvement of the limits of detection the method will allow the analysis of trace element-containing proteins present in the samples at low concentrations.