Combination of synchrotron radiation X-ray fluorescence with isoelectric focusing for study of metalloprotein distribution in cytosol of hepatocellular carcinoma and surrounding normal tissues

The combined use of synchrotron radiation X-ray fluorescence (SRXRF) and isoelectric focusing (IEF) has been developed that allows comparison of the distribution of metal-containing proteins in cytosol of human hepatocellular carcinoma (HCC) with its surrounding "normal'' tissues. Proteins in samples from two individuals were separated with thin layer IEF, and the contents of Fe, Cu and Zn in protein bands were determined with SRXRF after drying the IEF gel. The results show that the metal-containing proteins in these samples of hepatocellular cytosol are specific for a given patient, and the distribution patterns of metal-containing proteins are distinguishable between the HCC and "normal'' tissues. The technique has the advantages of quantifying trace elements and identifying proteins simultaneously.