Gel permeation studies of glycoprotein by high-performance liquid chromatography

The gel permeation method has contributed greatly to the isolation, purification and characterization of biological macromolecules. The development of high-performance liquid chromatography (HPLC) and its application to gel permeation augmented their importance in separation sciences. Although gel chromatography and gel electrophoresis on sodium dodecyl sulfate-poly-acrylamide have been widely used for the estimation of molecular weights of globular proteins because they are simple and accurate, the procedures when applied to glycoproteins often give a high estimate of molecular weight. In gel chromatography or gel electrophoresis, human cholrionic gonadotropin (hCG) has shown apparent molecular weight 2—3 times larger than the actual values. The purification of the modified subunits was achieved by Sephadex G-1000 gel chromatography. When the elution position of hCG subunits on a Sephadex column was compared with respect to the degree of deglycosylation, it was obvious that these modifications considerably affected the molecular size of glycoproteins.