Physicochemical characterization of recombinant human follicle stimulating hormone.

Here we describe the physicochemical characteriztics of recombinant human (rh) follicle stimulating hormone (FSH) and give an overview of the analytical methods which were used to describe the character of rhFSH. rhFSH is a glycoprotein comprised of two subunits which are held together by only non covalent bindings. The characterization of a glycoprotein means the complete elucidation of the primary structure of the molecule. This involves studies to confirm the protein backbone and elucidate the structure of the carbohydrate side-chains. A series of methodologies has been applied to the molecule to achieve this aim, e.g. sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, two-dimensional electrophoresis, isoelectric focusing, size exclusion high purification liquid chromatography (SE-HPLC), reverse phase HPLC (RP-HPLC), peptide mapping, N-terminal sequencing, mass spectrometry, carbohydrate composition analysis, sialic acid analysis and biological assay (Table I).