Proteomic analyses of recombinant human follicle-stimulating hormone and urinary-derived gonadotropin preparations.

OBJECTIVE To understand the properties of each available gonadotropin preparation, especially in terms of the differences between urinary-derived and recombinant preparations. STUDY DESIGN Human menopausal gonadotropin (hMG), highly purified urinary-derived follicle-stimulating hormone (uFSH-HP) and recombinant FSH (rFSH) were subjected to 2-dimensional gel electrophoresis (2-DE), and protein spots were visualized by silver-staining procedures. Major spots were analyzed by mass spectrometry. Fluorescent-labeled preparations were also subjected to 2-DE to evaluate the quantities of FSH isohormones contained in each preparation. RESULTS 2-DE and mass spectrometry analyses of hMG identified many extracellular proteins as major impurities and several plasma membrane proteins including prion proteins. Both uFSH-HP and rFSH demonstrated slight impurities and showed several alpha and beta subunit isohormones. rFSH contained higher amounts of the basic isohormones of the alpha subunit than uFSH-HP, whereas the predominance of the basic isohormones was less significant in the beta subunit. CONCLUSION Proteomic analyses demonstrated the detailed protein profiles of each preparation. Differences in the quantities of alpha subunit isohormones may contribute to the variations in FSH activity observed between recombinant and urinary-derived FSH preparations.