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.

Comparative assessment of the consistency and quality of a highly purified FSH extracted from human urine (urofollitropin) and a recombinant human FSH (follitropin alpha).

The revolutionary development of biotechnology-derived therapeutic proteins has provided the expected improvements in quality, purity and consistency, as demonstrated in recombinant human FSH (rhFSH). However, the development of urine-derived gonadotrophins has not always shown comparable improvements. More recently, highly purified urine-derived FSH (uFSH-HP) products have become widely available. The relative purity, level of urine-derived contaminants, and consistency of one such highly purified human uFSH (uhFSH) (urofollitropin) has been assessed and directly compared with rhFSH (follitropin alpha). It has been demonstrated that the highly purified urofollitropin contains variable levels of urine-derived contaminant proteins and demonstrates a variable level of FSH purity, FSH isoforms, and delivered dose. These variable factors may contribute to the control of ovarian stimulation. The relative purity, variable consistency and the presence of contaminants indicates that the urofollitropin is, at best, a partially purified uFSH that is not able to meet the quality attributes of follitropin alpha (rhFSH).