Sulfonation and Sialylation of Gonadotropins in Women during the Menstrual Cycle, after Menopause, and with Polycystic Ovarian Syndrome and in Men

Context: More basic isoforms of LH and FSH appear in blood at midcycle and more acidic after menopause. The LH isoforms are more basic in women with polycystic ovarian syndrome (PCOS). These charge alterations may reflect differences in the number of two negatively charged residues on the gonadotropins: sialic acid and sulfonated N-acetylgalactosamine, residues that modulate the half-life of the gonadotropins in blood.