Isolation and physicochemical properties of human chorionic gonadotropin of hydatidiform mole

HCG of chorionic tissues of hydatidiform mole was purified using ammonium sulfate fractionation, ion exchange chromatography and gel filtration. The purified hCG has a molecular weight of 1.5x10(5). Three subunits of molecular weights 11,000, 17,000 and 31,000 were obtained after treatment with sodium dodecyl sulfate and beta-mercaptoethanol. Amino acid analysis indicates a high content of Asp. and Glu., but a low content of Pro. Carbohydrate content is only 15.2%, and the amount of amino sugars and sialic acid are also comparatively low. The biologic activity of the purified hCG's of chorionic tissues is much lower than that from urine.