title: Purification and characterization of guinea-pig chorionic gonadotrophin.
abstract: A human chorionic gonadotrophin-like protein (GF-1, 1.0 g) from the placentae of 50 guinea-pigs killed at Day 26 of gestation was purified by pH and ammonium salt fractionation followed by column chromatography on DEAE-Sephadex and filtration on Sephadex G-100. Relative to the Second International hCG standard (MRC 61/6) GF-1 had an immunological potency of 21 000 i.u./mg as measured in a specific hCG-beta radioimmunoassay and, using the ovarian ascorbic acid depletion assay, an apparent biological potency of 24 064 i.u./mg. Isoelectric focusing yielded 6 bands between pH 4.4 and 5.7 and the material comprised two non-covalently linked subunits. The Stokes' radii were 3.40 nm for the native preparation, and 2.38 nm and 3.15 nm for GF-1-alpha and GF-1-beta subunits respectively. The guinea-pig placenta therefore produces a chorionic gonadotrophin which on purification has physicochemical, biological and immunological properties similar to those of hCG.
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000378:metabolism; D006063:Chorionic Gonadotropin / Q000302:isolation & purification / Q000494:pharmacology; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006168:Guinea Pigs; D007525:Isoelectric Focusing; D008970:Molecular Weight; D010053:Ovary / Q000187:drug effects / Q000378:metabolism; D010920:Placenta / Q000032:analysis*; D011247:Pregnancy; D011863:Radioimmunoassay
chemical_list: D006063:Chorionic Gonadotropin; D001205:Ascorbic Acid