title: The demonstration of two pregnancy-associated proteins with SP1 determinants in placental extracts.
abstract: The SP1 content of the placenta has been examined. It was found that, as in pregnancy serum, two variants of the protein existed in the placenta. The smaller molecule, with a beta 1 electrophoretic mobility, is readily extractable with phosphate buffered saline. The second larger molecule is more tightly bound in the placenta and requires Triton X-100 to be solubilized. The hypothesis is put forward that the larger alpha variant is the precursor form which is related more irregularly and in a smaller amount from the placenta into the maternal circulation.
mesh_terms: D001798:Blood Proteins / Q000032:analysis; D000939:Epitopes / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007122:Immunoelectrophoresis; D010920:Placenta / Q000032:analysis*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000032:analysis*; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis* / Q000235:genetics; D011268:Pregnancy-Specific beta 1-Glycoproteins / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification; D011863:Radioimmunoassay
chemical_list: D001798:Blood Proteins; D000939:Epitopes; D011257:Pregnancy Proteins; D011268:Pregnancy-Specific beta 1-Glycoproteins; D011266:Pregnancy-Associated Plasma Protein-A