title: Purification and characterization of pregnancy associated plasma protein A (PAPP-A).
abstract: Pregnancy Associated Plasma Protein A (PAPP-A) has been isolated from late pregnancy plasma using ammonium sulphate precipitation, ion exchange chromatography, affinity chromatography on Concanavalin-A, gel filtration and negative affinity chromatography. It was found that PAPP-A is an alpha 2-glycoprotein of 750-820 000 MW, probably a dimer with each monomer being composed of 2 polypeptide chains of 218 000 MW. The amino acid composition as well as other physicochemical characteristics are similar to human alpha 2-macroglobulin. PAPP-A exhibits in vitro an inhibition of the activity of the complement system, of the caseinolytic activity of plasmin and possibly of the urokinase activation of plasminogen. The hypothesis that PAPP-A plays a role in the regulation of fibrinolysis during pregnancy is put forward.
mesh_terms: D000595:Amino Acid Sequence; D005260:Female; D005342:Fibrinolysis; D006023:Glycoproteins / Q000302:isolation & purification; D006801:Humans; D008970:Molecular Weight; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000302:isolation & purification*
chemical_list: D006023:Glycoproteins; D011257:Pregnancy Proteins