title: Interaction of human pregnancy-associated plasma protein-A with serine proteinases.
abstract: Human pregnancy-associated plasma protein A (PAPP-A) inhibited significantly the proteolytic activity of bovine trypsin and human plasmin. Trypsin or plasmin treatment of PAPP-A resulted in the generation of a major 85 kDa component and the rapid cleavage of internal thiol esters. The results indicated that both of these serine proteinases bound in a 1:1 stoichiometry to PAPP-A. The PAPP-A-bound enzymes were found to be enzymatically active towards small synthetic substrates and inaccessible to inactivation by soybean trypsin inhibitor and alpha 1-proteinase inhibitor. The mechanism of proteinase inhibition was likely to be entrapment, as described for alpha 2-macroglobulin.
authors.affiliation: Central Research Laboratory, Postgraduate Physician Training Institute, Novokuznetsk, Russian Federation.
authors.forename: N A
authors.initials: NA
authors.lastname: Zorin
authors.forename: S G
authors.initials: SG
authors.lastname: Zhabin
authors.forename: N N
authors.initials: NN
authors.lastname: Semenkov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D005341:Fibrinolysin / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000494:pharmacology; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism / Q000494:pharmacology*; D011480:Protease Inhibitors / Q000494:pharmacology*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors; D000515:alpha 1-Antitrypsin / Q000494:pharmacology; D000516:alpha-Amylases / Q000037:antagonists & inhibitors
chemical_list: D010940:Plant Proteins; D011480:Protease Inhibitors; D015842:Serine Proteinase Inhibitors; D014361:Trypsin Inhibitors; D000515:alpha 1-Antitrypsin; D000516:alpha-Amylases; D014357:Trypsin; D005341:Fibrinolysin; D011266:Pregnancy-Associated Plasma Protein-A