Pregnancy-associated plasma protein A interaction with heparin: a critical appraisal.
Positive affinity chromatography on heparin-Sepharose has proved a most crucial step in the purification of pregnancy-associated plasma protein A (PAPP-A). In this chromatographic procedure, PAPP-A was purified almost 500-fold from term pregnancy serum. Further purification was achieved by gel filtration and negative immunoaffinity chromatography. Both PAPP-A and free heparin inhibited granulocyte elastase (HGE) activity. Whereas free heparin inhibited only in hypotonic buffers, PAPP-A inhibited HGE in hypertonic buffers also. However, PAPP-A did not inhibit other proteases (trypsin, chymotrypsin, plasmin, fibroblast collagenase) or proteolytic cascades (complement activation). Since heparin was not detected in the purified PAPP-A, the inhibition of HGE was not due to desorbed or leeched heparin ligand.
Sinosich
M J
MJ
Department of Obstetrics and Gynaecology, Royal North Shore Hospital, St. Leonards, Australia.
Zakher
A
A
D002021:Buffers; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D005260:Female; D006493:Heparin / Q000494:pharmacology*; D006801:Humans; D019272:Leukocyte Elastase; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D011247:Pregnancy; D011266:Pregnancy-Associated Plasma Protein-A / Q000302:isolation & purification* / Q000494:pharmacology
D002021:Buffers; D006493:Heparin; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D011266:Pregnancy-Associated Plasma Protein-A