title: Interaction of mature, unglycosylated and cell-free synthesized rat alpha 1-proteinase inhibitor with elastase.
abstract: Purified rat alpha 1-proteinase inhibitor (Mr 54 000) and porcine pancreatic elastase (Mr 26 000) formed a complex (Mr 82 000) resistant to heat treatment under denaturing and reducing conditions. A similar alpha 1-proteinase-inhibitor-elastase complex was detected by immunoprecipitation of alpha 1-proteinase inhibitor from the medium of [35S]methionine-labeled hepatocyte primary cultures after incubation with elastase. Treatment of hepatocytes with tunicamycin led to the secretion of an unglycosylated alpha 1-proteinase inhibitor (Mr 41 000) which also formed a complex with elastase (Mr 66 000). Complex formation (Mr 68 000) could also be observed between cell-free synthesized pre-alpha 1-proteinase inhibitor (Mr 43 000) and elastase (Mr 26 000). The results suggest that neither glycosylation nor removal of the signal peptide are required for the formation of a biologically active conformation of alpha 1-proteinase inhibitor.
mesh_terms: D000818:Animals; D001798:Blood Proteins; D002241:Carbohydrates; D002474:Cell-Free System; D055598:Chemical Phenomena; D002621:Chemistry; D008099:Liver; D008297:Male; D010179:Pancreas / Q000201:enzymology; D010196:Pancreatic Elastase; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship; D013552:Swine; D000515:alpha 1-Antitrypsin
chemical_list: D001798:Blood Proteins; D002241:Carbohydrates; D000515:alpha 1-Antitrypsin; D010196:Pancreatic Elastase