title: Inhibition of rat mast cell protease 1 by vitronectin.
abstract: Rat mast cell protease 1 (RMCP-1) is a chymotrypsin-like serine protease specifically expressed by connective tissue-type mast cells. The enzyme is stored in the secretory granules in a macromolecular complex with heparin proteoglycan. In the present investigation it was shown that RMCP-1 is inhibited by vitronectin (VN), an RGD-containing adhesive glycoprotein with heparin-binding properties. RMCP-1 that had been separated from heparin proteoglycan was less susceptible to inhibition than RMCP-1 present in complex with heparin proteoglycan. Pre-incubation of VN with purified heparin partially blocked the RMCP-1 inhibiting activity of VN. Plasma VN had negligible RMCP-1-inhibiting activity. However, heat treatment of plasma VN, which is known to expose the heparin-binding domain, induced RMCP-1-inhibiting activity. Affinity chromatography on immobilized VN showed that RMCP-1 bound with high affinity to VN. The binding of RMCP-1 to VN was not heparin-dependent since free RMCP-1 bound with equal affinity to the immobilized VN as RMCP-1 present in complex with heparin. The inhibition of RMCP-1 by VN was shown to be reversible.
authors.affiliation: Department of Veterinary Medical Chemistry, Biomedical Center, Uppsala, Sweden.
authors.forename: G
authors.initials: G
authors.lastname: Pejler
authors.forename: B R
authors.initials: BR
authors.lastname: Tomasini-Johansson
mesh_terms: D000818:Animals; D001665:Binding Sites; D002846:Chromatography, Affinity; D053818:Chymases; D006023:Glycoproteins / Q000737:chemistry / Q000494:pharmacology*; D006493:Heparin / Q000031:analogs & derivatives / Q000378:metabolism; D006358:Hot Temperature; D008407:Mast Cells / Q000201:enzymology*; D011480:Protease Inhibitors / Q000494:pharmacology*; D017510:Protein Folding; D011509:Proteoglycans / Q000378:metabolism; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology; D013329:Structure-Activity Relationship; D019096:Vitronectin
chemical_list: D006023:Glycoproteins; D011480:Protease Inhibitors; D011509:Proteoglycans; D019096:Vitronectin; C036090:heparin proteoglycan; D012965:Sodium Chloride; D006493:Heparin; D012697:Serine Endopeptidases; D053818:Chymases; C509231:Mcpt1 protein, rat