Title: Enzymatic inactivation of human plasma C-inhibitor and α1-antichymotrypsin by pseudomonas aeruginosa proteinase and elastase
Abstract: Two major human plasma proteinase inhibitors, C1-inhibitor and α1-antichymotrypsin, were enzymatically inactivated by Pseudomonas aeruginosa elastase and proteinase. Incubation of C1-inhibitor with the Pseudomonas enzymes at inhibitor / enzyme molar ratios of 1000: 1 (elastase) or 22:1 (proteinase) resulted in cleavage of the 104 kDa intact inhibitor to an 89 kDa intermediate which retained full inhibitory activity against plasmin and plasma kallikrein. The intermediate was then cleaved to an 83 kDa inactive product. The initial non-inactivating cleavage of C1-inhibitor occurred in a region of the molecule readily accessible to limited proteolysis by both enzymes. The inactivating cleavage, however, occurred more readily with the elastase. α1-Antichymotrypsin was inactivated by P. aeruginosa proteinase and elastase by limited proteolysis at inhibitor / enzyme molar ratios of 14 000: 1. The 64 kDa intact inhibitor was cleaved to form an inactive 60 kDa product, and a low molecular mass peptide fragment was observed. No stable enzyme-inhibitor complexes were detected, and no random proteolysis of the inactivated inhibitors was noted, even after prolonged incubation. Catalytic inactivation of C1-inhibitor and α1-antichymotrypsin by P. aeruginosa proteinase and elastase may contribute to the tissue damage and hemorrhagic lesions which occur during pseudomonal infections.
Publication Year: 1984
Publication Date: 1984-08-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
Access and Citation
Cited By Count: 42
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot