Ai-proteinase

There are several additional plasmin inhibitors in the blood, e.g., a2-macroglobulin, ai-proteinase inhibitor, antithrombin, but their role in the control of fibrinolysis is questionable, because their action on plasmin is eliminated by fibrin. 

Zhang, Z., Winyard, P.G., Chidwick, K., Farrell, A., Pemberton, P., Carrell, KW. and Blake, D.R. (1990). Increased proteolytic cleavage of ai-antitrypsin (ai-proteinase inhibitor) in knee-joint synovial fluid from patients with rheumatoid arthritis. Biochim. Soc. Trans. 18, 898-899. 

AP ai-antiproteinase also known as ai-antitrypsin and ai-proteinase inhibitor... 

J. A. Xramps, C. Franken, and J. H. DJjkmaiL Quantity of antileufcopufeage relative to ai-proteinase inhibitor in peripheral airspaces of die human iung. Cun Sel 75 351 (1988). 

Hall, P. Roberts, R. Methionine oxidation and inactivation of ai-proteinase inhibitor by Cu and glucose. Biochim. Biophys. Acta 1992, 1121, 325-330. 

D. Johnson and J. Travis. The oxidative inactivation of human ai-proteinase inhibitor./. BioL Chem. 254 4022(1979). 

K. Beatty, J. Bieth, and J. Travis. Kinetics of association of serine proteinases with native and oxidized ai-proteinase inhibitor. J. Biol. Chem. 255 3931 (1980). 

B. Wallaert, B. Gressier, C. Aerts, C. Mizon, C. Voisin, and J. Mizon. Oxidative inactivation of ai-proteinase inhibitor by alveolar macrophages from healthy smokers requires the presence of myeloperoxydase. Am. J. Respir. Cell. Mol. Biol. 5 437 (1991). 

M. Padrines, M. Schneider-Pozzer, and J. G. Bieth. Inhibition of neutrophil elastase by ai-proteinase inhibitor oxidized by activated neutrophils. Am. Rev. Respir. Dis. 739 783 (1989). 

P. E. Desrochers and S. Weiss. Proteolytic inactivation of ai-proteinase inhibitor by a neutrophil metalloproteinase. J. Clin. Invest. 7 1646 (1988). 

D. A. Johnson, A. J. Barrett, and R. W. Mason. Cathepsin L inactivates ai-proteinase inhibitor by cleavage in the active site region. 3. Biol. Chem. 267 14748 (1986). 

K. Morihara, H. Tsuzuki, M. Harada, and T. Iwata. Purification of human plasma ai-proteinase inhibitor and its inactivation by Pseudomonas elastase. J. Biochem. 95 795 (1984). 

M. Bruch and J. G. Bieth. Influence of elastin on the inhibition of neutrophil elastase by ai-proteinase inhibitor and bronchial inhibitor. Potent inhibition of elastin-bound elastase by bronchial inhibitor. Biochem. J. 269 73 (1986). 

Patients with asbestosis seem to have a high protection against neutrophil elastase at the alveolar level, not totally due to ai-proteinase inhibitor. Electrophoretic studies by Scharfman et aL (1989) demonstrated a functional activity of only a part of immunoreactive arproteinase inlubitor. Therefore, there is no doubt that other inhibitors of neutrophil elastase are present at the alveolar level, one of them being the human mucus proteinase inhibitor (or bronchial inhibitor ) but it represents only 14 % of ai-proteinase inhibitor molar concentration (Boudier et al. 1987). 

The tissue-destructive potential of neutrophil-derived enzymes are countered by powerful plasma antiproteinases. These include ai-proteinase inhibitor, a2-macroglobulin, leukoproteinase inhibitor, plasminogen activator inhibitor (PAI-1), and tissue inhibitor of metalloproteinases (TIMPs) (4). Together, these inhibitors create an antiprotease shield in both plasma and in interstitial fluids. There is growing evidence that this antiprotease shield can be overwhelmed by the over exuberant neutrophil response in chronic wounds. 

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