title: Acid-stable low molecular mass proteinase inhibitors in human lung lavage.
abstract: An acid-stable, low molecular mass proteinase inhibitor, bronchial mucus proteinase inhibitor (BMPI), has been isolated from sputum and partially characterised. A single band with a modal molecular mass of 18 700 was observed following SDS-polyacrylamide gel electrophoresis. BMPI inhibited human leukocyte elastase, cathepsin G, trypsin and chymotrypsin, but not porcine pancreatic elastase. Although BMPI had a molecular mass close to the similarly isolated inhibitor of Girard et al. (Girard, F., Tournier, J.M., Polu, J.M. & Sadoul, P. (1980), Bull. Eur. Physiopathol. Respir. 16 (Suppl.) 237-245), and although it showed immunological cross reactivity to the low molecular mass inhibitor of Kramps et al. (Kramps, J.A., Franken, C., Meyer, C.J.L.M. & Dijkman, J.H. (1981) J. Histochem. Cytochem. 29, 712-719), it was found to have an amino-acid profile different to any previously described inhibitor. BMPI was detectable in bronchoalveolar lavage fluid collected from healthy and diseased human lungs. The median molar ratio of BMPI/alpha 1-proteinase inhibitor (alpha 1 PI) observed in these lavage samples was 0.7, which is generally higher than those derived from the data of other authors. This suggests that BMPI is a different protein to those previously described, although its exact relationship to other low molecular mass proteinase inhibitors remains to be determined.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D003429:Cross Reactions; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D007700:Kinetics; D008168:Lung / Q000032:analysis*; D008970:Molecular Weight; D009093:Mucus / Q000032:analysis; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D011480:Protease Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D013183:Sputum / Q000032:analysis*; D007507:Therapeutic Irrigation
chemical_list: D000596:Amino Acids; D007106:Immune Sera; D011480:Protease Inhibitors; D010196:Pancreatic Elastase