title: Uptake of proteinase-alpha-macroglobulin complexes by macrophages.
abstract: Complexes of labelled proteinases (subtilopeptidase A, trypsin) with serum alpha 1-macroglobulin or alpha 2-macroglobulin are rapidly taken up in vitro by rabbit alveolar macrophages and peritoneal macrophages but not by mixed rabbit peripheral blood leukocytes. Enzyme, not bound to alpha 1- or alpha 2-macroglobulin, does not become associated with alveolar macrophages. Chemically inactivated subtilopeptidase A does not bind to alpha 1- or alpha 2-macroglobulin; chemically inactivated subtilopeptidase A in mixtures with alpha 1 - or alpha 2-microglobulin, does not interact with alveolar macrophages. Blocking experiments confirmed that the interaction of proteinase with alveolar macrophages is complex specific; uptake of labelled complex was prevented by the simultaneous addition of macroglobulin complexes formed with non-labelled subtilopeptidase A, subtilopeptidase B, trypsin or chymotrypsin but not by macroglobulin alone. The findings demonstrate a complex-specific interaction between proteinase-alpha-macroglobulin complexes and macrophages.
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000166:cytology; D001692:Biological Transport; D007700:Kinetics; D007962:Leukocytes / Q000378:metabolism; D008259:Macroglobulins / Q000378:metabolism* / Q000494:pharmacology; D046911:Macromolecular Substances; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism*; D011485:Protein Binding; D011650:Pulmonary Alveoli / Q000166:cytology; D011817:Rabbits
chemical_list: D008259:Macroglobulins; D046911:Macromolecular Substances; D010447:Peptide Hydrolases