Eight monoclonal antibodies, all IgG(2a), which recognize a 180/90-kDa glycoprotein similar in properties to the receptor for α2-macroglobulin of mouse embryo 3T3 cell plasma membranes, have been tested for their effect on the binding and uptake of α2-macroglobulin by live cells. One antibody directly inhibited binding of 125I-α2-macroglobulin under conditions in which 125I-transferrin binding to the transferrin receptor was unaffected. Another monoclonal antibody decreased α2-macroglobulin binding when preincubated with cells at 37°C. This antibody was also capable of specifically binding to ligand-receptor complexes formed by preincubating 125I-α2-macroglobulin with detergent extracts of Swiss 3T3 cells. Immunoelectron microscopy showed that the 180/90-kDa glycoprotein was localized in coated pits of the cell surface and in intracellular endocytic vesicles (receptosomes/endosomes). The data suggest that the 180/90-kDa glycoprotein is a component of the receptor for α2-macroglobulin.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - 1986|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology