Production and characterization of specific asialoglycoprotein receptor antibodies.

Monoclonal antibodies (MoAbs) were produced by immunizing BALB/c mice with asialoglycoprotein receptor (AGPR) purified from human liver. The purity of AGPR was confirmed by SDS-polyacrylamide gel electrophoresis and by amino acid sequence. An enzyme-linked immunoassay revealed 24 monoclonal antibodies which reacted with human AGPR. By Western blot analysis, all antibodies recognized the 46 kDa human AGPR under the non-reduced conditions and four MoAbs recognized reduced protein. Two MoAbs reacted with AGPR derived from rat, rabbit and mouse liver under both non-reduced and reduced conditions, suggesting that we could obtain antibodies which reacted with AGPR epitopes shared by different species. In immunohistochemical studies, 30201-MoAb reacted with human liver tissue but not with other tissues. This antibody immunoprecipitated two major bands of 46 kDa and 39 kDa from [35S]-methionine metabolically labeled human hepatoma HepG2 cells. The determinant recognized by 30201-MoAb is a common epitope of AGPR which is present in different species and in both the precursor and maturation forms of the receptor.