The isolation of a rat alveolar macrophage lectin.

摘要: A lectin in rat alveolar macrophage membranes with a high affinity for binding ligands containing L-fucose and N-acetyl-D-glucosamine has been isolated by chromatography on Fuc-BSA-Sepharose (where Fuc is fucosyl BSA bovine serum albumin). The was extracted from lung homogenates Triton X-100, absorbed the extract onto presence of Ca2+ eluted removal Ca2+. After second adsorption to elution Fuc-BSA-Sepharose, three protein species were detected electrophoretically fractions that bind Fuc-BSA. One, which mannose/N-acetylglucosamine (Mr = 32,000) found earlier hepatocytes, removed anti-lectin IgG-Sepharose. Another 46,000) galactose. remaining 180,000) bound fucose N-acetylglucosamine but not Binding maximal between pH 6.5 9.0 dependent Immunocytological analysis rabbit IgG fluorescein-labeled goat anti-rabbit revealed be macrophages nonparenchymal cells liver. Thus, appears present likely involved receptor-mediated endocytosis. It distinctly different structurally hepatocyte similar ligand-binding specificity.