title: Structural difference of the insulin receptors from circulating monocytes and erythrocytes.
abstract: We compared insulin receptors obtained from cells widely used in human studies, the circulating monocytes and erythrocytes. Biochemically, these receptors possess both binding (alpha-subunit) and tyrosine kinase (beta-subunit) activities similar to insulin receptors from other sources. Subtle differences in molecular weight, however, were detected between the alpha-subunits of these two cell types when analyzed by NaDodSO4-PAGE. Crosslinked [125I]insulin-labeled alpha-subunit of the monocyte insulin receptor was of higher apparent molecular weight than the alpha-subunit derived from red cells. Neuraminidase treatment of the alpha-subunits from each cell type indicated more sialic acid residues were present on the monocyte than the red cell alpha-subunit. The structural properties of the insulin receptors of human circulating cells are similar but not identical to insulin receptors of other characterized systems.
mesh_terms: D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004912:Erythrocytes / Q000378:metabolism*; D004854:Herpesvirus 4, Human; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism*; D009439:Neuraminidase; D010766:Phosphorylation; D011972:Receptor, Insulin / Q000032:analysis*
chemical_list: D011972:Receptor, Insulin; D009439:Neuraminidase