Interactions of a monoclonal antibody to the insulin receptor with receptors for insulin-like growth factors.
A monoclonal antibody to the human insulin receptor was tested for its ability to inhibit the binding of 125I-insulin-like growth factor I (IGF-I) and 125I-insulin-like growth factor II (IGF-II) to their receptors in human placenta membranes and cultured human IM-9 lymphocytes. In both placenta membranes and IM-9 cells, the antibody progressively inhibited the binding of 125I-IGF-I to its receptor with a potency that was 300-fold less than its ability to inhibit the binding of 125I-insulin to its own receptor. In contrast, in human placenta membranes, this antibody inhibited the binding of 125I-IGF-II to its receptor only slightly. These studies indicate, therefore, that this monoclonal antibody binds preferentially to the insulin receptor but also crossreacts to a lesser extent with the IGF-I receptor.
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007328:Insulin / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D008214:Lymphocytes / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011972:Receptor, Insulin / Q000276:immunology* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000276:immunology* / Q000378:metabolism; D017451:Receptors, Somatomedin
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D007328:Insulin; D011956:Receptors, Cell Surface; D017451:Receptors, Somatomedin; C008147:insulin, iodo-; D011972:Receptor, Insulin