A monoclonal antibody D51 recognizes the transferrin-receptor structure

Summary A monoclonal antibody D₅₁ has been obtained during immunization against human fetal thymus. The antibody binds to a variety of leukemic cells. This is similar to the staining pattern of the mAb OKT 9 and L 5.1, which recognize the transferrin receptor. However, there are some differences. The antibody immunoprecipitates a protein present on Molt-4 cells. Under reducing conditions this protein has a molecular weight of 90 K dalton. Under non-reducing conditions it has a molecular weight of 180 K dalton. This suggests a dimeric structure. The consecutive immunoprecipitation with D₅₁ and OKT 9, respectively, demonstrates that both antibodies recognize the structure of the transferrin receptor.Abbreviations mAb Monoclonal antibody - PHA Phytohemagglutinin - PMSF Phenyl-methyl-sulfonylfluoride - SDS Sodium-dodecylsulfate - EDTA Ethylenediaminetetra-acetic-acid - FCS Fetal Calf Serum. - PBL Peripheral blood lymphocytes - cpm Counts per minute - K Kilo - S. aureus Staphylococcus aureus Cowan I strain