Identification of a plasma membrane protein that specifically binds bleomycin.
In this paper, the association of radiolabelled bleomycin on the plasma membrane of DC-3F cells is shown to be saturable, displaying classical features of a ligand-receptor binding. This association corresponds to the presence of 140,000 to 400,000 binding sites at the surface of the cells with a half-saturating concentration of 5 microM. Moreover, using a gel electrophoresis procedure to separate membrane proteins incubated with radiolabelled bleomycin, we demonstrate the existence of a membrane protein of about 250kDa able to specifically bind bleomycin. This membrane bleomycin-binding protein could play a major part in the association of bleomycin with the cells and in its further internalization, a process that has not been elucidated yet.
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Laboratoire de Physicochimie et Pharmacologie des Macromolécules Biologiques URA 147 CNRS, U 140 INSERM, Institut Gustave Roussy, Villejuif, France.
Belehradek
J
J
Mir
L M
LM
D000818:Animals; D001345:Autoradiography; D001761:Bleomycin / Q000378:metabolism* / Q000031:analogs & derivatives; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D003037:Cobalt Radioisotopes; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight
D002352:Carrier Proteins; D003037:Cobalt Radioisotopes; D008565:Membrane Proteins; C030187:cobalt bleomycin; D001761:Bleomycin