Concanavalin A changes not only the number of insulin binding sites but also the binding affinity in rat hepatoma cells in culture.
When rat hepatoma cells (R-Y121B) were first incubated with labeled insulin, followed by concanavalin A, at 500 micrograms/ml at 23 degrees C, the total cell-associated radioactivity increased. At 4 degrees C, however, this increase was not observed. Scatchard analysis revealed that concanavalin A increased insulin binding affinity. The bound insulin was internalized together with concanavalin A. When the cells were incubated with concanavalin A prior to insulin addition, however, the total cell-associated radioactivity decreased at both temperatures. This was caused by the masking of insulin binding sites by the lectin.
Sorimachi
K
K
Okayasu
T
T
Yasumura
Y
Y
D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism*; D007700:Kinetics; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D051381:Rats; D011952:Receptors, Concanavalin A / Q000378:metabolism
D007328:Insulin; D011952:Receptors, Concanavalin A; D003208:Concanavalin A