Plasminogen-binding protein associated with the plasma membrane of cultured embryonic rat neocortical neurons

To investigate the receptor-like molecule(s) for plasminogen (PGn) on the neuronal surface, the properties of binding of PGn to the plasma membrane of cultured embryonic rat neocortical neurons were investigated. [125I]PGn was found to specifically bind to the plasma membrane depending on the incubation temperature and time. The binding was also affected strongly by ionic strength and slightly by Ca2+. Furthermore, ligand blotting analysis revealed that [125I]PGn binds to a major protein with an apparent molecular weight of 45 kDa among plasma membrane proteins. These results suggest that the 45-kDa protein is a PGn receptor-like molecule on the neuronal surface.