Binding constants of isolated NGF-receptors from different species.

It is known that NGF-responsive cells bind NGF at cell surface receptors in a specific and saturable fashion and there are two separate kinds of receptor-ligand binding interactions as judged by Rosenthal analyses. Following isolation of nerve growth factor receptors from embryonic chicken sensory ganglia, rat pheochromocytoma cells and human neuroblastoma cells, equilibrium binding studies were carried out and two different equilibrium binding constants similar to that described for whole cells were determined. This evidence is consistent with the hypothesis that there are two different receptors for NGF which have been conserved.