Binding of Nerve Growth Factor Receptor in Sympathetic Ganglia

¹²⁵I-Labeled nerve growth factor binds to membrane preparations from superior cervical ganglia of rabbit in a specific fashion indicative of an interaction with the physiological receptor. Of various tissues examined, binding was observed only in the superior cervical ganglia, a presumed target organ of nerve growth factor. Binding of labeled factor is displaced by nonradioactive factor but not by several other peptide hormones. Binding to ganglia of preparations of nerve growth factor treated with N-bromosuccinimide closely parallels their biological activity. Binding of nerve growth factor receptor is saturable with an affinity constant of about 0.2 nM, similar to the reported plasma levels of the factor. Nerve growth factor does not elicit insulin-like biological effects in isolated adipocytes, and it does not modify the binding of [¹²⁵I]insulin or [¹²⁵I]epidermal growth factor to fat cells or liver membranes.