THE NERVE GROWTH FACTOR RECEPTOR: DEMONSTRATION OF SPECIFIC BINDING IN SYMPATHETIC GANGLIA

Abstract

Membrane preparations from superior cervical ganglia of the rabbit and calf bind [I25I] nerve growth factor (NGF) in a specific fashion indicating that this binding represents an interaction with the physiological NGF receptors. Items of evidence supporting this conclusion include the following:(1)Of a variety of tissues studied, specific NGF binding has been observed only in the superior cervical ganglia, the presumed target organ for NGF.(2)[125I] NGF binding is highly specific for the NGF peptide sequence and is not displaced by several other peptide hormones, though it is displaced by low amounts of nonradioactive NGF.(3)N-bromosuccinimide treatment of NGF preparations produces a decrease in receptor binding which closely parallels the decrease in biological activity.(4)NGF receptor binding is saturable with an affinity constant of about 2 × 10−10 M, which is similar to reported plasma levels of NGF and to concentrations of NGF which produce biological effects.