Immunological properties of nerve growth factors.

Antisera were raised against nerve growth factors isolated from mouse salivary gland and five venoms representative of the three main families of poisonous snakes. Immunochemical cross-reactivity was assessed from the ability of the antisera to inhibit the biological activities of the heterologous antigens. The high and low molecular weight forms of the salivary gland factors were found to be immunologically identical but distinct from the snake venom factors. The snake venom factors, on the other hand, were immunologically closely related to each other but not identical.