[Interaction of substance P receptor from rat brain with antibodies to its synthetic fragments and to substance P].

The peptides which correspond to the fragments 55-64, 182-192, 225-236 and 236-245 (P1-P4, respectively) of the rat brain substance P receptor were synthesized. Antibodies (Ab1-Ab4, respectively) against the KLH-conjugates of these peptides were raised and purified by affinity chromatography. None of the antibodies inhibited the Bolton-Hunter labelled substance P, [125I]BH-SP, binding to the rat brain membranes. On the other hand, Ab2 and Ab3 recognition of the SP receptor was found in ELISA experiments: the CHAPS--solubilized rat brain membranes could inhibit binding of these antibodies to the immobilized P2 and P3. Antibodies Ab1-Ab4 did not interact with the CHAPS-solubilized DDS cross-linked complex of the [125I]BH-SP and SP receptor. However, this complex retained the capacity of interacting with the affinity-purified antibodies against SP and was purified by sequential gel-permeation HPLC and protein A-chromatography.