Topic summary
Substance P
Substance P (SP) is a neuropeptide, belonging to the tachykinin family of neuropeptides that acts as a neurotransmitter and a neuromodulator. Substance P and the closely related neurokinin A (NKA) are produced from a polyprotein precursor after alternative splicing of the preprotachykinin A gene. It is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) and has the following sequence:
with an amide group at the C-terminus. Substance P is released from the terminals of specific sensory nerves. It is found in the brain and spinal cord and is associated with inflammatory processes and pain.