Parallel bioassay on smooth muscle preparations demonstrated that: all TKs having a neutral or basic residue at position 7 from the C-terminus show a clear-cut preference for the NK1 TK receptor, reinforced by the presence of the aromatic doublet Phe-Phe or Phe-Tyr (aromatic TKs); all aliphatic TKs (Phe-Ile/Val) having an acidic residue at position 7 show a clear-cut preference for NK2/NK3 receptors, generally without selectivity for a single receptor. However, in aromatic TKs having the same acidic residue, the preference for NK2/NK3 receptors is weakened, with a more or less pronounced co-preference for the NK1 receptor. Amino acid substitutions in the C-terminal tripeptide may influence receptor affinity. (C) 2000 Elsevier Science Inc.
Severini, C., Salvadori, S., Guerrini, R., Falconieri-Erspamer, G., Mignogna, G., & Erspamer, V. (2000). Parallel bioassay of 39 tachykinins on 11 smooth muscle preparations. Structure and receptor selectivity/affinity relationship. Peptides, 21(11), 1587–1595. https://doi.org/10.1016/S0196-9781(00)00290-4