Physalaemin, a non-mammalian tachykinin, binds selectively to neurokinin-1 (NK1) receptor with high affinity.
Physalaemin (PHY), an undecapeptide with the sequence pGlu-Ala-Asp-Pro-Asn-Lys-Phe-Tyr-Gly-Leu-Met-NH2, is a member of the tachykinin family of neuropeptides. PHY is very close to the mammalian tachykinin substance P (SP) in its function and chemical composition, and SP is well studied and characterized[1]. Physalaemin is a bradykinin potentiating peptide (BPP-5a)[2].
[1]. Grace CR, et al. Solution conformation of non-mammalian tachykinin physalaemin in lipid micelles by nuclear magnetic resonance. Biopolymers. 2011;96(3):252-9. [2]. Kobayashi J, Hydrolytic cleavage of pyroglutamyl-peptide bond. V. selective removal of pyroglutamic acid from biologically active pyroglutamylpeptides in high concentrations of aqueous methanesulfonic acid. Chem Pharm Bull (Tokyo). 2006 Jun;54(6):827-31.