Uperolein (Upe)

Uperolein, a physalaemin-like endecapeptide, has been shown to be selective for Neurokinin 1 receptor. The conformational range of the peptide revealed by NMR and CD studies has been analysed in terms of characteristic secondary features. Analysis of NMR data indicates that the global fold of Uperolein can be explained in terms of equilibrium between 310-helix and α-helix from residues 5 to 11.

An extended highly flexible N-terminus displays some degree of order and a possible turn structure. A comparison between the structures of Uperolein and Substance P, a prototype and endogenous Neurokinin 1 receptor agonist, indicates several common features in the distribution of hydrophobic and hydrophilic residues.