Crystal structures of the human neurokinin 1 receptor in complex with clinically used antagonists

Abstract

Neurokinins (or tachykinins) are peptides that modulate a wide variety of human physiology through the neurokinin G protein-coupled receptor family, implicated in a diverse array of pathological processes. Here we report high-resolution crystal structures of the human NK1 receptor (NK1R) bound to two small-molecule antagonist therapeutics – aprepitant and netupitant and the progenitor antagonist CP-99,994. The structures reveal the detailed interactions between clinically approved antagonists and NK1R, which induce a distinct receptor conformation resulting in an interhelical hydrogen-bond network that cross-links the extracellular ends of helices V and VI. Furthermore, the high-resolution details of NK1R bound to netupitant establish a structural rationale for the lack of basal activity in NK1R. Taken together, these co-structures provide a comprehensive structural basis of NK1R antagonism and will facilitate the design of new therapeutics targeting the neurokinin receptor family.

Evaluation of Receptor Affinity, Analgesic Activity and Cytotoxicity of a Hybrid Peptide, AWL3020

“…Whether this is the case for AWL3020 cannot be stated as certain without further studies. A probable answer to this problem might come from molecular modelling using recently published structures of the receptor (Yin et al 2018;Schöppe et al 2019;Chen et al 2019b). We did not attempt such modelling, as the structures were unavailable at the time our study was being performed.…”

Crystal structure of the human oxytocin receptor

“…Recombinant baculovirus was generated using the MultiBac expression system. The receptor expression was performed as previously described 30 . Briefly, Spodoptera frugiperda (Sf9) insect cells were infected with high-titer P1 or P2 baculovirus stocks (multiplicity of infection 20 °C; however, for optimal crystal growth and diffraction the screening plates were subsequently transferred to a humidified incubator set to 16 °C.…”

In Vivo, In Vitro and In Silico Studies of the Hybrid Compound AA3266, an Opioid Agonist/NK1R Antagonist with Selective Cytotoxicity

“…At NK1R, the N -carboxybenzyl- d -tryptophan moiety occupies the deep portion of the binding pocket, forming interactions analogous to ones found experimentally for small molecular NK1R antagonists [ 65 , 71 , 72 ]. The opioid fragment extends towards the extracellular outlet of the receptor and the simulations suggest some mobility of this fragment, however an interaction between Tyr 1 amine and Glu193 is present for a great part of the collected trajectories.…”

“…In order to model AA3266 complex with the NK1 receptor, the acylated Ac-NH-NH<-Z- d -Trp fragment was docked to the 6HLL structure [ 65 ] with AutoDock 4.2.6 [ 59 ]. Docking predicted that the fragment goes deep in the binding pocket with d -Trp close to Pro112 and Met297 and the ring of the carboxybenzyl moiety close to His197 and Phe268, while the Ac-NH-NH would be directed to the middle part of the binding pocket.…”