Molecular determinants of peptide and nonpeptide NK-2 receptor antagonists binding sites of the human tachykinin NK-2 receptor by site-directed mutagenesis

Preliminary mutational analysis of the human kinin B2receptor for nonpeptide antagonist ligands recognition

“…1), we focused our analysis on receptor amino acid residues within the TM segments and facing into lipophilic pockets, as resulting from a GRID software analysis (Goodford 1985). By using the same analysis method, in previous modeling studies on the tachykinin NK 2 receptor, we found an agreement between our receptor model and the experimental mutagenesis data (Giolitti et al 2000). An additional criterion for selecting residues to be mutated that we also considered is that each ligand also bear defined hydrophilic functional moieties that could find a counterpart in the receptor sequence to strengthen or enable the interaction in addition to a putative hydrophobic match.…”

Multifaceted Approach to Determine the Antagonist Molecular Mechanism and Interaction of Ibodutant ([1-(2-Phenyl-1R-{[1-(tetrahydropyran-4-ylmethyl)-piperidin-4-ylmethyl]-carbamoyl}-ethylcarbamoyl)-cyclopentyl]-amide) at the Human Tachykinin NK2 Receptor

“…at ASPET Journals on May 9, 2018 jpet.aspetjournals.org used antagonist radioligand likewise reflects the different binding epitopes of nepadutant and saredutant (Giolitti et al, 2000;Almeida et al, 2004 (Giolitti et al, 2000(Giolitti et al, , 2002Meini et al, 2004Meini et al, , 2005. We already showed that critical determinants for the binding of the peptide antagonist nepadutant were located in TMs 4, 5, and 6, whereas those responsible for the binding of the nonpeptide saredutant were located in TMs 6 and 7 (Giolitti et al, 2000).…”

“…4 Mutagenesis Studies at the Human Tachykinin NK 2 R to Identify the Binding Site of Ibodutant. To build experimental data to identify the binding site of ibodutant, its affinity was investigated at a number of 11 mutant receptors that were used previously to model the human tachykinin NK 2 R interaction with nepadutant, saredutant (Giolitti et al, 2000), and two structurally related antagonists of ibodutant (MEN13918 and MEN14268; Meini et al, 2004). The investigated amino acidic residues in the human tachykinin NK 2 R sequence are schematically represented in Fig.…”

“…We already showed that critical determinants for the binding of the peptide antagonist nepadutant were located in TMs 4, 5, and 6, whereas those responsible for the binding of the nonpeptide saredutant were located in TMs 6 and 7 (Giolitti et al, 2000). On the basis of mutagenesis combined with molecular modeling, we hypothesize a model of ibodutant docked to the human tachykinin NK 2 R and a binding pocket comprised among TMs 3,4,5,6,and 7 (Fig.…”

The First de Novo-Designed Antagonists of the Human NK2 Receptor

“…Pharmacological characterization of site-specific NK 2 receptor mutants has suggested that these two classes of ligands bind to nonidentical receptor sites which overlap partially near the extra-cellular portions of helices VI and VII. [14][15] In the absence of X-ray crystal structural data for these receptors, a 3D molecular model has been developed 16 which utilizes the projection structure of the light-activated GPCR rhodopsin as a template. 17 The resultant model accommodates data derived from sequence analysis algorithms for the putative transmembrane segments and indicates the relative orientation of amino acid residues within each R helix.…”