Fecha de publicación: -- Fuente: WIPO "tomato" The present invention relates to G protein peptidomimetics, in particular Gq/11 protein peptidomimetics, capable of stabilizing a GPCR, in particular a Gq/11 protein-coupled receptor, in an active conformational state. The G protein peptidomimetics are derived from the α5 helix of Gαq/11 protein or mini-Gq protein, in particular they arise from modifications of peptides comprising or consisting of the amino acid sequence set forth in SEQ ID NO:13 or SEQ ID NO:14. The invention further provides complexes of the G protein peptidomimetics and a GPCR, fusion polypeptides of a GPCR and the G protein peptidomimetics and compositions comprising the same. Further disclosed herein are uses of the G protein peptidomimetics, complexes, fusion polypeptides and compositions for determining the structure of a GPCR conformer, for screening for compounds capable of specifically binding to a GPCR conformer and as allosteric modulator of a GPCR and as a biosensor.