Abstract: The invention provides a fusion protein comprising, from N-terminus to C-terminus: a) a first portion of a Family B G-protein coupled receptor (GPCR) that comprises transmembrane helix (TM)-1, TM2 and TM3 of the GPCR; b) a stable protein domain; and c) a second portion of the GPCR comprising TM4, TM5, TM6 and TM7 of the GPCR. The invention also provides a method of crystallising a GPCR comprising providing the fusion protein of the invention and crystallising it to obtain crystals.

Abstract: The invention provides an assay for assessing the conformational stability of a membrane protein, comprising: (a) providing a sample comprising a first population and a second population of a membrane protein; wherein the membrane protein in the first population is labelled with a donor label and the membrane protein in the second population is labelled with an acceptor label, or the membrane protein in the first population is labelled with an acceptor label and the membrane protein in the second population is labelled with a donor label, (b) exposing the first and second populations of the membrane protein to a stability modulating agent and/or condition, (c) and assessing aggregation between membrane proteins of the first and second populations by activating the donor label to permit a distance-dependent interaction with the acceptor label, which interaction produces a detectable signal.

Abstract: The invention provides a fusion protein comprising, from N-terminus to C-terminus: a) a first portion of a Family B G-protein coupled receptor (GPCR) that comprises transmembrane helix (TM)-1, TM2 and TM3 of the GPCR; b) a stable protein domain; and c) a second portion of the GPCR comprising TM4, TM5, TM6 and TM7 of the GPCR. The invention also provides a method of crystallising a GPCR comprising providing the fusion protein of the invention and crystallising it to obtain crystals.

Abstract: The invention provides a fusion protein comprising, from N-terminus to C-terminus: a) a first portion of a Family B G-protein coupled receptor (GPCR) that comprises transmembrane helix (TM)-1, TM2 and TM3 of the GPCR; b) a stable protein domain; and c) a second portion of the GPCR comprising TM4, TM5, TM6 and TM7 of the GPCR. The invention also provides a method of crystallizing a GPCR comprising providing the fusion protein of the invention and crystallizing it to obtain crystals.

Abstract: The invention provides a method of predicting a three dimensional structural representation of a target protein of unknown structure, or part thereof, comprising: providing the coordinates of the human corticotropin-releasing factor receptor-1 (CRF1R) structure listed in Table A, Table B or Table C, optionally varied by a root mean square deviation of residue backbone atoms of not more than 4.383 ?, or selected coordinates thereof; and predicting the three-dimensional structural representation of the target protein, or part thereof, by modelling the structural representation on all or the selected coordinates of the CRF1R structure. The invention also provides the use of the CRF1R coordinates to select or design one or more binding partners of CRF1R.

Abstract: The invention provides an assay for assessing the conformational stability of a membrane protein, comprising: (a) providing a sample comprising a first population and a second population of a membrane protein; wherein the membrane protein in the first population is labelled with a donor label and the membrane protein in the second population is labelled with an acceptor label, or the membrane protein in the first population is labelled with an acceptor label and the membrane protein in the second population is labelled with a donor label, (b) exposing the first and second populations of the membrane protein to a stability modulating agent and/or condition, (c) and assessing aggregation between membrane proteins of the first and second populations by activating the donor label to permit a distance-dependent interaction with the acceptor label, which interaction produces a detectable signal.

Abstract: The invention provides a fusion protein comprising, from N-terminus to C-terminus: a) a first portion of a Family B G-protein coupled receptor (GPCR) that comprises transmembrane helix (TM)-1, TM2 and TM3 of the GPCR; b) a stable protein domain; and c) a second portion of the GPCR comprising TM4, TM5, TM6 and TM7 of the GPCR. The invention also provides a method of crystallising a GPCR comprising providing the fusion protein of the invention and crystallising it to obtain crystals.

Abstract: A method for producing a mutant G-protein coupled receptor (GPCR) with increased stability relative to a parent GPCR, the method comprising making one or more mutations in the amino acid sequence that defines a parent GPCR, wherein (i) the one or more mutations are located within a window of/plus or minus 5 residues, where/is the position of amino acid residue 2.46 in the parent GPCR when the parent GPCR is a Class 1 GPCR, or where/is the position of an equivalent amino acid residue in the parent GPCR when the parent GPCR is a Class 2 or 3 GPCR, and/or (ii) the one or more mutations are located within an amino acid sequence of transmembrane helix 7 in the parent GPCR which amino acid sequence interacts with the window of/plus or minus 5 residues, to provide one or more mutants of the parent GPCR with increased stability.

Abstract: A method for producing a mutant G-protein coupled receptor (GPCR) with increased stability relative to a parent GPCR, the method comprising making one or more mutations in the amino acid sequence that defines a parent GPCR, wherein (i) the one or more mutations are located within a window of / plus or minus 5 residues, where / is the position of amino acid residue 2.46 in the parent GPCR when the parent GPCR is a Class 1 GPCR, or where / is the position of an equivalent amino acid residue in the parent GPCR when the parent GPCR is a Class 2 or 3 GPCR, and/or (ii) the one or more mutations are located within an amino acid sequence of transmembrane helix 7 in the parent GPCR which amino acid sequence interacts with the window of / plus or minus 5 residues, to provide one or more mutants of the parent GPCR with increased stability.