Abstract: Method of determining GPCR and mutateable ligand binding ability, includes providing a well microtiter plate with well array having rows and columns, GPCR or rhodopsin in wells, and parent ligand mutant binding to GPCR when GPCR resides in conformation, contacting parent ligand mutants in wells with GPCR, coupling parent ligand to GPCR, and determining mutant ligand binding strength compared to standard parent ligand and GPCR by determining coupled mutant-GPCR complex in wells. Rhodopsin binding 403 mutants covering arrestin sequence provides functional 4th dimension arrestin crystal structures. Resulting single amino acid resolution functional maps reveal critical interactions in arrestin polar core and C-tail interrupted during activation. Amino acid patches reduce binding and act as direct binding rhodopsin interfaces. This and computational molecular docking active arrestin4 and light-activated rhodopsin develop arrestin-rhodopsin complex model.

Abstract: The present application discloses in detail mutant ligands of the human G protein alpha-subunit -G?i1-, wherein at least one amino acid residue has been replaced with alanine if the at least one amino acid residue is a non-alanine residue, or at least one amino acid residue has been replace with glycine if the at least one amino acid residue is alanine and wherein the at least one amino acid residue is comprised in a first group containing of the amino acid residues with position R32A, K54A, I55A, I56A, H57A, R176A, E245A, Y296A, T327A, N331A, V332A and D350A or is comprised in a second group containing G42A, A59G, T177A, D200A, A226G, E297A, A300G and F334A or is comprised in a third group containing V50A, A59G, R178A 30 and K180A.

Abstract: The present application discloses in detail mutant ligands of the human G protein alpha-subunit—G?i1—, wherein at least one amino acid residue has been replaced with alanine if the at least one amino acid residue is a non-alanine residue, or at least one amino acid residue has been replace with glycine if the at least one amino acid residue is alanine and wherein the at least one amino acid residue is comprised in a first group containing of the amino acid residues with position R32A, K54A, I55A, I56A, H57A, R176A, E245A, Y296A, T327A, N331A, V332A and D350A or is comprised in a second group containing G42A, A59G, T177A, D200A, A226G, E297A, A300G and F334A or is comprised in a third group containing V50A, A59G, R178A 30 and K180A.

Abstract: Method of determining GPCR and mutatable ligand binding ability, includes providing a well microtiter plate with well array having rows and columns, GPCR or rhodopsin in wells, and parent ligand mutant binding to GPCR when GPCR resides in conformation, contacting parent ligand mutants in wells with GPCR, coupling parent ligand to GPCR, and determining mutant ligand binding strength compared to standard parent ligand and GPCR by determining coupled mutant-GPCR complex in wells. Rhodopsin binding 403 mutants covering arrestin sequence provides functional 4th dimension arrestin crystal structures. Resulting single amino acid resolution functional maps reveal critical interactions in arrestin polar core and C-tail interrupted during activation. Amino acid patches reduce binding and act as direct binding rhodopsin interfaces. This and computational molecular docking active arrestin4 and light-activated rhodopsin develop arrestin-rhodopsin complex model.