Forbes, B.McNeil, K.Scott, C.Surinya, K.Cosgrove, L.Wallace, J.2007-05-112007-05-112001Growth Factors, 2001; 19(3):163-1730897-71941029-2292http://hdl.handle.net/2440/28113The underlying specificity of the interaction between insulin-like growth factor-II (IGF-II) and mammalian Type 2 insulin-like growth factor/cation-independent mannose 6 phosphate receptor (IGF2R) is not understood. We have mutated residues A54 and L55 of IGF-II in the second A domain helix to arginine (found in the corresponding positions of IGF-I) and measured IGF2R binding. There is a 4- and 3.3-fold difference in dissociation constants for A54R IGF-II and L55R IGF-II, respectively, and a 6.6-fold difference for A54R L55R IGF-II compared with IGF-II as measured by BlAcore analysis using purified rat IGF2R. This is also confirmed using cross-linking and soluble rat placental membrane receptor binding assays. Binding to the type I IGF receptor (IGF1R) and IGF binding protein-2 (IGFBP-2) is not altered. We can, therefore, conclude that residues at positions 54 and 55 in IGF-II are important for and equally contribute to IGF2R binding.enCell MembranePlacentaAnimalsHumansRatsCationsReceptor, IGF Type 1PeptidesInsulin-Like Growth Factor IIProteinsReceptor, IGF Type 2Recombinant ProteinsCross-Linking ReagentsLigandsProtein Structure, TertiaryProtein BindingProtein FoldingDose-Response Relationship, DrugKineticsMutationPlasmidsModels, MolecularTime FactorsJournal article002001133710.3109/089771901090010840001733911000032-s2.0-003569554961458