The conformation of insulin-like growth factors: relationships with insulins.
The insulin-like growth factors and hystricomorph insulins have been modelled by interactive computer graphics on the assumption that their sequence homology to insulin implies that they will have a similar tertiary structure. These studies suggest that, although the insulin-related molecules can adopt the insulin fold, they are unlikely to form hexamers and if they form dimers they will be of reduced stability. The non-suppressibility of insulin-like growth factors by anti-insulin antibodies is explained in terms of differences of surface residues in the region A8-A10 and B1-B5. Receptor affinity of insulins and insulin-like growth factors for insulin receptors is explicable in terms of a receptor-binding site in the vicinity of B25 Phe on the insulin surface. An equivalent region around B25 Tyr of insulin-like growth factors may be responsible for their binding to type 1 receptors, although binding type 2 receptors must involve a different surface region not shared by insulin.
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D003201:Computers; D006168:Guinea Pigs; D006196:Hagfishes; D006801:Humans; D007328:Insulin / Q000032:analysis; D007330:Insulin Antibodies / Q000276:immunology; D008958:Models, Molecular; D011487:Protein Conformation; D011972:Receptor, Insulin / Q000378:metabolism; D013002:Somatomedins / Q000276:immunology / Q000378:metabolism*; D013552:Swine
D007328:Insulin; D007330:Insulin Antibodies; D013002:Somatomedins; D011972:Receptor, Insulin