title: Natural and synthetic forms of insulin-like growth factor-1 (IGF-1) and the potent derivative, destripeptide IGF-1: biological activities and receptor binding.
abstract: Insulin-like growth factor-1 (IGF-1), whether recombinant, chemically-synthesised or purified from bovine colostrum, was equipotent in radioreceptor assays with IGF-1 or insulin-like growth factor-2 (IGF-2) as radioligand as well as in its ability to stimulate protein synthesis in L6 myoblasts. The N-terminal truncated, destripeptide derivative of IGF-1 was approximately 7 times more potent than IGF-1 in the protein synthesis bioassay. This increased activity occurred equally with the peptide purified from bovine colostrum as with chemically-synthesised material. The higher potency of the truncated form was not associated with an increased ability to compete for IGF-1 binding to L6 myoblasts.
mesh_terms: D003429:Cross Reactions; D007334:Insulin-Like Growth Factor I / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D011869:Radioligand Assay; D011972:Receptor, Insulin / Q000032:analysis*; D017451:Receptors, Somatomedin; D011994:Recombinant Proteins / Q000378:metabolism; D013002:Somatomedins / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D017451:Receptors, Somatomedin; D011994:Recombinant Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin