Insulin-like growth factors I and II in fetal and adult bovine serum. Purification, primary structures, and immunological cross-reactivities.
Insulin-like growth factors I and II (IGF-I and IGF-II) were prepared from fetal calf serum and adult bovine serum by gel filtration, immunoaffinity chromatography, chromatofocusing, and reverse-phase high pressure liquid chromatography, and their complete amino acid sequences determined. IGF-I and -II are found in both adult and fetal serum. The sequence of bovine IGF-I is found to be identical to that of human IGF-I, whereas 3 out of 67 amino acid residues are found to be different between bovine and human IGF-II. The differences are located in the C-peptide region of the molecule. Bovine IGF-II shows less than 10% immunological cross-reactivity with antisera against human and rat IGF-II, but is equipotent to human IGF-II in displacing human 125I-labeled IGF-II from human placental receptor. Bovine IGF-I was equipotent to human IGF-I in both radioimmunoassays and radioreceptor assays within the limits of the assay.
D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000097:blood* / Q000276:immunology; D007526:Isoelectric Point; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D011247:Pregnancy; D051381:Rats; D013002:Somatomedins / Q000097:blood*; D014357:Trypsin / Q000378:metabolism
D010446:Peptide Fragments; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D014357:Trypsin