Honegger A, Humbel R E
J Biol Chem. 1986 Jan 15;261(2):569-75.
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.
通过凝胶过滤、免疫亲和色谱、聚焦色谱和反相高压液相色谱从胎牛血清和成年牛血清中制备了胰岛素样生长因子I和II（IGF-I和IGF-II），并测定了它们完整的氨基酸序列。IGF-I和-II在成年和胎儿血清中均有发现。发现牛IGF-I的序列与人IGF-I的序列相同，而牛和人IGF-II之间67个氨基酸残基中有3个不同。差异位于分子的C肽区域。牛IGF-II与抗人及大鼠IGF-II的抗血清的免疫交叉反应性小于10%，但在从人胎盘受体置换人125I标记的IGF-II方面与人IGF-II等效。在测定的限度内，牛IGF-I在放射免疫测定和放射受体测定中与人IGF-I等效。
