Petrides P E, Hintz R L, Bohlen P, Shively J E
Endocrinology. 1986 May;118(5):2034-8. doi: 10.1210/endo-118-5-2034.
Insulin-like growth factors (IGFs) I and II have been purified from Cohn fraction IV-1 of human plasma. After acid-ethanol extraction, the consecutive use of conventional gel filtration and reverse phase liquid chromatography has permitted the rapid isolation of these polypeptides. Purification was monitored by the use of specific RIAs. In both chromatography systems, separation was optimized by performing it on the same stationary phase but successively with mobile phases of different pH or different solute selectivity. The two polypeptides were shown to be pure by their unique amino acid composition, particularly by the absence of specific amino acids (histidine, tryptophan, and methionine), and their unique amino-terminal sequences. In addition, the lack of cross-contamination of the two growth factors with each other was established by the unique isoelectric focusing patterns of IGF-I at pI 8.25 and IGF-II at pI 6.5. From 900 g Cohn fraction IV-1, which is equivalent to 66 liters human plasma, approximately 100 micrograms of each IGF can be obtained by our procedure, which can easily be carried out in a clinical research laboratory.
胰岛素样生长因子（IGFs）I和II已从人血浆的Cohn IV-1组分中纯化出来。经过酸乙醇提取后，连续使用传统的凝胶过滤和反相液相色谱法能够快速分离出这些多肽。纯化过程通过使用特定的放射免疫分析法（RIAs）进行监测。在这两种色谱系统中，通过在相同的固定相上进行分离，但依次使用不同pH值或不同溶质选择性的流动相来优化分离效果。这两种多肽因其独特的氨基酸组成，特别是缺乏特定氨基酸（组氨酸、色氨酸和甲硫氨酸）以及独特的氨基末端序列，而显示为纯品。此外，通过IGF-I在pI 8.25和IGF-II在pI 6.5时独特的等电聚焦图谱，确定了这两种生长因子之间不存在相互交叉污染。从相当于66升人血浆的900克Cohn IV-1组分中，通过我们的方法大约可以获得每种IGF 100微克，该方法在临床研究实验室中易于实施。
