Axelsson K, Johansson S, Eketorp G, Zazzi H, Hemmendorf B, Gellerfors P
Kabi Pharmacia Peptide Hormones, Stockholm, Sweden.
Eur J Biochem. 1992 Jun 15;206(3):987-94. doi: 10.1111/j.1432-1033.1992.tb17010.x.
The disulfide arrangement of yeast derived human insulin-like growth factor I (yIGF-I) was determined using a combination of Staphylococcus aureus V8 protease mapping, fast-atom-bombardment mass spectrometry as well as amino acid sequence and composition analysis. Three disulfide bridges were found between the following cysteine residues: Cys6-Cys48, Cys47-Cys52 and Cys18-Cys61. IGF-I isolated from human plasma (pIGF-I) was found to have an identical disulfide configuration. A yeast-derived isomeric form of IGF-I (yisoIGF-I) exhibited an altered disulfide arrangement: Cys6-Cys47, Cys48-Cys52 and Cys18-Cys61. Radioreceptor analysis of pIGF-I and yIGF-I showed high specific activity, 20,000 U/mg. However, yisoIGF-I demonstrated a severely reduced ability to bind to the IGF-I receptor (19%) and was less potent in provoking a mitogenic response in Balb/C 3T3 fibroblasts (50% at doses 10-100 ng/ml). The data demonstrate the importance of correct disulfide arrangement in IGF-I for full biological activity.
利用金黄色葡萄球菌V8蛋白酶图谱分析、快原子轰击质谱分析以及氨基酸序列和组成分析相结合的方法，确定了酵母衍生的人胰岛素样生长因子I（yIGF-I）的二硫键排列方式。在以下半胱氨酸残基之间发现了三个二硫键：Cys6-Cys48、Cys47-Cys52和Cys18-Cys61。从人血浆中分离出的胰岛素样生长因子I（pIGF-I）具有相同的二硫键构型。一种酵母衍生的胰岛素样生长因子I异构体（yisoIGF-I）表现出二硫键排列改变：Cys6-Cys47、Cys48-Cys52和Cys18-Cys61。对pIGF-I和yIGF-I的放射受体分析显示其具有高比活性，为20,000 U/mg。然而，yisoIGF-I与胰岛素样生长因子I受体结合的能力严重降低（19%），并且在刺激Balb/C 3T3成纤维细胞的促有丝分裂反应方面效力较低（在剂量为10 - 100 ng/ml时为50%）。这些数据证明了胰岛素样生长因子I中正确的二硫键排列对于其完整生物学活性的重要性。
