RECEPTOR-BINDING AND TYROSINE KINASE ACTIVATION BY INSULIN ANALOGS WITH EXTREME AFFINITIES STUDIED IN HUMAN HEPATOMA HEPG2 CELLS
RECEPTOR-BINDING AND TYROSINE KINASE ACTIVATION BY INSULIN ANALOGS WITH EXTREME AFFINITIES STUDIED IN HUMAN HEPATOMA HEPG2 CELLS
复制标题
DOI：
10.2337/diabetes.40.11.1488
复制
发表时间：
1991-11-01
期刊：
影响因子：
7.7
通讯作者：
GAMMELTOFT, S
中科院分区：
文献类型：
--
作者：
DREJER, K;KRUSE, V;GAMMELTOFT, S
用人肝癌细胞(HepG2)测定了5个1~4个氨基酸取代的人胰岛素类似物的胰岛素受体亲和力。与人胰岛素的结合亲和力AspB25为0.05%，AspB9为18%，GluB27为18%，AspB26为80%，AspB10为327%，HisA8、HisB4、GluB10、HisB27为687%。通过[I-125]TyrA14标记的胰岛素和未标记的类似物的稳态竞争实验和[I-125]TyrA14标记的类似物和胰岛素的动力学研究得到的结合常数基本相同。动力学研究表明，类似物之间亲和力的差异是由于解离和缔合速率常数的差异。胰岛素样生长因子I受体亲和力较低，AspB25胰岛素亲和力为0.005%，HisA8、HisB4、GluB10、HisB27胰岛素亲和力为0.6%。用外源底物聚(Glu80-Tyr20)测量，胰岛素类似物在激活来自HepG2细胞的溶解和部分纯化的胰岛素受体的酪氨酸激酶方面的效力与结合亲和力的顺序相同，然而，对于高亲和力类似物，实际值略高。我们得出结论，这些人胰岛素类似物在胰岛素受体结合和酪氨酸激酶刺激中具有活性，但在亲和力方面表现出很大的差异。
The insulin-receptor affinity of five human insulin analogues with one to four amino acid substitutions was measured with human hepatoma cells (HepG2). The binding affinities ranged from 0.05% for AspB25 insulin, 18% for AspB9,GluB27 insulin, 80% for AspB26 insulin, and 327% for AspB10 insulin to 687% for HisA8,HisB4,GluB10,HisB27 insulin relative to human insulin. Binding constants obtained by competition experiments at steady state with [I-125]TyrA14-labeled insulin and unlabeled analogues and by kinetic studies with [I-125]TyrA14-labeled analogues and insulin gave essentially the same values. The kinetic studies showed that differences in affinity between analogues were due to differences in both dissociation and association rate constants. The affinity for insulinlike growth factor I receptor was low, ranging from < 0.005% for AspB25 insulin to 0.6% for HisA8,HisB4,GluB10,HisB27 insulin. The potencies of insulin analogues in activation of the tyrosine kinase of solubilized and partially purified insulin receptors from HepG2 cells, measured with the exogenous substrate poly(Glu80-Tyr20), ranked in the same order as the binding affinities, the actual values being somewhat elevated for the high-affinity analogues, however. We conclude that these human insulin analogues are active in insulin-receptor binding and tyrosine kinase stimulation but show wide variation in affinity.