不同年龄红细胞(人)的增溶胰岛素受体和胰岛素结合以及依赖于胰岛素的磷酸化反应

1.我们研究了人的不同年龄红细胞的胰岛素受体从膜上增溶后和胰岛素相结合的特征。结果表明,随着红细胞年龄的增加,增溶胰岛素受体和胰岛素的最大结合能力下降;ED_(50)降低,同时受体结合位点数减少。青年红细胞的增溶胰岛素受体数比去年的高一倍,但其亲和性不论在结合平衡状态或动力学状态都基本一致。 2.利用γ-~(32)P-ATP的~(32)P参入量研究了胰岛素对不同年龄红细胞增溶蛋白质及外源蛋白质的磷酸化的影响。在胰岛素存在时,磷酸化分别增加2.3—2.9倍,及3.4—4.4倍。胰岛素刺激青年红细胞的增溶蛋白质的磷酸化的敏感性为老年的2.4倍。 3.研究结果表明,单个人的血样可用来研究胰岛素受体的结合及激酶的性质。

INSULIN BINDING AND INSULIN DEPENDENT PHOSPHORYLATION OF SOLUBILIZED INSULIN RECEPTORS FROM HUMAN ERYTHROCYTES OF DIFFERENT AGES

1.The characteristics of insulin binding of solubilized insulin receptors from human erythrocytes of different ages have been studied.The results showed that the maximum binding,ED50 and the number of solubilized receptors were reduced as the age of erythrocytes increased.The number of insulin binding sites of young erythrocytes was twice as much as that of the old.Through equilibrium binding studies or kinetic studies of association,their binding affinities were found to be similar.2.Phosphorylation stimulated by insulin was studied by 32P incorporation from γ-32P-ATP into the solubilized protein obtained from human erythrocytes of different ages and into exogenous histone.Insulin stimulated phosphorylation of the solubilized protein by 2.3-2.6 fold and of histon by 3.4-4.4 fold.The amount of 32P incorporated into young erythrocytes was twice as much as that incorporated into old erythrocytes.