Il'in V S, Titova G V, Kliueva N N
Vopr Med Khim. 1977 Jan-Feb(1):59-65.
An immediate effect of hormones (insulin, oxytocin, glucocorticoids and sex hormones) on the conformation and activity of enzymatically active proteins (hexokinase, glutamate dehydrogenase) was studied. Hormone-enzyme complex of insulin-hexokinase was shown to be formed. This process was accompanied by dissociation of the enzyme into two dimers without a loss of the catalytic activity but with disappearance of the property to be inhibited by glucocorticoids. The effect of insulin on the hexokinase activity was postulated to occur due to reaction of thiol-disulphide exchange between disulphide group of insulin and free sulfhydryl group of hexokinase. The inhibitory effect of sex hormones on the glutamate dehydrogenase activity was shown to be determined by their association with the enzymatically active protein. This phenomenon did not occur under conditions of stabilization of the quaternary structure of the enzyme. If the guanidine groups of glutamate dehydrogenase were blocked the inhibitory effect of sex hormones was found to decrease. These data demonstrate the importance of the guanidine groups in binding of sex hormones.
研究了激素（胰岛素、催产素、糖皮质激素和性激素）对酶活性蛋白（己糖激酶、谷氨酸脱氢酶）构象和活性的即时影响。已证明胰岛素 - 己糖激酶的激素 - 酶复合物能够形成。此过程伴随着酶解离为两个二聚体，催化活性未丧失，但丧失了被糖皮质激素抑制的特性。推测胰岛素对己糖激酶活性的影响是由于胰岛素的二硫键与己糖激酶的游离巯基之间发生硫醇 - 二硫键交换反应所致。结果表明，性激素对谷氨酸脱氢酶活性的抑制作用取决于它们与酶活性蛋白的结合。在酶的四级结构稳定的条件下，这种现象不会发生。如果谷氨酸脱氢酶的胍基被封闭，发现性激素的抑制作用会降低。这些数据证明了胍基在性激素结合中的重要性。
