Glucose-dependent metabolic interconversion of fructose-1, 6-bisphosphatase in yeast.
Glucose-dependent metabolic interconversion of fructose-1, 6-bisphosphatase in yeast.
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酵母中果糖 1, 6-二磷酸酶的葡萄糖依赖性代谢相互转化。
DOI：
10.1016/s0006-291x(81)80230-6
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发表时间：
1981
影响因子：
3.1
通讯作者：
H. Holzer
中科院分区：
文献类型：
--
作者：
P. Tortora;M. Birtel;A. Lenz;H. Holzer
向葡萄糖去抑制的酵母细胞中添加葡萄糖会导致 3 至 5 分钟内果糖 1,6-双磷酸酶 60% 的活性消失。在无葡萄糖培养基中这种“分解代谢物失活”反应的可逆性独立于从头蛋白质合成。凝胶过滤粗提物中果糖-1,6-双磷酸酶活性的最佳 pH 值对于来自去抑制细胞的酶为 8.25，对于来自用葡萄糖处理 4 分钟的细胞的酶为 8.8。在与 |3H| 的研究中- 亮氨酸标记的葡萄糖去抑制细胞与抗果糖-1,6-二磷酸酶的抗体发生交叉反应的蛋白质在添加葡萄糖后的前10分钟内并未消失。这些发现表明，葡萄糖诱导的酶快速失活是共价修饰的结果，共价修饰降低了果糖-1,6-双磷酸酶活性并改变了酶的pH活性谱，但不改变其对抗体的免疫反应性。结论是共价修饰使酶对蛋白酶敏感，从而启动其选择性蛋白水解。
Addition of glucose to glucose-derepressed yeast cells causes disappearance of 60 % of the activity of fructose-1,6-bisphosphatase within 3 to 5 min. Reversibility of this “catabolite inactivation” reaction in a glucose-free medium is independent on de novo protein synthesis. The pH-optima of fructose-1,6-bisphosphatase activity in gel-filtrated crude extracts were shown to be 8.25 for the enzyme from derepressed cells and 8.8 for the enzyme from cells treated with glucose for 4 min. In studies with |3H| - leucine labelled glucose-derepressed cells the protein cross reacting with antibodies against fructose-1,6-bisphosphatase did not disappear within the first 10 min after addition of glucose. These findings suggest that the glucose induced rapid inactivation of the enzyme is the result of a covalent modification which decreases the fructose-1,6-bisphosphatase activity and changes the pH-activity profile of the enzyme, but does not change its immunological reactivity to antibodies. It is concluded that the covalent modification renders the enzyme susceptible to proteinases and thereby initiates its selective proteolysis.