Mojena M, Bosca L, Hue L
Biochem J. 1985 Dec 1;232(2):521-7. doi: 10.1042/bj2320521.
Glutamine caused a dose-dependent decrease in fructose 2,6-bisphosphate concentration in both HeLa cells and chick-embryo fibroblasts. The effect was complete within 15 min in HeLa cells, but required more than 9 h in the fibroblasts. Half-maximal effects were obtained with 0.1-0.3 mM-glutamine. In chick-embryo fibroblasts, but not in HeLa cells, glutamine induced a time-dependent decrease in the activity of phosphofructokinase-2, which correlated with the decrease in fructose 2,6-bisphosphate. Glutamine decreased the glycolytic flux by about 25% only in chick-embryo fibroblasts. The difference in glycolytic response between the two types of cells might correspond to a difference in the sensitivity of phosphofructokinase-1 for fructose 2,6-bisphosphate. In HeLa cells, glutamine caused a 2-3-fold stimulation of the synthesis of glycogen, a 50% decrease in the concentration of fructose 1,6-bisphosphate and a more than 80% decrease in the concentration of 5-phosphoribosyl pyrophosphate; the concentrations of hexose 6-phosphates and ATP were not affected.
谷氨酰胺使HeLa细胞和鸡胚成纤维细胞中的果糖2,6 - 二磷酸浓度呈剂量依赖性降低。在HeLa细胞中，该效应在15分钟内完成，但在成纤维细胞中则需要超过9小时。0.1 - 0.3 mM的谷氨酰胺可产生半数最大效应。在鸡胚成纤维细胞中，而非HeLa细胞中，谷氨酰胺诱导磷酸果糖激酶 - 2的活性随时间降低，这与果糖2,6 - 二磷酸的降低相关。谷氨酰胺仅使鸡胚成纤维细胞中的糖酵解通量降低约25%。两种细胞类型在糖酵解反应上的差异可能对应于磷酸果糖激酶 - 1对果糖2,6 - 二磷酸敏感性的差异。在HeLa细胞中，谷氨酰胺使糖原合成增加2 - 3倍，果糖1,6 - 二磷酸浓度降低50%，5 - 磷酸核糖焦磷酸浓度降低超过80%；己糖6 - 磷酸和ATP的浓度未受影响。
