Dietzler D N, Leckie M P, Sternheim W L, Ungar J M, Crimmins D L, Lewis J W
J Biol Chem. 1979 Sep 10;254(17):8276-87.
Treatment of nitrogen-starved cultures of Escherichia coli W4597(K) with sodium azide results in simultaneous changes in both glucose 6-phosphate and fructose 1,6-diphosphate as well as in the rate of glycogen synthesis. Based on these observations, a comprehensive equation was developed which relates the cellular levels of both of these hexose phosphates with the rate of glycogen synthesis. This relationship apparently represents the interaction in vivo between the rate-limiting enzyme of bacterial glycogen synthesis, glucose 1-phosphate adenylyltransferase (adenosine diphosphoglucose synthetase, EC 2.7.7.27), and its substrate glucose 1-phosphate (reflected by glucose 6-phosphate) and its major allosteric activator fructose diphosphate. The form of the equation that describes this relationship was determined from studies presented here of the kinetic properties of the E. coli W4597(K) enzyme in the presence of physiological concentrations of its substrates and modulators. We show here and in subsequent reports of this series that the comprehensive relationship between glycogen synthesis and hexose phosphates can serve as a reference to evaluate the possible participation of new factors in the regulation of glycogen synthesis. Treatment with NaN3 did not change the cellular level of glucose 1-phosphate adenylyltransferase. The value of the adenylate energy charge, (ATP + 1/2 ADP)/(ATP + ADP + AMP), was maintained despite losses of up to 35% in cellular adenylates. The quantitative co-variance between hexose phosphates and the cellular rate of glucose utilization that we previously described for other metabolic conditions was also observed in the azide-treated cultures. We integrate the new information into the system of coordinated regulation of glycogen synthesis, glycolysis, and glucose utilization that we proposed previously.
用叠氮化钠处理大肠杆菌W4597(K)的缺氮培养物，会导致6-磷酸葡萄糖和1,6-二磷酸果糖同时发生变化，以及糖原合成速率改变。基于这些观察结果，推导出了一个综合方程，该方程将这两种己糖磷酸的细胞水平与糖原合成速率联系起来。这种关系显然代表了细菌糖原合成的限速酶1-磷酸葡萄糖腺苷酸转移酶（二磷酸腺苷葡萄糖合成酶，EC 2.7.7.27）与其底物1-磷酸葡萄糖（由6-磷酸葡萄糖反映）及其主要变构激活剂二磷酸果糖在体内的相互作用。描述这种关系的方程形式是根据此处关于大肠杆菌W4597(K)酶在其底物和调节剂生理浓度存在下的动力学性质的研究确定的。我们在此处以及本系列的后续报告中表明，糖原合成与己糖磷酸之间的综合关系可作为评估新因素可能参与糖原合成调节的参考。用NaN3处理不会改变1-磷酸葡萄糖腺苷酸转移酶的细胞水平。尽管细胞腺苷酸损失高达35%，腺苷酸能荷值（ATP + 1/2 ADP）/（ATP + ADP + AMP）仍保持不变。我们之前描述的其他代谢条件下己糖磷酸与细胞葡萄糖利用速率之间的定量协变关系，在叠氮化钠处理的培养物中也观察到了。我们将新信息整合到我们之前提出的糖原合成、糖酵解和葡萄糖利用的协调调节系统中。
