Mason P W, Carbone D P, Cushman R A, Waggoner A S
J Biol Chem. 1981 Feb 25;256(4):1861-6.
This paper is concerned with the control of glycolysis in nongrowing Streptococcus lactis 7962. Changes were measured in the concentrations of glycolytic intermediates, intracellular inorganic phosphate (Pi), and adenine nucleotides following addition of glucose to cells that were in a starved condition. We find that intracellular Pi is a major factor in the control of glycolysis. In starved cells, the intracellular Pi concentration is high, greater than 40 mM. The large phosphoenolpyruvate pool that exists in starved cells can be explained as a result of inhibition of pyruvate kinase by the high concentration of Pi. On the other hand, in cells that are metabolizing glucose at a steady state rate, the cellular Pi concentration is low and pyruvate kinase is active. Upon depletion of glucose from the medium, the metabolite concentrations return to the values originally found in the starved state. This glucose depletion raises the intracellular Pi which again leads to inhibition of pyruvate kinase and the consequent buildup of the P-enolpyruvate pool.
本文关注的是无生长状态的乳酸链球菌7962中糖酵解的调控。在向处于饥饿状态的细胞添加葡萄糖后，测定了糖酵解中间产物、细胞内无机磷酸盐（Pi）和腺嘌呤核苷酸浓度的变化。我们发现细胞内Pi是糖酵解调控的主要因素。在饥饿细胞中，细胞内Pi浓度很高，大于40 mM。饥饿细胞中存在的大量磷酸烯醇丙酮酸池可以解释为高浓度Pi抑制丙酮酸激酶的结果。另一方面，在以稳定速率代谢葡萄糖的细胞中，细胞内Pi浓度较低，丙酮酸激酶具有活性。当培养基中的葡萄糖耗尽时，代谢物浓度恢复到最初在饥饿状态下发现的值。这种葡萄糖耗尽会提高细胞内Pi，这又会导致丙酮酸激酶受到抑制，从而使磷酸烯醇丙酮酸池积累。
