Sümegi B, Alkonyi I
Biochim Biophys Acta. 1983 Dec 12;749(2):163-71. doi: 10.1016/0167-4838(83)90248-0.
In this paper, physicochemical evidence is given for the association between the pyruvate dehydrogenase complex (EC 1.2.4.1) and citrate synthase (EC 4.1.3.7) with two gel chromatographic techniques with poly(ethylene glycol) co-precipitation and with ultracentrifugation. Experiments with active enzyme gel chromatography indicate that citrate synthase also associates with pyruvate dehydrogenase complex in its functioning state. Citrate synthase binds to the isolated transacetylase core of pyruvate dehydrogenase complex, but in the binding to the whole pyruvate dehydrogenase complex the two other components of the complex are also involved. One pyruvate dehydrogenase complex can bind 10-11 citrate synthase dimers, and the dissociation constant is about 5.7-6.0 microM as determined by two independent methods. The association between the pyruvate dehydrogenase complex and citrate synthase raises the possibility of the dynamic compartmentation of acetyl-CoA in the mitochondria which results in the direction of acetyl-CoA from pyruvate towards citrate.
本文通过聚乙二醇共沉淀和超速离心两种凝胶色谱技术，给出了丙酮酸脱氢酶复合体（EC 1.2.4.1）与柠檬酸合酶（EC 4.1.3.7）之间存在关联的物理化学证据。活性酶凝胶色谱实验表明，柠檬酸合酶在其功能状态下也与丙酮酸脱氢酶复合体相关联。柠檬酸合酶与丙酮酸脱氢酶复合体分离的转乙酰酶核心结合，但在与整个丙酮酸脱氢酶复合体结合时，复合体的另外两个组分也参与其中。一个丙酮酸脱氢酶复合体可以结合10 - 11个柠檬酸合酶二聚体，通过两种独立方法测定的解离常数约为5.7 - 6.0微摩尔。丙酮酸脱氢酶复合体与柠檬酸合酶之间的关联增加了线粒体中乙酰辅酶A动态分隔的可能性，这导致乙酰辅酶A从丙酮酸向柠檬酸的定向流动。
