Wolpert J S, Ernst-Fonberg M L
Biochemistry. 1975 Mar 25;14(6):1095-102. doi: 10.1021/bi00677a001.
Acetyl-coenzyme A carboxylase from Euglena gracilis strain Z was isolated as a component of a multienzyme complex which includes phosphoenolpyruvate carboxylase and malate dehydrogenase. The multienzyme complex was shown to exist in crude extracts and was purified to a homogeneous protein with a molecular weight of 360,000 by gel filtration. The ratio of the activities of the constituent enzymes was acetyl-CoA carboxylase:phosphoenolpyruvate carboxylase:malate dehydrogenase, 1:25:500. The complex is proposed to operate in conjunction with malic enzyme, which is present in Euglena, to facilitate the formation of substrates, malonyl-CoA, and NADPH, for fatty acid biosynthesis. The interaction of the enzymes may represent a means of control of acetyl-CoA carboxylase activity in organisms which do not possess an enzyme subject to allosteric regulation. The acetyl-CoA carboxylase activity from Euglena is unaffected by citrate and isocitrate.
纤细裸藻Z株的乙酰辅酶A羧化酶作为一种多酶复合物的组分被分离出来，该多酶复合物包括磷酸烯醇式丙酮酸羧化酶和苹果酸脱氢酶。多酶复合物在粗提物中被证实存在，并通过凝胶过滤被纯化至分子量为360,000的均一蛋白质。组成酶的活性比例为乙酰辅酶A羧化酶:磷酸烯醇式丙酮酸羧化酶:苹果酸脱氢酶 = 1:25:500。该复合物被认为与裸藻中存在的苹果酸酶协同作用，以促进脂肪酸生物合成底物丙二酰辅酶A和NADPH的形成。酶之间的相互作用可能代表了一种在不具有变构调节酶的生物体中控制乙酰辅酶A羧化酶活性的方式。来自裸藻的乙酰辅酶A羧化酶活性不受柠檬酸和异柠檬酸的影响。
