Mukerji S K, Yang S F
Department of Vegetable Crops, University of California, Davis, California 95616.
Plant Physiol. 1974 Jun;53(6):829-34. doi: 10.1104/pp.53.6.829.
Phosphoenolpyruvate carboxylase (EC 4.1.1.31), partially purified from spinach (Spinacia oleracea) leaves, is inhibited by SO(3) (2-) ion. The inhibition is competitive or mixed type with respect to HCO(3) (-) (Ki = 17 mm), and noncompetitive with respect to phosphoenolpyruvic acid (Ki = 11 mm), Mg(2+) (Ki = 10 mm), and Mn(2+) (Ki = 2.4 mm). The inhibitory effect of SO(3) (2-) is more significant in the presence of Mn(2+) than in the presence of Mg(2+). l-Malate, an inhibitor of phosphoenolpyruvate carboxylase activity, and SO(3) (2-) may bind at the same site on the enzyme. Glyoxal bisulfite and glyoxylate bisulfite are equally effective inhibitors of the enzyme activity as SO(3) (2-), but alpha-hydroxypyridinemethanesulfonate is a weak inhibitor. The data are discussed in relation to the physiological effect of the air pollutant (SO(2)) on plant leaf metabolism.
从菠菜（Spinacia oleracea）叶片中部分纯化得到的磷酸烯醇丙酮酸羧化酶（EC 4.1.1.31）受到亚硫酸根离子（SO(3) (2-)）的抑制。该抑制作用对于碳酸氢根离子（HCO(3) (-)）（Ki = 17 mM）而言是竞争性或混合型的，而对于磷酸烯醇丙酮酸（Ki = 11 mM）、镁离子（Mg(2+)）（Ki = 10 mM）和锰离子（Mn(2+)）（Ki = 2.4 mM）则是非竞争性的。在存在锰离子（Mn(2+)）的情况下，亚硫酸根离子（SO(3) (2-)）的抑制作用比存在镁离子（Mg(2+)）时更为显著。苹果酸（l-Malate）是磷酸烯醇丙酮酸羧化酶活性的抑制剂，它与亚硫酸根离子（SO(3) (2-)）可能结合在酶的同一部位。乙二醛亚硫酸氢盐和乙醛酸亚硫酸氢盐作为酶活性的抑制剂，其效果与亚硫酸根离子（SO(3) (2-)）相同，但α-羟基吡啶甲磺酸盐是一种弱抑制剂。本文结合空气污染物（二氧化硫（SO(2)））对植物叶片代谢的生理影响对这些数据进行了讨论。
