Paynter D I, Anderson J W
Department of Botany, La Trobe University, Bundoora, Victoria, 3083, Australia.
Plant Physiol. 1974 Feb;53(2):180-6. doi: 10.1104/pp.53.2.180.
ATP sulfurylase activity was partially purified from the swollen hypocotyl of beetroot (Beta vulgaris); activity was measured by sulfate-dependent PPi-ATP exchange. The ATP sulfurylase activity was separated from pyrophosphatase and ATPase activities which interfere with the assay of ATP sulfurylase activity. The ATP sulfurylase activity from hypocotyl tissue was invariably resolved into two approximately equal activities (hypocotyls I and II) by ion exchange chromatography and polyacrylamide gradient gel electrophoresis. Both enzymes catalyzed selenate- and sulfate-dependent PPi-ATP exchange; the affinity of hypocotyl II for these substrates was greater than for hypocotyl I. It is unlikely that the two activities arise by allelic variation or as an artifact of purification; they are most probably isoenzymes. Studies of the subcellular localization of the two hypocotyl enzymes were inconclusive.ATP sulfurylase was also purified from leaf tissue. Ion exchange chromatography resolved the ATP sulfurylase from leaf tissue into a major activity (which accounted for 98% of the total leaf activity) and a minor activity. The major leaf and hypocotyl II ATP sulfurylases were indistinguishable as judged by the properties investigated.
从甜菜根（Beta vulgaris）肿胀的下胚轴中部分纯化了ATP硫酸化酶活性；通过硫酸盐依赖性的焦磷酸-ATP交换来测定活性。将ATP硫酸化酶活性与干扰ATP硫酸化酶活性测定的焦磷酸酶和ATP酶活性分离开来。通过离子交换色谱法和聚丙烯酰胺梯度凝胶电泳，下胚轴组织中的ATP硫酸化酶活性总是被分解为两种大致相等的活性（下胚轴I和II）。两种酶都催化硒酸盐和硫酸盐依赖性的焦磷酸-ATP交换；下胚轴II对这些底物的亲和力大于下胚轴I。这两种活性不太可能是由等位基因变异或纯化假象产生的；它们很可能是同工酶。对两种下胚轴酶的亚细胞定位研究尚无定论。ATP硫酸化酶也从叶片组织中纯化出来。离子交换色谱法将叶片组织中的ATP硫酸化酶分解为一种主要活性（占叶片总活性的98%）和一种次要活性。根据所研究的特性判断，主要的叶片和下胚轴II的ATP硫酸化酶无法区分。
