Botany School, University of Cambridge, Downing Street, CB2 3EA, Cambridge, UK.
Planta. 1985 Feb;163(2):290-4. doi: 10.1007/BF00393520.
The aim of this work was to discover if there is enough ATP citrate lyase (EC 4.1.3.8) in the cytosol of the leaves of Pisum sativum L. to catalyse the synthesis of the acetyl CoA needed for terpenoid synthesis. Estimates of the maximum catalytic activity of the enzyme in leaves of 7-d-old peas gave values of 113 nmol min(-1) g(-1) fresh weight. The rate of carotenoid accumulation in these leaves corresponded to a requirement for acetyl CoA of 0.7 nmol min(-1) g(-1) fresh weight. The distribution of marker enzymes during fractionation of homogenates of leaves from 7 to 10-d-old peas showed that differential centrifugation led to the isolation in reasonable yields of chloroplasts, mitochondria, peroxisomes and the endomembrane system. None of the above components of the leaf contained appreciable detectable activity of ATP citrate lyase, the distribution of which closely paralleled that of the cytosolic marker. It was concluded that in young leaves of pea most of the ATP citrate lyase is in the cytosol.
本工作旨在探究豌豆叶片细胞溶质中是否存在足够的柠檬酸裂解酶 (EC 4.1.3.8) 来催化萜类合成所需的乙酰辅酶 A 的合成。对 7 天大的豌豆叶片中酶的最大催化活性的估计给出了 113 nmol min(-1) g(-1) 鲜重的数值。这些叶片中类胡萝卜素的积累速率相当于乙酰辅酶 A 的需求为 0.7 nmol min(-1) g(-1) 鲜重。7 至 10 天大的豌豆叶片匀浆的分级分离过程中标记酶的分布表明，差速离心导致叶绿体、线粒体、过氧化物酶体和内膜系统以合理的产量得到分离。叶片的上述任何成分都没有可检测到的柠檬酸裂解酶活性，其分布与胞质标记物密切相关。因此，在豌豆的幼叶中，大部分柠檬酸裂解酶存在于细胞质中。
