分离的液泡对阴离子摄取的ATP依赖性：对过量Mg2+的需求。

ATP dependence of anion uptake by isolated vacuoles: requirement for excess Mg2+.

作者信息

Dietz K J, Lang M, Schönrock M, Zink C

机构信息

Institut für Botanik und Pharmazeutische Biologie, Julius-Maximilians-Universität Würzburg, F.R.G.

出版信息

Biochim Biophys Acta. 1990 May 24;1024(2):318-22. doi: 10.1016/0005-2736(90)90360-z.

DOI:10.1016/0005-2736(90)90360-z

PMID:2141282

Abstract

Vacuoles were isolated from barley mesophyll protoplasts. [14C]Malate or 36Cl- were taken up from the surrounding medium. Uptake was only slightly increased in the presence of equimolar levels of ATP and Mg2+ (as magnesium gluconate). In the presence of excess Mg2+ in the medium, ATP-stimulated uptake of malate and chloride increased several-fold. Stimulation by excess Mg2+ was not observed for ATP-stimulated amino acid uptake by isolated vacuoles. Stimulation of uptake by excess Mg2+ was observed at all malate concentrations upto 10 mmol.l-1. The content of Mg2+ needed for half-maximum stimulation was about 3.5 mmol.l-1 in the presence of 1 mmol.l-1 ATP. The increase in Mg2+ concentration had no effect on the tonoplast ATPase activity.

摘要

从大麦叶肉原生质体中分离出液泡。从周围培养基中摄取[¹⁴C]苹果酸或³⁶Cl⁻。在等摩尔浓度的ATP和Mg²⁺（以葡萄糖酸镁形式）存在下，摄取量仅略有增加。在培养基中存在过量Mg²⁺的情况下，ATP刺激的苹果酸和氯离子摄取增加了几倍。分离的液泡对ATP刺激的氨基酸摄取未观察到过量Mg²⁺的刺激作用。在高达10 mmol·L⁻¹的所有苹果酸浓度下均观察到过量Mg²⁺对摄取的刺激作用。在1 mmol·L⁻¹ATP存在下，半最大刺激所需的Mg²⁺含量约为3.5 mmol·L⁻¹。Mg²⁺浓度的增加对液泡膜ATP酶活性没有影响。