Vacuolar uptake of the phytoalexin medicarpin by the glutathione conjugate pump
Vacuolar uptake of the phytoalexin medicarpin by the glutathione conjugate pump
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DOI：
10.1016/s0031-9422(97)00031-9
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发表时间：
1997-06-01
期刊：
影响因子：
3.8
通讯作者：
Dixon, RA
中科院分区：
文献类型：
--
作者：
Li, ZS;Alfenito, M;Dixon, RA
我们研究了绿豆黄化下胚轴液泡膜小泡对[H-3]-medicarpin及其谷胱甘肽结合物的吸收。在存在或不存在MgATP的情况下，未结合的medicarpin以低速率被摄取。然而，通过将medicarpin与总玉米谷胱甘肽S-转移酶制剂孵育制备的[H-3]-medicarpin-谷胱甘肽结合物的吸收速度比存在MgATP时的medicarpin快4倍以上，并且这种吸收具有MgATP依赖性。吸收的medicarpin谷胱甘肽没有显着抑制离子载体短杆菌肽-D，但强烈抑制钒酸盐和替代运输底物S-（2，4-二硝基苯基）谷胱甘肽。我们的研究结果表明，在一个模型系统中，潜在的利用高亲和力，高容量，解偶联剂不敏感的谷胱甘肽共轭泵的液泡运输的一种植物抗毒素。(C)1997年爱思唯尔科学有限公司
We have studied the uptake of [H-3]-medicarpin and its glutathione conjugate(s) into vacuolar membrane vesicles from etiolated hypocotyls of mung bean (Vigna radiata). Unconjugated medicarpin is taken up at a low rate in the presence or absence of MgATP. However, [H-3]-medicarpin-glutathione conjugate(s), prepared by incubation of medicarpin with a total maize glutathione S-transferase preparation, is taken up more than four-fold faster than medicarpin in the presence of MgATP, and this uptake is MgATP-dependent. Uptake of medicarpin-glutathione was not significantly inhibited by the ionophore gramicidin-D, but was strongly inhibited by vanadate and the alternative transport substrate S-(2,4-dinitrophenyl) glutathione. Our results demonstrate, in a model system, the potential utilization of the high affinity, high capacity, uncoupler-insensitive glutathione conjugate pump for the vacuolar transport of an isoflavonoid phytoalexin. (C) 1997 Elsevier Science Ltd.