Effects of efrapeptin and destruxin, metabolites of entomogenous fungi, on the hydrolytic activity of a vacuolar type ATPase identified on the brush border membrane vesicles of Galleria mellonella midgut and on plant membrane bound hydrolytic enzymes
Effects of efrapeptin and destruxin, metabolites of entomogenous fungi, on the hydrolytic activity of a vacuolar type ATPase identified on the brush border membrane vesicles of Galleria mellonella midgut and on plant membrane bound hydrolytic enzymes
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DOI：
10.1016/s0005-2736(00)00370-9
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发表时间：
2001-02-09
影响因子：
3.4
通讯作者：
Gordon-Weeks, R
中科院分区：
文献类型：
--
作者：
Bandani, AR;Amiri, B;Gordon-Weeks, R
昆虫中肠刷状缘膜是杀虫蛋白相互作用的起始部位。我们已经研究了它可能含有两种杀虫真菌毒素，destruxin和efrapeptin，这两种都是ATP酶抑制剂的靶位点的可能性。我们研究了毒素对液泡型ATP酶（V-ATP酶）水解活性的影响，我们已经确定了从大蜡螟中肠柱状细胞刷状缘膜囊泡（BBMV）的阳离子和pH值的依赖性，对质子泵抑制剂和K-M（0.49 mM ATP）的敏感性。Efrapeptin强烈抑制BBMV V-ATP酶，但破坏素影响不大。我们比较了已知的植物膜水解酶的抑制剂的影响，虽然液泡焦磷酸酶和质膜ATP酶没有抑制毒素，V-ATP酶从绿豆，但不是大麦，被抑制（50%）由10 μ M浓度的两种化合物。在ATP酶上测试了不同形式的毒素，并且destruxin B和efrapeptin F是最有效的。动力学分析表明，这两种化合物的纯化形式抑制V-ATP酶的非竞争性和Efrapeptin在0.06-12 μ M的浓度下抑制BBMV V-ATP酶的数据的建模产生0.125 μ M的Ki。(C)2001爱思唯尔科技有限公司。保留所有权利。
The brush border membrane of the insect midgut is an initial site fbr interaction of insecticidal proteins. We have investigated the possibility that it may contain a target site for two insecticidal fungal toxins, destruxin and efrapeptin, both of which are ATPase inhibitors. We have studied the effects of the toxins on the hydrolytic activity of a vacuolar type ATPase (V-ATPase) that we have identified from Galleria mellonella midgut columnar cell brush border membrane vesicles (BBMV) by its cation and pH dependence, sensitivity to proton pump inhibitors and K-m (0.49 mM ATP). Efrapeptin strongly inhibited the BBMV V-ATPase but destruxin had little effect. We compared the effects of the inhibitors on known plant membrane hydrolytic enzymes, and although the vacuolar pyrophosphatase and plasma membrane ATPase were not inhibited by the toxins, the V-ATPase from mung bean, but not barley, was inhibited (50%) by 10 muM concentrations of both compounds. Different forms of the toxins were tested on the ATPases and destruxin B and efrapeptin F were the most effective. Kinetic analysis showed that the purified forms of both compounds inhibited the V-ATPases uncompetitively and modelling of data for inhibition of the BBMV V-ATPase by efrapeptin at concentrations of 0.06-12 muM yielded a K-i of 0.125 muM. (C) 2001 Elsevier Science B.V. All rights reserved.