Aminopeptidase dependent pore formation of Bacillus thuringiensis Cry1Ac toxin on Trichoplusia ni membranes
Aminopeptidase dependent pore formation of Bacillus thuringiensis Cry1Ac toxin on Trichoplusia ni membranes
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DOI：
10.1016/s0014-5793(97)01014-4
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发表时间：
1997-09-08
期刊：
影响因子：
3.5
通讯作者：
Bravo, A
中科院分区：
文献类型：
--
作者：
Lorence, A;Darszon, A;Bravo, A
杀虫苏云金芽孢杆菌 Cry1Ac δ-内毒素与易感昆虫（如天蛾、夜蛾、舞毒蛾和小菜蛾）中肠中的 120 kDa 氨肽酶 N (APN) 特异性结合，120 kDa APN 具有糖基磷脂酰肌醇 (GPI) 锚点对 GPI 特异性磷脂酶 C (PIPLC) 的作用敏感。在这里，我们表明 Cry1Ac 成孔活性取决于粉纹夜蛾幼虫刷状缘膜囊泡 (BBMV) 上存在的 APN 量。用 bestatin 抑制 APN 活性并不影响 Cry1Ac 孔的形成，表明 Cry1Ac 的作用取决于 APN 的存在，而不取决于其酶活性。 N-乙酰基-D-半乳糖胺阻断毒素的作用，表明该糖也直接参与 Cry1Ac 毒素-受体相互作用。使用 PIPLC 处理和未处理的 BBMV 进行的膜电位测量表明，两种 APN 都可以作为 Cry1Ac 受体参与，PIPLC 敏感和耐药 APN 的动力学特征表明它们可能是不同的亚型，最后，我们表明，在 200 mM Cs+ 固有 BBMV 存在的情况下，未观察到 T. ni 通道通透性，而未观察到毒素诱导的通透性 受影响，从而可以准确分析 Cry1Ac 毒素对 T. ni 中肠膜的影响。 (C) 1997 年欧洲生化学会联合会。
The insecticidal Bacillus thuringiensis Cry1Ac delta-endotoxin specifically binds to a 120 kDa aminopeptidase N (APN) in the midgut of susceptible insects such as Manduca sexta, Heliothis virescens, Lymantria dispar and Plutella xylostella, The 120 kDa APN has a glycosylphosphatidylinositol (GPI) anchor susceptible to the action of GPI-specific phospholipase C (PIPLC). Here we show that Cry1Ac pore-forming activity depends on the amount of APN present on brush border membrane vesicles (BBMV) from Trichoplusia ni larvae. Inhibition of APN activity with bestatin did not affect Cry1Ac pore formation, suggesting that Cry1Ac action depends on the presence of APN, but not on its enzymatic activity. N-Acetyl-D-galactosamine blocks the actiono of the toxin, indicating that this sugar is also directly involved in the Cry1Ac toxin-receptor interaction. Membrane potential measurements using PIPLC treated and non-treated BBMV suggest that both APN could participate as Cry1Ac receptor, The kinetic characterization of PIPLC sensitive and resistant APN indicates that they could be different isoforms, Finally, we show that in the presence of 200 mM Cs+ intrinsic BBMV T. ni channel permeability is not observed, while the toxin induced permeability is not affected, allowing an accurate analysis of the effect of the Cry1Ac toxin on T. ni midgut membranes. (C) 1997 Federation of European Biochemical Societies.