对触发受体结合的结构变化的洞察,这些变化是在Bacillus thuringiensis Vip3Aa杀虫剂蛋白质的蛋白质分解激活时发生的
Oscar Infante1, Isabel Gómez1, Angel E Pélaez-Aguilar1
1Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
PLoS pathogens
|December 5, 2024
概括
林氏菌Vip3Aa毒素需要蛋白质分解激活以暴露其受体结合区域,从而使孔隙形成和杀虫活性对抗虫. 这种激活对于毒性至关重要.
科学领域:
- 分子生物学分子生物学
- 昆虫毒理学 昆虫毒理学
- 生物化学 生物化学
背景情况:
- 硫杆菌 (Bt) 产生杀虫剂Cry和Vip3蛋白质.
- 这两种毒素都在昆虫中肠细胞中形成毛孔,但有不同的机制.
- Vip3Aa原蛋白是一种四聚体,在激活时会发生构造变化.
研究的目的:
- 研究Vip3Aa激活和受体结合的机制.
- 为了确定Vip3Aa杀虫活性中涉及的特定域和残留物.
- 为了比较Vip3Aa原素与活性毒素的结合和毒性.
主要方法:
- 使用Spodoptera frugiperda刷边缘膜囊泡 (BBMV) 的结合试验.
- 对重叠的Vip3Aa的表达和分析.
- 确定的残留物的位点定向突变发生.
主要成果:
- Vip3Aa原毒素的BBMV结合程度较低,而激活毒素则特别结合.
- 域III被确定为Vip3Aa.的主要结合域.
- 关键残留物 (K385,K526,V529) 的变异性取消了结合和毒性.
结论:
- 蛋白质分解性激活Vip3Aa对于暴露其受体结合部位至关重要.
- 在域III和IV中的特定结构变化和残留物对Vip3Aa的杀虫功能至关重要.
- 了解Vip3Aa激活可以了解Bt毒素的机制.
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