通过使用小分子抑制剂的研究揭示了 site-one 蛋白酶对基质选择性的结构基础
Ashley V Bullington1, Ilaria Micallo2,3,4, Bilkish Bajaj1
1Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, TX 75390.
概括
对脂质生成和ER压力至关重要的Site-one蛋白酶 (S1P) 活性进行了研究,使用抑制剂PF-429242. 结构分析揭示了S1P如何识别基质,使得S1P可设计出耐药的S1P变体.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 第一个位点蛋白酶 (S1P) 对于激活高尔基的效应蛋白质至关重要,调节细胞的关键路径,如脂生和ER压力.
- S1P成熟涉及ER和辅因子SPRING中的自催化,其活动为信号提供而被空间控制.
- 了解S1P基质识别对于阐明这些信号通路至关重要.
研究的目的:
- 研究S1P/SPRING复合体对基质识别的结构基础.
- 使用竞争性抑制剂PF-429242探测S1P的活性部位和基质结合口袋.
- 设计和验证具有改变基质识别特性的S1P变体.
主要方法:
- 确定了与抑制剂PF-429242结合的S1P/SPRING复合物的晶体结构.
- 进行结构分析以确定涉及基质结合的关键残留物.
- 在生物化学和基于细胞的测试中设计并测试了一种S1P突变 (I308A) 对PF-429242的耐药性.
主要成果:
- PF-429242与基质的P4Arg残留物相同的口袋中的S1P活性部位结合.
- 结构数据表明,S1P经历了形状变化,以适应基质的P2 Leu/Ile/Val残留物.
- 该I308A突变赋予了对PF-429242的耐药性,表明P2位置的固体阻碍减少.
结论:
- 该研究揭示了S1P基质选择性的结构基础,特别是在P2位置.
- 这些发现提供了对S1P介导蛋白质解和辅因子SPRING相互作用的机制的见解.
- 这项工作为新型和改进的S1P抑制剂的合理设计提供了基础.
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