粉样蛋白形成的金属开关:洞察核的结构
David M Morgan1, Jijun Dong, Jaby Jacob
1Center for the Analysis of SupraMolecular Self-assemblies, Department of Chemistry, Emory University, 1521 Pierce Drive, Atlanta, Georgia 30322, USA.
Journal of the American Chemical Society
|October 24, 2002
概括
(Zn2+) 离子通过增加阿贝塔 (10-21) 的核化速率来加速粉样蛋白的形成. 然而,Zn2+不会影响纤维的传播或形态,这表明它在早期的粉样蛋白聚合中发挥了特定的作用.
科学领域:
- 生物化学 生化学
- 神经科学是一个神经科学.
- 材料科学 材料科学 材料科学
背景情况:
- 粉样蛋白的形成是神经退行性疾病的核心.
- 越来越多地认识到金属离子,如在调节粉样蛋白聚合中的作用.
- 阿贝塔 (10-21) 是一个关键片段,参与了粉样蛋白病理学.
研究的目的:
- 调查Zn2+在阿贝塔 (10-21) 的粉样蛋白形成中的特定作用.
- 确定Zn2+如何影响核形成和传播的动力学.
- 为了检查Zn2+对阿贝塔 (10-21) 纤维的形态学的影响.
主要方法:
- 小角度中子散射 (SANS) 用于分析纤维结构.
- 传输电子显微镜 (TEM) 用于可视化纤维的形态.
- 动力学研究以评估核和传播速率.
- 亚贝塔变种的特定位点突变 (10-21) 变种.
主要成果:
- Zn2+显著增加了阿贝塔10-21) 粉样蛋白形成的核化速度.
- Zn2+对现有纤维的传播速率的影响最小.
- 由SANS和TEM观察到的纤维细胞形态,在有或没有Zn2+的情况下保持不变.
- 一种特定的变异,Abeta(10-21) H13Q,显示金属独立性,表明Zn2+与histidine残留物相互作用.
结论:
- Zn2+优先影响阿贝塔的核化阶段.
- 观察到的核化增加归因于Zn2+介导的涉及histidine 13和14的板间相互作用.
- Zn2+不会改变Abeta的最终纤维结构或传播动态10-21).
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