通过双态运动机制观察到的最大蛋白质折叠不遵守接触顺序相关性
Kathryn Jones1, Pernilla Wittung-Stafshede
1Molecular and Cellular Biology Graduate Program and Chemistry Department, Tulane University, New Orleans, Louisiana 70118, USA.
Journal of the American Chemical Society
|August 9, 2003
概括
大型蛋白质折叠可以是两种状态的. 博雷莉亚burgdorferi VlsE蛋白质,一个大型α螺旋蛋白质,展示了两种状态的折叠,挑战了关于蛋白质折叠机制的先前假设.
科学领域:
- 蛋白质折叠的动态 蛋白质折叠的动态
- 生物物理学的生物物理.
- 结构生物学是结构生物学.
背景情况:
- 蛋白质的折叠能量格局决定了它们的功能结构.
- 传统上,假定蛋白质超过110个残留物通过复杂的多态机制折叠.
- 了解折叠机制对于蛋白质工程和药物开发至关重要.
研究的目的:
- 为了研究一个非常大的蛋白质Borrelia burgdorferi VlsE.的折叠能量景观.
- 为了确定大型蛋白质是否可以表现出双态折叠动力学.
- 评估现有模型 (联系订单,拓搜索) 对大型双状态文件的适用性.
主要方法:
- 利用时间解决的折叠和展开实验.
- 研究了Borrelia burgdorferi VlsE,一个341残留物,主要是α-螺旋蛋白.
- 在特定条件下 (pH 7,20°C) 在水溶液中测量折叠速度.
主要成果:
- 博雷利亚burgdorferi VlsE表现出了显著的两种状态的折叠行为,尽管它的大小 (341个残留物).
- 据记录,VlsE是通过双态运动机制折叠的最大蛋白质.
- VlsE的折叠速度 (5 ± 2 秒-1) 显著低于由原始状态接触顺序和拓体搜索模型预测的速度.
结论:
- 大型蛋白质 (>110个残留物) 通过多态机制折叠的常见假设需要重新评估.
- 大型双态蛋白质的折叠屏障高度可能不仅仅由整体拓学决定.
- 需要进一步的研究,以了解大型蛋白质的折叠动态的因素.
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