一个螺旋转螺旋蛋白的特定位置的展开热力学
Krista E Amunson1, Loren Ackels, Jan Kubelka
1Department of Chemistry, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming 82071, USA.
Journal of the American Chemical Society
|June 6, 2008
概括
网站特定的同位素标记揭示了病毒蛋白子域的独特的热展开热力学. 这种方法提供了对蛋白质展开的局部结构洞察力,超越了标准的光谱技术.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 生物物理学的生物物理.
背景情况:
- 螺旋转螺旋图案是基本的阿尔法螺旋结构,结合了二级和三级元素.
- 了解蛋白质子域的热展开对于预测蛋白质的稳定性和功能至关重要.
- 三级螺旋间相互作用稳定了P22病毒外套蛋白螺旋-转-螺旋子域.
研究的目的:
- 为了研究P22病毒外衣蛋白的40个残留螺旋转子子域的热展开.
- 为了确定热展开的特定位置的热力学参数.
- 为了证明特定地点的同位素标签的实用性,以解决局部展开的事件.
主要方法:
- 循环二重化 (CD) 光谱学.循环二重化 (CD) 光谱学.
- 福里埃变换红外光谱法 (FTIR) 采用特定地点的13C同位素标记.
- 单值分解 (SVD) 与目标转换和热力学分析的全球拟合相结合.
主要成果:
- 取决于温度的CD和FTIR数据表明,三态展开过程具有部分折叠的中间体.
- 对特定站点的13CIR信号的分析显示,不同标记站点的不同展开的热力学.
- P22子域表现出一个N端到螺旋段在转展开方向附近.
- 只有两个13C标记的残留物可以在蛋白质展开过程中提供局部结构信息.
结论:
- 特定位置的13C标签可以检测蛋白质中的局部展开事件.
- 这种方法提供了较高分辨率的结构信息,而不是非特定地点的光谱方法.
- 这项研究阐明了P22病毒外套蛋白子域的顺序展开路径.
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