通过DNP增强的NMR研究的蛋白质折叠中的Isoleucine侧链
Leonardo Levorin1,2, Nina Becker1,2, Boran Uluca-Yazgi1,2
1Institute of Physical Biology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf 40225, Germany.
Journal of the American Chemical Society
|April 26, 2025
概括
低温固态核磁共振 (ssNMR) 与动态核极化 (DNP) 显示了蛋白质侧链的动态. 这种技术捕获了各种蛋白质构造,从很好的折叠结构到粉状纤维,有助于了解蛋白质的功能.
科学领域:
- 结构生物学
- 生物物理
- 核磁共振光谱学
背景情况:
- 蛋白质侧链结构对于蛋白质的功能至关重要.
- 低温温度 (<110 K) 允许动态核极化增强固态NMR (DNP增强ssNMR) 捕获蛋白质构造,包括侧链.
研究的目的:
- 通过使用二维DNP增强的ssNMR来研究异黄素的骨干和侧链构造.
- 将13C化学转移和线形与二次结构元素和侧链角度 (χ1和χ2) 相关联.
主要方法:
- 在选择性标记模型蛋白质上使用2D DNP增强的ssNMR.
- 在各种蛋白质状态中分析了线形状和异黄素残留的峰值区域:内在无序蛋白质 (IDP),变性蛋白质,折蛋白质和粉样纤维.
- 检查的蛋白质包括GABARAP,PI3-激酶 (PI3K) SH3域和α-synuclein (α-syn).
主要成果:
- 素的化学转移和线形状准确地反映了脊柱和侧链的形状.
- 很好折叠的蛋白质显示出类似于溶液NMR的分离转移,线条扩大表明残留的移动性.
- 由于全侧链的形状自由,未折叠的蛋白质和IDP表现出不均的线路扩展.
- 粉状纤维呈现出类似β链的移位,与"模糊外套"区域的IDP类型线条形状.
- 蛋白质构成组显示依赖于溶剂和缓冲条件,区分不同的变性状态.
结论:
- 用DNP增强的ssNMR对于研究各种蛋白质状态中的蛋白质侧链结构和动态是有效的.
- 该方法提供了关于侧链运动如何影响蛋白质结构和功能的见解.
- 在蛋白质中,包括粉样纤维的形态异质性,可以使用这种技术来表征.
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