由RDC和PRE数据所限制的非结构化蛋白质的整体计算:用尿素去化的ubiquitin的案例研究
Jie-rong Huang1, Stephan Grzesiek
1Division of Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
Journal of the American Chemical Society
|December 17, 2009
概括
描述未折叠的蛋白质是一项挑战. 使用剩余二极合 (RDC) 和偏磁放松增强 (PRE) 数据的新计算方法允许对蛋白质构成组合进行详细分析.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 计算生物学 计算生物学
背景情况:
- 由于其复杂的形状组合,很难描述未折叠的蛋白质状态.
- 其余二极合 (RDC) 和偏磁放松增强 (PRE) 提供了关于这些状态的实验数据.
研究的目的:
- 使用RDC和PRE数据开发新的计算模块来分析未折叠的蛋白质状态.
- 为了创建展开的蛋白质组合的最小模型.
主要方法:
- 开发了XPLOR-NIH的新模块,以将硬质对齐RDC和PRE作为约束.
- 在用419个RDC和253个PRE对尿素脱化乌比奎丁进行了整体计算.
- 分析的C ((alpha) 接触者和形状群体.
主要成果:
- 只有少量的适配器 (大约10个) 足以复制实验RDC,PRE和旋转半径数据.
- 在展开的集合体中观察到大量 (10-20%) 的A态形状.
- 仅使用RDCs或PREs获得了类似的结果,这两种方法都允许检测低种群子构造.
结论:
- 开发的基于RDC和PRE的计算方法使得在未折叠的蛋白质组合中能够统计显著地检测出子构成.
- 尿素和甲醇/酸脱导致蛋白质组合中类似的低能量状态.
- 这些方法提供了一种强大的方法来定量表征蛋白质折叠中间体和未折叠状态.
相关概念视频
Protein Folding
Overview
Protein Folding
Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to its biological function. Interactions between its constituent amino acids guide protein folding, and hence the protein structure is primarily dependent on its amino acid sequence.
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Organization
Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular transport, catalysis, and structural support. Proteins have a hierarchical structure comprising at least three levels of organization: primary, secondary, and tertiary structure. Some large proteins have a quaternary structure where individual protein subunits are linked together.
The primary structure of a protein is its amino acid sequence.
The primary structure of a protein is its amino acid sequence.
Protein Folding Quality Check in the RER
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
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Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
These groups modify specific amino acids in a protein.
Intrinsically Disordered Proteins
Intrinsically disordered proteins are a group of proteins that do not fold into specific three-dimensional structures. Their structural flexibility allows them to complement ordered proteins to perform functions that are inaccessible to rigid structures. They are more common in eukaryotes than prokaryotes and may either be exclusively intrinsically disordered or hybrid proteins, consisting of a mix of ordered and disordered regions. The absence of a rigid structure in these proteins can be...


