类自我组装的机制研究:过渡性α螺旋到稳定的β片
Gai Liu1, Anabathula Prabhakar, Darryl Aucoin
1Carlson School of Chemistry and Biochemistry, Clark University, 950 Main Street, Worcester, Massachusetts 01610, USA.
Journal of the American Chemical Society
|December 9, 2010
概括
蛋白质自我组装,与2型糖尿病等疾病有关,涉及暂时的α螺旋. 这项研究揭示了小岛氨基多 (IAPP) 中的特定突变如何在聚合过程中影响螺旋式中间体和β片形成.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物物理学 分子生物物理学
背景情况:
- 病态蛋白质自我组装是神经退行性和代谢障碍的基础,包括阿尔茨海默病,帕金森病和2型糖尿病.
- 过渡性α螺旋越来越多地被认为是蛋白质自我组装的初始阶段的关键.
- 岛屿粉样聚 (IAPP) 聚合对胰腺β细胞有毒,有助于2型糖尿病的发病.
研究的目的:
- 阐明岛屿粉样聚 (IAPP) 自组合中的早期机械事件.
- 研究特定突变的作用,特别是在IAPP聚合和纤维状细胞形成中,在位置20 (S20G) 处的氨酸-甘氨酸突变的作用.
- 探索IAPP的结构动态及其与粉样蛋白形成的关系.
主要方法:
- 使用有限的蛋白质分解来确定IAPP单体中的灵活和暴露区域.
- 三种IAPP(11-25) 的合成和生物物理特征:野生类型 (WT),S20G突变和S20P突变.
- 溶液状态核磁共振 (NMR) 谱学被用于分析形状组合.
主要成果:
- 所有合成的都在短暂地占据了阿尔法螺旋形状空间.
- 不能自组装的S20P样本具有"断裂螺旋"形状,与WT和S20G不同.
- WT和S20G分别存在着不同的中间状态:分别是α-状和β-状,与纤维状形成倾向相关.
结论:
- 提出了IAPP自组装的机制,涉及通过NMR隐形中间体稳定短暂的α螺旋体,然后再通过α螺旋体对β片重新排列.
- S20G突变促进了β-sheet终点状态的种群,增强了粉样纤维素的形成,并与早期发病的2型糖尿病有关.
- 设计减少分子间螺旋螺旋接触的,如S20P变体,提供了一个有希望的策略来抑制的自我组装.
相关概念视频
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...
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Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Folding
Overview
Protein Folding
Overview
Protein Organization
Overview
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 and Protein Structure
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme can...
A protein's shape is critical to its function. For example, an enzyme can...


