阿斯巴拉金糖化对Pin WW折叠动力学和热力学的影响取决于背景
Joshua L Price1, Dalit Shental-Bechor, Apratim Dhar
1Department of Chemistry, Scripps Research Institute, La Jolla, California 92037, United States.
Journal of the American Chemical Society
|October 13, 2010
概括
在蛋白质中引入N-糖基化并不总是加速折叠或增强稳定性. 特定的蛋白质 - 甘氨酸相互作用,而不仅仅是一般的影响,对于对蛋白质折叠的有益影响至关重要.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 蛋白质科学 蛋白质科学
背景情况:
- 阿斯帕拉金糖基化是真核生物中常见的翻译后修饰.
- N-糖化发生在内 плазма网膜中,影响蛋白质折叠和相互作用.
- 之前的研究表明,近位糖是N-glycan对蛋白质折叠的有益作用的关键.
研究的目的:
- 测试引入N-糖化位是否普遍稳定蛋白质并增加折叠率.
- 调查这些影响是否独立于上下文,仅依赖于糖结构.
主要方法:
- 在Pin WW域内各个位置内集成的N链接GlcNAc.
- 利用实验和计算方法来评估蛋白质折叠和稳定性.
主要成果:
- N-糖化一般不会增加折叠率或热力学稳定性.
- 计算模型和实验表明,糖甘诱导的排斥体积效应破坏了结构区域的稳定.
- 灵活循环中的破坏稳定的效应并不能仅仅通过排除的体积来解释.
结论:
- N-糖化对蛋白质折叠的影响不是一个普遍的,独立于背景的现象.
- 特定的,进化的蛋白质-甘氨酸接触可能是赋予有益的能量效应的必要条件.
- 糖化在蛋白质折叠中的作用是复杂的,并且取决于特定的蛋白质环境.
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...
Protein Structure Is Critical to Its Biological Function
Proteins perform a wide range of biological functions such as catalyzing chemical reactions, providing...
Protein Folding
Overview
Protein Folding
Overview
Protein Glycosylation
Glycosylation, the most common post-translational modification for proteins, serves diverse functions. Adding sugars to proteins makes the proteins more resistant to proteolytic digestion. Glycosylated proteins can act as markers and receptors to promote cell-cell adhesion. Additionally, they have many essential quality control functions in the cell, such as correct protein folding and facilitating transport of misfolded proteins to the cytosol, which can be degraded.
Glycosylation occurs in...
Glycosylation occurs in...
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...
Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...

