EFFECTS OF GLUTAMINES ON THE SELF-ASSEMBLY OF A BETA-HAIRPIN FIBRILS

谷氨酰胺对 β-发夹原纤维自组装的影响

• 批准号: 7373165
• 负责人: Robert Fairman
• 金额: $ 0.07万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7373165
• 关键词: EFFECTS; GLUTAMINES; SELF; ASSEMBLY; BETA

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Amyloid fibrils, well-structured aggregates of misfolded protein, have been implicated in a number of prevalent human diseases such as Alzheimer's dementia and Creutzfeldt-Jacob's disease. While formed by a diverse repertoire of proteins and synthetic peptides, including many with glutamine-rich sequences, amyloid fibrils have a common cross-beta-structure. Even with this common arrangement and multiple models for the atomic structure of glutamine-rich amyloid, a dominant set of forces governing amyloid formation and stabilization have not been experimentally determined. Since the forces previously investigated have not included side-chain hydrogen bonding, we created a glutamine-rich model system by de novo design that is capable of these interactions. This model, in a disulfide-cyclized form, forms beta-sheet structures, as shown by circular dichroism, and exhibits a fibril morphology, as shown by atomic force microscopy. ATR-FTIR spectroscopy was used to determine the degree of polymerization of these peptides by monitoring the presence of a sharp vibrational band resulting from aggregation effects. Through the incorporation of multiple lysine residues, it is hoped that the kinetics of folding and polymerization involved in fibril formation can be controlled via changes in salt and pH and will facilitate the study of the early intermediates of this process. Future investigation using variations on this new model system will allow the determination of the importance of glutamine side-chain hydrogen bonding in fibril growth and stability.

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。淀粉样纤维是一种结构良好的错误折叠蛋白质的聚集体，与许多流行的人类疾病有关，如阿尔茨海默氏症和克雅氏病。虽然淀粉样蛋白纤维由多种蛋白质和合成肽组成，包括许多富含谷氨酰胺的序列，但它具有共同的交叉β结构。即使有了这种常见的排列和富含谷氨酰胺的淀粉样蛋白原子结构的多种模型，主导淀粉样蛋白形成和稳定的一组主导力量还没有被实验确定。由于之前研究的力不包括侧链氢键，我们通过从头设计创建了一个能够进行这些相互作用的富含谷氨酰胺的模型系统。该模型以二硫键环化的形式形成了β-折叠结构，如圆二色谱所示，并显示了原纤维的形态，如原子力显微镜所示。ATR-FTIR光谱被用来通过监测聚集效应导致的尖锐振动带的存在来确定这些多肽的聚合度。通过多个赖氨酸残基的掺入，可以通过改变盐和pH来控制参与纤维形成的折叠和聚合的动力学，并将有助于这一过程的早期中间体的研究。未来使用这一新模型系统的变体进行的研究将使我们能够确定谷氨酰胺侧链氢键在纤维生长和稳定性中的重要性。