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Lipid and Drug Effects on the Early Stages of hIAPP Aggregation on Membrane Surfaces Probed by Surface-Selective Chiral SFG Spectroscopy

通过表面选择性手性 SFG 光谱探测膜表面 hIAPP 聚集早期的脂质和药物效应

基本信息

批准号：
9001395
负责人：
E. Chui-Ying Yan
金额：
$ 8.09万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9001395
关键词：
3-Dimensional Adsorption Alzheimer&apos s Disease Amyloid Amyloid Proteins Amyloidosis Atomic Force Microscopy Biological Markers Cell membrane Cells Chemistry Clinical Research Complement Data Detection Diabetes Mellitus Disease Drug Design Fluorescence Microscopy Frequencies Future Generations Goals Health Human Huntington Disease In Situ Kinetics Knowledge Label Lipid Bilayers Lipids Measures Membrane Membrane Lipids Methods Microscopy Molecular Molecular Structure Monitor Non-Insulin-Dependent Diabetes Mellitus Optical Methods Outcome Pancreas Parkinson Disease Pathogenesis Peptides Pharmaceutical Preparations Phase Play Prion Diseases Proteins Research Resources Role Secondary Protein Structure Series Signal Transduction Signaling Protein Solutions Solvents Specificity Spectrum Analysis Staging Structure Sum Surface Symptoms Testing Time Transmission Electron Microscopy Water Work cytotoxicity drug candidate drug development early onset fighting improved innovation insight islet amyloid polypeptide monolayer mutant novel strategies protein folding research study response small molecule structural biology

项目摘要

DESCRIPTION (provided by applicant): Aggregation of amyloid proteins is associated with a number of diseases, including Alzheimer's disease, Parkinson's disease, and type II diabetes. Although there is still a debate on whether the aggregation is the symptoms or the cause of the diseases, a better understanding of amyloid aggregation at the molecular level can provide crucial information for steering strategies for drug development in fighting amyloid diseases. Membrane is known to play a crucial role in amyloid aggregation. Recent studies have shown that lipid molecules are reliable biomarkers for detecting amyloid diseases before the onset of symptoms. Moreover, interactions with membrane can catalyze amyloid aggregation and the aggregation product formed at the early stages can disrupt cell membrane and cause cytotoxicity. Thus, it is significant to understand amyloid aggregation on membrane surfaces. However, most previous molecular studies of amyloid aggregation were carried out in solution phase. Hence, there is a large gap of knowledge about the role of membrane surfaces in amyloid aggregation. Nonetheless, bridging the gap requires surface-specific physical methods that can monitor conformational changes in amyloid proteins upon interactions with membrane surfaces in situ and in real time. The challenge is the need of surface-specificity that can eliminate interference of signals from proteins in solution phase and from water solvent such that surface information can be preserved. For the last 5 years, we have developed surface-specific chiral sum frequency generation (cSFG) vibrational spectroscopy into a new approach for label-free characterization of protein secondary structures at interfaces. We successfully used cSFG to study human islet amyloid polypeptide (hIAPP) that is associated with type II diabetes. We monitored the kinetics of the misfolding of hIAPP from disordered structures to -helices and then -sheets upon interactions with lipid surfaces. Also, we preformed ab initio calculations for analyzing cSFG spectra and obtained molecular orientation of the -sheet aggregates of hIAPP on membrane surfaces. Here, we propose to use cSFG method combined with other surface chemistry methods to study the aggregation of hIAPP in early stages on membrane surfaces. We will focus on the effects of (1) lipid compositions, particularly those biomarker lipids proven to be useful for detecting amyloid diseases, (2) drug candidates, including small molecules and peptides, that are known to inhibit fibril formation, and (3) the S20G mutant of hIAPP, the only mutant associated with early onset of type II diabetes. We will measure the rates of conformational changes of hIAPP and the mutant on lipid membranes with various levels of biomarker lipids and addition of the drug candidates. The results will offer mechanistic understanding of amyloid aggregation in the early stages on the membrane surfaces, providing insights into the role of amyloid aggregation in pathogenesis of the diseases and offering guidance in prioritizing resource in amyloid research.

描述(申请人提供)：淀粉样蛋白的聚集与许多疾病有关，包括阿尔茨海默病、帕金森氏病和II型糖尿病。尽管对于聚集是疾病的症状还是病因仍存在争议，但在分子水平上更好地了解淀粉样蛋白聚集可以为指导抗击淀粉样蛋白疾病的药物开发策略提供关键信息。膜在淀粉样蛋白聚集过程中起着至关重要的作用。最近的研究表明，脂质分子是在症状出现之前检测淀粉样蛋白疾病的可靠生物标志物。此外，与膜的相互作用可以催化淀粉样蛋白的聚集，早期形成的聚集产物可以破坏细胞膜，导致细胞毒性。因此，了解膜表面的淀粉样蛋白聚集具有重要意义。然而，以往对淀粉样蛋白聚集的分子研究大多是在溶液相进行的。因此，关于膜表面在淀粉样蛋白聚集中的作用的知识有很大的差距。尽管如此，弥合这一差距需要特定于表面的物理方法，这种方法可以在原位和实时监测淀粉样蛋白与膜表面相互作用时的构象变化。挑战是需要表面专一性，可以消除来自溶液中蛋白质和来自水溶剂的信号的干扰，从而可以保留表面信息。在过去的5年里，我们发展了表面特定的手性和频产生(CSFG)振动光谱，成为一种无标记表征蛋白质界面二级结构的新方法。我们成功地使用cSFG研究了与II型糖尿病相关的人胰岛淀粉样多肽(HIAPP)。我们监测了hIAPP从无序结构到-螺旋再到-Sheet与脂质表面相互作用的错误折叠动力学。此外，我们还进行了从头计算分析cSFG光谱，得到了-Sheet聚集体在膜表面的分子取向。在这里，我们建议使用cSFG方法结合其他表面化学方法来研究hIAPP在膜表面的早期聚集。我们将集中讨论(1)脂质成分，特别是那些被证明有助于检测淀粉样疾病的生物标记物脂质的影响，(2)已知可抑制纤维形成的候选药物，包括小分子和多肽，以及(3)hIAPP的S20G突变，这是唯一与II型糖尿病早期发病相关的突变。我们将测量hIAPP和突变体在不同水平的生物标记物脂质和添加候选药物的脂膜上的构象变化率。这些结果将提供对膜表面早期淀粉样蛋白聚集的机制的理解，为深入了解淀粉样蛋白聚集在疾病发病机制中的作用提供见解，并为优先选择淀粉样蛋白研究中的资源提供指导。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

A narrow amide I vibrational band observed by sum frequency generation spectroscopy reveals highly ordered structures of a biofilm protein at the air/water interface.

DOI：
10.1039/c5cc05743d
发表时间：
2016-02-18
期刊：
Chemical communications (Cambridge, England)
影响因子：
0
作者：
Wang Z;Morales-Acosta MD;Li S;Liu W;Kanai T;Liu Y;Chen YN;Walker FJ;Ahn CH;Leblanc RM;Yan EC
通讯作者：
Yan EC

New Insights from Sum Frequency Generation Vibrational Spectroscopy into the Interactions of Islet Amyloid Polypeptides with Lipid Membranes.