Structural Characterization of hIAPP aggregates using MAS solid-state NMR

该项目的目标是使用MAS固态NMR以高分辨率确定hIAPPox和hIAPPred原纤维的结构。我们将特别关注肽激素的N-末端区域，以研究二硫桥在聚集体结构中的作用，并了解其在播种和氧化还原平衡中的功能。接种将使用从头产生的原纤维以及离体聚集材料进行。除了纯的hIAPPred和hIAPPox原纤维之外，我们将产生使用氧化还原缓冲液获得的hIAPP原纤维样品，所述氧化还原缓冲液在聚集之前在溶液中产生hIAPPred和hIAPPox的1：1混合物。我们的目标是找出是否只有hIAPPred肽被纳入原纤维，以及hIAPPox如何扰乱原纤维结构。除了静态结构，我们将研究这些淀粉样纤维中的蛋白质的动力学，并旨在将局部结构参数与纤维结构的热力学稳定性相关联。我们期望这些实验将允许获得淀粉样蛋白纤维的播种和交叉播种的更好的机械理解。

The goal of the project is the determination of the structure of hIAPPox and hIAPPred fibrils at high resolution using MAS solid-state NMR. We will focus in particular on the N-terminal region of the peptide hormone to investigate the role of the disulfide bridge in the aggregate structure, and to understand its function in seeding and redox balancing. Seeding will be done with de novo generated fibrils as well as with ex vivo aggregate material. In addition to the pure hIAPPred and hIAPPox fibrils, we will produce hIAPP fibril samples that are obtained using a redox buffer that yields a 1:1 mixture of hIAPPred and hIAPPox in solution prior to aggregation. We aim to find out if only hIAPPred peptides are incorporated into the fibril, and how hIAPPox perturbs the fibril structure. In addition to static structures, we will investigate the dynamics of proteins in these amyloid fibrils, and aim to correlate local structural parameters to the thermodynamic stability of fibril structure. We expect that these experiments will allow to obtain a better mechanistic understanding of seeding and cross-seeding of an amyloid fibril.