Center for Biotechnology and Interdisciplinary Studies, Department of Chemistry and Chemical Biology, Departments of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York, NY 12180, USA.
Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC 27514, USA.
Biomolecules. 2022 Oct 27;12(11):1573. doi: 10.3390/biom12111573.
(1) Background: Prion-like transcellular spreading of tau pathology in Alzheimer's disease (AD) is mediated by tau binding to the cell-surface glycan heparan sulfate (HS). However, the structural determinants for tau-HS interaction are not well understood. (2) Methods and Results: Binding-site mapping using NMR showed two major binding regions in full-length tau responsible for heparin interaction. Thus, two tau constructs, tau PRR2* and tau R2*, were designed to investigate the molecular details at the tau-heparin binding interface. The 2D H-N HSQC of tau PRR2* and tau R2* lacked dispersion, which is characteristic for intrinsically disordered proteins. NMR titration of Arixtra into N-labeled tau R2* induced large chemical shift perturbations (CSPs) in VQIINK and downstream residues K281-D283, in which L282 and I278 displayed the largest shifts. NMR titration of Arixtra into N-labeled tau PRR2* induced the largest CSPs for residue R209 followed by residues S210 and R211. Residue-based CSP fitting showed that tau PRR2*-Arixtra interaction had a much stronger binding affinity (0.37-0.67 mM) than that of tau R2*-Arixtra (1.90-5.12 mM) interaction. (3) Conclusions: Our results suggested that PRR2 is a crucial domain for tau-heparin and tau-HS interaction.
（1）背景：阿尔茨海默病（AD）中 tau 病理的类朊病毒样细胞间传播是由 tau 与细胞表面糖胺聚糖肝素硫酸（HS）结合介导的。然而，tau-HS 相互作用的结构决定因素尚不清楚。（2）方法和结果：使用 NMR 进行的结合位点映射显示全长 tau 中有两个主要的结合区域负责与肝素相互作用。因此，设计了两个 tau 构建体 tau PRR2* 和 tau R2*，以研究 tau-肝素结合界面的分子细节。tau PRR2* 和 tau R2的二维 H-N HSQC 缺乏弥散性，这是无规卷曲蛋白质的特征。Arixtra 对 N 标记的 tau R2 的 NMR 滴定引起 VQIINK 和下游残基 K281-D283 中的大化学位移扰动（CSP），其中 L282 和 I278 显示出最大的位移。Arixtra 对 N 标记的 tau PRR2* 的 NMR 滴定引起残基 R209 后的最大 CSP，其次是残基 S210 和 R211。基于残基的 CSP 拟合表明，tau PRR2*-Arixtra 相互作用的结合亲和力（0.37-0.67 mM）比 tau R2*-Arixtra（1.90-5.12 mM）相互作用要强得多。（3）结论：我们的结果表明，PRR2 是 tau-肝素和 tau-HS 相互作用的关键结构域。
