Application of DNP-enhanced solid-state NMR to studies of amyloid-β peptide interaction with lipid membranes.
Application of DNP-enhanced solid-state NMR to studies of amyloid-β peptide interaction with lipid membranes.
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DOI：
10.1016/j.chemphyslip.2021.105071
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发表时间：
2021-05
影响因子：
3.4
通讯作者：
Potapov A
中科院分区：
文献类型：
--
作者：
Deo T;Cheng Q;Paul S;Qiang W;Potapov A
由a β肽聚集引起的细胞膜破坏已被认为是阿尔茨海默病期间神经元细胞死亡的合理原因。Aβ与细胞膜相互作用的分子水平细节以前是用固态核磁共振（ssNMR）来探测的，然而，由于后者的灵敏度有限，研究仅限于具有高Aβ与脂质比的样品。动态核极化（DNP）是一种提高核磁共振灵敏度的技术。在这项工作中，我们证明了dnp增强的ssNMR研究a β40肽与各种模型脂质体相互作用的可行性：(1)两性离子1-棕榈酰-2-油基-甘油-3-磷酸胆碱（POPC）和带负电荷的1-棕榈酰-2-油基-sn-甘油-3-磷酸-（1ߣ-丙基甘油）（POPG）的混合物；(2) POPC、POPG、胆固醇、鞘磷脂和神经节苷脂GM1的混合物；(3)大鼠脑组织突触质膜囊（SPMVs）。此外，DNP-ssNMR应用于捕获肽插入POPG脂质体时Aβ40构象的变化。DNP条件下的信号增强允许使用约0.25 mg Aβ40肽（即达到Aβ40与脂质比例1:20 00）进行信息丰富的2D ssmr实验。在所研究的脂质体模型中，Aβ40的许多13C标记位点的13C NMR化学位移是β-片的特征。此外，在POPG脂质体中，肽形成疏水接触F19-L34和F19-I32。a - β40在POPG中的化学位移和疏水接触在培养8小时前后保持不变。这表明肽的13c标记位点的构象在插入过程前后是相似的。总之，我们的研究结果表明DNP有助于克服ssNMR的敏感性限制，从而扩大了ssNMR表征与脂质相互作用的Aβ肽的适用性。
The cellular membrane disruption induced by the aggregation of Aβ peptide has been proposed as a plausible cause of neuronal cell death during Alzheimer’s disease. The molecular-level details of the Aβ interaction with cellular membranes were previously probed using solid state NMR (ssNMR), however, due to the limited sensitivity of the latter, studies were limited to samples with high Aβ-to-lipid ratio. The dynamic nuclear polarization (DNP) is a technique for increasing the sensitivity of NMR. In this work we demonstrate the feasibility of DNP-enhanced ssNMR studies of Aβ40 peptide interacting with various model liposomes: (1) a mixture of zwitterionic 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1ߣ-rac-glycerol) (POPG); (2) a mixture of POPC, POPG, cholesterol, sphingomyelin and ganglioside GM1; (3) the synaptic plasma membrane vesicles (SPMVs) extracted from rat brain tissues. In addition, DNP-ssNMR was applied to capturing changes in Aβ40 conformation taking place upon the peptide insertion into POPG liposomes. The signal enhancements under conditions of DNP allow carrying out informative 2D ssNMR experiments with about 0.25 mg of Aβ40 peptides (i.e. reaching Aβ40-to-lipid ratio of 1:200). In the studied liposome models, the 13C NMR chemical shifts at many 13C-labelled sites of Aβ40 are characteristic of β-sheets. In addition, in POPG liposomes the peptide forms hydrophobic contacts F19-L34 and F19-I32. Both the chemical shifts and hydrophobic contacts of Aβ40 in POPG remain the same before and after 8 hours of incubation. This suggests that conformation at the 13C-labelled sites of the peptide is similar before and after the insertion process. Overall, our results demonstrate that DNP helps to overcome the sensitivity limitation of ssNMR, and thereby expand the applicability of ssNMR for charactering the Aβ peptide interacting with lipids.
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DOI：
10.1007/s00249-007-0251-2
发表时间：
2008-03-01
影响因子：
2
作者：
Gehman, John D.;O'Brien, Caitlin C.;Separovic, Frances
通讯作者：
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影响因子：
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作者：
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DOI：
10.1073/pnas.0900908106
发表时间：
2009-06-09
影响因子：
11.1
作者：
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通讯作者：
Griffin, Robert G.
影响因子：
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影响因子：
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