Side-by-side comparison of Notch- and C83 binding to γ-secretase in a complete membrane model at physiological temperature.
Side-by-side comparison of Notch- and C83 binding to γ-secretase in a complete membrane model at physiological temperature.
复制标题
在生理温度下完整的膜模型中，Notch-和C83与γ-分泌酶的并排比较。
作者：
γ-分泌酶切割淀粉样前体蛋白的C99片段，导致形成聚集的β-淀粉样肽和Notch，后者对阿尔茨海默病至关重要，对细胞调节至关重要。最近的低温电子显微镜（cryo-EM）结构表明，底物结合后发生了重大变化，β-折叠识别基序和可能的螺旋解旋使肽键暴露于亲核攻击。在这里，我们报告并排比较的303 K动态的两种蛋白质在现实的膜使用分子动力学模拟。我们的系综与cryo-EM数据（全蛋白Cα-RMSD = 1.62-2.19 μ m）一致，但揭示了不同的早老素螺旋构象状态和C83和Notch 100的热β-链到卷曲转变。我们确定不同的303 K氢键动力学和水的可及性的催化位点。RKRR基序（1758-1761）对Notch结合有显著贡献，并充当防止Notch置换的“膜锚”。与G1753和V1754短暂氢键结合的水可能代表催化亲核试剂。在303 K时，Notch和C83结合诱导出不同的构象状态，其中Notch主要以闭合状态存在，Asp-Asp距离较短。这可以解释Notch和C99切割的不同结果，因为后者对于许多产物更不精确。我们鉴定的构象状态可能有助于开发不同靶向C99和Notch切割的构象选择性药物，例如Notch保留γ-分泌酶调节剂。C83和Notch结合的γ-分泌酶的不同膜动力学和构象可能有助于开发阿尔茨海默病的Notch保留治疗。
γ-Secretase cleaves the C99 fragment of the amyloid precursor protein, leading to formation of aggregated β-amyloid peptide central to Alzheimer's disease, and Notch, essential for cell regulation. Recent cryogenic electron microscopy (cryo-EM) structures indicate major changes upon substrate binding, a β-sheet recognition motif, and a possible helix unwinding to expose peptide bonds towards nucleophilic attack. Here we report side-by-side comparison of the 303 K dynamics of the two proteins in realistic membranes using molecular dynamics simulations. Our ensembles agree with the cryo-EM data (full-protein Cα-RMSD = 1.62–2.19 Å) but reveal distinct presenilin helix conformation states and thermal β-strand to coil transitions of C83 and Notch100. We identify distinct 303 K hydrogen bond dynamics and water accessibility of the catalytic sites. The RKRR motif (1758–1761) contributes significantly to Notch binding and serves as a “membrane anchor” that prevents Notch displacement. Water that transiently hydrogen bonds to G1753 and V1754 probably represents the catalytic nucleophile. At 303 K, Notch and C83 binding induce different conformation states, with Notch mostly present in a closed state with shorter Asp–Asp distance. This may explain the different outcome of Notch and C99 cleavage, as the latter is more imprecise with many products. Our identified conformation states may aid efforts to develop conformation-selective drugs that target C99 and Notch cleavage differently, e.g. Notch-sparing γ-secretase modulators. Distinct membrane dynamics and conformations of C83- and Notch-bound γ-secretase may aid the development of Notch-sparing treatments of Alzheimer's disease.
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影响因子：
168.9
作者：
Ballard, Clive;Gauthier, Serge;Jones, Emma
通讯作者：
Jones, Emma
DOI：
10.1016/s0140-6736(20)32205-4
发表时间：
2021-04-24
期刊：
Lancet (London, England)
影响因子：
--
作者：
Scheltens P;De Strooper B;Kivipelto M;Holstege H;Chételat G;Teunissen CE;Cummings J;van der Flier WM
通讯作者：
van der Flier WM
影响因子：
4.6
作者：
Clemente N;Abdine A;Ubarretxena-Belandia I;Wang C
通讯作者：
Wang C
影响因子：
7.7
作者：
Bai, Xiao-chen;Rajendra, Eeson;Scheres, Sjors H. W.
通讯作者：
Scheres, Sjors H. W.
影响因子：
2.9
作者：
Deatherage, Catherine L.;Lu, Zhenwei;Sanders, Charles R.
通讯作者：
Sanders, Charles R.