PDF(Pubmed)
Abstract：
BACKGROUND: Archetypical cross-β spines sharpen the boundary between functional and pathological proteins including β-amyloid, tau, α-synuclein and transthyretin are linked to many debilitating human neurodegenerative and non-neurodegenerative amyloidoses. An increased focus on development of pathogenic β-sheet specific fluid and imaging structural biomarkers and conformation-specific monoclonal antibodies in targeted therapies has been recently observed. Identification and quantification of pathogenic oligomers remain challenging for existing neuroimaging modalities.
RESULTS: We propose two artificial β-sheets which can mimic the nanoscopic structural characteristics of pathogenic oligomers and fibrils for evaluating the performance of a label free, X-ray based biomarker detection and quantification technique. Highly similar structure with elliptical cross-section and parallel cross-β motif is observed among recombinant α-synuclein fibril, Aβ-42 fibril and artificial β-sheet fibrils. We then use these β-sheet models to assess the performance of spectral small angle X-ray scattering (sSAXS) technique for detecting β-sheet structures. sSAXS showed quantitatively accurate detection of antiparallel, cross-β artificial oligomers from a tissue mimicking environment and significant distinction between different oligomer packing densities such as diffuse and dense packings.
CONCLUSIONS: The proposed synthetic β-sheet models mimicked the nanoscopic structural characteristics of β-sheets of fibrillar and oligomeric states of Aβ and α-synuclein based on the ATR-FTIR and SAXS data. The tunability of β-sheet proportions and shapes of structural motifs, and the low-cost of these β-sheet models can become useful test materials for evaluating β-sheet or amyloid specific biomarkers in a wide range of neurological diseases. By using the proposed synthetic β-sheet models, our study indicates that the sSAXS has potential to evaluate different stages of β-sheet-enriched structures including oligomers of pathogenic proteins.
RESULTS: We propose two artificial β-sheets which can mimic the nanoscopic structural characteristics of pathogenic oligomers and fibrils for evaluating the performance of a label free, X-ray based biomarker detection and quantification technique. Highly similar structure with elliptical cross-section and parallel cross-β motif is observed among recombinant α-synuclein fibril, Aβ-42 fibril and artificial β-sheet fibrils. We then use these β-sheet models to assess the performance of spectral small angle X-ray scattering (sSAXS) technique for detecting β-sheet structures. sSAXS showed quantitatively accurate detection of antiparallel, cross-β artificial oligomers from a tissue mimicking environment and significant distinction between different oligomer packing densities such as diffuse and dense packings.
CONCLUSIONS: The proposed synthetic β-sheet models mimicked the nanoscopic structural characteristics of β-sheets of fibrillar and oligomeric states of Aβ and α-synuclein based on the ATR-FTIR and SAXS data. The tunability of β-sheet proportions and shapes of structural motifs, and the low-cost of these β-sheet models can become useful test materials for evaluating β-sheet or amyloid specific biomarkers in a wide range of neurological diseases. By using the proposed synthetic β-sheet models, our study indicates that the sSAXS has potential to evaluate different stages of β-sheet-enriched structures including oligomers of pathogenic proteins.
摘要：
背景：原型交叉β棘使功能蛋白和病理蛋白（包括β-淀粉样蛋白）之间的界限更加尖锐，tau,α-突触核蛋白和运甲状腺素蛋白与许多使人衰弱的人神经变性和非神经变性淀粉样蛋白有关。最近已经观察到在靶向治疗中对致病性β-折叠特异性流体和成像结构生物标志物和构象特异性单克隆抗体的开发越来越关注。致病性寡聚体的鉴定和定量对于现有的神经成像模式仍然具有挑战性。
结果：我们提出了两种人工β-折叠，可以模拟致病性寡聚体和原纤维的纳米级结构特征，用于评估无标签的性能，基于X射线的生物标志物检测和定量技术。在重组α-突触核蛋白原纤维中观察到具有椭圆形横截面和平行交叉β基序的高度相似结构，Aβ-42原纤维和人工β-折叠原纤维。然后，我们使用这些β-折叠模型来评估光谱小角X射线散射（sSAXS）技术用于检测β-折叠结构的性能。sSAXS显示了反平行的定量准确检测，来自组织模拟环境的cross-β人工寡聚物，以及不同寡聚物堆积密度之间的显着区别，例如扩散和致密堆积。
结论：所提出的合成β-折叠模型基于ATR-FTIR和SAXS数据模拟了Aβ和α-突触核蛋白的原纤维和寡聚状态的β-折叠的纳米级结构特征。β-折叠比例和结构基序形状的可调性，这些β-折叠模型的低成本可以成为在广泛的神经系统疾病中评估β-折叠或淀粉样蛋白特异性生物标志物的有用测试材料。通过使用提出的合成β-折叠模型，我们的研究表明，sSAXS有潜力评估β-折叠富集结构的不同阶段，包括致病蛋白的寡聚体。
结果：我们提出了两种人工β-折叠，可以模拟致病性寡聚体和原纤维的纳米级结构特征，用于评估无标签的性能，基于X射线的生物标志物检测和定量技术。在重组α-突触核蛋白原纤维中观察到具有椭圆形横截面和平行交叉β基序的高度相似结构，Aβ-42原纤维和人工β-折叠原纤维。然后，我们使用这些β-折叠模型来评估光谱小角X射线散射（sSAXS）技术用于检测β-折叠结构的性能。sSAXS显示了反平行的定量准确检测，来自组织模拟环境的cross-β人工寡聚物，以及不同寡聚物堆积密度之间的显着区别，例如扩散和致密堆积。
结论：所提出的合成β-折叠模型基于ATR-FTIR和SAXS数据模拟了Aβ和α-突触核蛋白的原纤维和寡聚状态的β-折叠的纳米级结构特征。β-折叠比例和结构基序形状的可调性，这些β-折叠模型的低成本可以成为在广泛的神经系统疾病中评估β-折叠或淀粉样蛋白特异性生物标志物的有用测试材料。通过使用提出的合成β-折叠模型，我们的研究表明，sSAXS有潜力评估β-折叠富集结构的不同阶段，包括致病蛋白的寡聚体。
