Tau phosphorylation shows direct clinical importance as the hyperphosphorylation and aggregation of tau exists in a range of tauopathies. However, it is still challenging to study tau phosphorylation owing to its multiple and adjacent phosphorylation sites in the tau sequence. To address this challenge, here, a designed T232K/K238Q mutant aerolysin nanopore is introduced which synergistically incorporates the enhanced electrostatic interaction at T232K site and the high repelling barrier at K238Q site. The distinct current blockages produced by a T232K/K238Q aerolysin sensor achieve nearly 100% identification accuracy for the characteristic distribution of unphosphorylated tau peptide, pS262‐, pT263‐tau peptide, and pS262/pT263‐tau peptide. The excellent sensing ability of the T232K/K238Q nanopore originates from the extremely slow translocation speed which prolongs the duration up to tens or hundreds milliseconds for a nine‐amino‐acid peptide. It is envisioned that the design ideas of the T232K/K238Q aerolysin nanopore can be further applied to analyze other protein/peptide post‐translational modification as it provides the exquisite sensitivity for identifying the modification of single amino acids.

中文翻译：

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T232K / K238Q溶血素纳米孔用于定位单个Tau肽的相邻磷酸化位点

Tau的磷酸化显示直接的临床重要性，因为tau的过度磷酸化和聚集存在于一系列的Tauopathies中。然而，由于tau序列中tau的多个和相邻的磷酸化位点，因此研究tau的磷酸化仍然具有挑战性。为了解决这一挑战，这里介绍了一种设计好的T232K / K238Q突变型溶血素纳米孔，该孔协同地整合了T232K位点增强的静电相互作用和K238Q位点的高排斥屏障。T232K / K238Q溶血素传感器产生的明显电流阻滞可将未磷酸化的tau肽，pS262-，pT263-tau肽和pS262 / pT263-tau肽的特征分布实现近100％的识别精度。T232K / K238Q纳米孔的出色传感能力源于极慢的易位速度，该速度可将九氨基酸肽的持续时间延长至数十或数百毫秒。可以预见，T232K / K238Q溶血素纳米孔的设计思想可以进一步应用于分析其他蛋白质/肽的翻译后修饰，因为它为鉴定单个氨基酸的修饰提供了出色的灵敏度。