Chemistry Department and Molecular Protein Science, Lund University, P.O. Box 124, SE221 00 Lund, Sweden.
ACS Chem Neurosci. 2010 Jan 20;1(1):13-8. doi: 10.1021/cn900015v. Epub 2009 Oct 9.
Protein aggregation can lead to major disturbances of cellular processes and is associated with several diseases. We report kinetic and equilibrium data by ThT fluorescence and enzyme-linked immunosorbent assay of sufficient quality and reproducibility to form a basis for mechanistic understanding of amyloid β-peptide (Aβ) fibril formation. Starting from monomeric peptide in a pure buffer system without cosolvents, we find that the kinetics of Aβ aggregation vary strongly with peptide concentration in a highly predictable manner. The free Aβ concentration in equilibrium with fibrils was found to vary with total peptide concentration in a manner expected for a two-phase system. The free versus total Aβ concentration was linear up to ca. 0.2 μM, after which free Aβ decreased with total Aβ toward an asymptotic value. Our results imply that Aβ fibril formation arises from a sequence of events in a highly predictable manner.
蛋白质聚集会导致细胞过程的重大紊乱，并与多种疾病有关。我们报告了通过 ThT 荧光和酶联免疫吸附试验获得的动力学和平衡数据，其质量和重现性足以形成对淀粉样 β-肽 (Aβ) 纤维形成的机制理解的基础。从无共溶剂的纯缓冲体系中的单体肽开始，我们发现 Aβ 聚集的动力学随着肽浓度的变化而呈现出高度可预测的方式。与纤维平衡的游离 Aβ浓度随着总肽浓度的变化而变化，这种变化方式与两相体系一致。游离 Aβ与总 Aβ的浓度在约 0.2μM 之前呈线性关系，之后游离 Aβ随着总 Aβ的增加而逐渐趋于一个渐近值。我们的结果表明，Aβ 纤维形成是一个高度可预测的序列事件的结果。
