Alzheimer's β-peptide oligomer formation at physiologic concentrations
Alzheimer's β-peptide oligomer formation at physiologic concentrations
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DOI：
10.1016/j.ab.2004.08.014
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发表时间：
2004-12-01
影响因子：
2.9
通讯作者：
LeVine, H
中科院分区：
文献类型：
--
作者：
LeVine, H
当从二甲基亚砜或1，1，1，3，3，3-六氟-2-丙醇中稀释时，合成的人Abeta(1-42)在接近生理浓度(1-20 nM)的情况下容易形成低聚结构。在夹心酶联免疫吸附试验中检测大于或等于40 kDa的寡聚体，其中捕获和检测抗体识别相同的主要序列表位。具有单一表位的单体多肽不会以这种形式发生反应。在这种条件下，Aβ(1-40)肽不容易齐聚。低聚物的形成速度与温度呈陡峭的线性关系，但受离子强度的影响很小，最高可达0.5M的氯化钠或氯化钾。吐温20和其他几种洗涤剂的浓度远低于其临界胶束浓度，可抑制齐聚物的形成。一旦形成，高相对分子质量的低聚物被吐温20稳定下来。以纳摩尔浓度形成的低聚物制剂的凝胶渗透层析表明，大多数Abeta(1-42)多肽层析为表观相对分子质量类似于10 kDa的单体/二聚体。最丰富的低聚物具有对应于220 kDa(48聚体)的表观迁移率和更高的迁移率，没有检测到中间低分子质量物种的浓度。在Superose 12柱的空隙体积(>；1.5mda)中出现非常少的免疫反应性多肽。低聚物是稳定的，在其原始位置重新层析。在生理浓度下形成α-β(1-42)低聚物是一个可重复的过程，可以进行动力学分析和抑制。(C)2004 Elsevier Inc.保留所有权利。
When diluted from dimethyl sulfoxide or 1,1,1,3,3,3-hexafluoro-2-propanol, synthetic human Abeta(1-42) readily forms oligomeric structures at near physiologic concentrations (1-20 nM). Oligomers greater than or equal to 40 kDa are detected in a sandwich enzyme-linked immunosorbant assay where the capture and detection antibodies recognize the same primary sequence epitope. Monomeric peptide with a single epitope does not react in this format. Abeta(1-40) peptide does not oligomerize readily under these conditions. The rate of oligomer formation has a steep linear temperature dependence but is weakly affected by ionic strength up to 0.5 M NaCl or KCl. Oligomer formation is inhibited by concentrations of Tween 20 and several other detergents well below their critical micelle concentrations. Once formed, high-molecular-weight oligomers are stabilized by Tween 20. Gel permeation chromatography of an oligomer preparation formed at nanomolar concentrations indicates that the majority of the Abeta(1-42) peptide chromatographs as monomers/dimers of apparent mw similar to10 kDa. The most abundant oligomers have apparent mobilities corresponding to 220 kDa (48-mer) and higher multiples of this without detectable concentrations of intermediate low-molecular-weight species. Very little immunoreactive peptide appears in the void volume (>1.5 MDa) of a Superose 12 column. The oligomers are stable, rechromatographing at their original position. Abeta(1-42) oligomer formation at physiologic concentrations is a reproducible process that is amenable to kinetic analysis and inhibition. (C) 2004 Elsevier Inc. All rights reserved.