Effect of different salt ions on the propensity of aggregation and on the structure of Alzheimer's Aβ(1-40) amyloid fibrils
Effect of different salt ions on the propensity of aggregation and on the structure of Alzheimer's Aβ(1-40) amyloid fibrils
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DOI：
10.1016/j.jmb.2007.08.068
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发表时间：
2007-11-09
影响因子：
5.6
通讯作者：
Faendrich, Marcus
中科院分区：
文献类型：
--
作者：
Klement, Karolin;Wieligmann, Karin;Faendrich, Marcus
淀粉样纤维和其他多肽聚集体的形成强烈依赖于物理化学环境。影响聚集的一个这样的因素是盐离子的存在和浓度。我们已经研究了盐离子对阿尔茨海默氏症A β（1-40）肽的聚集倾向和对溶解的和纤维状肽的结构的影响。所有检测的盐均强烈促进聚集。在阳离子系列中看到最显著的效果，即对于MgCl 2。对不同可能解释的评价表明，A β（1-40）聚集依赖于离子与A β（1-40）肽之间的直接相互作用，并与离子诱导的表面张力变化相关。盐对纤维结构有着深远的影响。在盐的存在下，原纤维与较小的直径，较窄的交叉距离和较低的酰胺I最大值。由于A β（1-40）聚集对盐的反应方式与其他多肽（如胰高血糖素、β（2）-微球蛋白或α-突触核蛋白）不同;这些数据表明，盐影响不同多肽链聚集的方式并不完全一致。这些观察结果对于根据简单的物理化学性质理解和预测聚集是重要的。(C)2007爱思唯尔有限公司保留所有权利。
The formation of amyloid fibrils and other polypeptide aggregates depends strongly on the physico-chemical environment. One such factor affecting aggregation is the presence and concentration of salt ions. We have examined the effects of salt ions on the aggregation propensity of Alzheimer's A beta(1-40) peptide and on the structure of the dissolved and of the fibrillar peptide. All salts examined promote aggregation strongly. The most pronounced effect is seen within the cationic series, i.e. for MgCl2. Evaluation of different possible explanations suggests that A beta(1-40) aggregation depends on direct interaction between ions and A beta(1-40) peptide, and correlates with ion-induced changes of the surface tension. Salts have profound effects on the fibril structure. In the presence of salts, fibrils are associated with smaller diameters, narrower crossover distances and lower amide I maxima. Since A beta(1-40) aggregation responds to salts in a manner unlike that for other polypeptides, such as glucagon, beta(2)-microglobulin or alpha-synuclein; these data argue that there is no fully uniform way in which salts affect aggregation of different polypeptide chains. These observations are important for understanding and predicting aggregation on the basis of simple physico-chemical properties. (C) 2007 Elsevier Ltd. All rights reserved.