RNA aptamers generated against oligomeric Abeta40 recognize common amyloid aptatopes with low specificity but high sensitivity.
RNA aptamers generated against oligomeric Abeta40 recognize common amyloid aptatopes with low specificity but high sensitivity.
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DOI：
10.1371/journal.pone.0007694
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发表时间：
2009-11-10
期刊：
影响因子：
3.7
通讯作者：
Bitan G
中科院分区：
文献类型：
--
作者：
Rahimi F;Murakami K;Summers JL;Chen CH;Bitan G
适体是研究、诊断和治疗中有用的分子识别工具。尽管在其他领域取得了可喜的成果，但在淀粉样蛋白研究（包括阿尔茨海默病（AD））中，适体的使用仍然很少。AD是一种进行性神经退行性疾病，被认为是由神经毒性淀粉样β蛋白（Aβ）寡聚体引起的。因此，Aβ寡聚体是开发诊断和治疗试剂的有吸引力的靶标。我们使用40个残基形式的Aβ（Aβ40）的共价稳定寡聚体进行适体选择。尽管逐渐增加选择条件的严格性，但所选择的适体不识别Aβ40寡聚体，而是与Aβ40、Aβ42和几种其他淀粉样蛋白的原纤维反应。适体与淀粉样纤维的反应性表现出一定程度的蛋白质序列依赖性。在未处理文库中也发现了显著的原纤维结合，并且不能通过使用Aβ40原纤维的反选择来消除，这表明适体与淀粉样蛋白原纤维的结合是RNA序列无关的。适体结合依赖于纤维形成，并表现出滞后期。有趣的是，适体检测原纤维形成的灵敏度比硫磺素T（ThT）高≥15倍，揭示了ThT未检测到的大量β-折叠和原纤维形成。这些数据表明，在生理条件下，由于寡核苷酸对淀粉样蛋白原纤维的高非特异性亲和力，不能选择淀粉样蛋白生成蛋白的寡聚体形式的适体。然而，适体检测β-折叠形成的高灵敏度表明它们可以用作上级淀粉样蛋白识别工具。
Aptamers are useful molecular recognition tools in research, diagnostics, and therapy. Despite promising results in other fields, aptamer use has remained scarce in amyloid research, including Alzheimer's disease (AD). AD is a progressive neurodegenerative disease believed to be caused by neurotoxic amyloid β-protein (Aβ) oligomers. Aβ oligomers therefore are an attractive target for development of diagnostic and therapeutic reagents. We used covalently-stabilized oligomers of the 40-residue form of Aβ (Aβ40) for aptamer selection. Despite gradually increasing the stringency of selection conditions, the selected aptamers did not recognize Aβ40 oligomers but reacted with fibrils of Aβ40, Aβ42, and several other amyloidogenic proteins. Aptamer reactivity with amyloid fibrils showed some degree of protein-sequence dependency. Significant fibril binding also was found for the naïve library and could not be eliminated by counter-selection using Aβ40 fibrils, suggesting that aptamer binding to amyloid fibrils was RNA-sequence-independent. Aptamer binding depended on fibrillogenesis and showed a lag phase. Interestingly, aptamers detected fibril formation with ≥15-fold higher sensitivity than thioflavin T (ThT), revealing substantial β-sheet and fibril formation undetected by ThT. The data suggest that under physiologic conditions, aptamers for oligomeric forms of amyloidogenic proteins cannot be selected due to high, non-specific affinity of oligonucleotides for amyloid fibrils. Nevertheless, the high sensitivity, whereby aptamers detect β-sheet formation, suggests that they can serve as superior amyloid recognition tools.
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影响因子：
15.1
作者：
Kayed R;Head E;Sarsoza F;Saing T;Cotman CW;Necula M;Margol L;Wu J;Breydo L;Thompson JL;Rasool S;Gurlo T;Butler P;Glabe CG
通讯作者：
Glabe CG
影响因子：
5.5
作者：
Bitan, G;Fradinger, EA;Teplow, DB
通讯作者：
Teplow, DB
影响因子：
2.9
作者：
Calamai, M;Taddei, N;Chiti, F
通讯作者：
Chiti, F
DOI：
10.1073/pnas.0409336102
发表时间：
2005-02-15
影响因子：
11.1
作者：
Georganopoulou, DG;Chang, L;Mirkin, CA
通讯作者：
Mirkin, CA
影响因子：
3
作者：
Khurana, R;Coleman, C;Singh, S
通讯作者：
Singh, S