Wang Min S, Zameer Andleeb, Emadi Sharareh, Sierks Michael R
Department of Chemical Engineering, Arizona State University, Tempe, Arizona 85287-6006, USA.
Langmuir. 2009 Jan 20;25(2):912-8. doi: 10.1021/la8025914.
Protein misfolding and aggregation can lead to several neurodegenerative diseases including Alzheimer's Disease (AD), Parkinson's Disease (PD) and Huntington's Disease (HD). While the respective proteins involved in each disease differ in their pathological effects and amino acid sequences, the aggregated forms all share a common cross beta-sheet conformation. Substantial controversy exists over the roles of the different aggregate morphologies in disease onset and progression, and analytical tools such as morphology specific antibodies are needed to distinguish between the different protein morphologies in situ. Here we utilize atomic force microscopy (AFM) to characterize the binding of three single chain antibody fragments (scFvs) to different morphologies of alpha-synuclein (alphaS). From the topographic images generated using the AFM, we were able to show that one scFv bound all morphologies of alphaS, a second bound only oligomeric alphaS, and a third bound only fibrillar alphaS by comparing the height distribution of the different alphaS morphologies with and without addition of the different scFvs. These results demonstrate the versatility of the AFM-based technique as an easy tool to characterize specific antigen-antibody binding and the potential applications of scFvs as promising immunodiagnostics for protein misfolding diseases.
蛋白质错误折叠和聚集可导致多种神经退行性疾病，包括阿尔茨海默病（AD）、帕金森病（PD）和亨廷顿病（HD）。虽然每种疾病中涉及的各自蛋白质在病理效应和氨基酸序列上有所不同，但聚集形式都具有共同的交叉β-折叠构象。关于不同聚集形态在疾病发生和进展中的作用存在大量争议，需要诸如形态特异性抗体等分析工具来原位区分不同的蛋白质形态。在这里，我们利用原子力显微镜（AFM）来表征三种单链抗体片段（scFvs）与不同形态的α-突触核蛋白（αS）的结合。从使用AFM生成的形貌图像中，通过比较添加和未添加不同scFvs时不同αS形态的高度分布，我们能够表明一种scFv结合所有形态的αS，第二种仅结合寡聚体αS，第三种仅结合纤维状αS。这些结果证明了基于AFM的技术作为一种表征特异性抗原-抗体结合的简便工具的多功能性，以及scFvs作为蛋白质错误折叠疾病有前景的免疫诊断方法的潜在应用。
