Institute of Applied Mechanics, Nation Taiwan University, Taipei, Taiwan.
Biochem Biophys Res Commun. 2012 Jan 6;417(1):109-15. doi: 10.1016/j.bbrc.2011.11.065. Epub 2011 Nov 22.
Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.
原子力显微镜（AFM）是纳米生物技术中不可或缺的仪器。本研究开发了一种方法，使 AFM 能够同时测量特定的非结合力，并在单个病毒颗粒水平上绘制病毒糖蛋白图谱。通过整合病毒颗粒的平均直径和病毒表面抗原与抗体探针之间的特异性，设计了一个三阶段的方法，在获得力测量值之前将测量区域设置为单个病毒颗粒，流感病毒被用作测量对象。基于提出的方法和进行的分析，可以从结果中得出几个发现。可以定量单个病毒颗粒的平均非结合力，并且在病毒颗粒之间，该值没有显著差异。此外，还证明了所提出方法的可重复性。力映射图像显示，在提出的方法和实验标准下，单个病毒颗粒的整个表面上，抗体探针识别的表面病毒抗原的分布是分散的；同时，颗粒之间的结合概率相似。该方法可以很容易地应用于大多数 AFM 系统，而无需特定的组件或配置。这些结果有助于理解单个病毒颗粒水平上的基于力的分析，从而增强 AFM 研究特定类型病毒表面蛋白及其分布的能力。
