使用碳纳米管AFM针尖的蛋白质高分辨率成像

High resolution protein AFM imaging using a carbon nanotube tip

原子力显微镜(AFM)是分析生物分子结构的有效手段,而目前使用的探针针尖的性质限制了高分辨率图像的获得。该文将碳纳米管安装到原子力显微镜的传统针尖上,制作出碳纳米管针尖以解决这个问题。运用碳纳米管针尖在大气常温条件下获得了由3个单元组成的小鼠抗体IgG蛋白质的Y形结构,并且分子的尺寸与X射线晶体衍射的结果非常接近,这种效果用传统针尖是无法获得的。获得的蛋白质分子超微结构的高分辨率图像为研究蛋白质分子功能提供了有价值的信息。

Atomic force microscopy （AFM） is a useful technique for biological molecule structure analyses; however, the image resolution is limited by the poor properties of the currently used scanning probe tips. A carbon nanotube probe tip was developed by attaching a carbon nanotube to a conventional probe tip to observe the mouse IgG protein Y-shaped structure visualized by AFM images at atmospheric 15ressure and ambient temperature. The protein was found to consist of three subunits with the molecule size determined using the improved tip consistent with X-ray diffraction measurements, which conventional AFM cantilever tips can not achieve. The high resolution images obtained using the carbon nanotube tip are valuable for studies of protein molecule ultramicrostructure and function.