Intrinsically disordered proteins (IDPs) are ubiquitous proteins that are disordered entirely or partly and play important roles in diverse biological phenomena. Their structure dynamically samples a multitude of conformational states, thus rendering their structural analysis very difficult. Here we explore the potential of high-speed atomic force microscopy (HS-AFM) for characterizing the structure and dynamics of IDPs. Successive HS-AFM images of an IDP molecule can not only identify constantly folded and constantly disordered regions in the molecule, but can also document disorder-to-order transitions. Moreover, the number of amino acids contained in these disordered regions can be roughly estimated, enabling a semiquantitative, realistic description of the dynamic structure of IDPs.

本质上无序的蛋白质 (IDP) 是普遍存在的完全或部分无序的蛋白质，在多种生物现象中发挥重要作用。它们的结构动态地采样了大量的构象状态，因此使得它们的结构分析非常困难。在这里，我们探讨了高速原子力显微镜 (HS-AFM) 在表征 IDP 的结构和动力学方面的潜力。IDP 分子的连续 HS-AFM 图像不仅可以识别分子中不断折叠和不断无序的区域，还可以记录无序到有序的转变。此外，可以粗略估计这些无序区域中包含的氨基酸数量，从而能够对 IDP 的动态结构进行半定量、真实的描述。