论文标题
直接和同时测量单个折叠蛋白的刚度和内部摩擦
Direct and simultaneous measurement of the stiffness and internal friction of a single folded protein
论文作者
论文摘要
折叠的单蛋白的纳米力学反应，即负责众多生物过程的天然纳米机器，可洞悉其功能。以其粘弹性为特征的折叠状态的构象灵活性使蛋白质可以采用不同的形状来执行其功能。尽管做出了努力，但到目前为止，它的直接测量是不可能的。我们使用特殊的基于干涉仪的原子力显微镜进行了直接且同时测量蛋白滴定折叠结构域的刚度和内部摩擦。我们通过仔细分离影响实验探针响应以获得折叠状态的粘弹性的不同贡献来分析数据。高于〜95 pn的力，从弹性固体状的天然状态到柔软的粘弹性中间体的单个免疫球蛋白的单个免疫球蛋白过渡。
The nanomechanical response of a folded single protein, the natural nanomachine responsible for myriad biological processes, provides insight into its function. The conformational flexibility of a folded state, characterized by its viscoelasticity, allows proteins to adopt different shapes to perform their function. Despite efforts, its direct measurement has not been possible so far. We present a direct and simultaneous measurement of the stiffness and internal friction of the folded domains of the protein titin using a special interferometer based atomic force microscope. We analysed the data by carefully separating different contributions affecting the response of the experimental probe to obtain the folded state's viscoelasticity. Above ~ 95 pN of force, the individual immunoglobulins of titin transition from an elastic solid-like native state to a soft viscoelastic intermediate.
