Determination of protein structural flexibility by microsecond force spectroscopy
Determination of protein structural flexibility by microsecond force spectroscopy
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DOI：
10.1038/nnano.2009.156
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发表时间：
2009-08-01
影响因子：
38.3
通讯作者：
Sahin, Ozgur
中科院分区：
文献类型：
--
作者：
Dong, Mingdong;Husale, Sudhir;Sahin, Ozgur
蛋白质是动态分子机器，具有允许构象变化的结构灵活性（1，2）。目前用于测定蛋白质柔性的方法主要依赖于测量蛋白质构象中的热波动和无序（3-5），并且往往具有实验挑战性。此外，它们反映了皮秒时间尺度上的原子波动，而蛋白质中的大型构象变化通常发生在微米至毫秒的时间尺度上（6，7）。在这里，我们直接确定细菌视紫红质的灵活性-一种蛋白质，利用光的能量移动质子穿过细胞膜-在微秒的时间尺度上，通过监测力引起的变形与基于原子力显微镜技术的蛋白质结构。与现有的方法相比，我们测量的变形涉及蛋白质残基的集体反应，并在与天然蛋白质生理相关的条件下操作。
Proteins are dynamic molecular machines having structural flexibility that allows conformational changes(1,2). Current methods for the determination of protein flexibility rely mainly on the measurement of thermal fluctuations and disorder in protein conformations(3-5) and tend to be experimentally challenging. Moreover, they reflect atomic fluctuations on pico-second timescales, whereas the large conformational changes in proteins typically happen on micro- to millisecond timescales(6,7). Here, we directly determine the flexibility of bacteriorhodopsin-a protein that uses the energy in light to move protons across cell membranes-at the microsecond timescale by monitoring force-induced deformations across the protein structure with a technique based on atomic force microscopy. In contrast to existing methods, the deformations we measure involve a collective response of protein residues and operate under physiologically relevant conditions with native proteins.