Probing force-induced unfolding intermediates of a single staphylococcal nuclease molecule and the effect of ligand binding.
Probing force-induced unfolding intermediates of a single staphylococcal nuclease molecule and the effect of ligand binding.
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DOI：
10.1016/j.bbrc.2008.08.073
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发表时间：
2008-10
影响因子：
3.1
通讯作者：
T. Ishii;Y. Murayama;Atsuto Katano;K. Maki;K. Kuwajima;M. Sano
中科院分区：
文献类型：
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作者：
T. Ishii;Y. Murayama;Atsuto Katano;K. Maki;K. Kuwajima;M. Sano
单分子操纵技术使人们能够在实验中获得在传统实验中无法获得的蛋白质的折叠中间产物。中间体的详细表征是一个具有挑战性的问题，它为直接探索蛋白质的能量格局提供了新的可能性。我们用原子力显微镜研究了一种小球状蛋白葡萄球菌核酸酶(SNase)的单分子机械去折叠。蛋白质的展开轨迹表现出亚分子和随机行为，典型的长度与展开的亚结构的大小相对应。我们的结果支持了最近的理论研究中提出的单一蛋白质沿着多条途径展开的观点。此外，我们还发现了由配体和抑制剂结合引起的机械去折叠动力学的剧烈变化。
Single-molecule manipulation techniques have given experimental access to unfolding intermediates of proteins that are inaccessible in conventional experiments. A detailed characterization of the intermediates is a challenging problem that provides new possibilities for directly probing the energy landscape of proteins. We investigated single-molecule mechanical unfolding of a small globular protein, staphylococcal nuclease (SNase), using atomic force microscopy. The unfolding trajectories of the protein displayed sub-molecular and stochastic behavior with typical lengths corresponding to the size of the unfolded substructures. Our results support the view that the single protein unfolds along multiple pathways as suggested in recent theoretical studies. Moreover, we found the drastic change, caused by the ligand and inhibitor bindings, in the mechanical unfolding dynamics.