Energy landscape of streptavidin-biotin complexes measured by atomic force microscopy
Energy landscape of streptavidin-biotin complexes measured by atomic force microscopy
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DOI：
10.1021/bi992715o
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发表时间：
2000-08-22
期刊：
影响因子：
2.9
通讯作者：
Moy, VT
中科院分区：
文献类型：
--
作者：
Yuan, CB;Chen, A;Moy, VT
配体和受体的解离涉及在解结合过程期间形成的中间状态之间的多个转变。在本文中，我们探索了链霉亲和素-生物素相互作用的能量景观，通过使用原子力显微镜（AFM）来测量单个配体-受体复合物的解结合动力学。链霉亲和素-生物素键的断裂力在100和5000 pN/s之间的加载速率范围内增加超过2倍。此外，力的测量结果表明，在链霉亲和素-生物素力谱中的两个制度的加载，揭示了存在两个激活障碍的解结合过程。用链霉亲和素突变体（W120 F）进行的平行实验被用来研究激活屏障的分子决定因素。从这些实验中，我们将能量景观中的外部活化屏障归因于在生物素后面闭合的链霉亲和素的“3-4”环的分子相互作用。
The dissociation of ligand and receptor involves multiple transitions between intermediate states formed during the unbinding process. In this paper, we explored the energy landscape of the streptavidin-biotin interaction by using the atomic force microscope (AFM) to measure the unbinding dynamics of individual ligand-receptor complexes. The rupture force of the streptavidin-biotin bond increased more than 2-fold over a range of loading rates between 100 and 5000 pN/s. Moreover, the force measurements showed two regimes of loading in the streptavidin-biotin force spectrum, revealing the presence of two activation barriers in the unbinding process. Parallel experiments carried out with a streptavidin mutant (W120F) were used to investigate the molecular determinants of the activation barriers. From these experiments, we attributed the outer activation barrier in the energy landscape to the molecular interaction of the '3-4' loop of streptavidin that closes behind biotin.