Department of Biomedical Engineering, Columbia University , 1210 Amsterdam Avenue, New York, New York 10027, United States.
Langmuir. 2013 Dec 10;29(49):15142-5. doi: 10.1021/la4030712. Epub 2013 Nov 27.
The height of polymers grafted to a surface is predicted to be constant at low densities ("mushroom" regime) and increase with the third root of the polymer surface density at high densities ("brush" regime). This mushroom-to-brush transition is explored with kinesin-1 proteins adhered to a surface at controlled densities. The kinesin height is measured by attaching fluorescently labeled microtubules to the kinesins and determining their elevation using fluorescence interference contrast microscopy. Our measurements are consistent with a mushroom regime and a brush regime and a transition near the theoretically predicted density. The mushroom-to-brush transition may play a role in protein behavior in crowded cellular environments and may be exploited as a signal in intracellular regulation and mechanotransduction.
聚合物在表面上的接枝高度预计在低密度时保持恒定（“蘑菇”状态），而在高密度时随聚合物表面密度的立方根增加（“刷”状态）。这种蘑菇到刷的转变通过控制密度附着在表面上的肌球蛋白-1 蛋白来探索。肌球蛋白的高度通过将荧光标记的微管附着到肌球蛋白上来测量，并使用荧光干涉对比显微镜确定它们的高度。我们的测量结果与蘑菇状态和刷状态以及理论预测密度附近的转变一致。蘑菇到刷的转变可能在拥挤的细胞环境中蛋白质行为中起作用，并可能被用作细胞内调节和力传导中的信号。
