Faulón Marruecos David, Kastantin Mark, Schwartz Daniel K, Kaar Joel L
Department of Chemical and Biological Engineering, University of Colorado , Boulder, Colorado 80309, United States.
Biomacromolecules. 2016 Mar 14;17(3):1017-25. doi: 10.1021/acs.biomac.5b01657. Epub 2016 Feb 23.
Polymer brushes, in which polymers are end-tethered densely to a grafting surface, are commonly proposed for use as stealth coatings for various biomaterials. However, although their use has received considerable attention, a mechanistic understanding of the impact of brush properties on protein adsorption and unfolding remains elusive. We investigated the effect of the grafting density of poly(ethylene glycol) (PEG) brushes on the interactions of the brush with fibronectin (FN) using high-throughput single-molecule tracking methods, which directly measure protein adsorption and unfolding within the brush. We observed that, as grafting density increased, the rate of FN adsorption decreased; however, surface-adsorbed FN unfolded more readily, and unfolded molecules were retained on the surface for longer residence times relative to those of folded molecules. These results, which are critical for the rational design of PEG brushes, suggest that there is a critical balance between protein adsorption and conformation that underlies the utility of such brushes in physiological environments.
聚合物刷是指聚合物通过末端紧密连接在接枝表面，通常被提议用作各种生物材料的隐形涂层。然而，尽管其应用受到了广泛关注，但对于刷特性对蛋白质吸附和展开影响的机理理解仍然难以捉摸。我们使用高通量单分子追踪方法研究了聚乙二醇（PEG）刷的接枝密度对刷与纤连蛋白（FN）相互作用的影响，该方法可直接测量刷内蛋白质的吸附和展开情况。我们观察到，随着接枝密度的增加，FN的吸附速率降低；然而，表面吸附的FN更容易展开，并且相对于折叠分子，展开的分子在表面上保留的停留时间更长。这些结果对于PEG刷的合理设计至关重要，表明在蛋白质吸附和构象之间存在关键平衡，这是此类刷在生理环境中发挥作用的基础。
