Imaging the binding ability of proteins immobilized on surfaces with different orientations by using liquid crystals
Imaging the binding ability of proteins immobilized on surfaces with different orientations by using liquid crystals
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DOI：
10.1021/ja0398565
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发表时间：
2004-07-28
影响因子：
15
通讯作者：
Abbott, NL
中科院分区：
文献类型：
--
作者：
Luk, YY;Tingey, ML;Abbott, NL
我们报告了一个固定在不同方向的表面上，但在相同的界面微环境中的蛋白质的结合能力的调查。表面呈现11-[19-羧甲基六（乙二醇）]十一烷基-1-硫醇、1和11-四（乙二醇）十一烷基-1-硫醇、2的混合自组装单层（SAMs）。而2是用来定义一个界面的微环境，防止非特异性吸附的蛋白质，1被激活的两个不同的计划，以使核糖核酸酶A（RNA酶A）在一个优选的方向或随机取向。核糖核酸酶抑制蛋白（RI）的结合，RNA酶A在这些表面上的特点是通过使用椭圆偏振和液晶的取向行为。椭圆偏振测量表明通过两种方案固定化RNase A的程度相同。然而，在用RI孵育两个表面之后，椭圆偏振测量表明以优选取向固定的RNA酶A的结合能力比以随机取向固定的RNA酶A高4倍。取向的RNase A的结合能力高于随机取向的RNase A，这在覆盖在这些表面上的4-氰基-4 '-戊基氰基联苯（5CB）的双相液晶的取向行为中也是明显的。这些结果表明，在受控的界面微环境中共价固定的蛋白质的取向可以影响固定化蛋白质的结合活性。在这篇文章中报道的结果还表明，固定在表面的蛋白质的取向状态可以通过检查液晶的光学外观来区分。
We report an investigation of the binding ability of a protein immobilized on surfaces with different orientations but in identical interfacial microenvironments. The surfaces present mixed self-assembled monolayers (SAMs) of 11-[19-carboxymethylhexa(ethylene glycol)]undecyl-l-thiol, 1, and 11-tetra(ethylene glycol) undecyl-1-thiol, 2. Whereas 2 is used to define an interfacial microenvironment that prevents nonspecific adsorption of proteins, 1 was activated by two different schemes to immobilize ribonuclease A (RNase A) in either a preferred orientation or random orientations. The binding of the ribonuclease inhibitor protein (RI) to RNase A on these surfaces was characterized by using ellipsometry and the orientational behavior of liquid crystals. Ellipsometric measurements indicate identical extents of immobilization of RNase A via the two schemes. Following incubation of both surfaces with RI, however, ellipsometric measurements indicate a 4-fold higher binding ability of the RNase A immobilized with a preferred orientation over RNase A immobilized with a random orientation. The higher binding ability of the oriented RNase A over the randomly oriented RNase A was also apparent in the orientational behavior of nematic liquid crystals of 4-cyano-4'-pentylcyanobiphenyl (5CB) overlayed on these surfaces. These results demonstrate that the orientations of proteins covalently immobilized in controlled interfacial microenvironments can influence the binding activities of the immobilized proteins. Results reported in this article also demonstrate that the orientational states of proteins immobilized at surfaces can be distinguished by examining the optical appearances of liquid crystals.