Immobilization of Metallothionein on Gold/Mica Surfaces: Relationship between Surface Morphology and Protein−Substrate Interaction
Immobilization of Metallothionein on Gold/Mica Surfaces: Relationship between Surface Morphology and Protein−Substrate Interaction
复制标题
DOI：
10.1021/la025712c
复制
发表时间：
2002-07
期刊：
影响因子：
3.9
通讯作者：
E. Casero;L. Vázquez;J. Martín-Benito;M. Morcillo;E. Lorenzo;F. Pariente
中科院分区：
文献类型：
--
作者：
E. Casero;L. Vázquez;J. Martín-Benito;M. Morcillo;E. Lorenzo;F. Pariente
我们通过基于（1）非特异性吸附/化学吸附（MT--Au 系统）、（2）共价结合（MT 修饰的 Au 系统）和（3）物理吸附（MT-云母）的三种不同策略，研究了固定在金和云母表面上的金属硫蛋白（MT）层的表面覆盖度以及形态和机械性能。这些系统已通过石英晶体微天平和原子力显微镜技术进行了研究。通过直接吸附到金表面上获得的金属硫蛋白单层是无序的并且相对粗糙，而通过将蛋白质共价结合到先前功能化的基底上获得的金属硫蛋白单层更光滑并且显示出紧密堆积的有序分子排列。对于 MT-云母系统，MT 层与 MT 修饰的 Au 层一样光滑，尽管成像的蛋白质尺寸较大，表明蛋白质-底物相互作用很强。这些不同的性质是根据控制 MT 吸附过程的不同 MT-基质相互作用以及每种情况下可用的 MT 吸附位点来解释的。此外，对于 MT-Au 系统，蛋白质在吸引力和排斥力状态下成像，蛋白质在后一种状态下弹性变形。我们的结果还表明，共价结合策略不仅可以控制蛋白质-底物相互作用，还可以导致蛋白质层排序。
We have studied the surface coverage as well as the morphological and mechanical properties of metallothionein (MT) layers immobilized on gold and mica surfaces by means of three different strategies based on (1) unspecific adsorption/chemisorption (MT--Au system), (2) covalent binding (MT-modified Au system), and (3) physisorption (MT-mica). These systems have been studied by quartz crystal microbalance and atomic force microscopy techniques. The monolayers of metallothionein obtained by direct adsorption onto gold surfaces are disordered and relatively rough in contrast to those obtained by covalent binding of the protein to a previously functionalized substrate, which are smoother and show a close-packed ordered molecular arrangement. For the MT-mica system the MT layer is as smooth as the MT-modified Au layer although the imaged protein dimensions are larger, indicating a strong protein-substrate interaction. These different properties are explained on the basis of the different MT-substrate interactions governing the MT adsorption process and the MT adsorption sites available in each case. Besides, for the MT-Au system the proteins are imaged in the attractive and repulsive force regimes, the proteins being elastically deformed in the latter regime. Our results also show that covalent binding strategies not only allow the protein-substrate interaction to be controlled but can also lead to the protein layer ordering.