Lee Ji-Hye, Hwang Hyun Joo, Bhak Ghibom, Jang Yeongseon, Paik Seung R, Char Kookheon
The National Creative Research Initiative Center for Intelligent Hybrids, The WCU Program of Chemical Convergence for Energy & Environment, and ‡School of Chemical & Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744, Korea.
The National Creative Research Initiative Center for Intelligent Hybrids, The WCU Program of Chemical Convergence for Energy & Environment, and School of Chemical & Biological Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-744, Korea.
ACS Macro Lett. 2013 Aug 20;2(8):688-693. doi: 10.1021/mz400276f. Epub 2013 Jul 19.
We have developed the in situ fibrillation of κ-casein, employed as amyloid precursor, within multilayer films consisting of κ-casein and poly(acrylic acid) (PAA) prepared by the layer-by-layer (LbL) deposition. The fibrillation of κ-casein within the multilayered films is strongly dependent on the extent of intermolecular interactions between κ-casein and PAA. When films constructed initially at pH 3 were heat treated at the same pH, κ-casein did not transform into fibrils. However, when the films were subjected to heat treatment at pH 5, κ-casein was transformed into fibrils within multilayer films due to weakened intermolecular interactions between κ-casein and PAA. We also noted that the multilayer film was swollen at pH 5 by the charge imbalance within the film, which we believe gives enough mobility for κ-caseins to form fibrils with adjacent κ-caseins within the multilayer. The fibrils were found to be uniformly distributed across the entire film thickness, and the aspect ratio as well as the number density of fibrils increased as a function of incubation time. The present study reveals a strategy to realize in situ nanocomposites within LbL multilayer films simply by triggering the formation of protein fibrils by controlling the intermolecular interactions between amyloid precursors and polyelectrolytes (PEs).
我们已经开发出一种方法，在通过层层（LbL）沉积制备的由κ-酪蛋白和聚丙烯酸（PAA）组成的多层膜中，使作为淀粉样蛋白前体的κ-酪蛋白发生原位纤维化。多层膜内κ-酪蛋白的纤维化强烈依赖于κ-酪蛋白与PAA之间分子间相互作用的程度。当初始在pH 3构建的膜在相同pH下进行热处理时，κ-酪蛋白不会转化为纤维。然而，当膜在pH 5下进行热处理时，由于κ-酪蛋白与PAA之间分子间相互作用减弱，κ-酪蛋白在多层膜内转化为纤维。我们还注意到，多层膜在pH 5时因膜内电荷不平衡而膨胀，我们认为这为κ-酪蛋白提供了足够的流动性，使其能够与多层膜内相邻的κ-酪蛋白形成纤维。发现纤维均匀分布在整个膜厚度上，并且纤维的长径比以及数量密度随孵育时间增加。本研究揭示了一种策略，即通过控制淀粉样蛋白前体与聚电解质（PEs）之间的分子间相互作用来触发蛋白质纤维的形成，从而在LbL多层膜中实现原位纳米复合材料。
