Salt-Induced Control of Supramolecular Order in Biocatalytic Hydrogelation
Salt-Induced Control of Supramolecular Order in Biocatalytic Hydrogelation
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DOI：
10.1021/la303388s
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发表时间：
2012-12-04
期刊：
影响因子：
3.9
通讯作者：
Ulijn, Rein V.
中科院分区：
文献类型：
--
作者：
Roy, Sangita;Javid, Nadeem;Ulijn, Rein V.
生物催化作用和特定离子效应对分子自组装和水凝胶化都有显著影响。在本文中，我们证明了这些影响是高度合作的。当组合应用时，在盐存在下Fmoc肽的生物催化水凝胶化结合了动力学（通过酶催化）和热力学（特定离子和蛋白质模板）贡献。光谱数据（通过荧光光谱和圆二色性获得）显示，疏水相互作用的影响很大，从而引起差分手性组织和超分子结构的形成。催化作用的动力学效应可以通过施加热/冷循环从系统中去除，从而深入了解蛋白质和盐对这些系统的热力学影响，并表明催化、模板和盐的作用是协同的。可变的分子相互作用表示为可变的材料性质，例如最终凝胶相材料的热稳定性和机械强度。为了更深入地了解酶的作用，除了催化作用，在潜在的机制中，进行静态光散射，这表明在水溶液中存在不同盐的情况下酶分子的不同聚集模式，其可能起到通过模板引导组装的作用。总体而言，结果表明，特定盐和酶促水凝胶化的组合可以产生复杂的自组装行为，其可以用于调节水凝胶性质。
Biocatalytic action and specific ion effects are both known to have dramatic effects on molecular self-assembly and hydrogelation. In this paper, we demonstrate that these effects are highly cooperative. Biocatalytic hydrogelation of Fmoc peptides in the presence of salts combines kinetic (through enzymatic catalysis) and thermodynamic (specific ion and protein templating) contributions when applied in combination. Spectroscopic data (obtained by fluorescence spectroscopy and circular dichroism) revealed that hydrophobic interactions are greatly affected, giving rise to differential chiral organization and supramolecular structure formation. The kinetic effects of catalytic action could be removed from the system by applying a heat/cool cycle, giving insight into the thermodynamic influence of both protein and salt on these systems and showing that the effects of catalysis, templating, and salts are cooperative. The variable molecular interactions are expressed as variable material properties, such as thermal stability and mechanical strength of the final gel-phase material. To gain more insight into the role of the enzyme, beyond catalysis, in the underlying mechanism, static light scattering is performed, which indicates the different mode of aggregation of the enzyme molecules in the presence of different salts in aqueous solution that may play a role to direct the assembly via templating. Overall, the results show that the combination of specific salts and enzymatic hydrogelation can give rise to complex self-assembly behaviors that may be exploited to tune hydrogel properties.