Molecular Dynamics Simulations Reveal a Dielectric-Responsive Coronal Structure in Protein-Polymer Surfactant Hybrid Nanoconstructs
Molecular Dynamics Simulations Reveal a Dielectric-Responsive Coronal Structure in Protein-Polymer Surfactant Hybrid Nanoconstructs
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DOI：
10.1021/ja507592b
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发表时间：
2014-12-03
影响因子：
15
通讯作者：
Mann, Stephen
中科院分区：
文献类型：
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作者：
Brogan, Alex P. S.;Sessions, Richard B.;Mann, Stephen
无溶剂型液体蛋白质是一类新型的热稳定性杂化生物材料，它是由蛋白质-聚合物表面活性剂纳米共轭水溶液广泛冷冻干燥后再经热处理而形成的。这种杂化结构由球状蛋白核心和单层静电耦合的聚合物表面活性分子组成，在很大的温度范围内表现出类似于自然的结构、功能和主干动力学。尽管聚合物表面活性剂壳层非常重要，但人们对电晕的原子结构以及它如何影响这些新的纳米级物体的相行为和性质知之甚少。在这里，我们提供了由肌红蛋白或溶菌酶的球状核心组成的蛋白质-聚合物表面活性物质纳米偶联物的分子动力学模拟，并证明了推导的结构参数与实验值高度一致。我们发现，冠层结构响应介质的介电常数，在无溶剂状态下，聚合物表面活性剂分子的迁移性受到显著阻碍，为这些新型生物流体中残留蛋白质动力学的起源提供了基础。综上所述，我们的结果表明，将分子动力学模拟扩展到混合纳米级对象可能在软物质化学、生物启发工程和生物分子纳米技术的不同领域具有普遍价值。
Solvent-free liquid proteins are a new class of thermally stable hybrid bionanomaterials that are produced by extensive lyophilization of aqueous solutions of protein-polymer surfactant nanoconjugates followed by thermal annealing. The hybrid constructs, which consist of a globular protein core surrounded by a monolayer of electrostatically coupled polymer surfactant molecules, exhibit nativelike structure, function, and backbone dynamics over a large temperature range. Despite the key importance of the polymer surfactant shell, very little is known about the atomistic structure of the corona and how it influences the phase behavior and properties of these novel nanoscale objects. Here we present molecular dynamics simulations of protein-polymer surfactant nanoconjugates consisting of globular cores of myoglobin or lysozyme and demonstrate that the derived structural parameters are highly consistent with experimental values. We show that the coronal layer structure is responsive to the dielectric constant of the medium and that the mobility of the polymer surfactant molecules is significantly hindered in the solvent-free state, providing a basis for the origins of retained protein dynamics in these novel biofluids. Taken together, our results suggest that the extension of molecular dynamics simulations to hybrid nanoscale objects could be of generic value in diverse areas of soft matter chemistry, bioinspired engineering, and biomolecular nanotechnology.