Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow, G4 0NG, UK.
Phys Chem Chem Phys. 2019 Feb 27;21(9):4907-4911. doi: 10.1039/c8cp06374e.
Lysozyme is one of the most commonly used proteins for encapsulating gold nanoclusters, yielding Ly-AuNC complexes. While possible applications of Ly-AuNCs in environmental, biological and trace metal sensing in solution have been demonstrated, there is currently a poor understanding of the physical characteristics of the Ly-AuNC complex. In this study we have employed fully atomistic molecular dynamics simulations to gain an understanding of the formation of Au clusters within the protein. It was found that in order to form AuNCs in the simulations, an approach of targeted insertion of Au atoms at a critical surface residue was needed. Tyrosine is known to be crucial for the reduction of Au salts experimentally, and our simulations showed that Tyr20 is the key residue for the formation of an AuNC beneath the protein surface in the α-helical domain. It is hoped these observations will aid future improvements and modification of Ly-AuNCs via alterations of the alpha-helix domain or Tyr20.
溶菌酶是最常用于包裹金纳米簇的蛋白质之一，可得到 Ly-AuNC 复合物。虽然已经证明了 Ly-AuNCs 在环境、生物和痕量金属检测方面的潜在应用，但目前对 Ly-AuNC 复合物的物理特性还了解甚少。在这项研究中，我们采用了全原子分子动力学模拟来深入了解蛋白质内 Au 簇的形成过程。结果发现，为了在模拟中形成 AuNC，需要采用靶向插入关键表面残基处的 Au 原子的方法。实验中已知酪氨酸对于 Au 盐的还原至关重要，我们的模拟表明，Tyr20 是在蛋白质表面的 α-螺旋域下方形成 AuNC 的关键残基。希望这些观察结果将有助于通过改变 α-螺旋域或 Tyr20 来改进和修饰 Ly-AuNCs。
