Liu Jie, Xie Yun, Peng Chunwang, Yu Gaobo, Zhou Jian
School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology , Guangzhou 510640, P. R. China.
Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology , Wuhan 430073, P. R. China.
J Phys Chem B. 2017 Nov 30;121(47):10610-10617. doi: 10.1021/acs.jpcb.7b08738. Epub 2017 Nov 16.
Controlling the orientation of laccase on electrodes is crucial for the achievement of fast direct electron transfer. It is important to find a short pathway between the T1 copper site of laccase and a substrate during the laccase immobilization. In this work, we studied the adsorption orientation and conformation of Trametes versicolor laccase (TvL) on two kinds of charged self-assembled monolayers (SAMs), including NH-SAM and COOH-SAM, by parallel tempering Monte Carlo and all-atom molecular dynamics simulations. TvL adsorbs on positively and negatively charged surface with "end-on" and "lying" orientation, respectively. On the positively charged surface, T1 copper site of TvL is closer to the surface. The orientation of TvL on positively charged surface is narrower than that on negatively charged surface. Thus, the positively charged surface is more conducive to the immobilization of TvL. The conformational changes of TvL on the charged surfaces are analyzed by RMSD, superimposed structures, dipole moment, gyration radius, and eccentricity. Results show that native structures of TvL are well preserved when it adsorbs on the charged surfaces. This work provides atomistic insight into the mechanism of TvL adsorption on charged surface and is helpful for the design and development of laccase-based electrodes.
控制漆酶在电极上的取向对于实现快速直接电子转移至关重要。在漆酶固定化过程中，找到漆酶的T1铜位点与底物之间的短路径很重要。在这项工作中，我们通过并行回火蒙特卡罗和全原子分子动力学模拟研究了云芝漆酶（TvL）在两种带电自组装单分子层（SAMs）上的吸附取向和构象，包括NH-SAM和COOH-SAM。TvL分别以“端对端”和“平躺”的取向吸附在带正电和带负电的表面上。在带正电的表面上，TvL的T1铜位点更靠近表面。TvL在带正电表面上的取向比在带负电表面上的更窄。因此，带正电的表面更有利于TvL的固定化。通过均方根偏差、叠加结构、偶极矩、回转半径和偏心率分析了TvL在带电表面上的构象变化。结果表明，TvL吸附在带电表面时其天然结构得到了很好的保留。这项工作为TvL在带电表面上的吸附机制提供了原子层面的见解，并有助于基于漆酶的电极的设计和开发。
