Adsorption of Amino Acids on Gold: Assessing the Accuracy of the GolP-CHARMM Force Field and Parametrization of Au-S Bonds
Adsorption of Amino Acids on Gold: Assessing the Accuracy of the GolP-CHARMM Force Field and Parametrization of Au-S Bonds
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DOI：
10.1021/acs.jctc.8b00992
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发表时间：
2019-01-01
影响因子：
5.5
通讯作者：
Blumberger, Jochen
中科院分区：
文献类型：
--
作者：
Futera, Zdenek;Blumberger, Jochen
氨基酸与金属电极的相互作用在生物电化学和新兴的生物纳米电子学领域中起着至关重要的作用。本文采用van-der-Waals密度泛函方法，计算了所有天然氨基酸在真空中Au（111）表面的吸附结构和吸附能（revPBE-vdW），其在弱结合二聚体的S22集合上显示出良好的性能（平均相对无符号误差（MRUE）wrt CCSD（T）/CBS = 13.3%）和有机小分子在Au（111）上的吸附能（相对于实验的MRUE = 11.2%）。vdw-DF的结果，然后用于评估一个流行的力场的准确性，金-氨基酸的相互作用，GolP-CHARMM，明确描述图像电荷相互作用通过刚性杆偶极子。我们发现，虽然力场低估了吸附距离，但它确实很好地再现了结合能（MRUE wrt revPBE-vdW = 11.3%），MRUE按Cys，Met >胺>脂肪族>羧酸>芳香族的顺序降低。我们还提出了一个参数化的含硫分子和Au（111）表面之间的成键相互作用，并报告力场参数与Go 1 P-CHARMM兼容。我们相信，本文提出的vdw-DF计算将为进一步的力场开发提供有用的参考数据，并且新的Au-S键合参数将能够改进通过S键固定在Au电极上的蛋白质的模拟。
The interaction of amino acids with metal electrodes plays a crucial role in bioelectrochemistry and the emerging field of bionanoelectronics. Here we present benchmark calculations of the adsorption structure and energy of all natural amino acids on Au(111) in vacuum using a van-der-Waals density functional (revPBE-vdW) that showed good performance on the S22 set of weakly bound dimers (mean relative unsigned error (MRUE) wrt CCSD(T)/CBS = 13.3%) and adsorption energies of small organic molecules on Au(111) (MRUE wrt experiment = 11.2%). The vdW-DF results are then used to assess the accuracy of a popular force field for Au-amino acid interactions, GolP-CHARMM, which explicitly describes image charge interactions via rigid-rod dipoles. We find that while the force field underestimates adsorption distances, it does reproduce the binding energy rather well (MRUE wrt revPBE-vdW = 11.3%) with the MRUE decreasing in the order Cys, Met > amines > aliphatic > carboxylic > aromatic. We also present a parametrization of the bonding interaction between sulfur-containing molecules and the Au(111) surface and report force field parameters that are compatible with Go1P-CHARMM. We believe the vdW-DF calculations presented herein will provide useful reference data for further force field development, and that the new Au-S bonding parameters will enable improved simulations of proteins immobilized on Au-electrodes via S-linkages.