Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
J Phys Chem A. 2013 May 16;117(19):4057-65. doi: 10.1021/jp402514w. Epub 2013 May 2.
The ability of hybrid, nonhybrid and meta-GGA density functional theory (DFT) based methods (B3LYP, BP86, M06 and M06L) to provide reliable structures and thermochemical properties of biochemically important Cu(I)/(II)···ESH (ergothioneine) and ···OSH (ovothiol) has been assessed. For all functionals considered, convergence in the optimized structures and Cu(I)/(II)···S/N bond lengths is only obtained using the 6-311+G(2df,p) basis set or larger, with the nonhybrid DFT method BP86 appearing, in general, to provide the most reliable structures. The reduction potentials associated with the reduction of Cu(II) to Cu(I) when complexed with either OSH and ESH were also determined. The implications for their ability to thus help protect against Cu-mediated oxidative damage are discussed. Importantly, the binding of OSH and ESH with Cu ions disfavors Cu(I)/Cu(II) recycling by increasing the reduction potential for the Cu(II) to Cu(I) reduction and as a result, inhibits the potential oxidative damage caused by such Cu ions.
已经评估了混合、非混合和基于泛函理论（DFT）的元泛函（B3LYP、BP86、M06 和 M06L）方法在提供生物化学中重要的 Cu(I)/(II)···ESH（ergothioneine）和···OSH（ovothiol）的可靠结构和热化学性质方面的能力。对于所有考虑的功能，只有使用 6-311+G(2df,p)基组或更大的基组才能获得优化结构和 Cu(I)/(II)···S/N 键长的收敛，一般来说，非混合 DFT 方法 BP86 提供的结构最可靠。还确定了与 OSH 和 ESH 配位时 Cu(II)还原为 Cu(I)的还原电位。讨论了它们帮助防止 Cu 介导的氧化损伤的能力的意义。重要的是，OSH 和 ESH 与 Cu 离子的结合通过增加 Cu(II)还原为 Cu(I)的还原电位来抑制 Cu(I)/Cu(II)的循环，从而抑制了这种 Cu 离子引起的潜在氧化损伤。
