FT方法对含铜亚硝酸盐还原酶远程三质子耦合电子转移（PCET）的计算性能评估

he reduction of NO2- to NO and water by copper-containing nitrite reductase requires one electron and two protons. There have been some studies showed a remote three-proton coupled triggered electron transfer (PCET) process in the copper-containing nitrite reductase (CuNiRs) catalytic reaction. However, there is no suitable method to calculate this complex protein reaction. Based on the long-range three-proton cooperative coupled electron transfer process from K128 to H260 in the prophase catalytic reaction mechanism of CuNiRs. In this paper, we used 15 different density functional theory (DFT) methods to research the PCET reactions, evaluating the accuracy of the PCET reactions from K128 to H260 by comparing the relationship between the reaction barrier, the proton transfer of K128 to H260 and the single-electron distribution of the two copper site. This results show that the hybrid functional with dispersion correction or the 100% long-range-corrected pure density functional or both add corrected functional works well, compared with M06, LC-BLYP, ωB97X-D, LC-BPW91, and B3LYP-D3 have get consistent results on the spin density distribution, but the functional optimal from the energy barrier and electron density is still M06. This result also provides a method choice for calculating biological macromolecules of the PCET reaction with metallic copper participation.