1
|
Ren HC, Ji LX, Chen TN, Yuan JN, Huang YY, Wei DQ, Ji GF, Zhang ZM. Quasi-Static Two-Dimensional Infrared Spectra of the Carboxyhemoglobin Subsystem under Electric Fields: A Theoretical Study. J Phys Chem B 2020; 124:9570-9578. [PMID: 33073576 DOI: 10.1021/acs.jpcb.0c06251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
There is no doubt that electric fields of a specific frequency and intensity could excite certain vibrational modes of a macromolecule, which alters its mode coupling and conformation. Motivated by recent experiments and theories, we study the mode coupling between the Fe-CO mode and CO-stretch mode and vibration energy transfer among the active site and proteins in carboxyhemoglobin (HbCO) under different electric fields using the quasi-static two-dimensional infrared spectra. This study uses iron-porphyrin-imidazole-CO and two distal histidines in HbCO as the subsystem. The potential energy and dipole moment surfaces of the subsystem are calculated using an all-electron ab initio (B3LYP-D3(BJ)) method with the basis set Lanl2dz for the Fe atom and 6-31G(d,p) for C, H, O, and N atoms. Although the subsystem is reduced dimensionally, the anharmonic frequency and anharmonicity of the CO-stretch mode show excellent agreement with experimental values. We use the revealing noncovalent interaction method to confirm the hydrogen bond between the Hε atom of the His63 and the CO molecule. Our study confirms that the mode coupling between the Fe-CO mode and CO-stretch mode does not exist when the subsystem is free of electric field perturbation, which is coupled when the electric field is -0.5142 V/nm. In addition, with the increases of distance between the active site and the His92, there is no vibrational energy transfer between them when the electric field is 1.028 V/nm. We believe that our work could provide new ideas for increasing the dissociation efficiency of the Fe-CO bond and theoretical references for experimental research.
Collapse
Affiliation(s)
- Hai Chao Ren
- School of Physical Sciences, University of Science and Technology of China, Hefei 230000, China.,National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621999, China
| | - Lin Xiang Ji
- Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N5E2, Canada
| | - Tu Nan Chen
- The First Affiliated Hospital, Army Medical University, Chongqing 400038, China
| | - Jiao Nan Yuan
- College of Science, Henan University of Technology, Zhengzhou 450001, China
| | - Yao Yao Huang
- National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621999, China
| | - Dong-Qing Wei
- College of Food Science and Engineering, Henan University of Technology, Zhengzhou 450001, China.,College of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Guang Fu Ji
- National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621999, China
| | - Zeng Ming Zhang
- School of Physical Sciences, University of Science and Technology of China, Hefei 230000, China
| |
Collapse
|