title: Molecular interaction mechanism between 2-mercaptobenzimidazole and copper-zinc superoxide dismutase.
abstract: 2-Mercaptobenzimidazole (MBI) is widely utilized as a corrosion inhibitor, copper-plating brightener and rubber accelerator. The residue of MBI in the environment is potentially harmful. In the present work, the toxic interaction of MBI with the important antioxidant enzyme copper-zinc superoxide dismutase (Cu/ZnSOD) was investigated using spectroscopic and molecular docking methods. MBI can interact with Cu/ZnSOD to form an MBI-Cu/ZnSOD complex. The binding constant, number of binding sites and thermodynamic parameters were measured, which indicated that MBI could spontaneously bind with Cu/ZnSOD with one binding site through hydrogen bonds and van der Waals forces. MBI bound into the Cu/ZnSOD interface of two subdomains, which caused some microenvironmental and secondary structure changes of Cu/ZnSOD and further resulted in the inhibition of Cu/ZnSOD activity. This work provides direct evidence at a molecular level to show that exposure to MBI could induce changes in the structure and function of the enzyme Cu/ZnSOD. The estimated methods in this work may be applied to probe molecular interactions of biomacromolecules and other pollutants and drugs.
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province, PR China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Teng
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province, PR China.
authors.forename: Luyi
authors.initials: L
authors.lastname: Zou
authors.affiliation: School of Environmental and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Huang
authors.affiliation: Laboratory of Molecular Design and Drug Discovery, School of Basic Science, China Pharmaceutical University, Nanjing, Jiangsu Province, PR China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000737:chemistry*; D055162:Biocatalysis; D020134:Catalytic Domain; D004785:Environmental Pollutants / Q000737:chemistry*; D007700:Kinetics; D062105:Molecular Docking Simulation; D010084:Oxidation-Reduction; D011485:Protein Binding; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D013482:Superoxide Dismutase / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry; D034421:Sus scrofa; D013816:Thermodynamics
chemical_list: D001562:Benzimidazoles; D004785:Environmental Pollutants; D013481:Superoxides; C030698:2-mercaptobenzimidazole; D013482:Superoxide Dismutase