title: Molecular Insights into the Potential Toxicological Interaction of 2-Mercaptothiazoline with the Antioxidant Enzyme-Catalase.
abstract: 2-mercaptothiazoline (2-MT) is widely used in many industrial fields, but its residue is potentially harmful to the environment. In this study, to evaluate the biological toxicity of 2-MT at protein level, the interaction between 2-MT and the pivotal antioxidant enzyme-catalase (CAT) was investigated using multiple spectroscopic techniques and molecular modeling. The results indicated that the CAT fluorescence quenching caused by 2-MT should be dominated by a static quenching mechanism through formation of a 2-MT/CAT complex. Furthermore, the identifications of the binding constant, binding forces, and the number of binding sites demonstrated that 2-MT could spontaneously interact with CAT at one binding site mainly via Van der Waals' forces and hydrogen bonding. Based on the molecular docking simulation and conformation dynamic characterization, it was found that 2-MT could bind into the junctional region of CAT subdomains and that the binding site was close to enzyme active sites, which induced secondary structural and micro-environmental changes in CAT. The experiments on 2-MT toxicity verified that 2-MT significantly inhibited CAT activity via its molecular interaction, where 2-MT concentration and exposure time both affected the inhibitory action. Therefore, the present investigation provides useful information for understanding the toxicological mechanism of 2-MT at the molecular level.
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. biogashuang@jiangnan.edu.cn.|Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China. biogashuang@jiangnan.edu.cn.|Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou 215009, China. biogashuang@jiangnan.edu.cn.
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Huang
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. huangmingjn@hotmail.com.
authors.forename: Ming
authors.initials: M
authors.lastname: Huang
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. michenyujn@hotmail.com.
authors.forename: Chenyu
authors.initials: C
authors.lastname: Mi
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. wangtaojn@hotmail.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. chendongjnedu@hotmail.com.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China. tengyue@jiangnan.edu.cn.|Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China. tengyue@jiangnan.edu.cn.
authors.forename: Yue
authors.initials: Y
authors.lastname: Teng
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D002374:Catalase / Q000737:chemistry* / Q000378:metabolism*; D002942:Circular Dichroism; D011485:Protein Binding; D011487:Protein Conformation; D053778:Thiazolidines / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D053778:Thiazolidines; C005104:2-mercaptothiazoline; D002374:Catalase
keywords: 2-mercaptothiazoline; catalase; molecular docking; protein conformation; spectroscopic technique; toxicity