title: 2,4-Dichlorophenol hydroxylase for chlorophenol removal: Substrate specificity and catalytic activity.
abstract: Chlorophenols (CPs) are common environmental pollutants. As such, different treatments have been assessed to facilitate their removal. In this study, 2,4-dichlorophenol (2,4-DCP) hydroxylase was used to systematically investigate the activity and removal ability of 19CP congeners at 25 and 0 °C. Results demonstrated that 2,4-DCP hydroxylase exhibited a broad substrate specificity to CPs. The activities of 2,4-DCP hydroxylase against specific CP congeners, including 3-CP, 2,3,6-trichlorophenol, 2-CP, and 2,3-DCP, were higher than those against 2,4-DCP, which is the preferred substrate of previously reported 2,4-DCP hydroxylase. To verify whether cofactors are necessary to promote hydroxylase activity against CP congeners, we added FAD and found that the added FAD induced a 1.33-fold to 5.13-fold significant increase in hydroxylase activity against different CP congeners. The metabolic pathways of the CP degradation in the enzymatic hydroxylation step were preliminarily proposed on the basis of the analyses of the enzymatic activities against 19CP congeners. We found that the high activity and removal rate of 2,4-DCP hydroxylase against CPs at 0 °C enhance the low-temperature-adaptability of this enzyme to the CP congeners; as such, the proposed removal process may be applied to biochemical, bioremediation, and industrial processes, particularly in cold environments.
authors.affiliation: Key Laboratory of Ground Water Resources and Environment of the Ministry of Education, College of Environment and Resources, Jilin University, 2519 Jiefang Road, Changchun 130021, PR China.
authors.forename: Hejun
authors.initials: H
authors.lastname: Ren
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Qingchao
authors.initials: Q
authors.lastname: Li
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China.
authors.forename: Xuexun
authors.initials: X
authors.lastname: Fang
authors.affiliation: Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, College of Life Science, Jilin University, 2699 Qianjin Street, Changchun 130012, PR China. Electronic address: yudahai@jlu.edu.cn.
authors.forename: Dahai
authors.initials: D
authors.lastname: Yu
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002384:Catalysis; D002733:Chlorophenols / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D003067:Coenzymes / Q000378:metabolism; D003080:Cold Temperature; D004785:Environmental Pollutants / Q000378:metabolism; D004926:Escherichia coli; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D002733:Chlorophenols; D003067:Coenzymes; D004785:Environmental Pollutants; D011993:Recombinant Fusion Proteins; D005182:Flavin-Adenine Dinucleotide; D006899:Mixed Function Oxygenases; C034354:2,4-dichlorophenol hydroxylase
keywords: 2,4-Dichlorophenol hydroxylase; Chlorophenols; Cold-active; Removal; Substrate specificity