Electronic Journal of Biotechnology
Universidad Católica de Valparaíso
Vol. 31, No. 1, 2018, pp. 10-16
Bioline Code: ej18002
Full paper language: English
Document type: Research Article
Document available free of charge
Electronic Journal of Biotechnology, Vol. 31, No. 1, 2018, pp. 10-16
© Copyright 2017 - Pontificia Universidad Católica de Valparaíso
A novel chlorpyrifos hydrolase CPD from Paracoccus sp. TRP: Molecular cloning, characterization and catalytic mechanism|
Fan, Shuanghu; Li, Kang; Yan, Yanchun; Wang, Junhuan; Wang, Jiayi; Qiao, Cheng; Yang, Ting; Jia, Yang & Zhao, Baisuo
Background: Biodegradation is a reliable approach for efficiently eliminating persistent pollutants such as
chlorpyrifos. Despite many bacteria or fungi isolated from contaminated environment and capable of
degrading chlorpyrifos, limited enzymes responsible for its degradation have been identified, let alone the
catalytic mechanism of the enzymes.
Results: In present study, the gene cpd encoding a chlorpyrifos hydrolase was cloned by analysis of genomic
sequence of Paracoccus sp. TRP. Phylogenetic analysis and BLAST indicated that CPD was a novel member of
organophosphate hydrolases. The purified CPD enzyme, with conserved catalytic triad (Ser155-Asp251-His281)
and motif Gly-Asp-Ser-Ala-Gly, was significantly inhibited by PMSF, a serine modifier. Molecular docking
between CPD and chlorpyrifos showed that Ser155 was adjacent to chlorpyrifos, which indicated that Ser155
may be the active amino acid involved in chlorpyrifos degradation. This speculation was confirmed by
site-directed mutagenesis of Ser155Ala accounting for the decreased activity of CPD towards chlorpyrifos.
According to the key role of Ser155 in chlorpyrifos degradation and molecular docking conformation, the
nucleophilic catalytic mechanism for chlorpyrifos degradation by CPD was proposed.
Conclusion: The novel enzyme CPD was capable of hydrolyze chlorpyrifos and Ser155 played key role during
degradation of chlorpyrifos.
Biodegradation; Chlorpyrifos degradation; Chlorpyrifos hydrolysis; Environment; Enzyme purification; Enzyme structure; Esterase; Nucleophilic catalysis; Organophosphate; Persistent pollutants
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