Abstract
The activity of organophosphorus hydrolase (OPH) that catalyzes the hydrolysis of neurotoxic organophosphates (OPs) was reported to evolve from lactonase. In this study, a putative OPH from Acinetobacter sp. (AbOPH) exhibited high lactonase activity with latent OPH activity. Sequence alignment and phylogenetic tree analysis revealed the unique status of AbOPH in evolution. The crystal structure of AbOPH was determined at 2.0 Å resolution and a semi-rational design was performed to enhance the OPH activity of AbOPH through a consensus sequence approach. Compared with wild-type AbOPH, which exhibited undetectable activity toward methyl-parathion (MP), the best variant AbOPHI211A showed markedly improved catalytic efficiency (1.1 μmol min−1 mg protein −1 ) toward MP. Docking studies suggested that the mutation Ile211Ala affects substrate recognition and stabilizes substrate conformation. This result presents the emergence of new enzyme function by a simple mutation strategy and confirms the high possibility that OPH was evolved from its lactonase ancestor.
Highlights
The activity of organophosphorus hydrolase (OPH) that catalyzes the hydrolysis of neurotoxic organo‐ phosphates (OPs) was reported to evolve from lactonase
Chemicals and strains OPs were purchased from Shanghai Pesticide Research Center. para-Nitrophenyl butyrate was synthesized in our laboratory. 3,4-Dihydrocoumarin, δ-nonanolactone and γ-decanolactone were obtained from TCI Co., Ltd. (Tokyo, Japan)
Identification and characterization of a putative OPH To identify new enzymes with potential OPH activities, OPH isolated from Pseudomonas pseudoalcaligenes (OPHC2) was chosen as a probe to search for homolog proteins based on BLAST (Basic Local Alignment Search Tool) Web server in the NCBI (National Center for Biotechnology Information) database
Summary
The activity of organophosphorus hydrolase (OPH) that catalyzes the hydrolysis of neurotoxic organo‐ phosphates (OPs) was reported to evolve from lactonase. Organophosphates (OPs) are common neurotoxic compounds (Singh 2008) that have been extensively used as agricultural insecticides (Raushel 2002). Massive use of these pesticides has brought serious threats to environmental safety and human health (Sapozhnikova et al 2004, 2005). 3.1.8.1) (Omburo et al 1992), paraoxonases (PONs; EC 3.1.8.1) (Ben-David et al 2012), phosphotriesterase-like lactonases (PLLs; EC 3.1.1.81) (Afriat et al 2006), and methyl-parathion hydrolases (MPHs; EC 3.1.8.1) (Hong et al 2005). Mammalian paraoxonase (PON) showed native lactonase activity (Khersonsky and Tawfik 2005), which was believed to evolve from mammalian
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
