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Li H, Lu C, Liu Z, Xiang F, Liu B, Wang H, Chang J, Pan L, Chen Y, Chen J. Advancements in bioscavenger mediated detoxification of organophosphorus poisoning. Toxicol Res (Camb) 2024; 13:tfae089. [PMID: 38863796 PMCID: PMC11163184 DOI: 10.1093/toxres/tfae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 06/04/2024] [Indexed: 06/13/2024] Open
Abstract
Background Organophosphorus compounds, widely used in agriculture and industry, pose a serious threat to human health due to their acute neurotoxicity. Although traditional interventions for organophosphate poisoning are effective, they often come with significant side effects. Objective This paper aims to evaluate the potential of enzymes within biological organisms as organophosphorus bioclearing agents. It analyses the technical challenges in current enzyme research, such as substrate specificity, stereoselectivity, and immunogenicity, while exploring recent advancements in the field. Methods A comprehensive review of literature related to detoxifying enzymes or proteins was conducted. Existing studies on organophosphorus bioclearing agents were summarised, elucidating the biological detoxification mechanisms, with a particular focus on advancements in protein engineering and novel delivery methods. Results Current bioclearing agents can be categorised into stoichiometric and catalytic bioclearing agents, both of which have shown some success in preventing organophosphate poisoning. Technological advancements have significantly improved various properties of bioclearing agents, yet challenges remain, particularly in substrate specificity, stereoselectivity, and immunogenicity. Future research will focus on expanding the substrate spectrum, enhancing catalytic efficiency, prolonging in vivo half-life, and developing convenient administration methods. Conclusion With the progression of clinical trials, bioclearing agents are expected to become widely used as a new generation of therapeutic organophosphate detoxifiers.
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Affiliation(s)
- Hexi Li
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 31666 of PLA, 1 New City Courtyard, Jinyang Town, Liangzhou District, Wuwei, Gansu 733000, China
| | - Cong Lu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 94347 of PLA, 24 Wenfu Road, Shenhe District, Shenyang, Liaoning 110000, China
| | - Zhenmin Liu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Fengshun Xiang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Bo Liu
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Hongjuan Wang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Jie Chang
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Li Pan
- State Key Laboratory of NBC Protection for Civilians, 30 South Central Street, Yangfang Town, Changping District, Beijing 102205, P. R. China
| | - Youwei Chen
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
| | - Jingfei Chen
- Institute of NBC Defence, PLA, ARMY, 1 North Street, Yangfang Town, Changping District, Beijing 102205, China
- Unit No. 32169 of PLA, 100 Shuangyong East Road, Nyingchi, Tibet 860000, China
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Chen J, Guo Z, Xin Y, Gu Z, Zhang L, Guo X. Effective remediation and decontamination of organophosphorus compounds using enzymes: From rational design to potential applications. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 867:161510. [PMID: 36632903 DOI: 10.1016/j.scitotenv.2023.161510] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/04/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Organophosphorus compounds (OPs) have been widely used in agriculture for decades because of their high insecticidal efficiency, which maintains and increases crop yields worldwide. More importantly, OPs, as typical chemical warfare agents, are a serious concern and significant danger for military and civilian personnel. The widespread use of OPs, superfluous and unreasonable use, has caused great harm to the environment and food chain. Developing efficient and environmentally friendly solutions for the decontamination of OPs is a long-term challenge. Microbial enzymes show potential application as natural and green biocatalysts. Thus, utilizing OP-degrading enzymes for environmental decontamination presents significant advantages, as these enzymes can rapidly hydrolyze OPs; are environmentally friendly, nonflammable, and noncorrosive; and can be discarded safely and easily. Here, the properties, structure and catalytic mechanism of various typical OP-degrading enzymes are reviewed. The methods and effects utilized to improve the expression level, catalytic performance and stability of OP-degrading enzymes were systematically summarized. In addition, the immobilization of OP-degrading enzymes was explicated emphatically, and the latest progress of cascade reactions based on immobilized enzymes was discussed. Finally, the latest applications of OP-degrading enzymes were summarized, including biosensors, nanozyme mimics and medical detoxification. This review provides guidance for the future development of OP-degrading enzymes and promotes their application in the field of environmental bioremediation and medicine.
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Affiliation(s)
- Jianxiong Chen
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Zitao Guo
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Yu Xin
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Zhenghua Gu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China
| | - Liang Zhang
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China; Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi 214122, China.
| | - Xuan Guo
- State Key Laboratory of NBC Protection for Civilian, Research Institute of Chemical Defense, Academy of Military Science, Beijing 102205, China; CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
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Job L, Köhler A, Eichinger A, Testanera M, Escher B, Worek F, Skerra A. Structural and Functional Analysis of a Highly Active Designed Phosphotriesterase for the Detoxification of Organophosphate Nerve Agents Reveals an Unpredicted Conformation of the Active Site Loop. Biochemistry 2023; 62:942-955. [PMID: 36752589 DOI: 10.1021/acs.biochem.2c00666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Neurotoxic organophosphorus compounds (OPs) pose a severe threat if misused in military conflicts or by terrorists. Administration of a hydrolytic enzyme that can decompose the circulating nerve agent into non-toxic metabolites in vivo offers a potential treatment. A promising candidate is the homo-dimeric phosphotriesterase originating from the bacterium Brevundimonas diminuta (BdPTE), which has been subject to several rational and combinatorial protein design studies. A series of engineered versions with much improved catalytic efficiencies toward medically relevant nerve agents was described, carrying up to 22 mutations per enzyme subunit. To provide a basis for further rational design, we have determined the crystal structure of the highly active variant 10-2-C3(C59V/C227V)─stabilized against oxidation by substitution of two unpaired Cys residues─in complex with a substrate analogue at 1.5 Å resolution. Unexpectedly, the long loop segment (residues 253-276) that covers the active site shows a totally new conformation, with drastic structural deviations up to 19 Å, which was neither predicted in any of the preceding protein design studies nor seen in previous crystallographic analyses of less far evolved enzyme versions. Inspired by this structural insight, additional amino acid exchanges were introduced and their effects on protein stability as well as on the catalytic efficiency toward several neurotoxic OPs were investigated. Somewhat surprisingly, our results suggest that the presently available engineered version of BdPTE, in spite of its design on the basis of partly false structural assumptions, constitutes a fairly optimized enzyme for the detoxification of relevant OP nerve agents.
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Affiliation(s)
- Laura Job
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Anja Köhler
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany.,Bundeswehr Institut für Pharmakologie und Toxikologie, Neuherbergstr. 11, 80937 München, Germany
| | - Andreas Eichinger
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Mauricio Testanera
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Benjamin Escher
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Franz Worek
- Bundeswehr Institut für Pharmakologie und Toxikologie, Neuherbergstr. 11, 80937 München, Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
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Job L, Köhler A, Testanera M, Escher B, Worek F, Skerra A. Engineering of a phosphotriesterase with improved stability and enhanced activity for detoxification of the pesticide metabolite malaoxon. Protein Eng Des Sel 2023; 36:gzad020. [PMID: 37941439 DOI: 10.1093/protein/gzad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 10/30/2023] [Accepted: 11/03/2023] [Indexed: 11/10/2023] Open
Abstract
Organophosphorus (OP) pesticides are still widely applied but pose a severe toxicological threat if misused. For in vivo detoxification, the application of hydrolytic enzymes potentially offers a promising treatment. A well-studied example is the phosphotriesterase of Brevundimonas diminuta (BdPTE). Whereas wild-type BdPTE can hydrolyse pesticides like paraoxon, chlorpyrifos-oxon and mevinphos with high catalytic efficiencies, kcat/KM >2 × 107 M-1 min-1, degradation of malaoxon is unsatisfactory (kcat/KM ≈ 1 × 104 M-1 min-1). Here, we report the rational engineering of BdPTE mutants with improved properties and their efficient production in Escherichia coli. As result, the mutant BdPTE(VRNVVLARY) exhibits 37-fold faster malaoxon hydrolysis (kcat/KM = 4.6 × 105 M-1 min-1), together with enhanced expression yield, improved thermal stability and reduced susceptibility to oxidation. Therefore, this BdPTE mutant constitutes a powerful candidate to develop a biocatalytic antidote for the detoxification of this common pesticide metabolite as well as related OP compounds.
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Affiliation(s)
- Laura Job
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Anja Köhler
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
- Institut für Pharmakologie und Toxikologie der Bundeswehr, Neuherbergstr, 11, 80937 München, Germany
| | - Mauricio Testanera
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Benjamin Escher
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Franz Worek
- Institut für Pharmakologie und Toxikologie der Bundeswehr, Neuherbergstr, 11, 80937 München, Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
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5
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Wang X, Wang Z, Yu L, Shi Q, Dong X, Sun Y. Zwitterionic polymer-mediated immobilization of organophosphorus hydrolase enhances hydrolysis of methyl parathion by substrate enrichment. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Wang B, Zhang M, Zhang W, Zhao S, Tian X, Fu G. Hemoperfusion in combination with hemofiltration for acute severe organophosphorus pesticide poisoning: A systematic review and meta-analysis. JOURNAL OF RESEARCH IN MEDICAL SCIENCES 2022; 27:33. [PMID: 35548179 PMCID: PMC9081518 DOI: 10.4103/jrms.jrms_822_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/31/2021] [Accepted: 03/08/2022] [Indexed: 11/12/2022]
Abstract
Background: Acute severe organophosphorus pesticide poisoning (ASOPP) is one of the major diseases that endanger human life and health. However, the effects of conventional therapy including gastric lavages, mechanical ventilation, muscarinic antagonist drugs, and cholinesterase reactivators were uncertain. This meta-analysis aims to investigate the safety and efficacy of hemoperfusion combined with hemofiltration besides routine therapy for ASOPP. Materials and Methods: A comprehensive search for candidate publications was performed through PubMed, Medline, Cochrane Library, WanFang, Chinese Biomedical Literature, and China National Knowledge Infrastructure from database inception to May 12, 2020. The retrieved studies were screened by the predefined inclusion and exclusion criteria. The data of important end points were extracted. The risk ratio (RR) and weighted mean difference (WMD) were pooled for categorical variables and continuous variables, respectively. Meta-analyses and publication bias were conducted by using STATA software version 15.1. Results: A total of 11 randomized controlled trials with 811 patients were included. Compared to conventional therapy group, patients in the hemoperfusion plus hemofiltration group were significantly superior with regard to mortality (RR 0.38, 95% confidence interval [CI] [0.25, 0.57], P < 0.001), total atropine dosing (WMD −147.34 mg, 95% CI [−199.49, −95.18], P < 0.001), duration of mechanical ventilation (WMD −2.34 days, 95% CI [−3.77, −0.92], P < 0.001), cholinesterase recovery time (WMD −2.49 days, 95% CI [−3.14, −1.83], P < 0.001), and length of stay (WMD −4.52 days, 95% CI [−5.31, −3.73], P < 0.001). Conclusion: Combined hemoperfusion and hemofiltration was a very safe and effective treatment protocol for ASOPP, not only resulting in significantly decreased mortality but also resulting in reduced total atropine dosing, duration of mechanical ventilation, cholinesterase recovery time, and length of stay.
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Stigler L, Köhler A, Koller M, Job L, Escher B, Potschka H, Thiermann H, Skerra A, Worek F, Wille T. Post-VX exposure treatment of rats with engineered phosphotriesterases. Arch Toxicol 2021; 96:571-583. [PMID: 34962578 PMCID: PMC8837561 DOI: 10.1007/s00204-021-03199-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/09/2021] [Indexed: 12/05/2022]
Abstract
The biologically stable and highly toxic organophosphorus nerve agent (OP) VX poses a major health threat. Standard medical therapy, consisting of reactivators and competitive muscarinic receptor antagonists, is insufficient. Recently, two engineered mutants of the Brevundimonas diminuta phosphotriesterase (PTE) with enhanced catalytic efficiency (kcat/KM = 21 to 38 × 106 M−1 min−1) towards VX and a preferential hydrolysis of the more toxic P(−) enantiomer were described: PTE-C23(R152E)-PAS(100)-10-2-C3(I106A/C59V/C227V/E71K)-PAS(200) (PTE-2), a single-chain bispecific enzyme with a PAS linker and tag having enlarged substrate spectrum, and 10-2-C3(C59V/C227V)-PAS(200) (PTE-3), a stabilized homodimeric enzyme with a double PASylation tag (PAS-tag) to reduce plasma clearance. To assess in vivo efficacy, these engineered enzymes were tested in an anesthetized rat model post-VX exposure (~ 2LD50) in comparison with the recombinant wild-type PTE (PTE-1), dosed at 1.0 mg kg−1 i.v.: PTE-2 dosed at 1.3 mg kg−1 i.v. (PTE-2.1) and 2.6 mg kg−1 i.v. (PTE-2.2) and PTE-3 at 1.4 mg kg−1 i.v. Injection of the mutants PTE-2.2 and PTE-3, 5 min after s.c. VX exposure, ensured survival and prevented severe signs of a cholinergic crisis. Inhibition of erythrocyte acetylcholinesterase (AChE) could not be prevented. However, medulla oblongata and diaphragm AChE activity was partially preserved. All animals treated with the wild-type enzyme, PTE-1, showed severe cholinergic signs and died during the observation period of 180 min. PTE-2.1 resulted in the survival of all animals, yet accompanied by severe signs of OP poisoning. This study demonstrates for the first time efficient detoxification in vivo achieved with low doses of heterodimeric PTE-2 as well as PTE-3 and indicates the suitability of these engineered enzymes for the development of highly effective catalytic scavengers directed against VX.
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Affiliation(s)
- Lisa Stigler
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany
| | - Anja Köhler
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany.,Chair of Biological Chemistry, Technical University of Munich, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - Marianne Koller
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany
| | - Laura Job
- Chair of Biological Chemistry, Technical University of Munich, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - Benjamin Escher
- Chair of Biological Chemistry, Technical University of Munich, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University Munich, Königinstraße 16, 80539, Munich, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany
| | - Arne Skerra
- Chair of Biological Chemistry, Technical University of Munich, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany
| | - Timo Wille
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstraße 11, 80937, Munich, Germany.
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Overview of a bioremediation tool: organophosphorus hydrolase and its significant application in the food, environmental, and therapy fields. Appl Microbiol Biotechnol 2021; 105:8241-8253. [PMID: 34665276 DOI: 10.1007/s00253-021-11633-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/01/2021] [Accepted: 10/03/2021] [Indexed: 12/14/2022]
Abstract
In the past decades, the organophosphorus compounds had been widely used in the environment and food industries as pesticides. Owing to the life-threatening and long-lasting problems of organophosphorus insecticide (OPs), an effective detection and removal of OPs have garnered growing attention both in the scientific and practical fields in recent years. Bacterial organophosphorus hydrolases (OPHs) have been extensively studied due to their high specific activity against OPs. OPH could efficiently hydrolyze a broad range of substrates both including the OP pesticides and some nerve agents, suggesting a great potential for the remediation of OPs. In this review, the microbial identification, molecular modification, and practical application of OPHs were comprehensively discussed.Key points• Microbial OPH is a significant bioremediation tool against OPs.• Identification and molecular modification of OPH was discussed in detail.• The applications of OPH in food, environmental, and therapy fields are presented.
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Köhler A, Escher B, Job L, Koller M, Thiermann H, Skerra A, Worek F. Catalytic activity and stereoselectivity of engineered phosphotriesterases towards structurally different nerve agents in vitro. Arch Toxicol 2021; 95:2815-2823. [PMID: 34160649 PMCID: PMC8298220 DOI: 10.1007/s00204-021-03094-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/15/2021] [Indexed: 12/20/2022]
Abstract
Highly toxic organophosphorus nerve agents, especially the extremely stable and persistent V-type agents such as VX, still pose a threat to the human population and require effective medical countermeasures. Engineered mutants of the Brevundimonas diminuta phosphotriesterase (BdPTE) exhibit enhanced catalytic activities and have demonstrated detoxification in animal models, however, substrate specificity and fast plasma clearance limit their medical applicability. To allow better assessment of their substrate profiles, we have thoroughly investigated the catalytic efficacies of five BdPTE mutants with 17 different nerve agents using an AChE inhibition assay. In addition, we studied one BdPTE version that was fused with structurally disordered PAS polypeptides to enable delayed plasma clearance and one bispecific BdPTE with broadened substrate spectrum composed of two functionally distinct subunits connected by a PAS linker. Measured kcat/KM values were as high as 6.5 and 1.5 × 108 M-1 min-1 with G- and V-agents, respectively. Furthermore, the stereoselective degradation of VX enantiomers by the PASylated BdPTE-4 and the bispecific BdPTE-7 were investigated by chiral LC-MS/MS, resulting in a several fold faster hydrolysis of the more toxic P(-) VX stereoisomer compared to P(+) VX. In conclusion, the newly developed enzymes BdPTE-4 and BdPTE-7 have shown high catalytic efficacy towards structurally different nerve agents and stereoselectivity towards the toxic P(-) VX enantiomer in vitro and offer promise for use as bioscavengers in vivo.
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Affiliation(s)
- Anja Köhler
- Institut für Pharmakologie und Toxikologie der Bundeswehr, 80937, Munich, Germany
- Lehrstuhl für Biologische Chemie, Technische Universität München, 85354, Freising, Germany
| | - Benjamin Escher
- Lehrstuhl für Biologische Chemie, Technische Universität München, 85354, Freising, Germany
| | - Laura Job
- Lehrstuhl für Biologische Chemie, Technische Universität München, 85354, Freising, Germany
| | - Marianne Koller
- Institut für Pharmakologie und Toxikologie der Bundeswehr, 80937, Munich, Germany
| | - Horst Thiermann
- Institut für Pharmakologie und Toxikologie der Bundeswehr, 80937, Munich, Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, 85354, Freising, Germany.
| | - Franz Worek
- Institut für Pharmakologie und Toxikologie der Bundeswehr, 80937, Munich, Germany.
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Köhler A, Job L, Worek F, Skerra A. Inhibition of an organophosphate-detoxifying bacterial phosphotriesterase by albumin and plasma thiol components. Toxicol Lett 2021; 350:194-201. [PMID: 34303790 DOI: 10.1016/j.toxlet.2021.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 11/28/2022]
Abstract
The phosphotriesterase of the bacterium Brevundimonas diminuta (BdPTE) is a naturally occurring enzyme that catalyzes the hydrolysis of organophosphate (OP) nerve agents as well as pesticides and offers a potential treatment of corresponding intoxications. While BdPTE mutants with improved catalytic efficiencies against several OPs have been described, unexpectedly, less efficient breakdown of an OP was observed upon application in an animal model compared with in vitro measurements. Here, we describe detailed inhibition studies with the high-activity BdPTE mutant 10-2C3(C59M/C227A) by human plasma components, indicating that this enzyme is inhibited by serum albumin. The inhibitory activity is mediated by depletion of crucial zinc ions from the BdPTE active site, either via the known high-affinity zinc binding site of albumin or via chemical complex formation with its free thiol side chain at position Cys34. Albumin pre-charged with zinc ions or carrying a chemically blocked Cys34 side chain showed significantly reduced inhibitory activity; in fact, the combination of both measures completely abolished BdPTE inhibition. Consequently, the available zinc ion concentration in blood plays an important role for BdPTE activity in vivo and should be taken into account for therapeutic development and application of a catalytic OP scavenger.
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Affiliation(s)
- Anja Köhler
- Chair of Biological Chemistry, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany; Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany.
| | - Laura Job
- Chair of Biological Chemistry, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany.
| | - Franz Worek
- Bundeswehr Institute of Pharmacology and Toxicology, Neuherbergstr. 11, 80937 Munich, Germany.
| | - Arne Skerra
- Chair of Biological Chemistry, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany.
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Galindo Casas M, Stargardt P, Mairhofer J, Wiltschi B. Decoupling Protein Production from Cell Growth Enhances the Site-Specific Incorporation of Noncanonical Amino Acids in E. coli. ACS Synth Biol 2020; 9:3052-3066. [PMID: 33150786 DOI: 10.1021/acssynbio.0c00298] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The site-specific incorporation of noncanonical amino acids (ncAAs) into proteins by amber stop codon suppression has become a routine method in academic laboratories. This approach requires an amber suppressor tRNACUA to read the amber codon and an aminoacyl-tRNA synthetase to charge the tRNACUA with the ncAA. However, a major drawback is the low yield of the mutant protein in comparison to the wild type. This effect primarily results from the competition of release factor 1 with the charged suppressor tRNACUA for the amber codon at the A-site of the ribosome. A number of laboratories have attempted to improve the incorporation efficiency of ncAAs with moderate results. We aimed at increasing the efficiency to produce high yields of ncAA-functionalized proteins in a scalable setting for industrial application. To do this, we inserted an ncAA into the enhanced green fluorescent protein and an antibody mimetic molecule using an industrial E. coli strain, which produces recombinant proteins independent of cell growth. The controlled decoupling of recombinant protein production from cell growth considerably increased the incorporation of the ncAA, producing substantially higher protein yields versus the reference E. coli strain BL21(DE3). The target proteins were expressed at high levels, and the ncAA was efficiently incorporated with excellent fidelity while the protein function was preserved.
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Affiliation(s)
- Meritxell Galindo Casas
- acib − Austrian Center of Industrial Biotechnology, 8010 Graz, Austria
- Institute of Molecular Biotechnology, Graz University of Technology, 8010 Graz, Austria
| | | | | | - Birgit Wiltschi
- acib − Austrian Center of Industrial Biotechnology, 8010 Graz, Austria
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Escher B, Köhler A, Job L, Worek F, Skerra A. Translating the Concept of Bispecific Antibodies to Engineering Heterodimeric Phosphotriesterases with Broad Organophosphate Substrate Recognition. Biochemistry 2020; 59:4395-4406. [PMID: 33146522 DOI: 10.1021/acs.biochem.0c00751] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have adopted the concept of bispecific antibodies, which can simultaneously block or cross-link two different biomolecular targets, to create bispecific enzymes by exploiting the homodimeric quaternary structure of bacterial phosphotriesterases (PTEs). The PTEs from Brevundimonas diminuta and Agrobacterium radiobacter, whose engineered variants can efficiently hydrolyze organophosphorus (OP) nerve agents and pesticides, respectively, have attracted considerable interest for the treatment of the corresponding intoxications. OP nerve agents and pesticides still pose a severe toxicological threat in military conflicts, including acts of terrorism, as well as in agriculture, leading to >100000 deaths per year. In principle, engineered conventional homodimeric PTEs may provoke hydrolytic inactivation of individual OPs in vivo, and their application as catalytic bioscavengers via administration into the bloodstream has been proposed. However, their narrow substrate specificity would necessitate therapeutic application of a set or mixture of different enzymes, which complicates biopharmaceutical development. We succeeded in combining subunits from both enzymes and to stabilize their heterodimerization by rationally designing electrostatic steering mutations, thus breaking the natural C2 symmetry. The resulting bispecific enzyme from two PTEs with different bacterial origin exhibits an ultrabroad OP substrate profile and allows the efficient detoxification of both nerve agents and pesticides. Our approach of combining two active sites with distinct substrate specificities within one artificial dimeric biocatalyst-retaining the size and general properties of the original enzyme without utilizing protein mixtures or much larger fusion proteins-not only should facilitate biological drug development but also may be applicable to oligomeric enzymes with other catalytic activities.
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Affiliation(s)
- Benjamin Escher
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Anja Köhler
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany.,Bundeswehr Institut für Pharmakologie und Toxikologie, Neuherbergstrasse 11, 80937 München, Germany
| | - Laura Job
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
| | - Franz Worek
- Bundeswehr Institut für Pharmakologie und Toxikologie, Neuherbergstrasse 11, 80937 München, Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising, Germany
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Zueva IV, Lushchekina SV, Daudé D, Chabrière E, Masson P. Steady-State Kinetics of Enzyme-Catalyzed Hydrolysis of Echothiophate, a P-S Bonded Organophosphorus as Monitored by Spectrofluorimetry. Molecules 2020; 25:molecules25061371. [PMID: 32192230 PMCID: PMC7144395 DOI: 10.3390/molecules25061371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 03/14/2020] [Accepted: 03/16/2020] [Indexed: 02/02/2023] Open
Abstract
Enzyme-catalyzed hydrolysis of echothiophate, a P–S bonded organophosphorus (OP) model, was spectrofluorimetrically monitored, using Calbiochem Probe IV as the thiol reagent. OP hydrolases were: the G117H mutant of human butyrylcholinesterase capable of hydrolyzing OPs, and a multiple mutant of Brevundimonas diminuta phosphotriesterase, GG1, designed to hydrolyze a large spectrum of OPs at high rate, including V agents. Molecular modeling of interaction between Probe IV and OP hydrolases (G117H butyrylcholinesterase, GG1, wild types of Brevundimonas diminuta and Sulfolobus solfataricus phosphotriesterases, and human paraoxonase-1) was performed. The high sensitivity of the method allowed steady-state kinetic analysis of echothiophate hydrolysis by highly purified G117H butyrylcholinesterase concentration as low as 0.85 nM. Hydrolysis was michaelian with Km = 0.20 ± 0.03 mM and kcat = 5.4 ± 1.6 min−1. The GG1 phosphotriesterase hydrolyzed echothiophate with a high efficiency (Km = 2.6 ± 0.2 mM; kcat = 53400 min−1). With a kcat/Km = (2.6 ± 1.6) × 107 M−1min−1, GG1 fulfills the required condition of potential catalytic bioscavengers. quantum mechanics/molecular mechanics (QM/MM) and molecular docking indicate that Probe IV does not interact significantly with the selected phosphotriesterases. Moreover, results on G117H mutant show that Probe IV does not inhibit butyrylcholinesterase. Therefore, Probe IV can be recommended for monitoring hydrolysis of P–S bonded OPs by thiol-free OP hydrolases.
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Affiliation(s)
- Irina V. Zueva
- Arbuzov Institute of Organic and Physical Chemistry, Federal Research Center “Kazan Scientific Center of the Russian Academy of Sciences”, Arbuzov str. 8, 420088 Kazan, Russia;
| | - Sofya V. Lushchekina
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin str 4, 119334 Moscow, Russia;
| | - David Daudé
- Gene&GreenTK, HU Méditerranée Infection, Jean Moulin Blvd 19–21, 13005 Marseille, France;
| | - Eric Chabrière
- Aix-Marseille University, IRD, APHM, MEPHI, IHU-Méditerranée Infection, 15005 Marseille, France;
| | - Patrick Masson
- Kazan Federal University, Neuropharmacology Laboratory, Kremlevskaya str 18, 480002 Kazan, Russia
- Correspondence: ; Tel.: +7-96-5581-0473
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