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de Castro AA, Soares FV, Pereira AF, Silva TC, Silva DR, Mancini DT, Caetano MS, da Cunha EFF, Ramalho TC. Asymmetric biodegradation of the nerve agents Sarin and VX by human dUTPase: chemometrics, molecular docking and hybrid QM/MM calculations. J Biomol Struct Dyn 2019; 37:2154-2164. [PMID: 30044197 DOI: 10.1080/07391102.2018.1478751] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Organophosphorus compounds (OP) nerve agents are among the most toxic chemical substances known. Their toxicity is due to their ability to bind to acetylcholinesterase. Currently, some enzymes, such as phosphotriesterase, human serum paraoxonase 1 and diisopropyl fluorophosphatase, capable of degrading OP, have been characterized. Regarding the importance of bioremediation methods for detoxication of OP, this work aims to study the interaction modes between the human human deoxyuridine triphosphate nucleotidohydrolase (dUTPase) and Sarin and VX, considering their Rp and Sp enantiomers, to evaluate the asymmetric catalysis of those compounds. In previous work, this enzyme has shown good potential to degrade phosphotriesters, and based on this characteristic, we have applied the human dUTPase to the OP degradation. Molecular docking, chemometrics and mixed quantum and molecular mechanics calculations have been employed, showing a good interaction between dUTPase and OP. Two possible reaction mechanisms were tested, and according to our theoretical results, the catalytic degradation of OP by dUTPase can take place via both mechanisms, beyond being stereoselective, that is, dUTPase cleaves one enantiomer preferentially in relation to other. Chemometric techniques provided excellent assistance for performing this theoretical investigation. The dUTPase study shows importance by the fact of it being a human enzyme. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Alexandre A de Castro
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Flávia Villela Soares
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Ander Francisco Pereira
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Telles Cardoso Silva
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Daniela Rodrigues Silva
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Daiana Teixeira Mancini
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Melissa Soares Caetano
- b Institute of Exact and Biological Sciences, Federal University of Ouro Preto, University Campus , Ouro Preto , Brazil
| | - Elaine F F da Cunha
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil
| | - Teodorico C Ramalho
- a Laboratory of Molecular Modeling, Chemistry Department , Federal University of Lavras , Lavras , Brazil.,c Center for Basic and Applied research, University Hradec Kralove , Hradec Kralove , Czech Republic
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Cho SS, Yu M, Kwon ST. Mutations in the palm subdomain of Twa DNA polymerase to enhance PCR efficiency and its function analysis. J Biotechnol 2014; 184:39-46. [PMID: 24865518 DOI: 10.1016/j.jbiotec.2014.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2013] [Revised: 04/19/2014] [Accepted: 05/12/2014] [Indexed: 10/25/2022]
Abstract
Among the family B DNA polymerases, the Twa DNA polymerase from T. wiotapuensis, a hyperthermophilic archaeon, has exceedingly high fidelity. For applications in PCR, however, the enzyme is limited by its low extension rate and processivity. To resolve these weaknesses, we focused on two amino acid residues (A381 and N501) located at the palm subdomain of Twa DNA polymerase. Following replacement of these residues by site-directed mutagenesis, Twa N501R DNA polymerase showed significantly improved polymerase function compared to the wild-type enzyme in terms of processivity (3-fold), extension rate (2-fold) and PCR efficiency. Kinetic analysis using DNA as template revealed that the kcat value of the Twa N501R mutant was similar to that of wild-type, but the Km of the Twa N501R mutant was about 1.5-fold lower than that of the wild-type. These results suggest that a positive charge at residue 501 located in the forked-point does not impede catalytic activity of the polymerase domain but stabilizes interactions between the polymerase domain and the DNA template.
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Affiliation(s)
- Sung Suk Cho
- Department of Genetic Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon 440-746, Republic of Korea
| | - Mi Yu
- Department of Genetic Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon 440-746, Republic of Korea
| | - Suk-Tae Kwon
- Department of Genetic Engineering, Sungkyunkwan University, 300 Chunchun-dong, Jangan-gu, Suwon 440-746, Republic of Korea.
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Archaeal genome guardians give insights into eukaryotic DNA replication and damage response proteins. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2014; 2014:206735. [PMID: 24701133 PMCID: PMC3950489 DOI: 10.1155/2014/206735] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 09/27/2013] [Accepted: 11/29/2013] [Indexed: 12/28/2022]
Abstract
As the third domain of life, archaea, like the eukarya and bacteria, must have robust DNA replication and repair complexes to ensure genome fidelity. Archaea moreover display a breadth of unique habitats and characteristics, and structural biologists increasingly appreciate these features. As archaea include extremophiles that can withstand diverse environmental stresses, they provide fundamental systems for understanding enzymes and pathways critical to genome integrity and stress responses. Such archaeal extremophiles provide critical data on the periodic table for life as well as on the biochemical, geochemical, and physical limitations to adaptive strategies allowing organisms to thrive under environmental stress relevant to determining the boundaries for life as we know it. Specifically, archaeal enzyme structures have informed the architecture and mechanisms of key DNA repair proteins and complexes. With added abilities to temperature-trap flexible complexes and reveal core domains of transient and dynamic complexes, these structures provide insights into mechanisms of maintaining genome integrity despite extreme environmental stress. The DNA damage response protein structures noted in this review therefore inform the basis for genome integrity in the face of environmental stress, with implications for all domains of life as well as for biomanufacturing, astrobiology, and medicine.
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