1
|
Sowińska A, Rostkowski M, Krzemińska A, Englman T, Gelman F, Dybala-Defratyka A. Insights into generalization of the rate-limiting steps of the dehalogenation by LinB and DhaA: A computational approach. Arch Biochem Biophys 2023:109675. [PMID: 37343813 DOI: 10.1016/j.abb.2023.109675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 06/23/2023]
Abstract
LinB and DhaA are well-known haloalkane dehalogenases (HLDs) capable of converting a plethora of halogenated alkanes, also those considered persistent pollutants. The dehalogenation reaction that these two enzymes catalyze has been studied to determine its rate-limiting step (rls) for the last two decades now. As a result, it has been determined that HLDs can show different rate-limiting steps for individual substrates, and at this point we do not have a basis for any generalization in this matter. Therefore, in this work we aimed at gaining insights into the enzymatic dehalogenation of selected dibromo- and bromochloro-ethanes and propanes by LinB and DhaA using computational approach to determine whether defined structural similarities of the substrates result in a unified mechanism and the same rls. By predicting halogen binding isotope effects (BIEs) as well as computing interaction energy for each HLD-ligand complex the nature of the protein-ligand interactions has been characterized. Furthermore, C and Br kinetic isotope effects (KIEs) as well as the minimum free energy paths (MFEPs) were computed to investigate the chemical reaction for the selected systems. Accuracy of the approach and robustness of the computational predictions were validated by measuring KIEs on the selected reactions. Overall results strongly indicate that any generalization with respect to the enzymatic process involving various ligands in the case of DhaA is impossible, even if the considered ligands are structurally very similar as those analyzed in the present study. Moreover, even small structural differences such as changing of one of the (non-leaving) halogen substituents may lead to significant changes in the enzymatic process and result in a different rls in the case of LinB. It has also been demonstrated that KIEs themselves cannot be used as rls indicators in the reactions catalyzed by the studied HLDs.
Collapse
Affiliation(s)
- Agata Sowińska
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland
| | - Michał Rostkowski
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland
| | - Agnieszka Krzemińska
- Institute of Physics, Lodz University of Technology, Wolczanska 217/221, 93-005, Lodz, Poland
| | - Tzofia Englman
- The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904, Israel
| | - Faina Gelman
- Geological Survey of Israel, Yeshayahu Leibowitz 32, Jerusalem, 9692100, Israel
| | - Agnieszka Dybala-Defratyka
- Institute of Applied Radiation Chemistry, Faculty of Chemistry, Lodz University of Technology, Zeromskiego 116, 90-924, Lodz, Poland.
| |
Collapse
|
2
|
Raczyńska A, Kapica P, Papaj K, Stańczak A, Shyntum D, Spychalska P, Byczek-Wyrostek A, Góra A. Transient binding sites at the surface of haloalkane dehalogenase LinB as locations for fine-tuning enzymatic activity. PLoS One 2023; 18:e0280776. [PMID: 36827335 PMCID: PMC9956002 DOI: 10.1371/journal.pone.0280776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 01/09/2023] [Indexed: 02/25/2023] Open
Abstract
The haloalkane dehalogenase LinB is a well-known enzyme that contains buried active site and is used for many modelling studies. Using classical molecular dynamics simulations of enzymes and substrates, we searched for transient binding sites on the surface of the LinB protein by calculating maps of enzyme-ligand interactions that were then transformed into sparse matrices. All residues considered as functionally important for enzyme performance (e.g., tunnel entrances) were excluded from the analysis to concentrate rather on non-obvious surface residues. From a set of 130 surface residues, twenty-six were proposed as a promising improvement of enzyme performance. Eventually, based on rational selection and filtering out the potentially unstable mutants, a small library of ten mutants was proposed to validate the possibility of fine-tuning the LinB protein. Nearly half of the predicted mutant structures showed improved activity towards the selected substrates, which demonstrates that the proposed approach could be applied to identify non-obvious yet beneficial mutations for enzyme performance especially when obvious locations have already been explored.
Collapse
Affiliation(s)
- Agata Raczyńska
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | - Patryk Kapica
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | - Katarzyna Papaj
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | - Agnieszka Stańczak
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | - Divine Shyntum
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | - Patrycja Spychalska
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
| | | | - Artur Góra
- Tunneling Group, Biotechnology Centre, Silesian University of Technology, Gliwice, Poland
- * E-mail:
| |
Collapse
|
3
|
Chan PWY, Chakrabarti N, Ing C, Halgas O, To TKW, Wälti M, Petit AP, Tran C, Savchenko A, Yakunin AF, Edwards EA, Pomès R, Pai EF. Defluorination Capability of l-2-Haloacid Dehalogenases in the HAD-Like Hydrolase Superfamily Correlates with Active Site Compactness. Chembiochem 2022; 23:e202100414. [PMID: 34643018 PMCID: PMC10281000 DOI: 10.1002/cbic.202100414] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/07/2021] [Indexed: 11/11/2022]
Abstract
l-2-Haloacid dehalogenases, industrially and environmentally important enzymes that catalyse cleavage of the carbon-halogen bond in S-2-halocarboxylic acids, were known to hydrolyse chlorinated, brominated and iodinated substrates but no activity towards fluorinated compounds had been reported. A screen for novel dehalogenase activities revealed four l-2-haloacid dehalogenases capable of defluorination. We now report crystal structures for two of these enzymes, Bpro0530 and Rha0230, as well as for the related proteins PA0810 and RSc1362, which hydrolyse chloroacetate but not fluoroacetate, all at ∼2.2 Å resolution. Overall structure and active sites of these enzymes are highly similar. In molecular dynamics (MD) calculations, only the defluorinating enzymes sample more compact conformations, which in turn allow more effective interactions with the small fluorine atom. Structural constraints, based on X-ray structures and MD calculations, correctly predict the defluorination activity of the homologous enzyme ST2570.
Collapse
Affiliation(s)
- Peter W Y Chan
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Present address: Zymeworks, Inc., 1385 West 8th Avenue Suite 540, Vancouver, British Columbia, V6H 3 V9, Canada
- Princess Margaret Cancer Centre, The Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada
| | | | - Chris Ing
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
- Present address: ProteinQure, Inc., 119 Spadina Avenue suite 304, Toronto, Ontario, M5V 2L1, Canada
| | - Ondrej Halgas
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
| | - Terence K W To
- Princess Margaret Cancer Centre, The Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada
- Present address: International Point of Care, Inc., 135 The West Mall, Unit 9, Toronto, Ontario, M9C 1C2, Canada
| | - Marielle Wälti
- Princess Margaret Cancer Centre, The Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada
- Present address: Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0510, USA
| | - Alain-Pierre Petit
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
- Present address: Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Christopher Tran
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
- Present address: Ramboll Environment & Health, 2400 Meadowpine Boulevard, Suite 100, Mississauga, Ontario, L5N 6S2, Canada
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
- Present address: Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Health Research Innovation Centre, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Alexander F Yakunin
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
- Centre for Environmental Biotechnology, School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2UW, UK
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada
| | - Régis Pomès
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Molecular Medicine, Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Emil F Pai
- Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S 1A8, Canada
- Princess Margaret Cancer Centre, The Campbell Family Cancer Research Institute, University Health Network, Toronto, Ontario, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| |
Collapse
|
4
|
Mazur A, Grinkevich P, Chaloupkova R, Havlickova P, Kascakova B, Kuty M, Damborsky J, Kuta Smatanova I, Prudnikova T. Structural Analysis of the Ancestral Haloalkane Dehalogenase AncLinB-DmbA. Int J Mol Sci 2021; 22:ijms222111992. [PMID: 34769421 PMCID: PMC8584953 DOI: 10.3390/ijms222111992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022] Open
Abstract
Haloalkane dehalogenases (EC 3.8.1.5) play an important role in hydrolytic degradation of halogenated compounds, resulting in a halide ion, a proton, and an alcohol. They are used in biocatalysis, bioremediation, and biosensing of environmental pollutants and also for molecular tagging in cell biology. The method of ancestral sequence reconstruction leads to prediction of sequences of ancestral enzymes allowing their experimental characterization. Based on the sequences of modern haloalkane dehalogenases from the subfamily II, the most common ancestor of thoroughly characterized enzymes LinB from Sphingobium japonicum UT26 and DmbA from Mycobacterium bovis 5033/66 was in silico predicted, recombinantly produced and structurally characterized. The ancestral enzyme AncLinB-DmbA was crystallized using the sitting-drop vapor-diffusion method, yielding rod-like crystals that diffracted X-rays to 1.5 Å resolution. Structural comparison of AncLinB-DmbA with their closely related descendants LinB and DmbA revealed some differences in overall structure and tunnel architecture. Newly prepared AncLinB-DmbA has the highest active site cavity volume and the biggest entrance radius on the main tunnel in comparison to descendant enzymes. Ancestral sequence reconstruction is a powerful technique to study molecular evolution and design robust proteins for enzyme technologies.
Collapse
Affiliation(s)
- Andrii Mazur
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Pavel Grinkevich
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Radka Chaloupkova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; (R.C.); (J.D.)
- Enantis Ltd., Kamenice 771/34, 625 00 Brno, Czech Republic
| | - Petra Havlickova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Barbora Kascakova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Michal Kuty
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; (R.C.); (J.D.)
- International Clinical Research Center, St Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Ivana Kuta Smatanova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
- Correspondence: (I.K.S.); (T.P.)
| | - Tatyana Prudnikova
- Faculty of Science, University of South Bohemia in Ceske Budejovice, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic; (A.M.); (P.G.); (P.H.); (B.K.); (M.K.)
- Correspondence: (I.K.S.); (T.P.)
| |
Collapse
|
5
|
Chen SF, Vysotski ES, Liu YJ. H 2O-Bridged Proton-Transfer Channel in Emitter Species Formation in Obelin Bioluminescence. J Phys Chem B 2021; 125:10452-10458. [PMID: 34520210 DOI: 10.1021/acs.jpcb.1c03985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bioluminescence of a number of marine organisms is conditioned by Ca2+-regulated photoprotein (CaRP) with coelenterazine as the reaction substrate. The reaction product, coelenteramide, at the first singlet excited state (S1) is the emitter of CaRP. The S1-state coelenteramide is produced via the decomposition of coelenterazine dioxetanone. Experiments suggested that the neutral S1-coelenteramide is the primary emitter species. This supposition contradicts with theoretical calculations showing that the anionic S1-coelenteramide is a primary product of the decomposition of coelenterazine dioxetanone. In this study, applying molecular dynamic (MD) simulations and the hybrid quantum mechanics/molecular mechanics (QM/MM) method, we investigated a proton-transfer (PT) process taking place in CaRP obelin from Obelia longissima for emitter formation. Our calculations demonstrate a concerted PT process with a water molecule as a bridge between anionic S1-coelenteramide and the nearest histidine residue. The low activation barrier as well as the strong hydrogen-bond network between the proton donor and the proton acceptor suggests a fast PT process comparable with that of the lifetime of excited anionic S1-coelenteramide. The existence of the PT process eliminates the discrepancy between experimental and theoretical studies. The fast PT process at emitter formation can also take place in other CaRPs.
Collapse
Affiliation(s)
- Shu-Feng Chen
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, People's Republic of China
| | - Eugene S Vysotski
- Photobiology Laboratory, Institute of Biophysics SB RAS, Federal Research Center "Krasnoyarsk Science Center SB RAS", Krasnoyarsk 660036, Russia
| | - Ya-Jun Liu
- Center for Advanced Materials Research, Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai, Zhuhai 519087, China.,Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| |
Collapse
|
6
|
Hess D, Dockalova V, Kokkonen P, Bednar D, Damborsky J, deMello A, Prokop Z, Stavrakis S. Exploring mechanism of enzyme catalysis by on-chip transient kinetics coupled with global data analysis and molecular modeling. Chem 2021. [DOI: 10.1016/j.chempr.2021.02.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
7
|
Microbial Enzymes in the Bioremediation of Pollutants: Emerging Potential and Challenges. Fungal Biol 2021. [DOI: 10.1007/978-3-030-54422-5_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
8
|
Knobloch MC, Schinkel L, Schilling I, Kohler HPE, Lienemann P, Bleiner D, Heeb NV. Transformation of short-chain chlorinated paraffins by the bacterial haloalkane dehalogenase LinB - Formation of mono- and di-hydroxylated metabolites. CHEMOSPHERE 2021; 262:128288. [PMID: 33182101 DOI: 10.1016/j.chemosphere.2020.128288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/04/2020] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Short-chain chlorinated paraffins (SCCPs) are listed as persistent organic pollutants (POPs) under the Stockholm Convention. Such substances are toxic, bioaccumulating, transported over long distances and degrade slowly in the environment. Certain bacterial strains of the Sphingomonadacea family are able to degrade POPs, such as hexachlorocyclohexanes (HCHs) and hexabromocyclododecanes (HBCDs). The haloalkane dehalogenase LinB, expressed in certain Sphingomonadacea, is able to catalyze the transformation of haloalkanes to hydroxylated compounds. Therefore, LinB is a promising candidate for conversion of SCCPs. Hence, a mixture of chlorinated tridecanes was exposed in vitro to LinB, which was obtained through heterologous expression in Escherichia coli. Liquid chromatography mass spectrometry (LC-MS) was used to analyze chlorinated tridecanes and their transformation products. A chloride-enhanced soft ionization method, which favors the formation of chloride adducts [M+Cl]- without fragmentation, was applied. Mathematical deconvolution was used to distinguish interfering mass spectra of paraffinic, mono-olefinic and di-olefinic compounds. Several mono- and di-hydroxylated products including paraffinic, mono-olefinic and di-olefinic compounds were found after LinB exposure. Mono- (rt = 5.9-6.9 min) and di-hydroxylated (rt = 3.2-4.5 min) compounds were separated from starting material (rt = 7.7-8.5 min) by reversed phase LC. Chlorination degrees of chlorinated tridecanes increased during LinB-exposure from nCl = 8.80 to 9.07, indicating a preferential transformation of lower chlorinated (Cl<9) tridecanes. Thus, LinB indeed catalyzed a dehalohydroxylation of chlorinated tridecanes, tridecenes and tridecadienes. The observed hydroxylated compounds are relevant CP transformation products whose environmental and toxicological effects should be further investigated.
Collapse
Affiliation(s)
- Marco C Knobloch
- Laboratory for Advanced Analytical Technologies, Swiss Federal Institute for Materials Science and Technology Empa, Überlandstrasse 129, 8600, Dübendorf, Switzerland; Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland.
| | - Lena Schinkel
- Swiss Federal Institute of Aquatic Research and Technology Eawag, Überlandstrasse 129, 8600, Dübendorf, Switzerland
| | - Iris Schilling
- Swiss Federal Institute of Aquatic Research and Technology Eawag, Überlandstrasse 129, 8600, Dübendorf, Switzerland
| | - Hans-Peter E Kohler
- Swiss Federal Institute of Aquatic Research and Technology Eawag, Überlandstrasse 129, 8600, Dübendorf, Switzerland
| | - Peter Lienemann
- Zürich University of Applied Sciences ZHAW, Einsiedlerstrasse 3, 8820, Wädenswil, Switzerland
| | - Davide Bleiner
- Laboratory for Advanced Analytical Technologies, Swiss Federal Institute for Materials Science and Technology Empa, Überlandstrasse 129, 8600, Dübendorf, Switzerland; Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Norbert V Heeb
- Laboratory for Advanced Analytical Technologies, Swiss Federal Institute for Materials Science and Technology Empa, Überlandstrasse 129, 8600, Dübendorf, Switzerland
| |
Collapse
|
9
|
Description of Transport Tunnel in Haloalkane Dehalogenase Variant LinB D147C+L177C from Sphingobium japonicum. Catalysts 2020. [DOI: 10.3390/catal11010005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The activity of enzymes with active sites buried inside their protein core highly depends on the efficient transport of substrates and products between the active site and the bulk solvent. The engineering of access tunnels in order to increase or decrease catalytic activity and specificity in a rational way is a challenging task. Here, we describe a combined experimental and computational approach to characterize the structural basis of altered activity in the haloalkane dehalogenase LinB D147C+L177C variant. While the overall protein fold is similar to the wild type enzyme and the other LinB variants, the access tunnels have been altered by introduced cysteines that were expected to form a disulfide bond. Surprisingly, the mutations have allowed several conformations of the amino acid chain in their vicinity, interfering with the structural analysis of the mutant by X-ray crystallography. The duration required for the growing of protein crystals changed from days to 1.5 years by introducing the substitutions. The haloalkane dehalogenase LinB D147C+L177C variant crystal structure was solved to 1.15 Å resolution, characterized and deposited to Protein Data Bank under PDB ID 6s06.
Collapse
|
10
|
A Haloalkane Dehalogenase from Saccharomonospora viridis Strain DSM 43017, a Compost Bacterium with Unusual Catalytic Residues, Unique ( S)-Enantiopreference, and High Thermostability. Appl Environ Microbiol 2020; 86:AEM.02820-19. [PMID: 32561584 DOI: 10.1128/aem.02820-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/08/2020] [Indexed: 11/20/2022] Open
Abstract
Haloalkane dehalogenases can cleave a carbon-halogen bond in a broad range of halogenated aliphatic compounds. However, a highly conserved catalytic pentad composed of a nucleophile, a catalytic base, a catalytic acid, and two halide-stabilizing residues is required for their catalytic activity. Only a few family members, e.g., DsaA, DmxA, or DmrB, remain catalytically active while employing a single halide-stabilizing residue. Here, we describe a novel haloalkane dehalogenase, DsvA, from a mildly thermophilic bacterium, Saccharomonospora viridis strain DSM 43017, possessing one canonical halide-stabilizing tryptophan (W125). At the position of the second halide-stabilizing residue, DsvA contains the phenylalanine F165, which cannot stabilize the halogen anion released during the enzymatic reaction by a hydrogen bond. Based on the sequence and structural alignments, we identified a putative second halide-stabilizing tryptophan (W162) located on the same α-helix as F165, but on the opposite side of the active site. The potential involvement of this residue in DsvA catalysis was investigated by the construction and biochemical characterization of the three variants, DsvA01 (F165W), DsvA02 (W162F), and DsvA03 (W162F and F165W). Interestingly, DsvA exhibits a preference for the (S)- over the (R)-enantiomers of β-bromoalkanes, which has not been reported before for any characterized haloalkane dehalogenase. Moreover, DsvA shows remarkable operational stability at elevated temperatures. The present study illustrates that protein sequences possessing an unconventional composition of catalytic residues represent a valuable source of novel biocatalysts.IMPORTANCE The present study describes a novel haloalkane dehalogenase, DsvA, originating from a mildly thermophilic bacterium, Saccharomonospora viridis strain DSM 43017. We report its high thermostability, remarkable operational stability at high temperatures, and an (S)-enantiopreference, which makes this enzyme an attractive biocatalyst for practical applications. Sequence analysis revealed that DsvA possesses an unusual composition of halide-stabilizing tryptophan residues in its active site. We constructed and biochemically characterized two single point mutants and one double point mutant and identified the noncanonical halide-stabilizing residue. Our study underlines the importance of searching for noncanonical catalytic residues in protein sequences.
Collapse
|
11
|
Vavra O, Filipovic J, Plhak J, Bednar D, Marques SM, Brezovsky J, Stourac J, Matyska L, Damborsky J. CaverDock: a molecular docking-based tool to analyse ligand transport through protein tunnels and channels. Bioinformatics 2020; 35:4986-4993. [PMID: 31077297 DOI: 10.1093/bioinformatics/btz386] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/11/2019] [Accepted: 05/05/2019] [Indexed: 12/20/2022] Open
Abstract
MOTIVATION Protein tunnels and channels are key transport pathways that allow ligands to pass between proteins' external and internal environments. These functionally important structural features warrant detailed attention. It is difficult to study the ligand binding and unbinding processes experimentally, while molecular dynamics simulations can be time-consuming and computationally demanding. RESULTS CaverDock is a new software tool for analysing the ligand passage through the biomolecules. The method uses the optimized docking algorithm of AutoDock Vina for ligand placement docking and implements a parallel heuristic algorithm to search the space of possible trajectories. The duration of the simulations takes from minutes to a few hours. Here we describe the implementation of the method and demonstrate CaverDock's usability by: (i) comparison of the results with other available tools, (ii) determination of the robustness with large ensembles of ligands and (iii) the analysis and comparison of the ligand trajectories in engineered tunnels. Thorough testing confirms that CaverDock is applicable for the fast analysis of ligand binding and unbinding in fundamental enzymology and protein engineering. AVAILABILITY AND IMPLEMENTATION User guide and binaries for Ubuntu are freely available for non-commercial use at https://loschmidt.chemi.muni.cz/caverdock/. The web implementation is available at https://loschmidt.chemi.muni.cz/caverweb/. The source code is available upon request. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Ondrej Vavra
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jiri Filipovic
- Institute of Computer Science, Masaryk University, Brno, Czech Republic
| | - Jan Plhak
- Institute of Computer Science, Masaryk University, Brno, Czech Republic
| | - David Bednar
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Sergio M Marques
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic
| | - Jan Stourac
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital Brno, Brno, Czech Republic
| | - Ludek Matyska
- Institute of Computer Science, Masaryk University, Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Brno, Czech Republic.,International Centre for Clinical Research, St. Anne's University Hospital Brno, Brno, Czech Republic
| |
Collapse
|
12
|
Dockalova V, Sanchez-Carnerero EM, Dunajova Z, Palao E, Slanska M, Buryska T, Damborsky J, Klán P, Prokop Z. Fluorescent substrates for haloalkane dehalogenases: Novel probes for mechanistic studies and protein labeling. Comput Struct Biotechnol J 2020; 18:922-932. [PMID: 32346465 PMCID: PMC7182704 DOI: 10.1016/j.csbj.2020.03.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 10/31/2022] Open
Abstract
Haloalkane dehalogenases are enzymes that catalyze the cleavage of carbon-halogen bonds in halogenated compounds. They serve as model enzymes for studying structure-function relationships of >100.000 members of the α/β-hydrolase superfamily. Detailed kinetic analysis of their reaction is crucial for understanding the reaction mechanism and developing novel concepts in protein engineering. Fluorescent substrates, which change their fluorescence properties during a catalytic cycle, may serve as attractive molecular probes for studying the mechanism of enzyme catalysis. In this work, we present the development of the first fluorescent substrates for this enzyme family based on coumarin and BODIPY chromophores. Steady-state and pre-steady-state kinetics with two of the most active haloalkane dehalogenases, DmmA and LinB, revealed that both fluorescent substrates provided specificity constant two orders of magnitude higher (0.14-12.6 μM-1 s-1) than previously reported representative substrates for the haloalkane dehalogenase family (0.00005-0.014 μM-1 s-1). Stopped-flow fluorescence/FRET analysis enabled for the first time monitoring of all individual reaction steps within a single experiment: (i) substrate binding, (ii-iii) two subsequent chemical steps and (iv) product release. The newly introduced fluorescent molecules are potent probes for fast steady-state kinetic profiling. In combination with rapid mixing techniques, they provide highly valuable information about individual kinetic steps and mechanism of haloalkane dehalogenases. Additionally, these molecules offer high specificity and efficiency for protein labeling and can serve as probes for studying protein hydration and dynamics as well as potential markers for cell imaging.
Collapse
Affiliation(s)
- Veronika Dockalova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | | | - Zuzana Dunajova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Eduardo Palao
- Department of Chemistry and RECETOX, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Michaela Slanska
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Tomas Buryska
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| | - Petr Klán
- Department of Chemistry and RECETOX, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital, Pekarska 53, 656 91 Brno, Czech Republic
| |
Collapse
|
13
|
Kokkonen P, Slanska M, Dockalova V, Pinto GP, Sánchez-Carnerero EM, Damborsky J, Klán P, Prokop Z, Bednar D. The impact of tunnel mutations on enzymatic catalysis depends on the tunnel-substrate complementarity and the rate-limiting step. Comput Struct Biotechnol J 2020; 18:805-813. [PMID: 32308927 PMCID: PMC7152659 DOI: 10.1016/j.csbj.2020.03.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/17/2020] [Accepted: 03/19/2020] [Indexed: 01/18/2023] Open
Abstract
Transport of ligands between bulk solvent and the buried active sites is a critical event in the catalytic cycle of many enzymes. The rational design of transport pathways is far from trivial due to the lack of knowledge about the effect of mutations on ligand transport. The main and an auxiliary tunnel of haloalkane dehalogenase LinB have been previously engineered for improved dehalogenation of 1,2-dibromoethane (DBE). The first chemical step of DBE conversion was enhanced by L177W mutation in the main tunnel, but the rate-limiting product release was slowed down because the mutation blocked the main access tunnel and hindered protein dynamics. Three additional mutations W140A + F143L + I211L opened-up the auxiliary tunnel and enhanced the product release, making this four-point variant the most efficient catalyst with DBE. Here we study the impact of these mutations on the catalysis of bulky aromatic substrates, 4-(bromomethyl)-6,7-dimethoxycoumarin (COU) and 8-chloromethyl-4,4'-difluoro-3,5-dimethyl-4-bora-3a,4a-diaza-s-indacene (BDP). The rate-limiting step of DBE conversion is the product release, whereas the catalysis of COU and BDP is limited by the chemical step. The catalysis of COU is mainly impaired by the mutation L177W, whereas the conversion of BDP is affected primarily by the mutations W140A + F143L + I211L. The combined computational and kinetic analyses explain the differences in activities between the enzyme-substrate pairs. The effect of tunnel mutations on catalysis depends on the rate-limiting step, the complementarity of the tunnels with the substrates and is clearly specific for each enzyme-substrate pair.
Collapse
Affiliation(s)
- Piia Kokkonen
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Michaela Slanska
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Veronika Dockalova
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Gaspar P. Pinto
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, St. Ann’s Hospital, Brno, Czech Republic
| | | | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, St. Ann’s Hospital, Brno, Czech Republic
| | - Petr Klán
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, St. Ann’s Hospital, Brno, Czech Republic
| | - David Bednar
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of Science, Masaryk University, Brno, Czech Republic
- International Clinical Research Centre, St. Ann’s Hospital, Brno, Czech Republic
| |
Collapse
|
14
|
Droplet-based optofluidic systems for measuring enzyme kinetics. Anal Bioanal Chem 2019; 412:3265-3283. [PMID: 31853606 DOI: 10.1007/s00216-019-02294-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 10/15/2019] [Accepted: 11/19/2019] [Indexed: 01/05/2023]
Abstract
The study of enzyme kinetics is of high significance in understanding metabolic networks in living cells and using enzymes in industrial applications. To gain insight into the catalytic mechanisms of enzymes, it is necessary to screen an enormous number of reaction conditions, a process that is typically laborious, time-consuming, and costly when using conventional measurement techniques. In recent times, droplet-based microfluidic systems have proved themselves to be of great utility in large-scale biological experimentation, since they consume a minimal sample, operate at high analytical throughput, are characterized by efficient mass and heat transfer, and offer high levels of integration and automation. The primary goal of this review is the introduction of novel microfluidic tools and detection methods for use in high-throughput and sensitive analysis of enzyme kinetics. The first part of this review focuses on introducing basic concepts of enzyme kinetics and describing most common microfluidic approaches, with a particular focus on segmented flow. Herein, the key advantages include accurate control over the flow behavior, efficient mass and heat transfer, multiplexing, and high-level integration with detection modalities. The second part describes the current state-of-the-art platforms for high-throughput and sensitive analysis of enzyme kinetics. In addition to our categorization of recent advances in measuring enzyme kinetics, we have endeavored to critically assess the limitations of each of these detection approaches and propose strategies to improve measurements in droplet-based microfluidics. Graphical abstract.
Collapse
|
15
|
Schilling IE, Bopp CE, Lal R, Kohler HPE, Hofstetter TB. Assessing Aerobic Biotransformation of Hexachlorocyclohexane Isomers by Compound-Specific Isotope Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:7419-7431. [PMID: 31132243 DOI: 10.1021/acs.est.9b01007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Contamination of soils and sediments with the highly persistent hexachlorocyclohexanes (HCHs) continues to be a threat for humans and the environment. Despite the existence of bacteria capable of biodegradation and cometabolic transformation of HCH isomers, such processes occur over time scales of decades and are thus challenging to assess. Here, we explored the use of compound-specific isotope analysis (CSIA) to track the aerobic biodegradation and biotransformation pathways of the most prominent isomers, namely, (-)-α-, (+)-α-, β-, γ-, and δ-HCH, through changes of their C and H isotope composition in assays of LinA2 and LinB enzymes. Dehydrochlorination of (+)-α-, γ-, and δ-HCH catalyzed by LinA2 was subject to substantial C and H isotope fraction with apparent 13C- and 2H-kinetic isotope effects (AKIEs) of up to 1.029 ± 0.001 and 6.7 ± 2.9, respectively, which are indicative of bimolecular eliminations. Hydrolytic dechlorination of δ-HCH by LinB exhibited even larger C but substantially smaller H isotope fractionation with 13C- and 2H-AKIEs of 1.073 ± 0.006 and 1.41 ± 0.04, respectively, which are typical for nucleophilic substitutions. The systematic evaluation of isomer-specific phenomena showed that, in addition to contaminant uptake limitations, diffusion-limited turnover ((-)-α-HCH), substrate dissolution (β-HCH), and potentially competing reactions catalyzed by constitutively expressed enzymes might bias the assessment of HCH biodegradation by CSIA at contaminated sites.
Collapse
Affiliation(s)
- Iris E Schilling
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Charlotte E Bopp
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Rup Lal
- Department of Zoology , University of Delhi , Delhi 110007 , India
| | - Hans-Peter E Kohler
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| |
Collapse
|
16
|
Burakova LP, Vysotski ES. Recombinant Ca 2+-regulated photoproteins of ctenophores: current knowledge and application prospects. Appl Microbiol Biotechnol 2019; 103:5929-5946. [PMID: 31172204 DOI: 10.1007/s00253-019-09939-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 11/26/2022]
Abstract
Bright bioluminescence of ctenophores is conditioned by Ca2+-regulated photoproteins. Although they share many properties characteristic of hydromedusan Ca2+-regulated photoproteins responsible for light emission of marine animals belonging to phylum Cnidaria, a substantial distinction still exists. The ctenophore photoproteins appeared to be extremely sensitive to light-they lose the ability for bioluminescence on exposure to light over the entire absorption spectrum. Inactivation is irreversible because keeping the inactivated photoprotein in the dark does not recover its activity. The capability to emit light can be restored only by incubation of inactivated photoprotein with coelenterazine in the dark at alkaline pH in the presence of oxygen. Although these photoproteins were discovered many years ago, only the cloning of cDNAs encoding these unique bioluminescent proteins in the early 2000s has provided a new impetus for their studies. To date, cDNAs encoding Ca2+-regulated photoproteins from four different species of luminous ctenophores have been cloned. The amino acid sequences of ctenophore photoproteins turned out to completely differ from those of hydromedusan photoproteins (identity less than 29%) though also similar to them having three EF-hand Ca2+-binding sites. At the same time, these photoproteins reveal the same two-domain scaffold characteristic of hydromedusan photoproteins. This review is an attempt to systemize and critically evaluate the data scattered through various articles regarding the structural features of recombinant light-sensitive Ca2+-regulated photoproteins of ctenophores and their bioluminescent and physicochemical properties as well as to compare them with those of hydromedusan photoproteins. In addition, we also discuss the prospects of their biotechnology applications.
Collapse
Affiliation(s)
- Lyudmila P Burakova
- Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Federal Research Center "Krasnoyarsk Science Center SB RAS", Krasnoyarsk, 660036, Russia
| | - Eugene S Vysotski
- Photobiology Laboratory, Institute of Biophysics, Russian Academy of Sciences, Siberian Branch, Federal Research Center "Krasnoyarsk Science Center SB RAS", Krasnoyarsk, 660036, Russia.
| |
Collapse
|
17
|
Beier A, Damborsky J, Prokop Z. Transhalogenation Catalysed by Haloalkane Dehalogenases Engineered to Stop Natural Pathway at Intermediate. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Andy Beier
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of ScienceMasaryk University Kamenice 5 A 625 00 Brno Czech Republic
- International Clinical Research CenterSt. Anne's University Hospital Pekarska 53 656 91 Brno Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of ScienceMasaryk University Kamenice 5 A 625 00 Brno Czech Republic
- International Clinical Research CenterSt. Anne's University Hospital Pekarska 53 656 91 Brno Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and RECETOX, Faculty of ScienceMasaryk University Kamenice 5 A 625 00 Brno Czech Republic
- International Clinical Research CenterSt. Anne's University Hospital Pekarska 53 656 91 Brno Czech Republic
| |
Collapse
|
18
|
Chaloupkova R, Liskova V, Toul M, Markova K, Sebestova E, Hernychova L, Marek M, Pinto GP, Pluskal D, Waterman J, Prokop Z, Damborsky J. Light-Emitting Dehalogenases: Reconstruction of Multifunctional Biocatalysts. ACS Catal 2019. [DOI: 10.1021/acscatal.9b01031] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Radka Chaloupkova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Veronika Liskova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Martin Toul
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Klara Markova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Eva Sebestova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Lenka Hernychova
- Regional Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, 656 53 Brno, Czech Republic
| | - Martin Marek
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Gaspar P. Pinto
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Daniel Pluskal
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jitka Waterman
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, United Kingdom
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| |
Collapse
|
19
|
Kokkonen P, Sykora J, Prokop Z, Ghose A, Bednar D, Amaro M, Beerens K, Bidmanova S, Slanska M, Brezovsky J, Damborsky J, Hof M. Molecular Gating of an Engineered Enzyme Captured in Real Time. J Am Chem Soc 2018; 140:17999-18008. [DOI: 10.1021/jacs.8b09848] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Piia Kokkonen
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Jan Sykora
- J. Heyrovsky Institute of Physical Chemistry of the ASCR, v. v. i., Dolejskova 3, 182 23 Prague 8, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Avisek Ghose
- J. Heyrovsky Institute of Physical Chemistry of the ASCR, v. v. i., Dolejskova 3, 182 23 Prague 8, Czech Republic
| | - David Bednar
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Mariana Amaro
- J. Heyrovsky Institute of Physical Chemistry of the ASCR, v. v. i., Dolejskova 3, 182 23 Prague 8, Czech Republic
| | - Koen Beerens
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Sarka Bidmanova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Michaela Slanska
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Martin Hof
- J. Heyrovsky Institute of Physical Chemistry of the ASCR, v. v. i., Dolejskova 3, 182 23 Prague 8, Czech Republic
| |
Collapse
|
20
|
Wang J, Tang X, Li Y, Zhang R, Zhu L, Chen J, Sun Y, Zhang Q, Wang W. Computational evidence for the degradation mechanism of haloalkane dehalogenase LinB and mutants of Leu248 to 1-chlorobutane. Phys Chem Chem Phys 2018; 20:20540-20547. [PMID: 30051124 DOI: 10.1039/c8cp03561j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The catalytic degradation ability of the haloalkane dehalogenase LinB toward 1-chlorobutane (1-CB) was studied using a combined quantum mechanics/molecular mechanics (QM/MM) approach. Two major processes are involved in the LinB-catalyzed removal of halogens: dechlorination and hydrolyzation. The present study confirmed the experimentally proposed reaction path at the molecular level. Moreover, based on nucleophilic substitution mechanism (SN2 reaction), dechlorination was found to be the rate-determining step of the entire reaction process. In this study, the Boltzmann-weighted average barrier for dechlorination was determined to be 17.0 kcal mol-1, which is fairly close to the experimental value (17.4 kcal mol-1). The state of His107 and the influence of Leu248 on the dechlorination process were also explored. In addition, an intriguing phenomenon was discovered: the potential energy barrier decreased by 7.5 kcal mol-1 when the Leu248 residue was mutated into Phe248. This discovery might be of great help to design new mutant enzymes or novel biocatalysts.
Collapse
Affiliation(s)
- Junjie Wang
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China.
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
In silico design of potentially functional artificial metallo-haloalkane dehalogenase containing catalytic zinc. 3 Biotech 2018; 8:314. [PMID: 30023146 DOI: 10.1007/s13205-018-1333-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/02/2018] [Indexed: 01/05/2023] Open
Abstract
Artificial metalloenzymes are unique as they combine the good features of homogeneous and enzymatic catalysts, and they can potentially improve some difficult catalytic assays. This study reports a method that can be used to create an artificial metal-binding site prior to proving it to be functional in a wet lab. Haloalkane dehalogenase was grafted into a metal-binding site to form an artificial metallo-haloalkane dehalogenase and was studied for its potential functionalities in silico. Computational protocols regarding dynamic metal docking were studied using native metalloenzymes and functional artificial metalloenzymes. Using YASARA Structure, a simulation box covering template structure was created to be filled with water molecules followed by one mutated water molecule closest to the metal-binding site to metal ion. A simple energy minimization step was subsequently run using an AMBER force field to allow the metal ion to interact with the metal-binding residues. Long molecular dynamic simulation using YASARA Structure was performed to analyze the stability of the metal-binding site and the distance between metal-binding residues. Metal ions fluctuating around 2.0 Å across a 20 ns simulation indicated a stable metal-binding site. Metal-binding energies were predicted using FoldX, with a native metalloenzyme (carbonic anhydrase) scoring 18.0 kcal/mol and the best mutant model (C1a) scoring 16.4 kcal/mol. Analysis of the metal-binding site geometry was performed using CheckMyMetal, and all scores for the metalloenzymes and mutant models were in an acceptable range. Like native metalloenzymes, the metal-binding site of C1a was supported by residues in the second coordination shell to maintain a more coordinated metal-binding site. Short-chain multihalogenated alkanes (1,2-dibromoethane and 1,2,3-trichloropropane) were able to dock in the active site of C1a. The halides of the substrate were in contact with both the metal and halide-stabilizing residues, thus indicating a better stabilization of the substrate. The simple catalytic mechanism proposed is that the metal ion interacted with halogen and polarized the carbon-halogen bond, thus making the alpha carbon susceptible to attack by nucleophilic hydroxide. The interaction between halogen in the metal ion and halide-stabilizing residues may help to improve the stabilization of the substrate-enzyme complex and reduce the activation energy. This study reports a modified dynamic metal-docking protocol and validation tests to verify the metal-binding site. These approaches can be applied to design different kinds of artificial metalloenzymes or metal-binding sites.
Collapse
|
22
|
Complete genome sequence of Bacillus sp. HBCD-sjtu, an efficient HBCD-degrading bacterium. 3 Biotech 2018; 8:291. [PMID: 29963351 DOI: 10.1007/s13205-018-1326-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 06/22/2018] [Indexed: 01/20/2023] Open
Abstract
Environmental pollution caused by the release of industrial chemicals is currently one of the most important environmental harms. Manufacturing chemicals can be biodegraded, and valuable intermediates can be used as pharmacophores in drug targeting and have several other useful purposes. Hexabromocyclododecane (HBCD), a non-aromatic brominated flame retardant, is a toxic compound that consists of a cycloaliphatic ring of 12 carbon atoms to which six bromine atoms are attached. It is formed by bromination of cis-trans-trans-1,5,9-cyclododecatriene, but its use is now restricted in several countries, because it is an environmental pollutant. Little is known about whether bacteria can degrade HBCD. A bacterial strain that degrades HBCD was recently isolated using enrichment culture techniques. Based on morphological, biochemical and phylogenetic analysis this isolate was categorized as Bacillus cereus and named strain HBCD-sjtu. Maximum growth and HBCD-degrading activity were observed when this strain was grown at 30 °C, pH 7.0 and 200 RPM in mineral salt medium containing 0.5 mm HBCD. The genome of strain HBCD-sjtu, which consists of only one circular chromosome, was sequenced. This whole genome sequence will be crucial for illuminating the molecular mechanisms of HBCD degradation.
Collapse
|
23
|
Eremeeva EV, Vysotski ES. Exploring Bioluminescence Function of the Ca2+
-regulated Photoproteins with Site-directed Mutagenesis. Photochem Photobiol 2018; 95:8-23. [DOI: 10.1111/php.12945] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Accepted: 05/25/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Elena V. Eremeeva
- Photobiology Laboratory; Institute of Biophysics SB RAS; Federal Research Center “Krasnoyarsk Science Center SB RAS”; Krasnoyarsk Russia
| | - Eugene S. Vysotski
- Photobiology Laboratory; Institute of Biophysics SB RAS; Federal Research Center “Krasnoyarsk Science Center SB RAS”; Krasnoyarsk Russia
| |
Collapse
|
24
|
Ang TF, Maiangwa J, Salleh AB, Normi YM, Leow TC. Dehalogenases: From Improved Performance to Potential Microbial Dehalogenation Applications. Molecules 2018; 23:E1100. [PMID: 29735886 PMCID: PMC6100074 DOI: 10.3390/molecules23051100] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/07/2018] [Accepted: 04/09/2018] [Indexed: 11/16/2022] Open
Abstract
The variety of halogenated substances and their derivatives widely used as pesticides, herbicides and other industrial products is of great concern due to the hazardous nature of these compounds owing to their toxicity, and persistent environmental pollution. Therefore, from the viewpoint of environmental technology, the need for environmentally relevant enzymes involved in biodegradation of these pollutants has received a great boost. One result of this great deal of attention has been the identification of environmentally relevant bacteria that produce hydrolytic dehalogenases—key enzymes which are considered cost-effective and eco-friendly in the removal and detoxification of these pollutants. These group of enzymes catalyzing the cleavage of the carbon-halogen bond of organohalogen compounds have potential applications in the chemical industry and bioremediation. The dehalogenases make use of fundamentally different strategies with a common mechanism to cleave carbon-halogen bonds whereby, an active-site carboxylate group attacks the substrate C atom bound to the halogen atom to form an ester intermediate and a halide ion with subsequent hydrolysis of the intermediate. Structurally, these dehalogenases have been characterized and shown to use substitution mechanisms that proceed via a covalent aspartyl intermediate. More so, the widest dehalogenation spectrum of electron acceptors tested with bacterial strains which could dehalogenate recalcitrant organohalides has further proven the versatility of bacterial dehalogenators to be considered when determining the fate of halogenated organics at contaminated sites. In this review, the general features of most widely studied bacterial dehalogenases, their structural properties, basis of the degradation of organohalides and their derivatives and how they have been improved for various applications is discussed.
Collapse
Affiliation(s)
- Thiau-Fu Ang
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Jonathan Maiangwa
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Abu Bakar Salleh
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Yahaya M Normi
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - Thean Chor Leow
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Enzyme and Microbial Technology Research Centre, Centre of Excellence, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
- Institute of Bioscience, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| |
Collapse
|
25
|
|
26
|
Marques SM, Dunajova Z, Prokop Z, Chaloupkova R, Brezovsky J, Damborsky J. Catalytic Cycle of Haloalkane Dehalogenases Toward Unnatural Substrates Explored by Computational Modeling. J Chem Inf Model 2017; 57:1970-1989. [PMID: 28696117 DOI: 10.1021/acs.jcim.7b00070] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The anthropogenic toxic compound 1,2,3-trichloropropane is poorly degradable by natural enzymes. We have previously constructed the haloalkane dehalogenase DhaA31 by focused directed evolution ( Pavlova, M. et al. Nat. Chem. Biol. 2009 , 5 , 727 - 733 ), which is 32 times more active than the wild-type enzyme and is currently the most active variant known against that substrate. Recent evidence has shown that the structural basis responsible for the higher activity of DhaA31 was poorly understood. Here we have undertaken a comprehensive computational study of the main steps involved in the biocatalytic hydrolysis of 1,2,3-trichloropropane to decipher the structural basis for such enhancements. Using molecular dynamics and quantum mechanics approaches we have surveyed (i) the substrate binding, (ii) the formation of the reactive complex, (iii) the chemical step, and (iv) the release of the products. We showed that the binding of the substrate and its transport through the molecular tunnel to the active site is a relatively fast process. The cleavage of the carbon-halogen bond was previously identified as the rate-limiting step in the wild-type. Here we demonstrate that this step was enhanced in DhaA31 due to a significantly higher number of reactive configurations of the substrate and a decrease of the energy barrier to the SN2 reaction. C176Y and V245F were identified as the key mutations responsible for most of those improvements. The release of the alcohol product was found to be the rate-limiting step in DhaA31 primarily due to the C176Y mutation. Mutational dissection of DhaA31 and kinetic analysis of the intermediate mutants confirmed the theoretical observations. Overall, our comprehensive computational approach has unveiled mechanistic details of the catalytic cycle which will enable a balanced design of more efficient enzymes. This approach is applicable to deepen the biochemical knowledge of a large number of other systems and may contribute to robust strategies in the development of new biocatalysts.
Collapse
Affiliation(s)
- Sérgio M Marques
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno , Pekarska 53, 656 91 Brno, Czech Republic
| | - Zuzana Dunajova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno , Pekarska 53, 656 91 Brno, Czech Republic
| | - Radka Chaloupkova
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno , Pekarska 53, 656 91 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno , Pekarska 53, 656 91 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University , Kamenice 5/A13, 625 00 Brno, Czech Republic.,International Clinical Research Center, St. Anne's University Hospital Brno , Pekarska 53, 656 91 Brno, Czech Republic
| |
Collapse
|
27
|
Tang X, Wang J, Zhao N, Zhang Q, Wang W. Theoretical study on the hydrolytic step in the biotransformation of β-hexachlorocyclohexane degraded by haloalkane dehalogenase LinB. CAN J CHEM 2017. [DOI: 10.1139/cjc-2016-0653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hydrolytic process of LinB-catalyzed biotransformation of a notorious contaminant β-HCH was investigated in atomistic detail with a combined quantum mechanics/molecular mechanics approach. The Boltzmann-weighted averaging method amended by disproportionate effect analysis was showed to capture the fluctuation of a single molecule enzyme reaction. With the potential barriers of 18.7 and 2.6 kcal/mol, two elementary steps that refer to formation and decomposition of a tetrahedral intermediate are involved in the hydrolytic reaction, respectively. Polarized by Glu132, His272 serves as a proton carrier along the whole hydrolysis reaction. The electrostatic influence analysis highlighted residue Leu248 as a possible mutation target for rational design of LinB in enzyme modification. Further spatial location analysis provided explanation for the opposite effect of Asn38 toward the two elementary steps. Getting insight into the catalytic details and the structure and function of LinB can enrich the knowledge of it and promote its application in bioremediation of chlorinated hydrocarbon pollutants.
Collapse
Affiliation(s)
- Xiaowen Tang
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
| | - Junjie Wang
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
| | - Nan Zhao
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
- Environment Research Institute, Shandong University, Jinan 250100, P. R. China
| |
Collapse
|
28
|
Tang X, Zhang R, Li Y, Zhang Q, Wang W. Enantioselectivity of haloalkane dehalogenase LinB on the degradation of 1,2-dichloropropane: A QM/MM study. Bioorg Chem 2017; 73:16-23. [PMID: 28527381 DOI: 10.1016/j.bioorg.2017.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/08/2017] [Accepted: 04/10/2017] [Indexed: 11/26/2022]
Abstract
The hydrolysis dechlorination mechanism of a chiral organochlorinepollutant, 1,2-dichloropropane (DCP), catalyzed by haloalkane dehalogenase LinB has been investigated by using a combined quantum mechanics/molecular mechanics method. LinB was confirmed to be enantioselective towards the catabolism of the racemic mixture. Based on the SN2 nucleophilic substitution mechanism, the dechlorination process was identified as the rate-determining step in LinB-catalyzed degradation of 1,2-dichloropropane, the Boltzmann-weighted average potential barrier of which is 18.8kcal/mol for the (R)-isomer and 24.0kcal/mol for the (S)-isomer. A particular water molecule near (S)-DCP in the reaction system can strongly disturb the dechlorination process, which can account for the enantioselectivity of LinB. Further electrostatic influence analysis indicates that proper mutation of Gly37 may improve the catalytic efficiency of LinB towards DCP.
Collapse
Affiliation(s)
- Xiaowen Tang
- Environment Research Institute, Shandong University, Jinan 250100, PR China
| | - Ruiming Zhang
- Environment Research Institute, Shandong University, Jinan 250100, PR China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Jinan 250100, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Jinan 250100, PR China.
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Jinan 250100, PR China
| |
Collapse
|
29
|
Kaushik S, Prokop Z, Damborsky J, Chaloupkova R. Kinetics of binding of fluorescent ligands to enzymes with engineered access tunnels. FEBS J 2016; 284:134-148. [DOI: 10.1111/febs.13957] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 09/30/2016] [Accepted: 11/04/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Shubhangi Kaushik
- Loschmidt Laboratories Department of Experimental Biology Research Centre for Toxic Compounds in the Environment (RECETOX) Masaryk University Brno Czech Republic
| | - Zbynek Prokop
- Loschmidt Laboratories Department of Experimental Biology Research Centre for Toxic Compounds in the Environment (RECETOX) Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Jiri Damborsky
- Loschmidt Laboratories Department of Experimental Biology Research Centre for Toxic Compounds in the Environment (RECETOX) Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| | - Radka Chaloupkova
- Loschmidt Laboratories Department of Experimental Biology Research Centre for Toxic Compounds in the Environment (RECETOX) Masaryk University Brno Czech Republic
- International Clinical Research Center St. Anne's University Hospital Brno Czech Republic
| |
Collapse
|
30
|
Gross J, Prokop Z, Janssen D, Faber K, Hall M. Regio- and Enantioselective Sequential Dehalogenation of rac-1,3-Dibromobutane by Haloalkane Dehalogenase LinB. Chembiochem 2016; 17:1437-41. [PMID: 27223496 DOI: 10.1002/cbic.201600227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Indexed: 11/06/2022]
Abstract
The hydrolytic dehalogenation of rac-1,3-dibromobutane catalyzed by the haloalkane dehalogenase LinB from Sphingobium japonicum UT26 proceeds in a sequential fashion: initial formation of intermediate haloalcohols followed by a second hydrolytic step to produce the final diol. Detailed investigation of the course of the reaction revealed favored nucleophilic displacement of the sec-halogen in the first hydrolytic event with pronounced R enantioselectivity. The second hydrolysis step proceeded with a regioselectivity switch at the primary position, with preference for the S enantiomer. Because of complex competition between all eight possible reactions, intermediate haloalcohols formed with moderate to good ee ((S)-4-bromobutan-2-ol: up to 87 %). Similarly, (S)-butane-1,3-diol was formed at a maximum ee of 35 % before full hydrolysis furnished the racemic diol product.
Collapse
Affiliation(s)
- Johannes Gross
- Department of Chemistry, University of Graz, Heinrichstrasse 28, 8010, Graz, Austria
| | - Zbyněk Prokop
- Department Experimental Biology, Faculty of Science, Masaryk University, Kamenice 5A13, 625 00, Brno, Czech Republic
| | - Dick Janssen
- Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, NL
| | - Kurt Faber
- Department of Chemistry, University of Graz, Heinrichstrasse 28, 8010, Graz, Austria
| | - Mélanie Hall
- Department of Chemistry, University of Graz, Heinrichstrasse 28, 8010, Graz, Austria.
| |
Collapse
|
31
|
Discovery of Novel Haloalkane Dehalogenase Inhibitors. Appl Environ Microbiol 2016; 82:1958-1965. [PMID: 26773086 DOI: 10.1128/aem.03916-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/12/2016] [Indexed: 12/27/2022] Open
Abstract
Haloalkane dehalogenases (HLDs) have recently been discovered in a number of bacteria, including symbionts and pathogens of both plants and humans. However, the biological roles of HLDs in these organisms are unclear. The development of efficient HLD inhibitors serving as molecular probes to explore their function would represent an important step toward a better understanding of these interesting enzymes. Here we report the identification of inhibitors for this enzyme family using two different approaches. The first builds on the structures of the enzymes' known substrates and led to the discovery of less potent nonspecific HLD inhibitors. The second approach involved the virtual screening of 150,000 potential inhibitors against the crystal structure of an HLD from the human pathogen Mycobacterium tuberculosis H37Rv. The best inhibitor exhibited high specificity for the target structure, with an inhibition constant of 3 μM and a molecular architecture that clearly differs from those of all known HLD substrates. The new inhibitors will be used to study the natural functions of HLDs in bacteria, to probe their mechanisms, and to achieve their stabilization.
Collapse
|
32
|
Properties and biotechnological applications of natural and engineered haloalkane dehalogenases. Appl Microbiol Biotechnol 2015; 99:9865-81. [DOI: 10.1007/s00253-015-6954-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/19/2015] [Accepted: 08/22/2015] [Indexed: 01/01/2023]
|
33
|
Fung HKH, Gadd MS, Drury TA, Cheung S, Guss JM, Coleman NV, Matthews JM. Biochemical and biophysical characterisation of haloalkane dehalogenases DmrA and DmrB in Mycobacterium strain JS60 and their role in growth on haloalkanes. Mol Microbiol 2015; 97:439-53. [PMID: 25899475 DOI: 10.1111/mmi.13039] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2015] [Indexed: 01/13/2023]
Abstract
Haloalkane dehalogenases (HLDs) catalyse the hydrolysis of haloalkanes to alcohols, offering a biological solution for toxic haloalkane industrial wastes. Hundreds of putative HLD genes have been identified in bacterial genomes, but relatively few enzymes have been characterised. We identified two novel HLDs in the genome of Mycobacterium rhodesiae strain JS60, an isolate from an organochlorine-contaminated site: DmrA and DmrB. Both recombinant enzymes were active against C2-C6 haloalkanes, with a preference for brominated linear substrates. However, DmrA had higher activity against a wider range of substrates. The kinetic parameters of DmrA with 4-bromobutyronitrile as a substrate were Km = 1.9 ± 0.2 mM, kcat = 3.1 ± 0.2 s(-1) . DmrB showed the highest activity against 1-bromohexane. DmrA is monomeric, whereas DmrB is tetrameric. We determined the crystal structure of selenomethionyl DmrA to 1.7 Å resolution. A spacious active site and alternate conformations of a methionine side-chain in the slot access tunnel may contribute to the broad substrate activity of DmrA. We show that M. rhodesiae JS60 can utilise 1-iodopropane, 1-iodobutane and 1-bromobutane as sole carbon and energy sources. This ability appears to be conferred predominantly through DmrA, which shows significantly higher levels of upregulation in response to haloalkanes than DmrB.
Collapse
Affiliation(s)
- Herman K H Fung
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | - Morgan S Gadd
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | - Thomas A Drury
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | - Samantha Cheung
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | - J Mitchell Guss
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | - Nicholas V Coleman
- School of Molecular Bioscience, University of Sydney, Sydney, NSW, 2006, Australia
| | | |
Collapse
|
34
|
Daniel L, Buryska T, Prokop Z, Damborsky J, Brezovsky J. Mechanism-Based Discovery of Novel Substrates of Haloalkane Dehalogenases Using in Silico Screening. J Chem Inf Model 2014; 55:54-62. [DOI: 10.1021/ci500486y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Lukas Daniel
- Loschmidt
Laboratories, Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Tomas Buryska
- Loschmidt
Laboratories, Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Zbynek Prokop
- Loschmidt
Laboratories, Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jiri Damborsky
- Loschmidt
Laboratories, Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| | - Jan Brezovsky
- Loschmidt
Laboratories, Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
| |
Collapse
|
35
|
Salamanca D, Engesser KH. Isolation and characterization of two novel strains capable of using cyclohexane as carbon source. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:12757-12766. [PMID: 24969427 DOI: 10.1007/s11356-014-3206-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/12/2014] [Indexed: 06/03/2023]
Abstract
Two strains capable of degrading cyclohexane were isolated from the soil and sludge of the wastewater treatment plant of the University of Stuttgart and a biotrickling filter system. The strains were classified as gram negative and identified as Acidovorax sp. CHX100 and Chelatococcus sp. CHX1100. Both strains have demonstrated the capability to degrade cycloalkanes (C5-C8), while only strain CHX1100 used as well short linear n-alkanes (C5-C8) as the sole source of carbon and energy. The growth of Acidovorax sp. CHX100 using cyclohexane was much faster compared to Chelatococcus sp. CHX1100. Degenerated primers were optimized from a set sequences of cyclohexanol dehydrogenase genes (chnA) as well as cyclohexanone monooxygenases (chnB) and used to amplify the gene cluster, which encodes the conversion of cyclohexanol to caprolactone. Phylogenetic analysis has indicated that the two gene clusters belong to different groups. The cyclohexane monooxygenase-induced activity which oxidizes also indole to 5-hydroxyindole has indicated the presence of a CYP-type system monooxygenase involved in the transformation of cyclohexane to cyclohexanol.
Collapse
Affiliation(s)
- Diego Salamanca
- Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University of Stuttgart, Bandtäle 2, 70569, Stuttgart, Germany,
| | | |
Collapse
|
36
|
Stepwise enhancement of catalytic performance of haloalkane dehalogenase LinB towards β-hexachlorocyclohexane. AMB Express 2014; 4:72. [PMID: 25401073 PMCID: PMC4230811 DOI: 10.1186/s13568-014-0072-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/18/2014] [Indexed: 11/15/2022] Open
Abstract
Two haloalkane dehalogenases, LinBUT and LinBMI, each with 296 amino acid residues, exhibit only seven amino acid residue differences between them, but LinBMI’s catalytic performance towards β-hexachlorocyclohexane (β-HCH) is considerably higher than LinBUT’s. To elucidate the molecular basis governing this difference, intermediate mutants between LinBUT and LinBMI were constructed and kinetically characterized. The activities of LinBUT-based mutants gradually increased by cumulative mutations into LinBUT, and the effects of the individual amino acid substitutions depended on combination with other mutations. These results indicated that LinBUT’s β-HCH degradation activity can be enhanced in a stepwise manner by the accumulation of point mutations.
Collapse
|
37
|
Wijma HJ, Marrink SJ, Janssen DB. Computationally efficient and accurate enantioselectivity modeling by clusters of molecular dynamics simulations. J Chem Inf Model 2014; 54:2079-92. [PMID: 24916632 DOI: 10.1021/ci500126x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Computational approaches could decrease the need for the laborious high-throughput experimental screening that is often required to improve enzymes by mutagenesis. Here, we report that using multiple short molecular dynamics (MD) simulations makes it possible to accurately model enantioselectivity for large numbers of enzyme-substrate combinations at low computational costs. We chose four different haloalkane dehalogenases as model systems because of the availability of a large set of experimental data on the enantioselective conversion of 45 different substrates. To model the enantioselectivity, we quantified the frequency of occurrence of catalytically productive conformations (near attack conformations) for pairs of enantiomers during MD simulations. We found that the angle of nucleophilic attack that leads to carbon-halogen bond cleavage was a critical variable that limited the occurrence of productive conformations; enantiomers for which this angle reached values close to 180° were preferentially converted. A cluster of 20-40 very short (10 ps) MD simulations allowed adequate conformational sampling and resulted in much better agreement to experimental enantioselectivities than single long MD simulations (22 ns), while the computational costs were 50-100 fold lower. With single long MD simulations, the dynamics of enzyme-substrate complexes remained confined to a conformational subspace that rarely changed significantly, whereas with multiple short MD simulations a larger diversity of conformations of enzyme-substrate complexes was observed.
Collapse
Affiliation(s)
- Hein J Wijma
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | | | | |
Collapse
|
38
|
Chaloupkova R, Prudnikova T, Rezacova P, Prokop Z, Koudelakova T, Daniel L, Brezovsky J, Ikeda-Ohtsubo W, Sato Y, Kuty M, Nagata Y, Kuta Smatanova I, Damborsky J. Structural and functional analysis of a novel haloalkane dehalogenase with two halide-binding sites. ACTA ACUST UNITED AC 2014; 70:1884-97. [DOI: 10.1107/s1399004714009018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 04/21/2014] [Indexed: 11/10/2022]
Abstract
The crystal structure of the novel haloalkane dehalogenase DbeA fromBradyrhizobium elkaniiUSDA94 revealed the presence of two chloride ions buried in the protein interior. The first halide-binding site is involved in substrate binding and is present in all structurally characterized haloalkane dehalogenases. The second halide-binding site is unique to DbeA. To elucidate the role of the second halide-binding site in enzyme functionality, a two-point mutant lacking this site was constructed and characterized. These substitutions resulted in a shift in the substrate-specificity class and were accompanied by a decrease in enzyme activity, stability and the elimination of substrate inhibition. The changes in enzyme catalytic activity were attributed to deceleration of the rate-limiting hydrolytic step mediated by the lower basicity of the catalytic histidine.
Collapse
|
39
|
Floor RJ, Wijma HJ, Colpa DI, Ramos-Silva A, Jekel PA, Szymański W, Feringa BL, Marrink SJ, Janssen DB. Computational library design for increasing haloalkane dehalogenase stability. Chembiochem 2014; 15:1660-72. [PMID: 24976371 DOI: 10.1002/cbic.201402128] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Indexed: 11/05/2022]
Abstract
We explored the use of a computational design framework for the stabilization of the haloalkane dehalogenase LinB. Energy calculations, disulfide bond design, molecular dynamics simulations, and rational inspection of mutant structures predicted many stabilizing mutations. Screening of these in small mutant libraries led to the discovery of seventeen point mutations and one disulfide bond that enhanced thermostability. Mutations located in or contacting flexible regions of the protein had a larger stabilizing effect than mutations outside such regions. The combined introduction of twelve stabilizing mutations resulted in a LinB mutant with a 23 °C increase in apparent melting temperature (Tm,app , 72.5 °C) and an over 200-fold longer half-life at 60 °C. The most stable LinB variants also displayed increased compatibility with co-solvents, thus allowing substrate conversion and kinetic resolution at much higher concentrations than with the wild-type enzyme.
Collapse
Affiliation(s)
- Robert J Floor
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen (The Netherlands)
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Novak HR, Sayer C, Isupov MN, Gotz D, Spragg AM, Littlechild JA. Biochemical and structural characterisation of a haloalkane dehalogenase from a marineRhodobacteraceae. FEBS Lett 2014; 588:1616-22. [DOI: 10.1016/j.febslet.2014.02.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 10/25/2022]
|
41
|
Hladilkova J, Prokop Z, Chaloupkova R, Damborsky J, Jungwirth P. Release of halide ions from the buried active site of the haloalkane dehalogenase LinB revealed by stopped-flow fluorescence analysis and free energy calculations. J Phys Chem B 2013; 117:14329-35. [PMID: 24151979 DOI: 10.1021/jp409040u] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Release of halide ions is an essential step of the catalytic cycle of haloalkane dehalogenases. Here we describe experimentally and computationally the process of release of a halide anion from the buried active site of the haloalkane dehalogenase LinB. Using stopped-flow fluorescence analysis and umbrella sampling free energy calculations, we show that the anion binding is ion-specific and follows the ordering I(-) > Br(-) > Cl(-). We also address the issue of the protonation state of the catalytic His272 residue and its effect on the process of halide release. While deprotonation of His272 increases binding of anions in the access tunnel, we show that the anionic ordering does not change with the switch of the protonation state. We also demonstrate that a sodium cation could relatively easily enter the active site, provided the His272 residue is singly protonated, and replace thus the missing proton. In contrast, Na(+) is strongly repelled from the active site containing the doubly protonated His272 residue. Our study contributes toward understanding of the reaction mechanism of haloalkane dehalogenase enzyme family. Determination of the protonation state of the catalytic histidine throughout the catalytic cycle remains a challenge for future studies.
Collapse
Affiliation(s)
- Jana Hladilkova
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Flemingovo nam. 2, 16610 Prague 6, Czech Republic
| | | | | | | | | |
Collapse
|
42
|
Štěpánková V, Paterová J, Damborský J, Jungwirth P, Chaloupková R, Heyda J. Cation-Specific Effects on Enzymatic Catalysis Driven by Interactions at the Tunnel Mouth. J Phys Chem B 2013; 117:6394-402. [DOI: 10.1021/jp401506v] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Veronika Štěpánková
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Masaryk University, Kamenice
5/A13, 625 00 Brno, Czech Republic
- International Clinical Research
Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Jana Paterová
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Jiří Damborský
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Masaryk University, Kamenice
5/A13, 625 00 Brno, Czech Republic
- International Clinical Research
Center, St. Anne’s University Hospital Brno, Pekarska 53, 656 91 Brno, Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| | - Radka Chaloupková
- Loschmidt Laboratories,
Department
of Experimental Biology and Research Centre for Toxic Compounds in
the Environment, Masaryk University, Kamenice
5/A13, 625 00 Brno, Czech Republic
| | - Jan Heyda
- Institute of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
| |
Collapse
|
43
|
Hasan K, Gora A, Brezovsky J, Chaloupkova R, Moskalikova H, Fortova A, Nagata Y, Damborsky J, Prokop Z. The effect of a unique halide-stabilizing residue on the catalytic properties of haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58. FEBS J 2013; 280:3149-59. [PMID: 23490078 DOI: 10.1111/febs.12238] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/05/2013] [Accepted: 03/06/2013] [Indexed: 11/28/2022]
Abstract
Haloalkane dehalogenases catalyze the hydrolysis of carbon-halogen bonds in various chlorinated, brominated and iodinated compounds. These enzymes have a conserved pair of halide-stabilizing residues that are important in substrate binding and stabilization of the transition state and the halide ion product via hydrogen bonding. In all previously known haloalkane dehalogenases, these residues are either a pair of tryptophans or a tryptophan-asparagine pair. The newly-isolated haloalkane dehalogenase DatA from Agrobacterium tumefaciens C58 (EC 3.8.1.5) possesses a unique halide-stabilizing tyrosine residue, Y109, in place of the conventional tryptophan. A variant of DatA with the Y109W mutation was created and the effects of this mutation on the structure and catalytic properties of the enzyme were studied using spectroscopy and pre-steady-state kinetic experiments. Quantum mechanical and molecular dynamics calculations were used to obtain a detailed analysis of the hydrogen-bonding patterns within the active sites of the wild-type and the mutant, as well as of the stabilization of the ligands as the reaction proceeds. Fluorescence quenching experiments suggested that replacing the tyrosine with tryptophan improves halide binding by 3.7-fold, presumably as a result of the introduction of an additional hydrogen bond. Kinetic analysis revealed that the mutation affected the substrate specificity of the enzyme and reduced its K(0.5) for selected halogenated substrates by a factor of 2-4, without impacting the rate-determining hydrolytic step. We conclude that DatA is the first natural haloalkane dehalogenase that stabilizes its substrate in the active site using only a single hydrogen bond, which is a new paradigm in catalysis by this enzyme family.
Collapse
Affiliation(s)
- Khomaini Hasan
- Loschmidt Laboratories, Department of Experimental Biology and Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Brno, Czech Republic
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Crystal structure and site-directed mutagenesis analyses of haloalkane dehalogenase LinB from Sphingobium sp. strain MI1205. J Bacteriol 2013; 195:2642-51. [PMID: 23564170 DOI: 10.1128/jb.02020-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The enzymes LinB(UT) and LinB(MI) (LinB from Sphingobium japonicum UT26 and Sphingobium sp. MI1205, respectively) catalyze the hydrolytic dechlorination of β-hexachlorocyclohexane (β-HCH) and yield different products, 2,3,4,5,6-pentachlorocyclohexanol (PCHL) and 2,3,5,6-tetrachlorocyclohexane-1,4-diol (TCDL), respectively, despite their 98% identity in amino acid sequence. To reveal the structural basis of their different enzymatic properties, we performed site-directed mutagenesis and X-ray crystallographic studies of LinB(MI) and its seven point mutants. The mutation analysis revealed that the seven amino acid residues uniquely found in LinB(MI) were categorized into three groups based on the efficiency of the first-step (from β-HCH to PCHL) and second-step (from PCHL to TCDL) conversions. Crystal structure analyses of wild-type LinB(MI) and its seven point mutants indicated how each mutated residue contributed to the first- and second-step conversions by LinB(MI). The dynamics simulation analyses of wild-type LinB(MI) and LinB(UT) revealed that the entrance of the substrate access tunnel of LinB(UT) was more flexible than that of LinB(MI), which could lead to the different efficiencies of dehalogenation activity between these dehalogenases.
Collapse
|
45
|
Eremeeva EV, Natashin PV, Song L, Zhou Y, van Berkel WJH, Liu ZJ, Vysotski ES. Oxygen activation of apo-obelin-coelenterazine complex. Chembiochem 2013; 14:739-45. [PMID: 23494831 DOI: 10.1002/cbic.201300002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2013] [Indexed: 11/09/2022]
Abstract
Ca(2+) -regulated photoproteins use a noncovalently bound 2-hydroperoxycoelenterazine ligand to emit light in response to Ca(2+) binding. To better understand the mechanism of formation of active photoprotein from apoprotein, coelenterazine and molecular oxygen, we investigated the spectral properties of the anaerobic apo-obelin-coelenterazine complex and the kinetics of its conversion into active photoprotein after exposure to air. Our studies suggest that coelenterazine bound within the anaerobic complex might be a mixture of N7-protonated and C2(-) anionic forms, and that oxygen shifts the equilibrium in favor of the C2(-) anion as a result of peroxy anion formation. Proton removal from N7 and further protonation of peroxy anion and the resulting formation of 2-hydroperoxycoelenterazine in obelin might occur with the assistance of His175. It is proposed that this conserved His residue might play a key role both in formation of active photoprotein and in Ca(2+) -triggering of the bioluminescence reaction.
Collapse
Affiliation(s)
- Elena V Eremeeva
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
| | | | | | | | | | | | | |
Collapse
|
46
|
Biedermannová L, Prokop Z, Gora A, Chovancová E, Kovács M, Damborsky J, Wade RC. A single mutation in a tunnel to the active site changes the mechanism and kinetics of product release in haloalkane dehalogenase LinB. J Biol Chem 2012; 287:29062-74. [PMID: 22745119 DOI: 10.1074/jbc.m112.377853] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many enzymes have buried active sites. The properties of the tunnels connecting the active site with bulk solvent affect ligand binding and unbinding and also the catalytic properties. Here, we investigate ligand passage in the haloalkane dehalogenase enzyme LinB and the effect of replacing leucine by a bulky tryptophan at a tunnel-lining position. Transient kinetic experiments show that the mutation significantly slows down the rate of product release. Moreover, the mechanism of bromide ion release is changed from a one-step process in the wild type enzyme to a two-step process in the mutant. The rate constant of bromide ion release corresponds to the overall steady-state turnover rate constant, suggesting that product release became the rate-limiting step of catalysis in the mutant. We explain the experimental findings by investigating the molecular details of the process computationally. Analysis of trajectories from molecular dynamics simulations with a tunnel detection software reveals differences in the tunnels available for ligand egress. Corresponding differences are seen in simulations of product egress using a specialized enhanced sampling technique. The differences in the free energy barriers for egress of a bromide ion obtained using potential of mean force calculations are in good agreement with the differences in rates obtained from the transient kinetic experiments. Interactions of the bromide ion with the introduced tryptophan are shown to affect the free energy barrier for its passage. The study demonstrates how the mechanism of an enzymatic catalytic cycle and reaction kinetics can be engineered by modification of protein tunnels.
Collapse
Affiliation(s)
- Lada Biedermannová
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany.
| | | | | | | | | | | | | |
Collapse
|
47
|
Westerbeek A, Szymański W, Wijma HJ, Marrink SJ, Feringa BL, Janssen DB. Kinetic Resolution of α-Bromoamides: Experimental and Theoretical Investigation of Highly Enantioselective Reactions Catalyzed by Haloalkane Dehalogenases. Adv Synth Catal 2011. [DOI: 10.1002/adsc.201000726] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
48
|
Abhilash PC, Srivastava S, Singh N. Comparative bioremediation potential of four rhizospheric microbial species against lindane. CHEMOSPHERE 2011; 82:56-63. [PMID: 21044795 DOI: 10.1016/j.chemosphere.2010.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 07/25/2010] [Accepted: 10/03/2010] [Indexed: 05/30/2023]
Abstract
Four microbial species (Kocuria rhizophila, Microbacterium resistens, Staphylococcus equorum and Staphylococcus cohnii subspecies urealyticus) were isolated from the rhizospheric zone of selected plants growing in a lindane contaminated environment and acclimatized in lindane spiked media (5-100 μg mL⁻¹). The isolated species were inoculated with soil containing 5, 50 and 100 mg kg⁻¹ of lindane and incubated at room temperature. Soil samples were collected periodically to evaluate the microbial dissipation kinetics, dissipation rate, residual lindane concentration and microbial biomass carbon (MBC). There was a marked difference (p < 0.05) in the MBC content and lindane dissipation rate of microbial isolates cultured in three different lindane concentrations. Further, the dissipation rate tended to decrease with increasing lindane concentrations. After 45 d, the residual lindane concentrations in three different spiked soils were reduced to 0%, 41% and 33%, respectively. Among the four species, S. cohnii subspecies urealyticus exhibited maximum dissipation (41.65 mg kg⁻¹) and can be exploited for the in situ remediation of low to medium level lindane contaminated soils.
Collapse
Affiliation(s)
- P C Abhilash
- National Botanical Research Institute, Lucknow, Uttar Pradesh, India.
| | | | | |
Collapse
|
49
|
Cofactor-independent oxidases and oxygenases. Appl Microbiol Biotechnol 2010; 86:791-804. [DOI: 10.1007/s00253-010-2455-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 01/14/2010] [Accepted: 01/14/2010] [Indexed: 10/19/2022]
|
50
|
Pavlova M, Klvana M, Prokop Z, Chaloupkova R, Banas P, Otyepka M, Wade RC, Tsuda M, Nagata Y, Damborsky J. Redesigning dehalogenase access tunnels as a strategy for degrading an anthropogenic substrate. Nat Chem Biol 2009; 5:727-33. [PMID: 19701186 DOI: 10.1038/nchembio.205] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Accepted: 05/28/2009] [Indexed: 01/17/2023]
Abstract
Engineering enzymes to degrade anthropogenic compounds efficiently is challenging. We obtained Rhodococcus rhodochrous haloalkane dehalogenase mutants with up to 32-fold higher activity than wild type toward the toxic, recalcitrant anthropogenic compound 1,2,3-trichloropropane (TCP) using a new strategy. We identified key residues in access tunnels connecting the buried active site with bulk solvent by rational design and randomized them by directed evolution. The most active mutant has large aromatic residues at two out of three randomized positions and two positions modified by site-directed mutagenesis. These changes apparently enhance activity with TCP by decreasing accessibility of the active site for water molecules, thereby promoting activated complex formation. Kinetic analyses confirmed that the mutations improved carbon-halogen bond cleavage and shifted the rate-limiting step to the release of products. Engineering access tunnels by combining computer-assisted protein design with directed evolution may be a valuable strategy for refining catalytic properties of enzymes with buried active sites.
Collapse
Affiliation(s)
- Martina Pavlova
- Loschmidt Laboratories, Institute of Experimental Biology and National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | | | | | | | | | | | | | | | | | | |
Collapse
|