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Ranjan B, Choi PH, Pillai S, Permaul K, Tong L, Singh S. Crystal structure of a thermophilic fungal cyanase and its implications on the catalytic mechanism for bioremediation. Sci Rep 2021; 11:277. [PMID: 33431973 PMCID: PMC7801690 DOI: 10.1038/s41598-020-79489-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 09/04/2020] [Indexed: 11/22/2022] Open
Abstract
Cyanase catalyzes the bicarbonate-dependent degradation of cyanate to produce ammonia and carbon dioxide, and ammonia is a considerable alternative nitrogen source. Strikingly, the cyanase from the thermophilic fungus Thermomyces lanuginosus (Tl-Cyn) has the highest catalytic efficiency reported among these enzymes. However, its molecular mechanism of action is not clearly understood, because currently there is no structural information available on fungal cyanases. Here we report the crystal structure of Tl-Cyn in complex with inhibitors malonate and formate at 2.2 Å resolution. The structure reveals extensive interactions at the subunit interfaces in a dimer, and a decamer is formed by a pentamer of these dimers. Our biochemical, kinetic and mutagenesis studies confirm the structural observations on the complex and provide further insights into its catalytic mechanism and inhibition. The structure has also aided the creation of a mutant enzyme with enhanced catalytic activity, and such enzymes may have the potential for biotechnological applications, including biotransformation and bioremediation. Moreover, other fungal cyanases with potentially high catalytic activity could also be predicted based on the Tl-Cyn structure, as the active site region among fungal cyanases are highly conserved.
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Affiliation(s)
- Bibhuti Ranjan
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, 4000, South Africa
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Santhosh Pillai
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, 4000, South Africa
| | - Kugenthiren Permaul
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, 4000, South Africa
| | - Liang Tong
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, 4000, South Africa.
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
| | - Suren Singh
- Department of Biotechnology and Food Science, Faculty of Applied Sciences, Durban University of Technology, Durban, 4000, South Africa.
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2
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Sáez LP, Cabello P, Ibáñez MI, Luque-Almagro VM, Roldán MD, Moreno-Vivián C. Cyanate Assimilation by the Alkaliphilic Cyanide-Degrading Bacterium Pseudomonas pseudoalcaligenes CECT5344: Mutational Analysis of the cyn Gene Cluster. Int J Mol Sci 2019; 20:ijms20123008. [PMID: 31226739 PMCID: PMC6627978 DOI: 10.3390/ijms20123008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/07/2019] [Accepted: 06/18/2019] [Indexed: 11/20/2022] Open
Abstract
The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 can grow with cyanate, cyanide, or cyanide-containing industrial residues as the sole nitrogen source, but the assimilation of cyanide and cyanate takes place through independent pathways. Therefore, cyanide degradation involves a chemical reaction between cyanide and oxaloacetate to form a nitrile that is hydrolyzed to ammonium by the nitrilase NitC, whereas cyanate assimilation requires a cyanase that catalyzes cyanate decomposition to ammonium and carbon dioxide. The P. pseudoalcaligenes CECT5344 cynFABDS gene cluster codes for the putative transcriptional regulator CynF, the ABC-type cyanate transporter CynABD, and the cyanase CynS. In this study, transcriptional analysis revealed that the structural cynABDS genes constitute a single transcriptional unit, which was induced by cyanate and repressed by ammonium. Mutational characterization of the cyn genes indicated that CynF was essential for cynABDS gene expression and that nitrate/nitrite transporters may be involved in cyanate uptake, in addition to the CynABD transport system. Biodegradation of hazardous jewelry wastewater containing high amounts of cyanide and metals was achieved in a batch reactor operating at an alkaline pH after chemical treatment with hydrogen peroxide to oxidize cyanide to cyanate.
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Affiliation(s)
- Lara Paloma Sáez
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
| | - Purificación Cabello
- Departamento de Botánica, Ecología y Fisiología Vegetal, Edificio Celestino Mutis, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
| | - María Isabel Ibáñez
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
| | - Víctor Manuel Luque-Almagro
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
| | - María Dolores Roldán
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
| | - Conrado Moreno-Vivián
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, 1ª Planta, Campus de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain.
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3
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Kebeish R, Al-Zoubi O. Expression of the cyanobacterial enzyme cyanase increases cyanate metabolism and cyanate tolerance in Arabidopsis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:11825-11835. [PMID: 28343358 DOI: 10.1007/s11356-017-8866-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 03/17/2017] [Indexed: 06/06/2023]
Abstract
Cyanate and its derivatives are considered as environmental hazardous materials. Cyanate is released to the environment through many chemical industries and mining wastewater. Cyanase enzyme converts cyanate into CO2 and NH3 in a bicarbonate-dependent reaction. At low cyanate concentrations, the endogenous plant cyanases play a vital role in cyanate detoxification. However, such cyanate biodegradation system is probably insufficient due to the excess cyanate concentrations at contaminated sites. In this study, we have transferred the activity of the cyanobacterial cyanase into Arabidopsis thaliana plants in order to enhance plant resistance against cyanate toxicity. The enzyme was shown to be active in planta. Transgenic plants exposed to cyanate, either applied by foliar spray or supplemented in growth medium, showed less reduction in pigment contents, antioxidant enzymes, carbohydrate contents, and reduced levels of plant growth retardation. Plant growth assays under cyanate stress showed enhanced growth and biomass accumulation in cyanase overexpressors compared to control plants. Results of this study provide evidence for developing novel eco-friendly phytoremediation systems for cyanate detoxification.
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Affiliation(s)
- Rashad Kebeish
- Biology Department, Faculty of Science Yanbu, Taibah University, KSA, King Khalid Rd, Al amoedi, Yanbu El-Bahr, 46423, Saudi Arabia.
- Plant Biotechnology Laboratory (PBL), Botany and Microbiology Department, Faculty of Science, Zagazig University, El-Gamaa Street 1, Zagazig, Sharkia, 44519, Egypt.
| | - Omar Al-Zoubi
- Biology Department, Faculty of Science Yanbu, Taibah University, KSA, King Khalid Rd, Al amoedi, Yanbu El-Bahr, 46423, Saudi Arabia
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4
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Čobeljić B, Milenković M, Pevec A, Turel I, Vujčić M, Janović B, Gligorijević N, Sladić D, Radulović S, Jovanović K, Anđelković K. Investigation of antitumor potential of Ni(II) complexes with tridentate PNO acylhydrazones of 2-(diphenylphosphino)benzaldehyde and monodentate pseudohalides. J Biol Inorg Chem 2015; 21:145-62. [PMID: 26612231 DOI: 10.1007/s00775-015-1315-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/14/2015] [Indexed: 02/04/2023]
Abstract
Square-planar azido Ni(II) complex with condensation product of 2-(diphenylphosphino)benzaldehyde and Girard's T reagent was synthesized and its crystal structure was determined. Cytotoxic activity of the azido complex and previously synthesized isothiocyanato, cyanato and chlorido Ni(II) complexes with this ligand was examined on six tumor cell lines (HeLa, A549, K562, MDA-MB-453, MDA-MB-361 and LS-174) and two normal cell line (MRC-5 and BEAS-2B). All the investigated nickel(II) complexes were cytotoxic against all tumor cell lines. The newly synthesized azido complex showed selectivity to HeLa and A549 tumor cell lines compared to the normal cells (for A549 IC50 was similar to that of cisplatin). Azido complex interferes with cell cycle phase distribution of A549 and HeLa cells and possesses nuclease activity towards supercoiled DNA. The observed selectivity of the azido complex for some tumor cell lines can be connected with its strong DNA damaging activity.
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Affiliation(s)
- Božidar Čobeljić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia
| | - Milica Milenković
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia
| | - Andrej Pevec
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Iztok Turel
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Miroslava Vujčić
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, P.O. Box 815, 11000, Belgrade, Serbia
| | - Barbara Janović
- Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Njegoševa 12, P.O. Box 815, 11000, Belgrade, Serbia
| | - Nevenka Gligorijević
- Laboratory for Experimental Pharmacology, Department of Experimental Oncology, Institute for Oncology and Radiology of Serbia, Pasterova 14, Belgrade, Serbia
| | - Dušan Sladić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia
| | - Siniša Radulović
- Laboratory for Experimental Pharmacology, Department of Experimental Oncology, Institute for Oncology and Radiology of Serbia, Pasterova 14, Belgrade, Serbia
| | - Katarina Jovanović
- Laboratory for Experimental Pharmacology, Department of Experimental Oncology, Institute for Oncology and Radiology of Serbia, Pasterova 14, Belgrade, Serbia
| | - Katarina Anđelković
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11000, Belgrade, Serbia.
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Widner B, Mulholland MR, Mopper K. Chromatographic Determination of Nanomolar Cyanate Concentrations in Estuarine and Sea Waters by Precolumn Fluorescence Derivatization. Anal Chem 2013; 85:6661-6. [DOI: 10.1021/ac400351c] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brittany Widner
- Department of Ocean,
Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn
Ave. Norfolk, Virginia 23529, United States
| | - Margaret R. Mulholland
- Department of Ocean,
Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn
Ave. Norfolk, Virginia 23529, United States
| | - Kenneth Mopper
- Department of Ocean,
Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn
Ave. Norfolk, Virginia 23529, United States
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Spang A, Poehlein A, Offre P, Zumbrägel S, Haider S, Rychlik N, Nowka B, Schmeisser C, Lebedeva EV, Rattei T, Böhm C, Schmid M, Galushko A, Hatzenpichler R, Weinmaier T, Daniel R, Schleper C, Spieck E, Streit W, Wagner M. The genome of the ammonia-oxidizing Candidatus Nitrososphaera gargensis: insights into metabolic versatility and environmental adaptations. Environ Microbiol 2012; 14:3122-45. [PMID: 23057602 DOI: 10.1111/j.1462-2920.2012.02893.x] [Citation(s) in RCA: 217] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 09/01/2012] [Indexed: 01/21/2023]
Abstract
The cohort of the ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota is a diverse, widespread and functionally important group of microorganisms in many ecosystems. However, our understanding of their biology is still very rudimentary in part because all available genome sequences of this phylum are from members of the Nitrosopumilus cluster. Here we report on the complete genome sequence of Candidatus Nitrososphaera gargensis obtained from an enrichment culture, representing a different evolutionary lineage of AOA frequently found in high numbers in many terrestrial environments. With its 2.83 Mb the genome is much larger than that of other AOA. The presence of a high number of (active) IS elements/transposases, genomic islands, gene duplications and a complete CRISPR/Cas defence system testifies to its dynamic evolution consistent with low degree of synteny with other thaumarchaeal genomes. As expected, the repertoire of conserved enzymes proposed to be required for archaeal ammonia oxidation is encoded by N. gargensis, but it can also use urea and possibly cyanate as alternative ammonia sources. Furthermore, its carbon metabolism is more flexible at the central pyruvate switch point, encompasses the ability to take up small organic compounds and might even include an oxidative pentose phosphate pathway. Furthermore, we show that thaumarchaeota produce cofactor F420 as well as polyhydroxyalkanoates. Lateral gene transfer from bacteria and euryarchaeota has contributed to the metabolic versatility of N. gargensis. This organisms is well adapted to its niche in a heavy metal-containing thermal spring by encoding a multitude of heavy metal resistance genes, chaperones and mannosylglycerate as compatible solute and has the genetic ability to respond to environmental changes by signal transduction via a large number of two-component systems, by chemotaxis and flagella-mediated motility and possibly even by gas vacuole formation. These findings extend our understanding of thaumarchaeal evolution and physiology and offer many testable hypotheses for future experimental research on these nitrifiers.
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Affiliation(s)
- Anja Spang
- Department of Genetics in Ecology, University of Vienna, Althanstr. 14, 1090, Vienna, Austria
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7
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Pieniazek A, Brzeszczynska J, Kruszynska I, Gwozdzinski K. Investigation of albumin properties in patients with chronic renal failure. Free Radic Res 2009; 43:1008-18. [DOI: 10.1080/10715760903165003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Characterization of the Pseudomonas pseudoalcaligenes CECT5344 Cyanase, an enzyme that is not essential for cyanide assimilation. Appl Environ Microbiol 2008; 74:6280-8. [PMID: 18708510 DOI: 10.1128/aem.00916-08] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyanase catalyzes the decomposition of cyanate into CO(2) and ammonium, with carbamate as an unstable intermediate. The cyanase of Pseudomonas pseudoalcaligenes CECT5344 was negatively regulated by ammonium and positively regulated by cyanate, cyanide, and some cyanometallic complexes. Cyanase activity was not detected in cell extracts from cells grown with ammonium, even in the presence of cyanate. Nevertheless, a low level of cyanase activity was detected in nitrogen-starved cells. The cyn gene cluster of P. pseudoalcaligenes CECT5344 was cloned and analyzed. The cynA, cynB, and cynD genes encode an ABC-type transporter, the cynS gene codes for the cyanase, and the cynF gene encodes a novel sigma(54)-dependent transcriptional regulator which is not present in other bacterial cyn gene clusters. The CynS protein was expressed in Escherichia coli and purified by following a simple and rapid protocol. The P. pseudoalcaligenes cyanase showed an optimal pH of 8.5 degrees C and a temperature of 65 degrees C. An insertion mutation was generated in the cynS gene. The resulting mutant was unable to use cyanate as the sole nitrogen source but showed the same resistance to cyanate as the wild-type strain. These results, in conjunction with the induction pattern of the enzymatic activity, suggest that the enzyme has an assimilatory function. Although the induction of cyanase activity in cyanide-degrading cells suggests that some cyanate may be generated from cyanide, the cynS mutant was not affected in its ability to degrade cyanide, which unambiguously indicates that cyanate is not a central metabolite in cyanide assimilation.
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Huang CW, Huang CC, Huang MH, Wu SN, Hsieh YJ. Sodium cyanate-induced opening of calcium-activated potassium currents in hippocampal neuron-derived H19-7 cells. Neurosci Lett 2005; 377:110-4. [PMID: 15740847 DOI: 10.1016/j.neulet.2004.11.081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Revised: 11/23/2004] [Accepted: 11/23/2004] [Indexed: 11/18/2022]
Abstract
We investigated the chemical toxic agent sodium cyanate (NaOCN) on the large conductance calcium-activated potassium channels (BK(Ca)) on hippocampal neuron-derived H19-7 cells. The whole-cell and cell-attach configuration of patch-clamp technique were applied to investigate the BK(Ca) currents in H19-7 cells in the presence of NaOCN (0.3 mM). NaOCN activated BK(Ca) channels on H19-7 cells. The single-channel conductance of BK(Ca) channels was 138+/-7pS. The presence of NaOCN (0.3 mM) caused an obvious increase in open probability of BK(Ca) channels. NaOCN did not exert effect on the slope of the activation curve and stimulated the activity of BK(Ca) channels in a voltage-dependent fashion in H19-7 cells. The presence of paxilline or EGTA significantly reduced the BK(Ca) amplitude, in comparison with the presence of NaOCN. These findings suggest that during NaOCN exposure, the activation of BK(Ca) channels in neurons could be one of the ionic mechanisms underlying the decreased neuronal excitability and neurological disorders.
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Affiliation(s)
- Chin-Wei Huang
- Department of Neurology, National Cheng-Kung University Medical Center, No. 1, University Road, Tainan, Taiwan
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Koshiishi I, Imanari T. Quantification of carbamylated dehydroascorbate derivative produced from cyanate and dehydroascorbate. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1998; 709:150-6. [PMID: 9653937 DOI: 10.1016/s0378-4347(98)00044-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We established a high-performance liquid chromatographic method for separating and quantifying carbamylated dehydroascorbate derivative (CDA), a reaction product of cyanate with dehydroascorbate. The separation of CDA from interfering substances was achieved by anion-exchange HPLC using a TSK gel SAX (250x4.6 mm I.D.) column and 0.12 M NaCl eluent. The detection of CDA was achieved through two steps: (1) degradation of CDA to cyanate and amino compounds in alkaline solution, and (2) detection of these products by an indophenol reaction. For the processing of plasma and urine samples, anion-exchange solid-phase extraction was used. The detection limit for quantitative determination was 0.1 microM CDA (S/N=3). The linear range found applying the optimized conditions was 0.2 to 200 microM. The intra- and inter-day assay precision (R.S.D.) of CDA (10 microM) were 4.8 and 7.2% for rat plasma, and 4.0 and 4.9% for rat urine, respectively. The usefulness of the present method was proved by the application to plasma and urine samples. The study of the biokinetics of CDA in rats revealed that the elimination of CDA is due to urinary excretion.
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Affiliation(s)
- I Koshiishi
- Faculty of Pharmaceutical Sciences, Chiba University, Japan
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Koshiishi I, Mamura Y, Imanari T. Simultaneous determination of vitamin C and its carbamylated derivatives by high-performance liquid chromatography with post-column derivatization. J Chromatogr A 1998. [DOI: 10.1016/s0021-9673(98)00074-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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