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Illeová V, Šefčík J, Polakovič M. Thermal inactivation of jack bean urease. Int J Biol Macromol 2020; 151:1084-1090. [PMID: 31739065 DOI: 10.1016/j.ijbiomac.2019.10.150] [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: 07/30/2019] [Revised: 10/16/2019] [Accepted: 10/16/2019] [Indexed: 10/25/2022]
Abstract
Thermal inactivation of oligomeric enzymes results in complex structural changes. This work deals with thermal inactivation of a native hexamer, jack bean urease. In order to find the mechanism and kinetics of thermal inactivation corresponding well with the modification of tertiary and quaternary structure of this enzyme, several types of experiments were carried out in the temperature range of 65-85 °C. Inactivation data exhibited the characteristic biphasic character. Dynamic light scattering experiments revealed a significant increase of the mean hydrodynamic radius of urease with temperature and time. A significant contribution to understanding the mechanism of inactivation was provided by native gel electrophoresis data of inactivated samples. Simultaneous fit of inactivation data verified a two-step mechanism composed of reversible unfolding/folding reaction followed by a relatively fast aggregation of the denatured urease form. A complex reaction scheme containing numerous oligomeric forms was thus described by a relatively simple model which suitably represents the main types of reactions involved in the urease activity loss.
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Affiliation(s)
- Viera Illeová
- Department of Chemical and Environmental Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovakia
| | - Ján Šefčík
- Department of Chemical and Process Engineering, University of Strathclyde, 75 Montrose Street, Glasgow G1 1XJ, United Kingdom
| | - Milan Polakovič
- Department of Chemical and Environmental Engineering, Institute of Chemical and Environmental Engineering, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovakia.
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2
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Multipoint TvDAAO Mutants for Cephalosporin C Bioconversion. Int J Mol Sci 2019; 20:ijms20184412. [PMID: 31500317 PMCID: PMC6770189 DOI: 10.3390/ijms20184412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/29/2019] [Accepted: 09/04/2019] [Indexed: 12/05/2022] Open
Abstract
d-amino acid oxidase (DAAO, EC 1.4.3.3) is used in many biotechnological processes. The main industrial application of DAAO is biocatalytic production of 7-aminocephalosporanic acid from cephalosporin C with a two enzymes system. DAAO from the yeast Trigonopsis variabilis (TvDAAO) shows the best catalytic parameters with cephalosporin C among all known DAAOs. We prepared and characterized multipoint TvDAAO mutants to improve their activity towards cephalosporin C and increase stability. All TvDAAO mutants showed better properties in comparison with the wild-type enzyme. The best mutant was TvDAAO with amino acid changes E32R/F33D/F54S/C108F/M156L/C298N. Compared to wild-type TvDAAO, the mutant enzyme exhibits a 4 times higher catalytic constant for cephalosporin C oxidation and 8- and 20-fold better stability against hydrogen peroxide inactivation and thermal denaturation, respectively. This makes this mutant promising for use in biotechnology. The paper also presents the comparison of TvDAAO catalytic properties with cephalosporin C reported by others.
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Shimekake Y, Furuichi T, Abe K, Kera Y, Takahashi S. A novel thermostable D-amino acid oxidase of the thermophilic fungus Rasamsonia emersonii strain YA. Sci Rep 2019; 9:11948. [PMID: 31420577 PMCID: PMC6697736 DOI: 10.1038/s41598-019-48480-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/06/2019] [Indexed: 11/16/2022] Open
Abstract
d-Amino acid oxidase (DAAO) is a valuable flavoenzyme capable of being used in various practical applications, such as in determining d-amino acids and producing a material for semisynthetic cephalosporins, requiring higher thermal stability, higher catalytic activity, and broad substrate specificity. In this study, we isolated the thermophilic fungus Rasamsonia emersonii strain YA, which can grow on several d-amino acids as the sole nitrogen source, from a compost and characterized DAAO (ReDAAO) of the fungus. ReDAAO expressed in Escherichia coli exhibited significant oxidase activity against various neutral and basic d-amino acids, in particular hydrophobic d-amino acids. In addition, the enzyme also significantly acted on cephalosporin C, a starting material for semisynthetic antibiotics, and d-Glu, a general substrate for d-aspartate oxidase but not for DAAO, showing its unique and practically useful substrate specificity. The apparent kcat and Km values of the enzyme toward good substrates were comparable to those of higher catalytic fungal DAAOs, and the thermal stability (T50 value of ~60 °C) was comparable to that of a thermophilic bacterial DAAO and significantly higher than that of other eukaryotic DAAOs. These results highlight the great potential of ReDAAO for use in practical applications.
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Affiliation(s)
- Yuya Shimekake
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Takehiro Furuichi
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Katsumasa Abe
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Yoshio Kera
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Shouji Takahashi
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan.
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Takahashi S, Osugi K, Shimekake Y, Shinbo A, Abe K, Kera Y. Characterization and improvement of substrate-binding affinity of D-aspartate oxidase of the thermophilic fungus Thermomyces dupontii. Appl Microbiol Biotechnol 2019; 103:4053-4064. [PMID: 30937498 DOI: 10.1007/s00253-019-09787-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 03/05/2019] [Accepted: 03/19/2019] [Indexed: 12/23/2022]
Abstract
D-Aspartate oxidase (DDO) is a valuable enzyme that can be utilized in the determination of acidic D-amino acids and the optical resolution of a racemic mixture of acidic amino acids, which require its higher stability, higher catalytic activity, and higher substrate-binding affinity. In the present study, we identified DDO gene (TdDDO) of a thermophilic fungus, Thermomyces dupontii, and characterized the recombinant enzyme expressed in Escherichia coli. In addition, we generated a variant that has a higher substrate-binding affinity. The recombinant TdDDO expressed in E. coli exhibited oxidase activity toward acidic D-amino acids and a neutral D-amino acid, D-Gln, with the highest activity toward D-Glu. The Km and kcat values for D-Glu were 2.16 mM and 217 s-1, respectively. The enzyme had an optimum pH and temperature 8.0 and 60 °C, respectively, and was stable between pH 5.0 and 10.0, with a T50 of ca. 51 °C, which was much higher than that in DDOs from other origins. Enzyme stability decreased following a decrease in protein concentration, and externally added FAD could not repress the destabilization. The mutation of Phe248, potentially located in the active site of TdDDO, to Tyr residue, conserved in DDOs and D-amino acid oxidases, markedly increased substrate-binding affinity. The results showed the great potential of TdDDO and the variant for practical applications.
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Affiliation(s)
- Shouji Takahashi
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan.
| | - Kohei Osugi
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Yuya Shimekake
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Akira Shinbo
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Katsumasa Abe
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
| | - Yoshio Kera
- Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Niigata, 940-2188, Japan
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Effects of an extra Trp113Tyr substitution on yeast D-amino acid oxidase variant. SPRINGERPLUS 2015. [PMCID: PMC4798228 DOI: 10.1186/2193-1801-4-s2-p6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Du K, Sun J, Song X, Song C, Feng W. Enhancement of the solubility and stability of D-amino acid oxidase by fusion to an elastin like polypeptide. J Biotechnol 2015. [PMID: 26216181 DOI: 10.1016/j.jbiotec.2015.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
An elastin-like polypeptide (ELP) was fused to D-amino acid oxidases (DAAO). ELP-DAAO exhibited a better solubility in aqueous solutions than DAAO, and its enzymatic activity is about 1.6 times that of DAAO. The stability of the proteins was investigated by interacting with urea at various concentrations. The circular dichroism and fluorescence spectra were measured. The results demonstrated that that ELP-DAAO exhibited a much better stability than DAAO, and ELP-DAAO has retained the α-helix content with a high percentage even at a high urea concentration. The results of this work have demonstrated that the ELP tag can be utilized to purify DAAO, in the meantime the solubility and stability of the enzyme are improved.
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Affiliation(s)
- Kun Du
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Jian Sun
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xiaoqiang Song
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Cuidan Song
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | - Wei Feng
- Department of Biochemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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Yoshimoto M, Okamoto M, Ujihashi K, Okita T. Selective oxidation of D-amino acids catalyzed by oligolamellar liposomes intercalated with D-amino acid oxidase. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:6180-6186. [PMID: 24821597 DOI: 10.1021/la500786m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
D-Amino acid oxidase (DAO) is structurally unstable and exhibits broad specificity to D-amino acids. In this work, we fabricated a stable liposomal DAO system with high apparent substrate specificity. Permeability of the membrane composed of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) was highly selective between the d-forms of alanine (Ala) and serine (Ser). The permeability coefficient of d-Ala and d-Ser at 25 °C was 3.59 and 0.27 pm/s, respectively, as determined with the dialysis method. On the other hand, the chiral environment of POPC membrane showed no clear selectivity between the enantiomers of Ala or Ser. POPC liposomes encapsulating DAO from porcine kidney selectively catalyzed the oxidation of hydrophobic D-phenylalanine (D-Phe) over D-Ala and D-Ser because of their intrinsic membrane permeability. As a different type of liposomal DAO, the enzyme molecules were conjugated to the surface of activated lipids-bearing liposomes. The activity of liposome-conjugated DAO showed significantly higher stability at 50 °C than free DAO at low enzyme concentrations ranging from 2.5 to 10 mg/L. Then, the DAO-conjugated liposomes were coated with POPC bilayers to give the oligolamellar structure intercalated with the DAO molecules. The additional bilayers allowed to induce the permeability resistance-based substrate specificity and strengthened the stabilizing effect on the DAO activity. The oligolamellar liposomes fabricated can be a colloidal platform for integrating the functions of lipid membrane to stabilize DAO and to modulate its substrate specificity.
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Affiliation(s)
- Makoto Yoshimoto
- Department of Applied Molecular Bioscience, Yamaguchi University , 2-16-1 Tokiwadai, Ube 755-8611, Japan
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Xu YP, Guan YH, Yu HL, Ni Y, Ma BD, Xu JH. Improved o-chlorobenzoylformate bioreduction by stabilizing aldo-keto reductase YtbE with additives. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.molcatb.2014.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Shaking and stirring: Comparison of controlled laboratory stress conditions applied to the human growth hormone. Process Biochem 2013. [DOI: 10.1016/j.procbio.2012.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Abstract
Oligolamellar phospholipid vesicles incorporated with d-amino acid oxidase from porcine kidney (OV-DAO) were prepared by encapsulating pre-formed enzyme-bound unilamellar vesicles (UV-DAO) with bilayers of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The bilayer of UV-DAO was composed of POPC, 30 mol% of cholesterol and 15 mol% of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(glutaryl) (NGPE) that was responsible for covalent linking to D-amino acid oxidase (DAO). OV-DAO and UV-DAO showed the activity to catalyze the oxidation of D-alanine as measured based on the hydrogen peroxide produced. The oligolamellar and unilamellar structure of OV-DAO and UV-DAO, respectively was elucidated based on the quenching characteristics of bilayers-incorporated fluorescent lipid 7-nitro-2,1,3-benzoxadiazol-4-yl-phosphoethanolamine (NBD-PE) and the size distribution of the vesicles measured with the dynamic light scattering method. The enzyme activity of OV-DAO and UV-DAO was significantly stabilized at 50°C compared to that of free DAO at the fixed enzyme concentration of 3.29 μg/mL. At the temperature, OV-DAO and UV-DAO showed the remaining activity of 52.7 and 29.6%, respectively at the incubation time of 20 min while free DAO was completely deactivated. Thus the dimeric form of DAO could be stabilized by its coupling to the surface of UV-DAO membrane being the inner bilayer of OV-DAO. Furthermore, the thermal denaturation of DAO and dissociation of flavin adenine dinucleotide (FAD) from the subunits of enzyme were prevented in the aqueous phase formed between the bilayers of OV-DAO.
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Grancic P, Illeova V, Polakovic M, Sefcik J. Thermally induced inactivation and aggregation of urease: Experiments and population balance modelling. Chem Eng Sci 2012. [DOI: 10.1016/j.ces.2011.07.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Abad S, Nahalka J, Winkler M, Bergler G, Speight R, Glieder A, Nidetzky B. High-level expression of Rhodotorula gracilis D-amino acid oxidase in Pichia pastoris. Biotechnol Lett 2010; 33:557-63. [PMID: 21053050 DOI: 10.1007/s10529-010-0456-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 10/22/2010] [Indexed: 12/01/2022]
Abstract
By combining gene design and heterologous over-expression of Rhodotorula gracilis D-amino acid oxidase (RgDAO) in Pichia pastoris, enzyme production was enhanced by one order of magnitude compared to literature benchmarks, giving 350 kUnits/l of fed-batch bioreactor culture with a productivity of 3.1 kUnits/l h. P. pastoris cells permeabilized by freeze-drying and incubation in 2-propanol (10% v/v) produce a highly active (1.6 kUnits/g dry matter) and stable oxidase preparation. Critical bottlenecks in the development of an RgDAO catalyst for industrial applications have been eliminated.
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Affiliation(s)
- Sandra Abad
- Austrian Centre of Industrial Biotechnology, Petersgasse 14, Graz, 8010, Austria
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The role of Cys108 in Trigonopsis variabilis d-amino acid oxidase examined through chemical oxidation studies and point mutations C108S and C108D. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1483-91. [DOI: 10.1016/j.bbapap.2010.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 01/19/2010] [Accepted: 02/10/2010] [Indexed: 12/20/2022]
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Wong KS, Fong WP, Tsang PWK. A single Phe54Tyr substitution improves the catalytic activity and thermostability of Trigonopsis variabilis D-amino acid oxidase. N Biotechnol 2009; 27:78-84. [PMID: 19909828 DOI: 10.1016/j.nbt.2009.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 10/07/2009] [Accepted: 11/04/2009] [Indexed: 11/17/2022]
Abstract
The industrial importance of Trigonopsis variabilisd-amino acid oxidase (TvDAAO) is represented by its biocatalytic oxidative deamination of cephalosporin C (CPC) to yield glutaryl-7-aminocephalosporanic acid (GL-7-ACA). The process has been incorporated into a two-step bioconversion to produce 7-aminocephalosporanic acid, the crucial synthetic nucleus for several semi-synthetic cephalosporin antibiotics. A homology model of TvDAAO indicated that residue F54 is in a close proximity to the in silico docked CPC. Substitution of this F54 to Tyr (F54Y) resulted in 6-fold improvement in k(cat,app) and approximately 2.5-fold increase in K(i) of GL-7-ACA. Heat treatment (55 degrees C, 60 min) did not decrease the activity of F54Y. It is suggested that the Tyr substitution might initiate hydrogen bond formation with the amino group of CPC and facilitate deamination. Faster substrate turnover, reduced GL-7-ACA inhibition and improved thermostability of the F54Y substitution render it a useful candidate in industrial production of semi-synthetic cephems.
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Affiliation(s)
- Kin-Sing Wong
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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Slavica A, Ačai P, Riethorst W, Nidetzky B. Study of the thermal stability of D-amino acid oxidase fromTrigonopsis variabilisreveals enzyme inactivation via multiple steps. BIOCATAL BIOTRANSFOR 2009. [DOI: 10.1080/10242420601034025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Dib I, Nidetzky B. The stabilizing effects of immobilization in D-amino acid oxidase from Trigonopsis variabilis. BMC Biotechnol 2008; 8:72. [PMID: 18798979 PMCID: PMC2557008 DOI: 10.1186/1472-6750-8-72] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 09/17/2008] [Indexed: 11/29/2022] Open
Abstract
Background Immobilization of Trigonopsis variabilis D-amino acid oxidase (TvDAO) on solid support is the key to a reasonably stable performance of this enzyme in the industrial process for the conversion of cephalosporin C as well as in other biocatalytic applications. Results To provide a mechanistic basis for the stabilization of the carrier-bound oxidase we analyzed the stabilizing effects of immobilization in TvDAO exposed to the stress of elevated temperature and operational conditions. Two different strategies of immobilization were used: multi-point covalent binding to epoxy-activated Sepabeads EC-EP; and non-covalent oriented immobilization of the enzyme through affinity of its N-terminal Strep-tag to Strep-Tactin coated on insoluble particles. At 50°C, the oriented immobilizate was not stabilized as compared to the free enzyme. The structure of TvDAO was stabilized via covalent attachment to Sepabeads EC-EP but concomitantly, binding of the FAD cofactor was weakened. FAD release from the enzyme into solution markedly reduced the positive effect of immobilization on the overall stability of TvDAO. Under conditions of substrate conversion in a bubble-aerated stirred tank reactor, both immobilization techniques as well as the addition of the surfactant Pluronic F-68 stabilized TvDAO by protecting the enzyme from the deleterious effect of gas-liquid interfaces. Immobilization of TvDAO on Sepabeads EC-EP however stabilized the enzyme beyond this effect and led to a biocatalyst that could be re-used in multiple cycles of substrate conversion. Conclusion Multi-point covalent attachment of TvDAO on an isoluble porous carrier provides stabilization against the denaturing effects of high temperature and exposure to a gas-liquid interface. Improvement of binding of the FAD cofactor, probably by using methods of protein engineering, would further enhance the stability of the immobilized enzyme.
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Affiliation(s)
- Iskandar Dib
- Research Centre Applied Biocatalysis, Petersgasse 14, A-8010 Graz, Austria.
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Gindy ME, Ji S, Hoye TR, Panagiotopoulos AZ, Prud’homme RK. Preparation of Poly(ethylene glycol) Protected Nanoparticles with Variable Bioconjugate Ligand Density. Biomacromolecules 2008; 9:2705-11. [DOI: 10.1021/bm8002013] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marian E. Gindy
- Department of Chemical Engineering and Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Shengxiang Ji
- Department of Chemical Engineering and Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Thomas R. Hoye
- Department of Chemical Engineering and Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Athanassios Z. Panagiotopoulos
- Department of Chemical Engineering and Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Robert K. Prud’homme
- Department of Chemical Engineering and Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, and Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
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Properties and applications of microbial D-amino acid oxidases: current state and perspectives. Appl Microbiol Biotechnol 2008; 78:1-16. [DOI: 10.1007/s00253-007-1282-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 11/09/2007] [Accepted: 11/09/2007] [Indexed: 10/22/2022]
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Nahalka J, Dib I, Nidetzky B. Encapsulation of Trigonopsis variabilis D-amino acid oxidase and fast comparison of the operational stabilities of free and immobilized preparations of the enzyme. Biotechnol Bioeng 2008; 99:251-60. [PMID: 17680679 DOI: 10.1002/bit.21579] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A one-step procedure of immobilizing soluble and aggregated preparations of D-amino acid oxidase from Trigonopsis variabilis (TvDAO) is reported where carrier-free enzyme was entrapped in semipermeable microcapsules produced from the polycation poly(methylene-co-guanidine) in combination with CaCl2 and the polyanions alginate and cellulose sulfate. The yield of immobilization, expressed as the fraction of original activity present in microcapsules, was approximately 52 +/- 5%. The effectiveness of the entrapped oxidase for O2-dependent conversion of D-methionine at 25 degrees C was 85 +/- 10% of the free enzyme preparation. Because continuous spectrophotometric assays are generally not well compatible with insoluble enzymes, we employed a dynamic method for the rapid in situ estimation of activity and relatedly, stability of free and encapsulated oxidases using on-line measurements of the concentration of dissolved O2. Integral and differential modes of data acquisition were utilized to examine cases of fast and slow inactivation of the enzyme, respectively. With a half-life of 60 h, encapsulated TvDAO was approximately 720-fold more stable than the free enzyme under conditions of bubble aeration at 25 degrees C. The soluble oxidase was stabilized by added FAD only at temperatures of 35 degrees C or greater.
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Affiliation(s)
- Jozef Nahalka
- Research Centre Applied Biocatalysis, Petersgasse 14, A-8010 Graz, Austria
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21
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Stability and stabilization of D-amino acid oxidase from the yeast Trigonopsis variabilis. Biochem Soc Trans 2007; 35:1588-92. [DOI: 10.1042/bst0351588] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The use of DAO (D-amino acid oxidase) for the conversion of cephalosporin C has provided a significant case for the successful implementation of an O2-dependent biocatalyst on an industrial scale. Improvement of the operational stability of the immobilized oxidase is, however, an important goal of ongoing process optimization. We have examined DAO from the yeast Trigonopsis variabilis with the aim of developing a rational basis for the stabilization of the enzyme activity at elevated temperature and under conditions of substrate turnover. Loss of activity in the resting enzyme can occur via different paths of denaturation. Partial thermal unfolding and release of the FAD cofactor, kinetically coupled with aggregation, contribute to the overall inactivation rate of the oxidase at 50°C. Oxidation of Cys108 into a stable cysteine sulfinic acid causes both decreased activity and stability of the enzyme. Strategies to counteract each of the denaturation steps in DAO are discussed. Fusion to a pull-down domain is a novel approach to produce DAO as protein-based insoluble particles that display high enzymatic activity per unit mass of catalyst.
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Arroyo M, Menéndez M, García JL, Campillo N, Hormigo D, de la Mata I, Castillón MP, Acebal C. The role of cofactor binding in tryptophan accessibility and conformational stability of His-tagged d-amino acid oxidase from Trigonopsis variabilis. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:556-65. [PMID: 17466607 DOI: 10.1016/j.bbapap.2007.03.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 03/07/2007] [Accepted: 03/07/2007] [Indexed: 11/30/2022]
Abstract
d-amino acid oxidase from Trigonopsis variabilis (TvDAAO) is a flavoenzyme with high biotechnological and industrial interest. The overexpression and purification of the apoprotein form of a recombinant His-tagged TvDAAO allowed us to go deep into the structural differences between apoenzyme and holoenzyme, and on the cofactor binding and its contribution to enzyme stability. A significant decrease in intrinsic fluorescence emission took place upon FAD binding, associated to cofactor induced conformational transitions or subunit dimerization that could affect the local environment of protein tryptophan residues. Furthermore, acrylamide-quenching experiments indicated that one of the five tryptophan residues of TvDAAO became less accessible upon FAD binding. A K(d)=1.5+/-0.1x10(-7) M for the dissociation of FAD from TvDAAO was calculated from binding experiments based on both quenching of FAD fluorescence and activity titration curves. Secondary structure prediction indicated that TvDAAO is a mixed alpha/beta protein with 8 alpha-helices and 14 beta-sheets connected by loops. Prediction results were in good agreement with the estimates obtained by circular dichroism which indicated that both the apoenzyme and the holoenzyme had the same structural component ratios: 34% alpha-helix content, 20% beta-structure content (14% antiparallel and 6% parallel beta-sheet), 15% beta-turns and 31% of random structure. Circular dichroism thermal-transition curves suggested single-step denaturation processes with apparent midpoint transition temperatures (T(m)) of 37.9 degrees C and 41.4 degrees C for the apoenzyme and the holoenzyme, respectively. A three-dimensional model of TvDAAO built by homology modelling and consistent with the spectroscopic studies is shown. Comparing our results with those reported for pig kidney (pkDAAO) and Rhodotorula gracilis (RgDAAO) d-amino acid oxidases, a "head-to-head" interaction between subunits in the TvDAAO dimer might be expected.
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Affiliation(s)
- Miguel Arroyo
- Departamento de Bioquímica y Biología Molecular I, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, José Antonio Novais 2, 28040 Madrid, Spain.
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Nahalka J, Nidetzky B. Fusion to a pull-down domain: a novel approach of producingTrigonopsis variabilisD-amino acid oxidase as insoluble enzyme aggregates. Biotechnol Bioeng 2007; 97:454-61. [PMID: 17089401 DOI: 10.1002/bit.21244] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Insoluble protein particles showing high specific enzyme activity are potentially useful biocatalysts. The commercialized crosslinked enzyme crystals and aggregates have the disadvantage that their preparation requires isolation of the protein before the critical precipitation step. We introduce a novel concept of controlled precipitation in vivo in which the target enzyme is fused to the cellulose-binding domain (CBD) of Clostridium cellulovorans, and expression in Escherichia coli is performed under conditions that induce selective pull down of the folded chimeric protein via intermolecular self-aggregation of the CBD. The case of D-amino acid oxidase from Trigonopsis variabilis shows that upon fusion of the CBD to its N-terminus, the otherwise mainly soluble recombinant enzyme was quantitatively precipitated in protein particles, which displayed 40% of the specific activity of the highly purified oxidase. By contrast, inclusion bodies derived from an enzyme chimera, which harbored a C-terminal peptide tag, showed only little oxidase activity (<or= 10%). The aggregated CBD retained the ability to bind microcrystalline cellulose and flocculated polysaccharide particles upon attachment to them. The cellulose-bound oxidase was stabilized about 36 times against inactivation of the soluble enzyme during conversion of D-methionine and bubble aeration.
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Affiliation(s)
- Jozef Nahalka
- Research Centre Applied Biocatalysis, c/o Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12, A-8010 Graz, Austria
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Dib I, Stanzer D, Nidetzky B. Trigonopsis variabilis D-amino acid oxidase: control of protein quality and opportunities for biocatalysis through production in Escherichia coli. Appl Environ Microbiol 2006; 73:331-3. [PMID: 17056691 PMCID: PMC1797113 DOI: 10.1128/aem.01569-06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trigonopsis variabilis D-amino acid oxidase accounts for 35% of Escherichia coli protein when added D-methionine suppresses the toxic activity of the recombinant product. Permeabilized E. coli cells are reusable and stabilized enzyme preparations. The purified oxidase lacks the microheterogeneity of the natural enzyme. Oriented immobilization of a chimeric oxidase maintains 80% of the original activity in microparticle-bound enzymes.
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Affiliation(s)
- Iskandar Dib
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/I, A-8010 Graz, Austria
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Slavica A, Dib I, Nidetzky B. Selective modification of surface-exposed thiol groups inTrigonopsis variabilisD-amino acid oxidase using poly(ethylene glycol) maleimide and its effect on activity and stability of the enzyme. Biotechnol Bioeng 2006; 96:9-17. [PMID: 16948164 DOI: 10.1002/bit.21181] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Covalent modification of purified Trigonopsis variabilis D-amino acid oxidase using maleimide-activated poly(ethylene glycol) 5000 yielded a stable bioconjugate in which three surface-exposed cysteine side chains were selectively derivatized. Compared with the native enzyme, the PEGylated variant displayed substantially (approximately 3.3-fold) slowed dissociation rate of FAD cofactor at 50 degrees C, and this caused a twofold thermostabilization of the enzyme activity. The stability under reaction conditions at 30 degrees C was also markedly enhanced in the PEG-oxidase conjugate. PEGylation did not affect steady-state kinetic parameters for oxidative deamination of D-methionine when 2,6-dichloroindophenol replaced dioxygen as the cosubstrate while it caused a ninefold decrease in substrate catalytic efficiency for the dioxygen-dependent reaction.
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Affiliation(s)
- Anita Slavica
- Research Centre Applied Biocatalysis, Petersgasse 14, A-8010 Graz, Austria
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