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Dusíková A, Baranová T, Krahulec J, Dakošová O, Híveš J, Naumowicz M, Gál M. Electrochemical Impedance Spectroscopy for the Sensing of the Kinetic Parameters of Engineered Enzymes. Sensors (Basel) 2024; 24:2643. [PMID: 38676260 PMCID: PMC11054234 DOI: 10.3390/s24082643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/28/2024]
Abstract
The study presents a promising approach to enzymatic kinetics using Electrochemical Impedance Spectroscopy (EIS) to assess fundamental parameters of modified enteropeptidases. Traditional methods for determining these parameters, while effective, often lack versatility and convenience, especially under varying environmental conditions. The use of EIS provides a novel approach that overcomes these limitations. The enteropeptidase underwent genetic modification through the introduction of single amino acid modifications to assess their effect on enzyme kinetics. However, according to the one-sample t-test results, the difference between the engineered enzymes and hEKL was not statistically significant by conventional criteria. The kinetic parameters were analyzed using fluorescence spectroscopy and EIS, which was found to be an effective tool for the real-time measurement of enzyme kinetics. The results obtained through EIS were not significantly different from those obtained through traditional fluorescence spectroscopy methods (p value >> 0.05). The study validates the use of EIS for measuring enzyme kinetics and provides insight into the effects of specific amino acid changes on enteropeptidase function. These findings have potential applications in biotechnology and biochemical research, suggesting a new method for rapidly assessing enzymatic activity.
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Affiliation(s)
- Adriána Dusíková
- Department of Molecular Biology, Faculty of Natural Sciences, Commenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia; (A.D.); (J.K.)
| | - Timea Baranová
- Department of Inorganic Technology, Faculty of Chemical and Food Technology STU in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia; (T.B.); (O.D.); (J.H.)
| | - Ján Krahulec
- Department of Molecular Biology, Faculty of Natural Sciences, Commenius University, Ilkovičova 6, 842 15 Bratislava, Slovakia; (A.D.); (J.K.)
| | - Olívia Dakošová
- Department of Inorganic Technology, Faculty of Chemical and Food Technology STU in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia; (T.B.); (O.D.); (J.H.)
| | - Ján Híveš
- Department of Inorganic Technology, Faculty of Chemical and Food Technology STU in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia; (T.B.); (O.D.); (J.H.)
| | - Monika Naumowicz
- Faculty of Chemistry, University of Białystok, ul. K. Ciołkowskiego 1K, 15-245 Białystok, Poland;
| | - Miroslav Gál
- Department of Inorganic Technology, Faculty of Chemical and Food Technology STU in Bratislava, Radlinského 9, 812 37 Bratislava, Slovakia; (T.B.); (O.D.); (J.H.)
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Krivoňáková N, Šoltýsová A, Tamáš M, Takáč Z, Krahulec J, Ficek A, Gál M, Gall M, Fehér M, Krivjanská A, Horáková I, Belišová N, Bímová P, Škulcová AB, Mackuľak T. Mathematical modeling based on RT-qPCR analysis of SARS-CoV-2 in wastewater as a tool for epidemiology. Sci Rep 2021; 11:19456. [PMID: 34593871 PMCID: PMC8484274 DOI: 10.1038/s41598-021-98653-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 09/09/2021] [Indexed: 02/06/2023] Open
Abstract
Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerges to scientific research and monitoring of wastewaters to predict the spread of the virus in the community. Our study investigated the COVID-19 disease in Bratislava, based on wastewater monitoring from September 2020 until March 2021. Samples were analyzed from two wastewater treatment plants of the city with reaching 0.6 million monitored inhabitants. Obtained results from the wastewater analysis suggest significant statistical dependence. High correlations between the number of viral particles in wastewater and the number of reported positive nasopharyngeal RT-qPCR tests of infected individuals with a time lag of 2 weeks/12 days (R2 = 83.78%/R2 = 52.65%) as well as with a reported number of death cases with a time lag of 4 weeks/27 days (R2 = 83.21%/R2 = 61.89%) was observed. The obtained results and subsequent mathematical modeling will serve in the future as an early warning system for the occurrence of a local site of infection and, at the same time, predict the load on the health system up to two weeks in advance.
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Affiliation(s)
- Naďa Krivoňáková
- Institute of Information Engineering, Automation, and Mathematics, Department of Mathematics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Andrea Šoltýsová
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15, Bratislava, Slovakia
- Institute for Clinical and Translational Research, Biomedical Research Center, Slovak Academy of Sciences, Dúbravska Cesta 9, 84505, Bratislava, Slovakia
| | - Michal Tamáš
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic.
| | - Zdenko Takáč
- Institute of Information Engineering, Automation, and Mathematics, Department of Mathematics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Ján Krahulec
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15, Bratislava, Slovakia
| | - Andrej Ficek
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, 842 15, Bratislava, Slovakia
| | - Miroslav Gál
- Department of Inorganic Technology, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Marián Gall
- Institute of Information Engineering, Automation, and Mathematics, Department of Mathematics, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Miroslav Fehér
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Anna Krivjanská
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Ivana Horáková
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Noemi Belišová
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Paula Bímová
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Andrea Butor Škulcová
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
| | - Tomáš Mackuľak
- Department of Environmental Engineering, Faculty of Chemistry and Food Technology, Slovak University of Technology in Bratislava, Radlinského 9, 812 37, Bratislava, Slovak Republic
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Krahulec J, Šafránek M. Impact of media components from different suppliers on enterokinase productivity in Pichia pastoris. BMC Biotechnol 2021; 21:19. [PMID: 33678175 PMCID: PMC7938543 DOI: 10.1186/s12896-021-00681-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/22/2021] [Indexed: 11/16/2022] Open
Abstract
Background The aim of this study was to provide an information about the homogeneity on the level of enterokinase productivity in P. pastoris depending on different suppliers of the media components. Results In previous studies, we performed the optimisation process for the production of enterokinase by improving the fermentation process. Enterokinase is the ideal enzyme for removing fusion partners from target recombinant proteins. In this study, we focused our optimization efforts on the sources of cultivation media components. YPD media components were chosen as variables for these experiments. Several suppliers for particular components were combined and the optimisation procedure was performed in 24-well plates. Peptone had the highest impact on enterokinase production, where the difference between the best and worst results was threefold. The least effect on the production level was recorded for yeast extract with a 1.5 fold difference. The worst combination of media components had a activity of only 0.15 U/ml and the best combination had the activity of 0.88 U/ml, i.e., a 5.87 fold difference. A substantially higher impact on the production level of enterokinase was observed during fermentation in two selected media combinations, where the difference was almost 21-fold. Conclusions Results demonstrated in the present study show that the media components from different suppliers have high impact on enterokinase productivity and also provide the hypothesis that the optimization process should be multidimensional and for achieving best results it is important to perform massive process also in terms of the particular media component supplier .
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Affiliation(s)
- Ján Krahulec
- Department of Molecular Biology, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic.
| | - Martin Šafránek
- Department of Molecular Biology, Comenius University in Bratislava, Faculty of Natural Sciences, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
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Čierna M, Naumowicz M, Bírošová L, Krahulec J, Sokolová R, Kolivoška V, Sebechlebská T, Kielar F, Gál M. Study of permeabilization of bacterial membrane by electrochemical methods. J Electroanal Chem (Lausanne) 2020. [DOI: 10.1016/j.jelechem.2019.113761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Gál M, Sokolová R, Naumowicz M, Híveš J, Krahulec J. Electrochemical and AFM study of the interaction of recombinant human cathelicidin LL-37 with various supported bilayer lipid membranes. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Janovjáková A, Gál M, Krahulec J, Sokolová R, Naumowicz M, Híveš J. Native and denatured enzyme enterokinase determined by electrochemical methods. Monatsh Chem 2017. [DOI: 10.1007/s00706-016-1915-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Melicherová K, Krahulec J, Šafránek M, Lišková V, Hopková D, Széliová D, Turňa J. Optimization of the fermentation and downstream processes for human enterokinase production in Pichia pastoris. Appl Microbiol Biotechnol 2016; 101:1927-1934. [PMID: 27826720 DOI: 10.1007/s00253-016-7960-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 10/17/2016] [Accepted: 10/21/2016] [Indexed: 12/16/2022]
Abstract
Enterokinase is one of the most frequently used enzymes for the removal of affinity tags from target recombinant proteins. In this study, several fermentation strategies were assayed for the production of human enterokinase in Pichia pastoris under constitutive GAP promoter. Two of them with controlled specific growth rate during whole cultivation showed a very low enterokinase activity, under 1 U/ml, of the fermentation medium. On the contrary, the combined fermentation with a maximum specific growth rate at the initial phase of the fermentation and stationary-like phase during the rest of the fermentation showed a significant accumulation of the enterokinase in the medium, which counted up to 1400 U/ml. Lower cultivation temperature had a negative impact on the enzyme accumulation during this fermentation strategy. Downstream processes were focused on buffer environment optimization directly after cultivation, as at this time, the most amount of the activity is eliminated by endogenous proteases. Slightly positive effect on enzyme activity in the medium had an addition of liquid storage solution of EDTA and KOH to adjust pH to 8 and molarity of the EDTA to 50 mM. During the purification process, a significant amount of the enzyme was detected to be lost, which counted up to 90%. The purified enzyme, enterokinase, kept quality standard of the published enzymes.
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Affiliation(s)
- Kristína Melicherová
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
| | - Ján Krahulec
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic.
| | - Martin Šafránek
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
| | - Veronika Lišková
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
| | - Diana Hopková
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
| | - Diana Széliová
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
| | - Ján Turňa
- Faculty of Natural Sciences, Department of Molecular Biology, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15, Bratislava 4, Slovak Republic
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Boňková H, Osadská M, Krahulec J, Lišková V, Stuchlík S, Turňa J. Upstream regulatory regions controlling the expression of the Candida utilis maltase gene. J Biotechnol 2014; 189:136-42. [DOI: 10.1016/j.jbiotec.2014.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/05/2014] [Accepted: 09/08/2014] [Indexed: 10/24/2022]
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Levarski Z, Šoltýsová A, Krahulec J, Stuchlík S, Turňa J. High-level expression and purification of recombinant human growth hormone produced in soluble form in Escherichia coli. Protein Expr Purif 2014; 100:40-7. [DOI: 10.1016/j.pep.2014.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Revised: 05/07/2014] [Accepted: 05/12/2014] [Indexed: 11/24/2022]
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Osadska M, Šafranek M, Boňková H, Krahulec J, Stuchlík S, Turňa J. Strategy for on-column refolding of human recombinant His-tagged prethrombin-2 produced using the Escherichia coli-based expression system. N Biotechnol 2014. [DOI: 10.1016/j.nbt.2014.05.936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Krahulec J, Boňková H, Lišková V, Osadská M, Stuchlík S, Turňa J. The effect of carbon sources on upstream regulatory regions controlling the expression of the Candida utilis maltase gene. N Biotechnol 2014. [DOI: 10.1016/j.nbt.2014.05.1009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Osadská M, Boňková H, Krahulec J, Stuchlík S, Turňa J. Optimization of expression of untagged and histidine-tagged human recombinant thrombin precursors in Escherichia coli. Appl Microbiol Biotechnol 2014; 98:9259-70. [PMID: 24878753 DOI: 10.1007/s00253-014-5840-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 05/09/2014] [Accepted: 05/15/2014] [Indexed: 10/25/2022]
Abstract
The present study is focused on preparation of proper Escherichia coli expression system to ensure high yields of various modified precursors of human recombinant thrombin, a potential biopharmaceutical reagent. Two thrombin precursors, the smallest single-chain α-thrombin precursor prethrombin-2 and its shortened form prethrombin-2∆13, and their His-tagged forms were used. In order to determine the effect of the different lengths and amino acid compositions of affinity His-tag on the target protein expression level, a variety of the His-tag sequences were used. We found out that the protein expression efficiency was closely related to the codons used for encoding of amino acids of fusion histidine tag. Optimization of culture medium composition is another way to increase yield of the target protein. Suitable medium composition can ensure cell growth to high densities which is related to total yield of expressed protein. In this study, a new optimized complex medium for batch fermentation was developed. Addition of nutrients like a yeast extract and enzymatic casein hydrolysate to the defined medium components had a positive impact on protein expression, where relatively high expression level of the target protein from total amount of cellular proteins was achieved. Further, we have focused on trace element solution composition, and the optimized nickel and selenium concentrations were determined. Our results show that the composition of essential trace metal solution has a major impact not only on expression level, but it can also affect cell growth rate.
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Affiliation(s)
- Michaela Osadská
- Department of Molecular Biology, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, 842 15, Bratislava 4, Slovak Republic,
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Abstract
This study addresses the influence of upstream region sequence on the strength of has operon promoter in highly encapsulated S. equi subsp. zooepidemicus (SEZ). For this purpose, seven different strains were constructed. Each strain carries a point mutation in one of the following positions upstream of the has promoter: -43, -44, -49, and -50 bp. To facilitate measuring of the recombinant promoter relative strength, ß-glucuronidase gene was used as a reporter gene. Three mutations located in positions -49 and -50: AT, GT, and AG, positively impacted has promoter strength when compared to the wild type sequence GG. Conversely, two other mutations: TG and TT, exhibited a slight inhibitory effect. Further, three different strains carrying chromosomal mutations in the has promoter region were constructed. In two cases, the has operon is under the control of a stronger promoter and in the third strain the has operon is controlled by a weaker promoter. The laboratory fermenter scale cultivations confirmed the increase of hyaluronan yields for SEZPhasAG and SEZPhas2G, resulting 116 and 105 %, respectively. As expected, the yield of the hyaluronic acid of SEZPhas2B strain fell to 41 %.
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Affiliation(s)
- Marcela Tlustá
- Contipro Biotech s r.o., Dolní Dobrouč 401, Czech Republic.
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Pepeliaev S, Krahulec J, Černý Z, Jílková J, Tlustá M, Dostálová J. High level expression of human enteropeptidase light chain in Pichia pastoris. J Biotechnol 2011; 156:67-75. [PMID: 21884736 DOI: 10.1016/j.jbiotec.2011.08.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 05/11/2011] [Accepted: 08/12/2011] [Indexed: 11/17/2022]
Abstract
Human enterokinase (enteropeptidase, rhEP), a serine protease expressed in the proximal part of the small intestine, converts the inactive form of trypsinogen to active trypsin by endoproteolytic cleavage. The high specificity of the target site makes enterokinase an ideal tool for cleaving fusion proteins at defined cleavage sites. The mature active enzyme is comprised of two disulfide-linked polypeptide chains. The heavy chain anchors the enzyme in the intestinal brush border membrane, whereas the light chain represents the catalytic enzyme subunit. The synthetic gene encoding human enteropeptidase light chain with His-tag added at the C-terminus to facilitate protein purification was cloned into Pichia pastoris expression plasmids under the control of an inducible AOX1 or constitutive promoters GAP and AAC. Cultivation media and conditions were optimized as well as isolation and purification of the target protein. Up to 4 mg/L of rhEP was obtained in shake-flask experiments and the expression level of about 60-70 mg/L was achieved when cultivating in lab-scale fermentors. The constitutively expressing strains proved more efficient and less labor-demanding than the inducible ones. The rhEP was immobilized on AV 100 sorbent (Iontosorb) to allow repeated use of enterokinase, showing specific activity of 4U/mL of wet matrix.
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Krahulec J, Hyršová M, Pepeliaev S, Jílková J, Černý Z, Machálková J. High level expression and purification of antimicrobial human cathelicidin LL-37 in Escherichia coli. Appl Microbiol Biotechnol 2010; 88:167-75. [DOI: 10.1007/s00253-010-2736-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 06/09/2010] [Accepted: 06/12/2010] [Indexed: 12/25/2022]
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Krahulec J, Krahulcová J. Characterization of the new beta-glucuronidase from Streptococcus equi subsp. zooepidemicus. Appl Microbiol Biotechnol 2007; 74:1016-22. [PMID: 17221200 DOI: 10.1007/s00253-006-0745-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 10/27/2006] [Accepted: 10/27/2006] [Indexed: 11/29/2022]
Abstract
Recently, a new gene encoding beta-glucuronidase from Streptococcus equi subsp. zooepidemicus (SEZ) was identified and expressed in Escherichia coli. In this paper, the characterization of the enzyme is described. Specific enzyme activity was 120,000 U/mg purified protein at 37 degrees C and pH = 7.0. The temperature and pH value, at which the enzyme has the highest specific activity, were determined and were found to be approximately 52 degrees C and 5.6, respectively. The mutant strain SEZ glcHis was designed for the efficient isolation of beta-glucuronidase from S. equi subsp. zooepidemicus. It was observed that the specific activity of beta-glucuronidase in the cytoplasmic extract of a mutated strain was about 45% lower than in the cytoplasmic extract of a wild-type strain. The specific activity of purified beta-glucuronidase from SEZ glcHis was four times as low as beta-glucuronidase purified from E. coli. Comparing the specific activity of purified streptococcal beta-glucuronidase from E. coli with E. coli beta-glucuronidase (the enzyme with the highest specific activity was supplied by Sigma), the former is 1.8 higher than the latter.
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Affiliation(s)
- Ján Krahulec
- Laboratory of Genetic Modification, CPN spol. s r.o., Dolní Dobrouc 401, Czech Republic.
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Krahulec J, Krahulcová J. Increase in hyaluronic acid production by Streptococcus equi subsp. zooepidemicus strain deficient in beta-glucuronidase in laboratory conditions. Appl Microbiol Biotechnol 2005; 71:415-22. [PMID: 16292534 DOI: 10.1007/s00253-005-0173-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 08/03/2005] [Accepted: 09/02/2005] [Indexed: 11/24/2022]
Abstract
Streptococcus equi subsp. zooepidemicus is known to produce a hyaluronic acid capsule to resist the host immune defense. As the structure of the polysaccharide is identical to the one produced by humans, the bacteria S. equi subsp. zooepidemicus is used in biotechnological production of hyaluronic acid. In our laboratory we prepared mutated strains that are beta-glucuronidase deficient. Comparing the wild-type strain, which is positive in beta-glucuronidase activity, with the mutated strains named clone1 and clone2 in laboratory conditions, we observed that beta-glucuronidase influences the production of hyaluronic acid considerably and the molecular weight of hyaluronan slightly. The production of hyaluronic acid by the mutated strains is higher by approximately 20% and the molecular weight is larger by about 2%. The significant increase in the production of hyaluronic acid and the slight increase in the molecular weight are probably caused by an absence of free beta-glucuronic acid, due to its removal from the non-reducing termini of the polysaccharide by beta-glucuronidase. The presence of free beta-glucuronic acid would likely induce the expression of the beta-glucuronic-acid-utilizing operon, which in turn would reflect into a misuse of energy in the glucose-rich media.
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Affiliation(s)
- Ján Krahulec
- Department of Molecular Biology, Comenius University, Bratislava, Slovak Republic.
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Abstract
An enzyme KfoG with unknown function is coded by the gene kfoG. Gene kfoG belongs to genes from region 2, which are responsible for structure of capsular polysaccharide. Only two enzymes, KfoG and KfoC, coded by genes from region 2, have a glycosyltransferase motif. KfoC is the bifunctional enzyme, which is able to add both GalNAc and GlcUA on nascent polysaccharide, termed chondroitin polymerase. KfoG was predicted to be a fructosyltransferase. The gene that codes the KfoG enzyme was disrupted using homological recombination and absence of this gene was confirmed on both DNA and RNA levels. After disruption no structural changes have been observed, what indicates that fructose branching of the chondroitin backbone is not caused by enzymes, which are coded by genes from region 2 of the K4 capsular gene cluster.
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Affiliation(s)
- Ján Krahulec
- CPN spol. s r.o., Dolní Dobrou 401, 56102 Czech Republic.
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Abstract
Four cryptic plasmids pAP1, pAP2, pAP3, and pAP4 with their replication regions AP were isolated from Gram-negative bacteria Acetobacter pasteurianus 2374 and characterised by sequence analyses. All plasmids were carrying the kanamycin resistance gene. Three of four plasmids pAP2, pAP3, and pAP4 encode an enzyme that confers ampicillin resistance to host cells. Moreover, the tetracycline resistance gene was identified only in pAP2 plasmid. All plasmids are capable to coexist with each other in Acetobacter cells. On the other hand, the coexistence of more than one plasmid is excluded in Escherichia coli. The nucleotide sequence of replication regions showed significant homology. The nucleotide and protein sequence analyses of resistance genes of all plasmids were compared with transposons Tn3, Tn10, and Tn903 which revealed significant differences in the primary structure, however no functional changes of gene were obtained.
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Affiliation(s)
- Ján Krahulec
- Department of Molecular Biology, Faculty of Natural Science, Comenius University, Mlynska dolina B-2, 842 15, Bratislava 4, Slovak Republic
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