1
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Ebrahimi Fana S, Fazaeli A, Aminian M. Directed evolution of cholesterol oxidase with improved thermostability using error-prone PCR. Biotechnol Lett 2023; 45:1159-1167. [PMID: 37289346 DOI: 10.1007/s10529-023-03401-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 04/14/2023] [Accepted: 05/19/2023] [Indexed: 06/09/2023]
Abstract
Cholesterol oxidase is industrially important as it is frequently used as a biosensor in food and agriculture industries and measurement of cholesterol. Although, most natural enzymes show low thermostability, which limits their application. Here, we obtained an improved variant of Chromobacterium sp. DS1 cholesterol oxidase (ChOS) with enhanced thermostability by random mutant library applying two forms of error-prone PCR (serial dilution and single step). Wild-type ChOS indicated an optimal temperature and pH of 70 ºC and pH 7.5, respectively. The best mutant ChOS-M acquired three amino acid substitutions (S112T, I240V and A500S) and enhanced thermostability (at 50 °C for 5 h) by 30%. The optimum temperature and pH in the mutant were not changed. In comparison to wild type, circular dichroism disclosed no significant secondary structural alterations in mutants. These findings show that error-prone PCR is an effective method for enhancing enzyme characteristics and offers a platform for the practical use of ChOS as a thermal-resistance enzyme in industrial fields and clinical diagnosis.
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Affiliation(s)
- Saeed Ebrahimi Fana
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, P.O. Box: 14155-6447, Tehran, Iran
- Student Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Aliakbar Fazaeli
- Department of Clinical Biochemistry, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Mahdi Aminian
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, P.O. Box: 14155-6447, Tehran, Iran.
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2
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Doukyu N, Ikehata Y, Sasaki T. Expression and characterization of cholesterol oxidase with high thermal and pH stability from Janthinobacterium agaricidamnosum. Prep Biochem Biotechnol 2023; 53:331-339. [PMID: 35697335 DOI: 10.1080/10826068.2022.2084626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cholesterol oxidases (COXases) have a diverse array of applications including analysis of blood cholesterol levels, synthesis of steroids, and utilization as an insecticidal protein. The COXase gene from Janthinobacterium agaricidamnosum was cloned and expressed in Escherichia coli. The purified COXase showed an optimal temperature of 60 °C and maintained about 96 and 72% of its initial activity after 30 min at 60 and 70 °C, respectively. In addition, the purified COXase exhibited a pH optimum at 7.0 and high pH stability over the broad pH range of 3.0-12.0. The pH stability of the COXase at pH 12.0 was higher than that of highly stable COXase from Chromobacterium sp. DS-1. The COXase oxidized cholesterol and β-cholestanol at higher rates than other 3β-hydroxysteroids. The Km, Vmax, and kcat values for cholesterol were 156 μM, 13.7 μmol/min/mg protein, and 14.4 s-1, respectively. These results showed that this enzyme could be very useful in the clinical determination of cholesterol in serum and the production of steroidal compounds. This is the first report to characterize a COXase from the genus Janthinobacterium.
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Affiliation(s)
| | - Yuuki Ikehata
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | - Taichi Sasaki
- Department of Life Sciences, Toyo University, Gunma, Japan
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3
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Zhao S, Guo D, Zhu Q, Dou W, Guan W. Display of Microbial Glucose Dehydrogenase and Cholesterol Oxidase on the Yeast Cell Surface for the Detection of Blood Biochemical Parameters. BIOSENSORS 2020; 11:13. [PMID: 33396921 PMCID: PMC7823397 DOI: 10.3390/bios11010013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/20/2020] [Accepted: 12/28/2020] [Indexed: 01/16/2023]
Abstract
High levels of blood glucose are always associated with numerous complications including cholesterol abnormalities. Therefore, it is important to simultaneously monitor blood glucose and cholesterol levels in patients with diabetes during the management of chronic diseases. In this study, a glucose dehydrogenase from Aspergillus oryzae TI and a cholesterol oxidase from Chromobacterium sp. DS-1 were displayed on the surface of Saccharomyces cerevisiae, respectively, using the yeast surface display system at a high copy number. In addition, two whole-cell biosensors were constructed through the immobilization of the above yeast cells on electrodes, for electrochemical detection of glucose and cholesterol. The assay time was 8.5 s for the glucose biosensors and 30 s for the cholesterol biosensors. Under optimal conditions, the cholesterol biosensor exhibited a linear range from 2 to 6 mmol·L-1. The glucose biosensor responded efficiently to the presence of glucose at a concentration range of 20-600 mg·dL-1 (1.4-33.3 mmol·L-1) and showed excellent anti-xylose interference properties. Both biosensors exhibited good performance at room temperature and remained stable over a three-week storage period.
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Affiliation(s)
- Shiyao Zhao
- Institute of Pharmaceutical Biotechnology and the Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310012, China; (S.Z.); (Q.Z.); (W.D.)
| | - Dong Guo
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310012, China;
| | - Quanchao Zhu
- Institute of Pharmaceutical Biotechnology and the Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310012, China; (S.Z.); (Q.Z.); (W.D.)
| | - Weiwang Dou
- Institute of Pharmaceutical Biotechnology and the Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310012, China; (S.Z.); (Q.Z.); (W.D.)
| | - Wenjun Guan
- Institute of Pharmaceutical Biotechnology and the Children’s Hospital, Zhejiang University School of Medicine, Hangzhou 310012, China; (S.Z.); (Q.Z.); (W.D.)
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4
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Doukyu N, Ishikawa M. Cholesterol oxidase from Rhodococcus erythropolis with high specificity toward β-cholestanol and pytosterols. PLoS One 2020; 15:e0241126. [PMID: 33104755 PMCID: PMC7588053 DOI: 10.1371/journal.pone.0241126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/08/2020] [Indexed: 12/05/2022] Open
Abstract
Two genes (choRI and choRII) encoding cholesterol oxidases belonging to the vanillyl-alcohol oxidase (VAO) family were cloned on the basis of putative cholesterol oxidase gene sequences in the genome sequence data of Rhodococcus erythropolis PR4. The genes corresponding to the mature enzymes were cloned in a pET vector and expressed in Escherichia coli. The two cholesterol oxidases produced from the recombinant E. coli were purified to examine their properties. The amino acid sequence of ChoRI showed significant similarity (57%) to that of ChoRII. ChoRII was more stable than ChoRI in terms of pH and thermal stability. The substrate specificities of these enzymes differed distinctively from one another. Interestingly, the activities of ChoRII toward β-cholestanol, β-sitosterol, and stigmasterol were 2.4-, 2.1-, and 1.7-fold higher, respectively, than those of cholesterol. No cholesterol oxidases with high activity toward these sterols have been reported so far. The cholesterol oxidation products from these two enzymes also differed. ChoRI and ChoRII oxidized cholesterol to form cholest-4-en-3-one and 6β-hydroperoxycholest-4-en-3-one, respectively.
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Affiliation(s)
- Noriyuki Doukyu
- Department of Life Sciences, Toyo University, Itakura-machi, Gunma, Japan
- Graduate School of Life Sciences, Toyo University, Itakura-machi, Gunma, Japan
- Bio-Nano Electronic Research Center, Toyo University, Kawagoe, Saitama, Japan
- * E-mail:
| | - Makoto Ishikawa
- Graduate School of Life Sciences, Toyo University, Itakura-machi, Gunma, Japan
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5
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Fazaeli A, Golestani A, Lakzaei M, Rasi Varaei SS, Aminian M. Expression optimization, purification, and functional characterization of cholesterol oxidase from Chromobacterium sp. DS1. PLoS One 2019; 14:e0212217. [PMID: 30759160 PMCID: PMC6373949 DOI: 10.1371/journal.pone.0212217] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/29/2019] [Indexed: 12/17/2022] Open
Abstract
Cholesterol oxidase is a bifunctional bacterial flavoenzyme which catalyzes oxidation and isomerization of cholesterol. This valuable enzyme has attracted a great deal of attention because of its wide application in the clinical laboratory, synthesis of steroid derived drugs, food industries, and its potentially insecticidal activity. Therefore, development of an efficient protocol for overproduction of cholesterol oxidase could be valuable and beneficial in this regard. The present study examined the role of various parameters (host strain, culture media, induction time, isopropyl ß-D-1-thiogalactopyranoside concentration, as well as post-induction incubation time and temperature) on over-expression of cholesterol oxidase from Chromobacterium sp. DS1. Applying the optimized protocol, the yield of recombinant cholesterol oxidase significantly increased from 92 U/L to 2115 U/L. Under the optimized conditions, the enzyme was produced on a large-scale, and overexpressed cholesterol oxidase was purified from cell lysate by column nickel affinity chromatography. Km and Vmax values of the purified enzyme for cholesterol were estimated using Lineweaver-Burk plot. Further, the optimum pH and optimum temperature for the enzyme activity were determined. This study reports a straightforward protocol for cholesterol oxidase production which can be performed in any laboratory.
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Affiliation(s)
- Aliakbar Fazaeli
- Department of Clinical Biochemistry, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Abolfazl Golestani
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Ardabil, Iran
| | - Mostafa Lakzaei
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Ardabil, Iran
| | - Samaneh Sadat Rasi Varaei
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Ardabil, Iran
| | - Mahdi Aminian
- Department of Biochemistry, School of Medicine, Tehran University of Medical Sciences, Ardabil, Iran
- Recombinant Vaccine Research Center, Tehran University of Medical Sciences, Tehran, Iran
- * E-mail:
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6
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Fazaeli A, Golestani A, Lakzaei M, Rasi Varaei SS, Aminian M. Expression optimization of recombinant cholesterol oxidase in Escherichia coli and its purification and characterization. AMB Express 2018; 8:183. [PMID: 30421362 PMCID: PMC6232189 DOI: 10.1186/s13568-018-0711-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/29/2018] [Indexed: 12/22/2022] Open
Abstract
Cholesterol oxidase is a bacterial flavoenzyme which catalyzes oxidation and isomerization of cholesterol. This enzyme has a great commercial value because of its wide applications in cholesterol analysis of clinical samples, synthesis of steroid-derived drugs, food industries, and potentially insecticidal activity. Accordingly, development of an efficient protocol for overexpression of cholesterol oxidase can be very valuable and beneficial. In this study, expression optimization of cholesterol oxidase from Streptomyces sp. SA-COO was investigated in Escherichia coli host strains. Various parameters that may influence the yield of a recombinant enzyme were evaluated individually. The optimal host strain, culture media, induction time, Isopropyl ß-d-1-thiogalactopyranoside concentration, as well as post-induction incubation time and temperature were determined in a shaking flask mode. Applying the optimized protocol, the production of recombinant cholesterol oxidase was significantly enhanced from 3.2 to 158 U/L. Under the optimized condition, the enzyme was produced on a large-scale, and highly expressed cholesterol oxidase was purified from cell lysate by column nickel affinity chromatography. Km and Vmax values of the purified enzyme for cholesterol were estimated using Lineweaver–Burk plot. Further, the optimum pH and optimum temperature for the enzyme activity were also determined. We report a straightforward and easy protocol for cholesterol oxidase production which can be performed in any laboratory.
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7
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Srivastava A, Singh V, Haque S, Pandey S, Mishra M, Jawed A, Shukla PK, Singh PK, Tripathi CKM. Response Surface Methodology-Genetic Algorithm Based Medium Optimization, Purification, and Characterization of Cholesterol Oxidase from Streptomyces rimosus. Sci Rep 2018; 8:10913. [PMID: 30026563 PMCID: PMC6053457 DOI: 10.1038/s41598-018-29241-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/02/2018] [Indexed: 11/18/2022] Open
Abstract
The applicability of the statistical tools coupled with artificial intelligence techniques was tested to optimize the critical medium components for the production of extracellular cholesterol oxidase (COD; an enzyme of commercial interest) from Streptomyces rimosus MTCC 10792. The initial medium component screening was performed using Placket-Burman design with yeast extract, dextrose, starch and ammonium carbonate as significant factors. Response surface methodology (RSM) was attempted to develop a statistical model with a significant coefficient of determination (R2 = 0.89847), followed by model optimization using Genetic Algorithm (GA). RSM-GA based optimization approach predicted that the combination of yeast extract, dextrose, starch and ammonium carbonate at concentrations 0.99, 0.8, 0.1, and 0.05 g/100 ml respectively, has resulted in 3.6 folds increase in COD production (5.41 U/ml) in comparison with the un-optimized medium (1.5 U/ml). COD was purified 10.34 folds having specific activity of 12.37 U/mg with molecular mass of 54 kDa. The enzyme was stable at pH 7.0 and 40 °C temperature. The apparent Michaelis constant (Km) and Vmax values of COD were 0.043 mM and 2.21 μmol/min/mg, respectively. This is the first communication reporting RSM-GA based medium optimization, purification and characterization of COD by S. rimosus isolated from the forest soil of eastern India.
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Affiliation(s)
- Akanksha Srivastava
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, India.,Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, New Delhi, 110001, India
| | - Vineeta Singh
- Department of Biotechnology, Institute of Engineering & Technology, Lucknow, 226021, Uttar Pradesh, India
| | - Shafiul Haque
- Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
| | - Smriti Pandey
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, India
| | - Manisha Mishra
- Plant Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India
| | - Arshad Jawed
- Research and Scientific Studies Unit, College of Nursing & Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia
| | - P K Shukla
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, India
| | - P K Singh
- Plant Molecular Biology Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India
| | - C K M Tripathi
- Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, 226031, India. .,Department of Biotechnology, Shri Ramswaroop Memorial University, Lucknow, 225003, Uttar Pradesh, India.
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8
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Chernov KG, Neuvonen M, Brock I, Ikonen E, Verkhusha VV. Introducing inducible fluorescent split cholesterol oxidase to mammalian cells. J Biol Chem 2017; 292:8811-8822. [PMID: 28391244 DOI: 10.1074/jbc.m116.761718] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 04/05/2017] [Indexed: 11/06/2022] Open
Abstract
Cholesterol oxidase (COase) is a bacterial enzyme catalyzing the first step in the biodegradation of cholesterol. COase is an important biotechnological tool for clinical diagnostics and production of steroid drugs and insecticides. It is also used for tracking intracellular cholesterol; however, its utility is limited by the lack of an efficient temporal control of its activity. To overcome this we have developed a regulatable fragment complementation system for COase cloned from Chromobacterium sp. The enzyme was split into two moieties that were fused to FKBP (FK506-binding protein) and FRB (rapamycin-binding domain) pair and split GFP fragments. The addition of rapamycin reconstituted a fluorescent enzyme, termed split GFP-COase, the fluorescence level of which correlated with its oxidation activity. A rapid decrease of cellular cholesterol induced by intracellular expression of the split GFP-COase promoted the dissociation of a cholesterol biosensor D4H from the plasma membrane. The process was reversible as upon rapamycin removal, the split GFP-COase fluorescence was lost, and cellular cholesterol levels returned to normal. These data demonstrate that the split GFP-COase provides a novel tool to manipulate cholesterol in mammalian cells.
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Affiliation(s)
| | - Maarit Neuvonen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland.,Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland, and
| | - Ivonne Brock
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland.,Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland, and
| | - Elina Ikonen
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland, .,Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland, and
| | - Vladislav V Verkhusha
- From the Department of Biochemistry and Developmental Biology and .,Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461
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9
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El-Naggar NEA, Deraz SF, Soliman HM, El-Deeb NM, El-Shweihy NM. Purification, characterization and amino acid content of cholesterol oxidase produced by Streptomyces aegyptia NEAE 102. BMC Microbiol 2017; 17:76. [PMID: 28356065 PMCID: PMC5372259 DOI: 10.1186/s12866-017-0988-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 03/21/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is an increasing demand on cholesterol oxidase for its various industrial and clinical applications. The current research was focused on extracellular cholesterol oxidase production under submerged fermentation by a local isolate previously identified as Streptomyces aegyptia NEAE 102. The crude enzyme extract was purified by two purification steps, protein precipitation using ammonium sulfate followed by ion exchange chromatography using DEAE Sepharose CL-6B. The kinetic parameters of purified cholesterol oxidase from Streptomyces aegyptia NEAE 102 were studied. RESULTS The best conditions for maximum cholesterol oxidase activity were found to be 105 min of incubation time, an initial pH of 7 and temperature of 37 °C. The optimum substrate concentration was found to be 0.4 mM. The higher thermal stability behavior of cholesterol oxidase was at 50 °C. Around 63.86% of the initial activity was retained by the enzyme after 20 min of incubation at 50 °C. The apparent molecular weight of the purified enzyme as sized by sodium dodecyl sulphate-polyacryalamide gel electrophoresis was approximately 46 KDa. On DEAE Sepharose CL-6B column cholesterol oxidase was purified to homogeneity with final specific activity of 16.08 U/mg protein and 3.14-fold enhancement. The amino acid analysis of the purified enzyme produced by Streptomyces aegyptia NEAE 102 illustrated that, cholesterol oxidase is composed of 361 residues with glutamic acid as the most represented amino acid with concentration of 11.49 μg/mL. CONCLUSIONS Taking into account the extracellular production, wide pH tolerance, thermal stability and shelf life, cholesterol oxidase produced by Streptomyces aegyptia NEAE 102 suggested that the enzyme could be industrially useful.
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Affiliation(s)
- Noura El-Ahmady El-Naggar
- Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt.
| | - Sahar F Deraz
- Department of Protein Research, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research & Technological Applications, Alexandria, Egypt
| | - Hoda M Soliman
- Department of Botany, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Nehal M El-Deeb
- Biopharmacetical Product Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
| | - Nancy M El-Shweihy
- Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, Alexandria, Egypt
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10
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Coenzyme-like ligands for affinity isolation of cholesterol oxidase. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1021:169-174. [DOI: 10.1016/j.jchromb.2016.01.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 01/24/2016] [Accepted: 01/27/2016] [Indexed: 11/22/2022]
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11
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Protein engineering of microbial cholesterol oxidases: a molecular approach toward development of new enzymes with new properties. Appl Microbiol Biotechnol 2016; 100:4323-36. [DOI: 10.1007/s00253-016-7497-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 03/22/2016] [Accepted: 03/24/2016] [Indexed: 10/22/2022]
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12
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Cholesterol oxidase with high catalytic activity from Pseudomonas aeruginosa: Screening, molecular genetic analysis, expression and characterization. J Biosci Bioeng 2015; 120:24-30. [PMID: 25573142 DOI: 10.1016/j.jbiosc.2014.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/19/2014] [Accepted: 12/02/2014] [Indexed: 11/23/2022]
Abstract
An extracellular cholesterol oxidase producer, Pseudomonas aeruginosa strain PA157, was isolated by a screening method to detect 6β-hydroperoxycholest-4-en-3-one-forming cholesterol oxidase. On the basis of a putative cholesterol oxidase gene sequence in the genome sequence data of P. aeruginosa strain PAO1, the cholesterol oxidase gene from strain PA157 was cloned. The mature form of the enzyme was overexpressed in Escherichia coli cells. The overexpressed enzyme formed inclusion bodies in recombinant E. coli cells grown at 20 °C and 30 °C. A soluble and active PA157 enzyme was obtained when the recombinant cells were grown at 10 °C. The purified enzyme was stable at pH 5.5 to 10 and was most active at pH 7.5-8.0, showing optimal activity at pH 7.0 and 70 °C. The enzyme retained about 90% of its activity after incubation for 30 min at 70 °C. The enzyme oxidized 3β-hydroxysteroids such as cholesterol, β-cholestanol, and β-sitosterol at high rates. The Km value and Vmax value for the cholesterol were 92.6 μM and 15.9 μmol/min/mg of protein, respectively. The Vmax value of the enzyme was higher than those of commercially available cholesterol oxidases. This is the first report to characterize a cholesterol oxidase from P. aeruginosa.
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13
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Cloning, expression and biochemical characterization of the cholesterol oxidase CgChoA from Chryseobacterium gleum. BMC Biotechnol 2014; 14:46. [PMID: 24885249 PMCID: PMC4053396 DOI: 10.1186/1472-6750-14-46] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 03/25/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cholesterol oxidases are important enzymes for applications such as the analysis of cholesterol in clinical samples, the synthesis of steroid derived drugs, and are considered as potential antibacterial drug targets. RESULTS The gene choA encoding a cholesterol oxidase from Chryseobacterium gleum DSM 16776 was cloned into the pQE-30 expression vector and heterologously expressed in Escherichia coli JM109 co-transformed with pRARE2. The N-terminally His-tagged cholesterol oxidase (CgChoA) was assigned to be a monomer in solution by size exclusion chromatography, showed a temperature optimum of 35°C, and a pH optimum at 6.75 using 0.011 M MOPS buffer under the tested conditions. The purified protein showed a maximum activity of 15.5 U/mg. CgChoA showed a Michaelis-Menten like kinetic behavior only when the substrate was dissolved in water and taurocholate (apparent K(m) = 0.5 mM). In addition, the conversion of cholesterol by CgChoA was studied via biocatalytic batches at analytical scale, and cholest-4-en-3-one was confirmed as product by HPLC-MS. CONCLUSION CgChoA is a true cholesterol oxidase which activity ranges among the high performing described cholesterol oxidases from other organisms. Thus, the enzyme broadens the available toolbox of cholesterol oxidases for e.g. synthetic and biosensing applications.
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14
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An overview on alcohol oxidases and their potential applications. Appl Microbiol Biotechnol 2013; 97:4259-75. [DOI: 10.1007/s00253-013-4842-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 03/06/2013] [Accepted: 03/07/2013] [Indexed: 10/27/2022]
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15
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Mathieu JM, Wang F, Segatori L, Alvarez PJ. Increased resistance to oxysterol cytotoxicity in fibroblasts transfected with a lysosomally targeted Chromobacterium oxidase. Biotechnol Bioeng 2012; 109:2409-15. [DOI: 10.1002/bit.24506] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/14/2012] [Accepted: 03/12/2012] [Indexed: 11/06/2022]
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17
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Fernández de las Heras L, Mascaraque V, García Fernández E, Navarro-Llorens JM, Perera J, Drzyzga O. ChoG is the main inducible extracellular cholesterol oxidase of Rhodococcus sp. strain CECT3014. Microbiol Res 2011; 166:403-18. [DOI: 10.1016/j.micres.2010.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 05/10/2010] [Accepted: 05/15/2010] [Indexed: 10/19/2022]
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18
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Xin Y, Yang H, Xia X, Zhang L, Cheng C, Mou G, Shi J, Han Y, Wang W. Affinity purification of a cholesterol oxidase expressed in Escherichia coli. J Chromatogr B Analyt Technol Biomed Life Sci 2011; 879:853-8. [DOI: 10.1016/j.jchromb.2011.02.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Revised: 02/09/2011] [Accepted: 02/15/2011] [Indexed: 11/16/2022]
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19
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de Gonzalo G, Mihovilovic MD, Fraaije MW. Recent developments in the application of Baeyer-Villiger monooxygenases as biocatalysts. Chembiochem 2011; 11:2208-31. [PMID: 20936617 DOI: 10.1002/cbic.201000395] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Baeyer-Villiger monooxygenases (BVMOs) represent a specific class of monooxygenases that are capable of catalyzing a variety of oxidation reactions, including Baeyer-Villiger oxidations. The recently elucidated BVMO crystal structures have provided a more detailed insight into the complex mechanism of these flavin-containing enzymes. Biocatalytic studies on a number of newly discovered BVMOs have shown that they are very potent oxidative biocatalysts. In addition to catalyzing the regio- and enantioselective Baeyer-Villiger oxidations of a wide range of carbonylic compounds, epoxidations, and enantioselective sulfoxidations have also been shown to be part of their catalytic repertoire. This review provides an overview on the recent developments in BVMO-mediated biocatalytic processes, identification of the catalytic role of these enzymes in metabolic routes and prodrug activation, as well as the efforts in developing effective biocatalytic methodologies to apply BVMOs for the synthesis of high added value compounds.
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Affiliation(s)
- Gonzalo de Gonzalo
- Laboratory of Biochemistry, University of Groningen, Groningen, The Netherlands.
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Volontè F, Pollegioni L, Molla G, Frattini L, Marinelli F, Piubelli L. Production of recombinant cholesterol oxidase containing covalently bound FAD in Escherichia coli. BMC Biotechnol 2010; 10:33. [PMID: 20409334 PMCID: PMC2890692 DOI: 10.1186/1472-6750-10-33] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 04/21/2010] [Indexed: 11/10/2022] Open
Abstract
Background Cholesterol oxidase is an alcohol dehydrogenase/oxidase flavoprotein that catalyzes the dehydrogenation of C(3)-OH of cholesterol. It has two major biotechnological applications, i.e. in the determination of serum (and food) cholesterol levels and as biocatalyst providing valuable intermediates for industrial steroid drug production. Cholesterol oxidases of type I are those containing the FAD cofactor tightly but not covalently bound to the protein moiety, whereas type II members contain covalently bound FAD. This is the first report on the over-expression in Escherichia coli of type II cholesterol oxidase from Brevibacterium sterolicum (BCO). Results Design of the plasmid construct encoding the mature BCO, optimization of medium composition and identification of the best cultivation/induction conditions for growing and expressing the active protein in recombinant E. coli cells, concurred to achieve a valuable improvement: BCO volumetric productivity was increased from ~500 up to ~25000 U/L and its crude extract specific activity from 0.5 up to 7.0 U/mg protein. Interestingly, under optimal expression conditions, nearly 55% of the soluble recombinant BCO is produced as covalently FAD bound form, whereas the protein containing non-covalently bound FAD is preferentially accumulated in insoluble inclusion bodies. Conclusions Comparison of our results with those published on non-covalent (type I) COs expressed in recombinant form (either in E. coli or Streptomyces spp.), shows that the fully active type II BCO can be produced in E. coli at valuable expression levels. The improved over-production of the FAD-bound cholesterol oxidase will support its development as a novel biotool to be exploited in biotechnological applications.
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Affiliation(s)
- Federica Volontè
- Dipartimento di Biotecnologie e Scienze Molecolari, Università degli Studi dell'Insubria via JH Dunant 3, 21100 Varese, Italy
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Structural characterization of the organic solvent-stable cholesterol oxidase from Chromobacterium sp. DS-1. J Struct Biol 2010; 170:32-40. [PMID: 20102741 DOI: 10.1016/j.jsb.2010.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 01/19/2010] [Accepted: 01/21/2010] [Indexed: 11/20/2022]
Abstract
Cholesterol oxidase is of significant commercial interest as it is widely used as a biosensor for the detection of cholesterol in clinical samples, blood serum and food. Increased stability of this enzyme with regards to temperature and different solvent conditions are of great importance to the reliability and versatility of its applications. We here report the crystal structure of the cholesterol oxidase of Chromobacterium sp. DS-1 (CHOLOX). In contrast to other previously characterized cholesterol oxidases, this enzyme retains high activity in organic solvents and detergents at temperatures above 85 degrees C despite its mesophilic origin. With the availability of one other homologous oxidase of known three-dimensional structure, a detailed comparison of its sequence and structure was performed to elucidate the mechanisms of stabilization. In contrast to factors that typically contribute to the stability of thermophilic proteins, the structure of CHOLOX exhibits a larger overall cavity volume, less charged residues and less salt bridge interactions. Moreover, the vast majority of residue substitutions were found on or near the protein's solvent exposed surface. We propose that the engineering of enhanced stability may also be accomplished through selective engineering of the protein periphery rather than by redesigning its entire core.
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Abstract
Cholesterol oxidase is a bacterial FAD-containing flavooxidase that catalyzes the first reaction in cholesterol catabolism. Indeed, this enzyme catalyzes two reactions: the oxidation of the C(3)-OH group of cholesterol (and other sterols) to give cholest-5-en-3-one; and its isomerization to cholest-4-en-3-one. In the past several years, the structural and functional characterization of cholesterol oxidase has been developed together with its application as a biological tool. Cholesterol oxidase has been used in biocatalysis for the production of a number of steroids, as an insecticidal protein against boll weevil larvae and, in particular, as a diagnostic enzyme for determining serum levels of cholesterol. These applications prompted various laboratories worldwide to isolate this flavooxidase from different sources and to improve its properties by protein engineering, further increasing our knowledge on its structure-function relationships. These studies also discovered new physiological roles for cholesterol oxidase (e.g. in virulence and as an antifungal sensor). We assume that the investigations of cholesterol oxidase and its applications will continue to grow quickly in the near future, in particular to uncover unexpected, new areas of application.
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Affiliation(s)
- Loredano Pollegioni
- Dipartimento di Biotecnologie e Scienze Molecolari, Università degli studi dell'Insubria, Varese, Italy.
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Doukyu N. Characteristics and biotechnological applications of microbial cholesterol oxidases. Appl Microbiol Biotechnol 2009; 83:825-37. [PMID: 19495743 DOI: 10.1007/s00253-009-2059-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 05/22/2009] [Accepted: 05/23/2009] [Indexed: 11/27/2022]
Abstract
Microbial cholesterol oxidase is an enzyme of great commercial value, widely employed by laboratories routinely devoted to the determination of cholesterol concentrations in serum, other clinical samples, and food. In addition, the enzyme has potential applications as a biocatalyst which can be used as an insecticide and for the bioconversion of a number of sterols and non-steroidal alcohols. The enzyme has several biological roles, which are implicated in the cholesterol metabolism, the bacterial pathogenesis, and the biosynthesis of macrolide antifungal antibiotics. Cholesterol oxidase has been reported from a variety of microorganisms, mostly from actinomycetes. We recently reported cholesterol oxidases from gram-negative bacteria such as Burkholderia and Chromobacterium. These enzymes possess thermal, detergent, and organic solvent tolerance. There are two forms of cholesterol oxidase, one containing a flavin adenine dinucleotide cofactor non-covalently bound to the enzyme (class I) and the other containing the cofactor covalently linked to the enzyme (class II). These two enzymes have no significant sequence homology. The phylogenetic tree analyses show that both class I and class II enzymes can be further divided into at least two groups.
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Affiliation(s)
- Noriyuki Doukyu
- Bio-Nano Electronic Research Center, Toyo University, Kujirai, Kawagoe, Saitama, Japan.
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