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Shapira M, Dobysh A, Liaudanskaya A, Aucharova H, Dzichenka Y, Bokuts V, Jovanović-Šanta S, Yantsevich A. New insights into the substrate specificity of cholesterol oxidases for more aware application. Biochimie 2023; 220:1-10. [PMID: 38104713 DOI: 10.1016/j.biochi.2023.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/20/2023] [Accepted: 12/15/2023] [Indexed: 12/19/2023]
Abstract
Cholesterol oxidases (ChOxes) are enzymes that catalyze the oxidation of cholesterol to cholest-4-en-3-one. These enzymes find wide applications across various diagnostic and industrial settings. In addition, as a pathogenic factor of several bacteria, they have significant clinical implications. The current classification system for ChOxes is based on the type of bond connecting FAD to the apoenzyme, which does not adequately illustrate the enzymatic and structural characteristics of these proteins. In this study, we have adopted an integrative approach, combining evolutionary analysis, classic enzymatic techniques and computational approaches, to elucidate the distinct features of four various ChOxes from Rhodococcus sp. (RCO), Cromobacterium sp. (CCO), Pseudomonas aeruginosa (PCO) and Burkhoderia cepacia (BCO). Comparative and evolutionary analysis of substrate-binding domain (SBD) and FAD-binding domain (FBD) helped to reveal the origin of ChOxes. We discovered that all forms of ChOxes had a common ancestor and that the structural differences evolved later during divergence. Further examination of amino acid variations revealed SBD as a more variable compared to FBD independently of FAD coupling mechanism. Revealed differences in amino acid positions turned out to be critical in determining common for ChOxes properties and those that account for the individual differences in substrate specificity. A novel look with the help of chemical descriptors on found distinct features were sufficient to attempt an alternative classification system aimed at application approach. While univocal characteristics necessary to establish such a system remain elusive, we were able to demonstrate the substrate and protein features that explain the differences in substrate profile.
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Affiliation(s)
- Michail Shapira
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus.
| | - Alexandra Dobysh
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | | | - Hanna Aucharova
- Technical University of Dortmund, Faculty of Chemistry and Chemical Biology, Dortmund, Germany
| | - Yaraslau Dzichenka
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Volha Bokuts
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Suzana Jovanović-Šanta
- University of Novi Sad Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Novi Sad, Serbia
| | - Aliaksey Yantsevich
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
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Lotfy WA, Badawy HM, Ghanem KM, El-Aassar SA. Improved production of Bacillus subtilis cholesterol oxidase by optimization of process parameters using response surface methodology. J Genet Eng Biotechnol 2023; 21:141. [PMID: 37999804 PMCID: PMC10673797 DOI: 10.1186/s43141-023-00576-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
BACKGROUND Cholesterol oxidase has numerous biomedical and industrial applications. In the current study, a new bacterial strain was isolated from sewage and was selected for its high potency for cholesterol degradation (%) and production of high cholesterol oxidase activity (U/OD600). RESULTS Based on the sequence of 16S rRNA gene, the bacterium was identified as Bacillus subtilis. The fermentation conditions affecting cholesterol degradation (%) and the activity of cholesterol oxidase (U/OD600) of B. subtilis were optimized through fractional factorial design (FFD) and response surface methodology (RSM). According to this sequential optimization approach, 80.152% cholesterol degradation was achieved by setting the concentrations of cholesterol, inoculum size, and magnesium sulphate at 0.05 g/l, 6%, and 0.05 g/l, respectively. Moreover, 85.461 U of cholesterol oxidase/OD600 were attained by adjusting the fermentation conditions at initial pH, 6; volume of the fermentation medium, 15 ml/flask; and concentration of cholesterol, 0.05 g/l. The optimization process improved cholesterol degradation (%) and the activity of cholesterol oxidase (U/OD600) by 139% and 154%, respectively. No cholesterol was detected in the spectroscopic analysis of the optimized fermented medium via gas chromatography-mass spectroscopy (GC-MS). CONCLUSION The current study provides principal information for the development of efficient production of cholesterol oxidase by B. subtilis that could be used in various applications.
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Affiliation(s)
- Walid A Lotfy
- Department of Microbiology, Faculty of Dentistry, Pharos University in Alexandria, Alexandria, Egypt.
| | - Hala M Badawy
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Khaled M Ghanem
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Samy A El-Aassar
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, Egypt
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Loop pathways are responsible for tuning the accumulation of C19- and C22-sterol intermediates in the mycobacterial phytosterol degradation pathway. Microb Cell Fact 2023; 22:19. [PMID: 36710325 PMCID: PMC9885637 DOI: 10.1186/s12934-022-02008-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 12/20/2022] [Indexed: 01/31/2023] Open
Abstract
4-Androstene-3,17-dione (4-AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (BA) are the most important and representative C19- and C22-steroidal materials. The optimalization of sterol production with mycobacterial phytosterol conversion has been investigated for decades. One of the major challenges is that current industrial mycobacterial strains accumulate unignorable impurities analogous to desired sterol intermediates, significantly hampering product extractions and refinements. Previously, we identified Mycobacterium neoaurum HGMS2 as an efficient 4-AD-producing strain (Wang et al. in Microb Cell Fact. 19:187, 2020). Recently, we have genetically modified the HGMS2 strain to remove its major impurities including ADD and 9OH-AD (Li et al. in Microb Cell Fact. 20:158, 2021). Unexpectedly, the modified mutants started to significantly accumulate BA compared with the HGMS2 strain. In this work, while we attempted to block BA occurrence during 4-AD accumulation in HGMS2 mutants, we identified a few loop pathways that regulated metabolic flux switching between 4-AD and BA accumulations and found that both the 4-AD and BA pathways shared a 9,10-secosteroidial route. One of the key enzymes in the loop pathways was Hsd4A1, which played an important role in determining 4-AD accumulation. The inactivation of the hsd4A1 gene significantly blocked the 4-AD metabolic pathway so that the phytosterol degradation pathway flowed to the BA metabolic pathway, suggesting that the BA metabolic pathway is a complementary pathway to the 4-AD pathway. Thus, knocking out the hsd4A1 gene essentially made the HGMS2 mutant (HGMS2Δhsd4A1) start to efficiently accumulate BA. After further knocking out the endogenous kstd and ksh genes, an HGMS2Δhsd4A1 mutant, HGMS2Δhsd4A1/Δkstd1, enhanced the phytosterol conversion rate to BA in 1.2-fold compared with the HGMS2Δhsd4A1 mutant in pilot-scale fermentation. The final BA yield increased to 38.3 g/L starting with 80 g/L of phytosterols. Furthermore, we knocked in exogenous active kstd or ksh genes to HGMS2Δhsd4A1/Δ kstd1 to construct DBA- and 9OH-BA-producing strains. The resultant DBA- and 9OH-BA-producing strains, HGMS2Δhsd4A1/kstd2 and HGMS2Δkstd1/Δhsd4A1/kshA1B1, efficiently converted phytosterols to DBA- and 9OH-BA with the rates of 42.5% and 40.3%, respectively, and their final yields reached 34.2 and 37.3 g/L, respectively, starting with 80 g/L phytosterols. Overall, our study not only provides efficient strains for the industrial production of BA, DBA and 9OH-BA but also provides insights into the metabolic engineering of the HGMS2 strain to produce other important steroidal compounds.
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Key Words
- 1,4-androstadiene-3,17-dione (ADD)
- 22-hydroxy-23,24-bisnorchol-4-ene-3-one (BA)
- 3-hydroxy-9,10-secoandrost-1,3,5(10)-triene-9,17-dione (HSA)
- 3-ketosteroid-1,2-dehydrogenase (KstD)
- 3-ketosteroid-9α-hydroxylase (Ksh)
- 4-androstene-3,17-dione (4-AD)
- 9α-hydroxyl-4-androstene-3,17-dione (9OH-AD)
- Bioconversion
- Biotransformation
- Cholesterol oxidases (Cho)
- Monooxygenase (Mon)
- Phytosterols and Mycobacterium sp.
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Karimiabar M, Ahari H, Amini K. Molecular Cloning, Expression, and Enzyme Activity of Glucose Oxidase Gene from Soil Thermophilic Streptomyces. IRANIAN JOURNAL OF BIOTECHNOLOGY 2022; 20:e2979. [PMID: 35891952 PMCID: PMC9284247 DOI: 10.30498/ijb.2021.272122.2979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Background Glucose oxidase is an oxidoreductase that depletes oxygen in food processing and is used in biosensors, glucose diagnostic kits, food processing, cosmetics, and chemical industries. This enzyme is often isolated from fungi, such as Penicillium and Aspergillus Niger. Objectives The objective of this study was to clone and express a full-length GOX gene from soil thermophilic streptomyces for bioinformatic and enzyme activity evaluations. Materials and Methods After collecting samples from the Gandom Beryan area of Kerman province, Iran, Streptomyces strains were identified with specific biochemical and molecular tests. Streptomyces strains with glucose oxidase gene were detected by PCR, and the amplified gene fragment was cloned into Escherichia coli host bacterium using TA cloning technique. The expression of the cloned GOX gene in the host bacterium was measured using real-time PCR, and the recombinant plasmids were sequenced. The enzymatic activity was measured in the extracts of E. coli cells carrying the plasmids. Results After screening the samples, 12 strains of Streptomyces were identified, 4 of which carried the GOX gene. The GOX open reading frame, obtained by PCR, was cloned into a vector and transformed into Escherichia coli origami to generate GOX-producing bacteria. Enzyme activity was confirmed and a phylogenetic tree showed the degree of kinship between Streptomyces species and other species, including Streptomyces SP MI02-7b. The expression levels of GOX genes mRNA were found to be approximately 4-fold higher in transformed E. coli than in soil thermophilic Streptomyces (P <0.001). Conclusion This study showed that natural thermostable streptomyces producing glucose oxidase enzyme could be found in Iran. The enzyme gene was successfully transformed into Escherichia coli generating a recombinant host with high yield capability that can be a major step towards the production of this enzyme from indigenous strains. It should be emphasized that the GOX enzyme produced by these strains is profitable due to high production levels correlated to the optimum condition in cheap culture media, short fermentation cycles, high expression capability, and ease of growth.
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Affiliation(s)
- Mahsa Karimiabar
- Department of Food Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Hamed Ahari
- Department of Food Science and Technology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Kumarss Amini
- Department of Microbiology, Faculty of Basic Science, Saveh Branch, Islamic Azad University, Saveh, Iran
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Zhu WY, Niu K, Liu P, Fan YH, Liu ZQ, Zheng YG. Identification and Characterization of an O-Succinyl-L-Homoserine Sulfhydrylase From Thioalkalivibrio sulfidiphilus. Front Chem 2021; 9:672414. [PMID: 33937207 PMCID: PMC8080516 DOI: 10.3389/fchem.2021.672414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 03/23/2021] [Indexed: 11/13/2022] Open
Abstract
L-methionine is an important natural amino acid with broad application prospects. A novel gene encoding the enzyme with the ability to catalyze O-succinyl-L-homoserine (OSH) to L-methionine was screened and characterized. The recombinant O-succinyl-L-homoserine sulfhydrylase from Thioalkalivibrio sulfidiphilus (tsOSHS) exhibited maximum activity at 35°C and pH 6.5. OSHS displayed an excellent thermostability with a half-life of 21.72 h at 30°C. Furthermore, the activity of OSHS increased 115% after Fe2+ added. L-methionine was obtained with a total yield reaching 42.63 g/L under the concentration of O-succinyl-L-homoserine 400 mM (87.6 g/L). These results indicated that OSHS is a potential candidate for applying in the large-scale bioproduction of L-methionine.
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Affiliation(s)
- Wen-Yuan Zhu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Kun Niu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Peng Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yu-Hang Fan
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Zhi-Qiang Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yu-Guo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, China.,Key Laboratory of Bioorganic Synthesis of Zhejiang, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
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Schmitz R, Tweed K, Walsh C, Walsh AJ, Skala MC. Extracellular pH affects the fluorescence lifetimes of metabolic co-factors. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210047LR. [PMID: 34032035 PMCID: PMC8144436 DOI: 10.1117/1.jbo.26.5.056502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 05/11/2021] [Indexed: 06/12/2023]
Abstract
SIGNIFICANCE Autofluorescence measurements of the metabolic cofactors NADH and flavin adenine dinucleotide (FAD) provide a label-free method to quantify cellular metabolism. However, the effect of extracellular pH on flavin lifetimes is currently unknown. AIM To quantify the relationship between extracellular pH and the fluorescence lifetimes of FAD, flavin mononucleotide (FMN), and reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H]. APPROACH Human breast cancer (BT474) and HeLa cells were placed in pH-adjusted media. Images of an intracellular pH indicator or endogenous fluorescence were acquired using two-photon fluorescence lifetime imaging. Fluorescence lifetimes of FAD and FMN in solutions were quantified over the same pH range. RESULTS The relationship between intracellular and extracellular pH was linear in both cell lines. Between extracellular pH 4 to 9, FAD mean lifetimes increased with increasing pH. NAD(P)H mean lifetimes decreased with increasing pH between extracellular pH 5 to 9. The relationship between NAD(P)H lifetime and extracellular pH differed between the two cell lines. Fluorescence lifetimes of FAD, FAD-cholesterol oxidase, and FMN solutions decreased, showed no trend, and showed no trend, respectively, with increasing pH. CONCLUSIONS Changes in endogenous fluorescence lifetimes with extracellular pH are mostly due to indirect changes within the cell rather than direct pH quenching of the endogenous molecules.
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Affiliation(s)
- Rebecca Schmitz
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Kelsey Tweed
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, Wisconsin, United States
| | - Christine Walsh
- Morgridge Institute for Research, Madison, Wisconsin, United States
| | - Alex J. Walsh
- Morgridge Institute for Research, Madison, Wisconsin, United States
- Texas A&M University, Department of Biomedical Engineering, College Station, Texas, United States
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, Wisconsin, United States
- University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, Wisconsin, United States
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Wang H, Song S, Peng F, Yang F, Chen T, Li X, Cheng X, He Y, Huang Y, Su Z. Whole-genome and enzymatic analyses of an androstenedione-producing Mycobacterium strain with residual phytosterol-degrading pathways. Microb Cell Fact 2020; 19:187. [PMID: 33008397 PMCID: PMC7532642 DOI: 10.1186/s12934-020-01442-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 09/25/2020] [Indexed: 01/29/2023] Open
Abstract
Mycobacterium neoaurum strains can transform phytosterols to 4-androstene-3,17-dione (4-AD), a key intermediate for the synthesis of advanced steroidal medicines. In this work, we presented the complete genome sequence of the M. neoaurum strain HGMS2, which transforms β-sitosterol to 4-AD. Through genome annotation, a phytosterol-degrading pathway in HGMS2 was predicted and further shown to form a 9,10-secosteroid intermediate by five groups of enzymes. These five groups of enzymes included three cholesterol oxidases (ChoM; group 1: ChoM1, ChoM2 and Hsd), two monooxygenases (Mon; group 2: Mon164 and Mon197), a set of enzymes for side-chain degradation (group 3), one 3-ketosteroid-1,2-dehydrogenase (KstD; group 4: KstD211) and three 3-ketosteroid-9a-hydroxylases (Ksh; group 5: KshA226, KshA395 and KshB122). A gene cluster encoding Mon164, KstD211, KshA226, KshB122 and fatty acid β-oxidoreductases constituted one integrated metabolic pathway, while genes encoding other key enzymes were sporadically distributed. All key enzymes except those from group 3 were prepared as recombinant proteins and their activities were evaluated, and the proteins exhibited distinct activities compared with enzymes identified from other bacterial species. Importantly, we found that the KstD211 and KshA395 enzymes in the HGMS2 strain retained weak activities and caused the occurrence of two major impurities, i.e., 1,4-androstene-3,17-dione (ADD) and 9-hydroxyl-4-androstene-3,17-dione (9OH-AD) during β-sitosterol fermentation. The concurrence of these two 4-AD analogs not only lowered 4-AD production yield but also hampered 4-AD purification. HGMS2 has the least number of genes encoding KstD and Ksh enzymes compared with current industrial strains. Therefore, HGMS2 could be a potent strain by which the 4-AD production yield could be enhanced by disabling the KstD211 and KshA395 enzymes. Our work also provides new insight into the engineering of the HGMS2 strain to produce ADD and 9OH-AD for industrial application.
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Affiliation(s)
- Hongwei Wang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Shikui Song
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Fei Peng
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Fei Yang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Tian Chen
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Xin Li
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Xiyao Cheng
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China.,Wuhan Amersino Biodevelop Inc., B1-Building, Biolake Park, Wuhan, 430075, Hubei, China
| | - Yijun He
- Hubei Goto Biotech Inc., No. 1 Baiguoshu Road, Shuidu Industrial Park, Danjiangkou, 442700, Hubei, China
| | - Yongqi Huang
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China
| | - Zhengding Su
- Key Laboratory of Industrial Fermentation (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei University of Technology, Wuhan, 430068, China. .,Wuhan Amersino Biodevelop Inc., B1-Building, Biolake Park, Wuhan, 430075, Hubei, China.
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9
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Devi S, Sharma B, Kumar R, Singh Kanwar S. Purification, characterization, and biological cytotoxic activity of the extracellular cholesterol oxidase produced by Castellaniella sp. COX. J Basic Microbiol 2019; 60:253-267. [PMID: 31750957 DOI: 10.1002/jobm.201900365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 01/19/2023]
Abstract
A new bacterial strain producing extracellular cholesterol oxidase (ChOx) was isolated and identified as Castellaniella sp. COX. The ChOx was purified by salting-out and ion-exchange chromatography up to 10.4-fold, with a specific activity of 15 U/mg with a molecular mass of 59 kDa. The purified ChOx exhibited pH 8.0 and temperature 40°C for its optimum activity. The enzyme showed stability over a wide pH range and was most stable at pH value 7.0, and at pH 8.0, it retained almost 86% of its initial activity after 3 h of incubation at 37°C. The enzyme possessed a half-life of 8 h at 37°C, 7 h at 40°C, and 3 h at 50°C. A Lineweaver-Burk plot was calibrated to determine its Km (0.16 mM) and Vmax (18.7 μmol·mg-1 ·min-1 ). The ChOx activity was enhanced with Ca2+ , Mg2+ , and Mn2+ while it was inhibited by Hg2+ , Ba2+ , Fe2+ , Cu2+ , and Zn2+ ions. Organic solvents like acetone, n-butanol, toluene, dimethyl sulfoxide, chloroform, benzene, and methanol were well tolerated by the enzyme while iso-propanol and ethanol were found to enhance the activity of purified ChOx. ChOx induced cytotoxicity with an IC50 value of 1.78 and 1.88 U/ml against human RD and U87MG established cell lines, respectively, while broadly sparing the normal human cells.
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Affiliation(s)
- Sunita Devi
- Department of Biotechnology, Himachal Pradesh University, Shimla, Himachal Pradesh, India
| | - Bhupender Sharma
- Department of Biotechnology, Himachal Pradesh University, Shimla, Himachal Pradesh, India
| | - Rakesh Kumar
- Department of Biotechnology, Himachal Pradesh University, Shimla, Himachal Pradesh, India
| | - Shamsher Singh Kanwar
- Department of Biotechnology, Himachal Pradesh University, Shimla, Himachal Pradesh, India
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10
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Characterization and overproduction of cell-associated cholesterol oxidase ChoD from Streptomyces lavendulae YAKB-15. Sci Rep 2019; 9:11850. [PMID: 31413341 PMCID: PMC6694107 DOI: 10.1038/s41598-019-48132-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/25/2019] [Indexed: 11/30/2022] Open
Abstract
Cholesterol oxidases are important enzymes with a wide range of applications from basic research to industry. In this study, we have discovered and described the first cell-associated cholesterol oxidase, ChoD, from Streptomyces lavendulae YAKB-15. This strain is a naturally high producer of ChoD, but only produces ChoD in a complex medium containing whole yeast cells. For characterization of ChoD, we acquired a draft genome sequence of S. lavendulae YAKB-15 and identified a gene product containing a flavin adenine dinucleotide binding motif, which could be responsible for the ChoD activity. The enzymatic activity was confirmed in vitro with histidine tagged ChoD produced in Escherichia coli TOP10, which lead to the determination of basic kinetic parameters with Km 15.9 µM and kcat 10.4/s. The optimum temperature and pH was 65 °C and 5, respectively. In order to increase the efficiency of production, we then expressed the cholesterol oxidase, choD, gene heterologously in Streptomyces lividans TK24 and Streptomyces albus J1074 using two different expression systems. In S. albus J1074, the ChoD activity was comparable to the wild type S. lavendulae YAKB-15, but importantly allowed production of ChoD without the presence of yeast cells.
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11
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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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Metabolic engineering of E. coli for the production of O-succinyl-l-homoserine with high yield. 3 Biotech 2018; 8:310. [PMID: 30002999 DOI: 10.1007/s13205-018-1332-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 07/02/2018] [Indexed: 12/14/2022] Open
Abstract
O-succinyl-l-homoserine (OSH) is a promising platform chemical for the production of C4 chemicals with huge market potential which can be produced by fermentation from glucose. To construct a strain capable of producing OSH with high yield, the metJ (encodes transcriptional repressor) and metI (encodes a subunit of dl-methionine transporter) were deleted in Escherichia coli W3110 to obtain a strain E. coli ∆JI. Then, overexpression of metL (encodes bifunctional aspartate kinase/homoserine dehydrogenase II) and inactivation of metB (encodes cystathionine γ-synthase) were implemented in one step, and the OSH titer of the resulting strain E. coli ∆JIB* TrcmetL was dramatically increased to 7.30 g/L. The feedback regulation was further relieved by progressively overexpressing metAfbr (encodes homoserine O-succinyltransferase), yjeH (encodes l-methionine exporter), and thrAfbr (encodes bifunctional aspartate kinase/homoserine dehydrogenase I) to increase the metabolic flux from aspartate to OSH. The 100% rationally designed strain E. coli ∆JIB* TrcmetL/pTrc-metAfbr -Trc-thrAfbr -yjeH produced 9.31 g/L OSH from 20 g/L glucose (0.466 g/g glucose) in batch fermentation, which represents the highest OSH yield from glucose reported to date. The culture profiles of the newly constructed strains were recorded to investigate their productive properties. The effects of l-methionine addition on the fermentation process of the optimal strain were also studied. Our results demonstrate that tuning the expression level of metL, inactivation of metB, and attenuation of feedback resistance of the crucial enzymes in the biosynthetic pathway are the key factors that impact the OSH production in E. coli.
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