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Lee K, Yeom M, Vu TTH, Do HQ, Na W, Lee M, Jeong DG, Cheon DS, Song D. Characterization of highly pathogenic avian influenza A (H5N1) viruses isolated from cats in South Korea, 2023. Emerg Microbes Infect 2024; 13:2290835. [PMID: 38044871 PMCID: PMC10810616 DOI: 10.1080/22221751.2023.2290835] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Affiliation(s)
- Kyungmoon Lee
- Department of Virology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
| | - Minjoo Yeom
- Department of Virology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
| | | | - Hai-Quynh Do
- Department of Virology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
| | - Woonsung Na
- College of Veterinary Medicine, Chonnam University, Gwangju, South Korea
| | | | - Dae Gwin Jeong
- Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | | | - Daesub Song
- Department of Virology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
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Hang Vu TT, Le VP, Jeong DG, Yeom M, Oh J, Kang B, Park SK, Song D. Establishment of a p30-based lateral flow assay for African swine fever virus detection. J Virol Methods 2023; 322:114823. [PMID: 37748737 DOI: 10.1016/j.jviromet.2023.114823] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 09/27/2023]
Abstract
African swine fever virus (ASFV) has continuously devastated the global pig industry. Viral persistence causes problems in large pig farms and kills small farms. Timely diagnostic tools play an important role in controlling outbreaks and minimizing losses. In this study, we developed a lateral flow assay to detect ASFV on-site. The VDRG® ASFV Ag Rapid Kit was established using two monoclonal antibodies (mAbs) against the p30 protein. The conjunction pad of the kit was coated with a mixture of the mAb and colloidal gold. This rapid kit was capable of detecting 11.5 ng of antigen and 0.16 HAD50 of virus from samples, in 20 min for the entire procedure. It passed cross-specific tests using common viruses that cause infectious diseases in pigs. ASFV was detected after 4 days in experimental infection in pigs by the kit. The specificity and sensitivity of the kit for clinical samples were 99.88% and 84.52% (93.8% for samples with a Ct value below 30), respectively. Finally, the kit can detect 100% positive herd outbreaks. The VDRG® ASFV Ag Rapid Kit presents a useful point-of-care tool for ASFV detection.
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Affiliation(s)
- Thi Thu Hang Vu
- College of Pharmacy, Korea University, Sejong, Republic of Korea
| | - Van Phan Le
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 131001, Viet Nam
| | - Dae Gwin Jeong
- Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea; Bio-Analytical Science Division, University of Science and Technology, Daejeon, Republic of Korea
| | - Minjoo Yeom
- College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea
| | - Jinsik Oh
- Median Diagnostics, Chuncheon, Gangwon-do 24399, Republic of Korea
| | - BoKyu Kang
- Median Diagnostics, Chuncheon, Gangwon-do 24399, Republic of Korea
| | - Song-Kyu Park
- College of Pharmacy, Korea University, Sejong, Republic of Korea.
| | - Daesub Song
- College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea.
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Lim JW, Vu TTH, Le VP, Yeom M, Song D, Jeong DG, Park SK. Advanced Strategies for Developing Vaccines and Diagnostic Tools for African Swine Fever. Viruses 2023; 15:2169. [PMID: 38005846 PMCID: PMC10674204 DOI: 10.3390/v15112169] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 11/26/2023] Open
Abstract
African swine fever (ASF) is one of the most lethal infectious diseases affecting domestic pigs and wild boars of all ages. Over a span of 100 years, ASF has continued to spread over continents and adversely affects the global pig industry. To date, no vaccine or treatment has been approved. The complex genome structure and diverse variants facilitate the immune evasion of the ASF virus (ASFV). Recently, advanced technologies have been used to design various potential vaccine candidates and effective diagnostic tools. This review updates vaccine platforms that are currently being used worldwide, with a focus on genetically modified live attenuated vaccines, including an understanding of their potential efficacy and limitations of safety and stability. Furthermore, advanced ASFV detection technologies are presented that discuss and incorporate the challenges that remain to be addressed for conventional detection methods. We also highlight a nano-bio-based system that enhances sensitivity and specificity. A combination of prophylactic vaccines and point-of-care diagnostics can help effectively control the spread of ASFV.
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Affiliation(s)
- Jong-Woo Lim
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea; (J.-W.L.); (M.Y.); (D.S.)
| | - Thi Thu Hang Vu
- College of Pharmacy, Korea University, Sejong 30019, Republic of Korea;
| | - Van Phan Le
- Department of Veterinary Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 131000, Vietnam;
| | - Minjoo Yeom
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea; (J.-W.L.); (M.Y.); (D.S.)
| | - Daesub Song
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, Republic of Korea; (J.-W.L.); (M.Y.); (D.S.)
| | - Dae Gwin Jeong
- Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
- Bio-Analytical Science Division, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Song-Kyu Park
- College of Pharmacy, Korea University, Sejong 30019, Republic of Korea;
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Lee H, Lee S, Park C, Yeom M, Lim JW, Vu TTH, Kim E, Song D, Haam S. Rapid Visible Detection of African Swine Fever Virus Using Hybridization Chain Reaction-Sensitized Magnetic Nanoclusters and Affinity Chromatography. Small 2023:e2207117. [PMID: 36960666 DOI: 10.1002/smll.202207117] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/09/2023] [Indexed: 06/18/2023]
Abstract
African swine fever virus (ASFV) is a severe and persistent threat to the global swine industry. As there are no vaccines against ASFV, there is an immense need to develop easy-to-use, cost-effective, and rapid point-of-care (POC) diagnostic platforms to detect and prevent ASFV outbreaks. Here, a novel POC diagnostic system based on affinity column chromatography for the optical detection of ASFV is presented. This system employs an on-particle hairpin chain reaction to sensitize magnetic nanoclusters with long DNA strands in a target-selective manner, which is subsequently fed into a column chromatography device to produce quantitatively readable and colorimetric signals. The detection approach does not require expensive analytical apparatus or immobile instrumentation. The system can detect five genes constituting the ASFV whole genome with a detection limit of ≈19.8 pm in swine serum within 30 min at laboratory room temperature. With an additional pre-amplification step using polymerase chain reaction (PCR), the assay is successfully applied to detect the presence of ASFV in 30 suspected swine samples with 100% sensitivity and specificity, similar to quantitative PCR. Thus, this simple, inexpensive, portable, robust, and customizable platform for the early detection of ASFV can facilitate the timely surveillance and implementation of control measures.
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Affiliation(s)
- Hyo Lee
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Sojeong Lee
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Chaewon Park
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Minjoo Yeom
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jong-Woo Lim
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Thi Thu Hang Vu
- Department of Preclinical Science, College of Pharmacy, Korea University Sejong Campus, Sejong City, 30019, Republic of Korea
| | - Eunjung Kim
- Division of Bioengineering, Incheon National University, Incheon, 22012, Republic of Korea
- Department of Bioengineering & Nano-Bioengineering, Research Center for Bio Materials and Process Development, Incheon National University, Incheon, 22012, Republic of Korea
| | - Daesub Song
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seungjoo Haam
- Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea
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Vu TTH, Yeom M, Moon H, Tran TN, Le VP, Song D. Characteristics and Pathogenicity of the Cell-Adapted Attenuated Porcine Epidemic Diarrhea Virus of the Non-S INDEL Cluster. Pathogens 2021; 10:pathogens10111479. [PMID: 34832634 PMCID: PMC8618312 DOI: 10.3390/pathogens10111479] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/07/2021] [Accepted: 11/10/2021] [Indexed: 11/30/2022] Open
Abstract
The high antigenic diversity of porcine epidemic diarrhea virus (PEDV) means that porcine epidemic diarrhea (PED) is a challenge for the global pig industry. Understanding the circulation of the virus to determine an optimal vaccine strategy is important in controlling the disease. In this study, we describe the genetic diversity of circulating PEDV based on the full sequences of spike genes of eight positive samples collected in Vietnam since 2018. Additionally, we developed a live attenuated vaccine candidate from the cell-adapted PEDV2 strain, which was continuously passaged until level 103 in VERO-CCL81 cells. PEDV2-p103, which belongs to the emerging non-S INDEL cluster, exhibited low virus shedding, did not induce lesions in the small intestine of challenged piglets, and had a high titer in the VERO-CCL81 cell at 48 h post-infection. These results suggest that the PEDV2-p103 strain could be a potential oral attenuated vaccine, and its immunogenicity and efficacy should be further assessed through in vivo tests.
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Affiliation(s)
- Thi Thu Hang Vu
- College of Pharmacy, Korea University, Sejong 30019, Korea; (T.T.H.V.); (M.Y.)
| | - Minjoo Yeom
- College of Pharmacy, Korea University, Sejong 30019, Korea; (T.T.H.V.); (M.Y.)
| | - Hyoungjoon Moon
- College of Healthcare & Biotechnology, Semyung University, Jecheon 27136, Korea;
- Research Unit, Green Cross Veterinary Products, Yongin 17066, Korea
| | - Thi Nhan Tran
- R&D laboratory, AVAC Vietnam Company Limited, Hung Yen 163530, Vietnam;
| | - Van Phan Le
- College of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi 131001, Vietnam
- Correspondence: (V.P.L.); (D.S.)
| | - Daesub Song
- College of Pharmacy, Korea University, Sejong 30019, Korea; (T.T.H.V.); (M.Y.)
- Correspondence: (V.P.L.); (D.S.)
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Le VP, Jeong DG, Yoon SW, Kwon HM, Trinh TBN, Nguyen TL, Bui TTN, Oh J, Kim JB, Cheong KM, Van Tuyen N, Bae E, Vu TTH, Yeom M, Na W, Song D. Outbreak of African Swine Fever, Vietnam, 2019. Emerg Infect Dis 2019; 25:1433-1435. [PMID: 31075078 PMCID: PMC6590755 DOI: 10.3201/eid2507.190303] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
African swine fever is one of the most dangerous diseases of swine. We confirmed the 2019 outbreak in Vietnam by real-time reverse transcription PCR. The causative strain belonged to p72 genotype II and was 100% identical with viruses isolated in China (2018) and Georgia (2007). International prevention and control collaboration is needed.
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Le VP, Song S, An BH, Park GN, Pham NT, Le DQ, Nguyen VT, Vu TTH, Kim KS, Choe S, An DJ. A novel strain of porcine deltacoronavirus in Vietnam. Arch Virol 2017; 163:203-207. [PMID: 29022111 PMCID: PMC7087264 DOI: 10.1007/s00705-017-3594-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 08/20/2017] [Indexed: 11/29/2022]
Abstract
Two porcine deltacoronavirus (PDCoV) strains (Binh21 and HaNoi6) were isolated from two pig farms in North Vietnam. Phylogenetic analysis of the complete genomes and the Spike and Membrane genes revealed that the two Vietnam PDCoVs belong to the same lineage as PDCoVs from Thailand and Laos; however, the N genes belonged to the same lineage as PDCoVs from the USA, Korea, China, and Hong Kong. The recombination detection program subsequently identified the major parent (S5011 strain) and minor parent (HKU15-44 strain) of the two Vietnam PDCoV strains (p < 0.01).
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Affiliation(s)
- Van Phan Le
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Sok Song
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongbuk-do, 39660, Republic of Korea
| | - Byung-Hyun An
- Applied Chemistry and Biological Engineering, Ajou University, Suwon, 443-749, Republic of Korea
| | - Gyu-Nam Park
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongbuk-do, 39660, Republic of Korea
| | - Ngoc Thach Pham
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Dinh Quyen Le
- Research and Development Laboratory, AVAC Vietnam Company Limited (AVAC), Hanoi, Vietnam
| | - Van Tam Nguyen
- Research and Development Laboratory, AVAC Vietnam Company Limited (AVAC), Hanoi, Vietnam
| | - Thi Thu Hang Vu
- Research and Development Laboratory, AVAC Vietnam Company Limited (AVAC), Hanoi, Vietnam
| | - Ki-Sun Kim
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongbuk-do, 39660, Republic of Korea
| | - SeEun Choe
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongbuk-do, 39660, Republic of Korea
| | - Dong-Jun An
- Virus Disease Division, Animal and Plant Quarantine Agency, Gimcheon, Gyeongbuk-do, 39660, Republic of Korea.
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Le VP, Vu TTH, Duong HQ, Than VT, Song D. Evolutionary phylodynamics of foot-and-mouth disease virus serotypes O and A circulating in Vietnam. BMC Vet Res 2016; 12:269. [PMID: 27894299 PMCID: PMC5126991 DOI: 10.1186/s12917-016-0896-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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: 03/12/2016] [Accepted: 11/22/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Foot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006-2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally. RESULTS Phylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1-100, 92.9-100, and 92.8-100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes. CONCLUSIONS This study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.
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Affiliation(s)
- Van Phan Le
- Department of Microbiology and Infectious Disease, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.
| | - Thi Thu Hang Vu
- Research and Development Laboratory, Rural Technology Development JSC, Hung Yen, Vietnam
| | - Hong-Quan Duong
- Institute of Research and Development, Duy Tan University, Danang, Vietnam
| | - Van Thai Than
- Department of Microbiology, Chung-Ang University College of Medicine, Seoul, South Korea.
| | - Daesub Song
- College of Pharmacy, Korea University, Sejong, South Korea
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Do HQ, Trinh DT, Nguyen TL, Vu TTH, Than DD, Van Lo T, Yeom M, Song D, Choe S, An DJ, Le VP. Molecular evolution of type 2 porcine reproductive and respiratory syndrome viruses circulating in Vietnam from 2007 to 2015. BMC Vet Res 2016; 12:256. [PMID: 27855667 PMCID: PMC5112882 DOI: 10.1186/s12917-016-0885-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [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: 07/14/2016] [Accepted: 11/10/2016] [Indexed: 11/24/2022] Open
Abstract
Background Porcine respiratory and reproductive syndrome (PRRS) virus is one of the most economically significant pathogens in the Vietnamese swine industry. ORF5, which participates in many functional processes, including virion assembly, entry of the virus into the host cell, and viral adaptation to the host immune response, has been widely used in molecular evolution and phylogeny studies. Knowing of molecular evolution of PRRSV fields strains might contribute to PRRS control in Vietnam. Results The results showed that phylogenetic analysis indicated that all strains belonged to sub-lineages 8.7 and 5.1. The nucleotide and amino acid identities between strains were 84.5–100% and 82–100%, respectively. Furthermore, the results revealed differences in nucleotide and amino acid identities between the 2 sub-lineage groups. N-glycosylation prediction identified 7 potential N-glycosylation sites and 11 glycotypes. Analyses of the GP5 sequences, revealed 7 sites under positive selective pressure and 25 under negative selective pressure. Conclusions Phylogenetic analysis based on ORF5 sequence indicated the diversity of PRRSV in Vietnam. Furthermore, the variance of N-glycosylation sites and position under selective pressure were demonstrated. This study expands existing knowledge on the genetic diversity and evolution of PRRSV in Vietnam and assists the effective strategies for PRRS vaccine development in Vietnam. Electronic supplementary material The online version of this article (doi:10.1186/s12917-016-0885-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hai Quynh Do
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Dinh Thau Trinh
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi Lan Nguyen
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi Thu Hang Vu
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Duc Duong Than
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Thi Van Lo
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Minjoo Yeom
- College of Pharmacy, Korea University, Sejong, Republic of Korea
| | - Daesub Song
- College of Pharmacy, Korea University, Sejong, Republic of Korea
| | - SeEun Choe
- Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo, Republic of Korea
| | - Dong-Jun An
- Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo, Republic of Korea
| | - Van Phan Le
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.
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Vu TTH, Quyen DT, Dao TT, Nguyen SLT. Cloning, high-level expression, purification, and properties of a novel endo-beta-1,4-mannanase from Bacillus subtilis G1 in Pichia pastoris. J Microbiol Biotechnol 2012; 22:331-8. [PMID: 22450788 DOI: 10.4014/jmb.1106.06052] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
A novel gene coding for an endo-beta-1,4-mannanase (manA) from Bacillus subtilis strain G1 was cloned and overexpressed in P. pastoris GS115, and the enzyme was purified and characterized. The manA gene consisted of an open reading frame of 1,092 nucleotides, encoding a 364-aa protein, with a predicted molecular mass of 41 kDa. The beta-mannanase showed an identity of 90.2-92.9% (< or =95%) with the corresponding amino acid sequences from B. subtilis strains deposited in GenBank. The purified beta- mannanase was a monomeric protein on SDS-PAGE with a specific activity of 2,718 U/mg and identified by MALDITOF mass spectrometry. The recombinant beta-mannanase had an optimum temperature of 45 degrees C and optimum pH of 6.5. The enzyme was stable at temperatures up to 50 degrees C (for 8 h) and in the pH range of 5-9. EDTA and most tested metal ions showed a slightly to an obviously inhibitory effect on enzyme activity, whereas metal ions (Hg2+, Pb2+, and Co2+) substantially inhibited the recombinant beta-mannanase. The chemical additives including detergents (Triton X- 100, Tween 20, and SDS) and organic solvents (methanol, ethanol, n-butanol, and acetone) decreased the enzyme activity, and especially no enzyme activity was observed by addition of SDS at the concentrations of 0.25-1.0% (w/v) or n-butanol at the concentrations of 20-30% (v/v). These results suggested that the beta-mannanase expressed in P. pastoris could potentially be used as an additive in the feed for monogastric animals.
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Affiliation(s)
- Thi Thu Hang Vu
- Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Distr. Caugiay, 10600 Hanoi, Vietnam
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Basnet DB, Oh TJ, Vu TTH, Sthapit B, Liou K, Lee HC, Yoo JC, Sohng JK. Angucyclines Sch 47554 and Sch 47555 from Streptomyces sp. SCC-2136: cloning, sequencing, and characterization. Mol Cells 2006; 22:154-62. [PMID: 17085966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023] Open
Abstract
The entire gene cluster involved in the biosynthesis of angucyclines Sch 47554 and Sch 47555 was cloned, sequenced, and characterized. Analysis of the nucleotide sequence of genomic DNA spanning 77.5-kb revealed a total of 55 open reading frames, and the deduced products exhibited strong sequence similarities to type II polyketide synthases, deoxysugar biosynthetic enzymes, and a variety of accessory enzymes. The involvement of this gene cluster in the pathway of Sch 47554 and Sch 47555 was confirmed by genetic inactivation of the aromatase, including a portion of the ketoreductase, which was disrupted by inserting the thiostrepton gene.
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Affiliation(s)
- Devi Bahdur Basnet
- Institute of Biomolecule Reconstruction (iBR), Department of Pharmaceutical Engineering, Sun Moon University, Asan 336-708, Korea
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