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Kim K, Hou CY, Choe D, Kang M, Cho S, Sung BH, Lee DH, Lee SG, Kang TJ, Cho BK. Adaptive laboratory evolution of Escherichia coli W enhances gamma-aminobutyric acid production using glycerol as the carbon source. Metab Eng 2021; 69:59-72. [PMID: 34775076 DOI: 10.1016/j.ymben.2021.11.004] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/19/2021] [Accepted: 11/06/2021] [Indexed: 11/25/2022]
Abstract
The microbial conversion of glycerol into value-added commodity products has emerged as an attractive means to meet the demands of biosustainability. However, glycerol is a non-preferential carbon source for productive fermentation because of its low energy density. We employed evolutionary and metabolic engineering in tandem to construct an Escherichia coli strain with improved GABA production using glycerol as the feedstock carbon. Adaptive evolution of E. coli W under glycerol-limited conditions for 1300 generations harnessed an adapted strain with a metabolic system optimized for glycerol utilization. Mutation profiling, enzyme kinetic assays, and transcriptome analysis of the adapted strain allowed us to decipher the basis of glycerol adaptation at the molecular level. Importantly, increased substrate influx mediated by the mutant glpK and modulation of intracellular cAMP levels were the key drivers of improved fitness in the glycerol-limited condition. Leveraging the enhanced capability of glycerol utilization in the strain, we constructed a GABA-producing E. coli W-derivative with superior GABA production compared to the wild-type. Furthermore, rationally designed inactivation of the non-essential metabolic genes, including ackA, mgsA, and gabT, in the glycerol-adapted strain improved the final GABA titer and specific productivity by 3.9- and 4.3-fold, respectively, compared with the wild-type.
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Affiliation(s)
- Kangsan Kim
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Chen Yuan Hou
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 04620, Republic of Korea
| | - Donghui Choe
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Minjeong Kang
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Suhyung Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Bong Hyun Sung
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Dae-Hee Lee
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Seung-Goo Lee
- Synthetic Biology & Bioengineering Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 04620, Republic of Korea.
| | - Byung-Kwan Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
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Ju C, Gao JC, Zhang PX, Zhang KN, Yang S, Kang TJ, Zhao HZ, Qi WJ, Zhang QP, Kong FD, Guan HW, Shi H. [Expression and significance of PD-1 and PD-L1 in the specimens of epithelial ovarian cancer]. Zhonghua Fu Chan Ke Za Zhi 2020; 55:529-534. [PMID: 32854477 DOI: 10.3760/cma.j.cn112141-20200301-00155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To examine the expression of programmed cell death 1 (PD-1) and its ligand (PD-L1) in epithelial ovarian cancer (EOC) tissues, and investigate the correlation among their expression, clinicopathological features and prognosis. Methods: The specimens of 180 patients with EOC treated in the First Affiliated Hospital of Dalian Medical University from October 2002 to December 2013 were confirmed by pathological examination. The pathological tissue specimens of subtypes ,included 120 cases of serous carcinoma, 30 cases of mucinous carcinoma, 20 cases of endometrioid carcinoma, and 20 cases of clear cell carcinoma. The normal paracancerous tissues of 50 cases randomly selected from the 180 patients as control group. Immunohistochemical SP method was used to detect the expressions of both PD-1 and PD-L1 in epithelial ovarian cancer tissues, and the relationships among their expressions,the clinicopathological parameters and prognosis were respectively analyzed. Results: (1) PD-1 was expressed in lymphocytes infiltrated in EOC tissues, and PD-L1 was expressed in the cell membranes of cancer tissues. In all EOC cases, 33 cases (18.3%, 33/180) of both PD-1 and PD-L1 were highly expressed, and only 1 (2.0%, 1/50) of control group showed high expression. There was statistically significant difference between two groups (P<0.01). (2) Among the four subtypes tissue specimens of EOC, the high expression rate of PD-1 was 25.0% (30/120) for serous carcinoma, 3/15 for endometrioid carcinoma, 0 (0/30) for mucinous carcinoma, and 0 (0/15) for clear cell carcinoma. The high expression rate of PD-L1 was 23.3% (28/120) for serous carcinoma, 3.3% (1/30) for mucinous carcinoma, 2/15 for endometrioid carcinoma, and 2/15 for clear cell carcinoma. Both PD-1 and PD-L1 expressions in the four sub-types of tissue specimens were significantly different (P<0.05). The high expression rate of both PD-1 and PD-L1 was 9.2% (8/87) in the early stage and 26.9% (25/93) in the late stage. There was a statistically significant difference between the two groups (P<0.01). Similarly, the expression of both PD-1 and PD-L1 were significantly higher in the cases of high-grade EOC (type Ⅱ) than those of low-grade (type Ⅰ) and in the cases of EOC distributed bilaterally than that distributed unilaterally, and there were statistically significant differences (P<0.05). (3) The Kaplan-Meier survival analysis showed that the survival time were respectively 35 and 36 months in the cases with high expressions of both PD-1 and PD-L1, and the survival time were the same as 61 months in the cases with low expression of both PD-1 and PD-L1, and the comparison was statistically significant (P<0.05). Conclusions: The expression levels of PD-1 and PD-L1 in EOC tissues are higher than those in adjacent tissues, especially in serous carcinomas. The expression of both PD-1 and PD-L1 is higher in specimens of the patients with advanced stages. The results showed that the high expression of both PD-1 and PD-L1 is an indicator of poor prognosis of patients suffering from EOC.
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Affiliation(s)
- C Ju
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - J C Gao
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - P X Zhang
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - K N Zhang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - S Yang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - T J Kang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - H Z Zhao
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - W J Qi
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - Q P Zhang
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - F D Kong
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - H W Guan
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - H Shi
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
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3
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Jiang XL, Gao JC, Jiang L, Zhang PX, Kang TJ, Sun Q, Qi WJ, Zhang QP, Guan HW, Shi H. [Expression and significance of MAPK/ERK in the specimens and cells of epithelial ovarian cancer]. Zhonghua Fu Chan Ke Za Zhi 2019; 54:541-547. [PMID: 31461811 DOI: 10.3760/cma.j.issn.0529-567x.2019.08.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To detect phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) protein expression in epithelial ovarian cancer and cell lines, and to examine the effects of mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor AZD6244 on cell proliferation, apoptosis as well as cell cycle of ovarian cancer cells. To explore the function and significance of MAPK/extracellular signal-regulated kinase (ERK) signaling pathway in the development of ovarian cancer. Methods: (1) A total of 104 cases of patients with ovarian cancer who accepted the treatment of gynecological surgery and being confirmed by pathological examination in First Affiliated Hospital, Dalian Medical University from January 2004 to December 2013 were selected. The expressions of p-ERK1/2 protein were detected by immunohistochemistry in ovarian cancer specimens, and the relationship between the expressions of p-ERK1/2 and the clinical features of patients was analyzed. (2) p-ERK1/2 and other related proteins were determined by western blot in various ovarian cancer cells, including SKOV3, OV2008, C13, A2780S, A2780CP, OVCAR4, OVCAR5, OVCAR8 and CAOV3 treated with or without MEK inhibitor. The cellular proliferation, apoptosis and cell cycle of ovarian cancer cells after treatment with MEK inhibitor were analyzed by methyl thiazolyl tetrazolium (MTT) assay and flow cytometry, respectively. Results: (1) The immunohistochemical method showed that p-ERK1/2 between low grade serous carcinoma and clear cell carcinoma were not significantly higher expressed (P>0.05) . However, a lower level of the p-ERK1/2 expression were observed among high grade serous carcinoma, mucinous carcinoma and endometrioid carcinoma (all P<0.05) . There was no significant correlation between the protein expression of p-ERK1/2 and patients' age, pathological stage of surgery, and preoperative serum CA(125) level (P>0.05). (2) Western blot showed that the protein p-ERK1/2 was widely expressed in various ovarian cancer cell lines such as SKOV3, OV2008, C13, A2780S, A2780CP, OVCAR4, OVCAR5, OVCAR8 and CAOV3. After treatment with AZD6244 (5, 10 μmol/L), the level of p-ERK1/2 in OVCAR5 and OVCAR8 decreased significantly in dose-dependent manner. Additionally, we found a reduction of the expression level of cyclin D1, caspase-3 and appeared cleaved poly adenosine diphosphate ribose polymerase (PARP) in OVCAR5 and OVCAR8, compared with control groups. MTT assays showed that OVCAR5, OVCAR8 and A2780S were differently inhibited in the dose-dependent manner after being treated with different concentrations of AZD6244 (0, 2.5, 5, 10, 25, 50 and 100 μmol/L, all P<0.05). Further tested by flow cytometry, the results showed that AZD6244 (5, 10 μmol/L) was able to induce the apoptosis of OVCAR5, OVCAR8 and A2780S, as well as G(0)/G(1) phase arrest, both in a dose-dependent manner (P<0.05). Conclusions: As the main active and functional unit of MAPK/ERK signaling pathway, p-ERK1/2 protein is expressed in both the tissues and various ovarian cancer cell lines. AZD6244 could down-regulated the expression of p-ERK1/2 in ovarian cancer cells, accompanied by the decreased proliferation and increased cell apoptosis of ovarian cancer cells. In conclusion, MAPK/ERK signaling pathway might play a role in the development and progression of ovarian cancer, and may be provide a novel option for molecular targeted therapies of the disease.
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Affiliation(s)
- X L Jiang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China (is working on the Department of Obstetrics and Gynecology, University-town Hospital of Chongqing Medical University, Chongqing 401331, China)
| | - J C Gao
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - L Jiang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - P X Zhang
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - T J Kang
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - Q Sun
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - W J Qi
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - Q P Zhang
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - H W Guan
- Department of Pathology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
| | - H Shi
- Department of Obstetrics and Gynecology, First Affiliated Hospital, Dalian Medical University, Dalian 116011, China
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4
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Min MW, Kim CE, Chauhan S, Park HJ, Park CS, Yoo TH, Kang TJ. Identification of peptide inhibitors of matrix metalloproteinase 1 using an in-house assay system for the enzyme. Enzyme Microb Technol 2019; 127:65-69. [DOI: 10.1016/j.enzmictec.2019.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/08/2019] [Accepted: 04/19/2019] [Indexed: 11/30/2022]
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Abstract
Caprolactam is a monomer used for the synthesis of nylon-6, and a recombinant microbial strain for biobased production of nylon-6 was recently developed. An intracellular biosensor for caprolactam can facilitate high-throughput metabolic engineering of recombinant microbial strains. Because of the mixed production of caprolactam and valerolactam in the recombinant strain, a caprolactam biosensor should be highly specific for caprolactam. However, a highly specific caprolactam sensor has not been reported. Here, we developed an artificial riboswitch that specifically responds to caprolactam. This riboswitch was prepared using a coupled in vitro- in vivo selection strategy with a heterogeneous pool of RNA aptamers obtained from in vitro selection to construct a riboswitch library used in in vivo selection. The caprolactam riboswitch successfully discriminated caprolactam from valerolactam. Moreover, the riboswitch was activated by 3.36-fold in the presence of 50 mM caprolactam. This riboswitch enabled caprolactam-dependent control of cell growth, which will be useful for improving caprolactam production and is a valuable tool for metabolic engineering.
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Affiliation(s)
- Sungyeon Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Sungho Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Dae-Kyun Im
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-Ro, Seongbuk-Gu, Seoul 02841, Korea
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, 30 Pildong-Ro 1-Gil, Jung-Gu, Seoul 04620, Korea
| | - Min-Kyu Oh
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-Ro, Seongbuk-Gu, Seoul 02841, Korea
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
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6
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Chisholm CF, Kang TJ, Dong M, Lewis K, Namekar M, Lehrer AT, Randolph TW. Thermostable Ebola virus vaccine formulations lyophilized in the presence of aluminum hydroxide. Eur J Pharm Biopharm 2019; 136:213-220. [PMID: 30703544 DOI: 10.1016/j.ejpb.2019.01.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 10/27/2022]
Abstract
No United States Food and Drug Administration-licensed vaccines protective against Ebola virus (EBOV) infections are currently available. EBOV vaccine candidates currently in development, as well as most currently licensed vaccines in general, require transport and storage under a continuous cold chain in order to prevent potential decreases in product efficacy. Cold chain requirements are particularly difficult to maintain in developing countries. To improve thermostability and reduce costly cold chain requirements, a subunit protein vaccine against EBOV was formulated as a glassy solid using lyophilization. Formulations of the key antigen, Ebola glycoprotein (EBOV-GP), adjuvanted with microparticulate aluminum hydroxide were prepared in liquid and lyophilized forms, and the vaccines were incubated at 40 °C for 12 weeks. Aggregation and degradation of EBOV-GP were observed in liquid formulations during the 12-week incubation period, whereas changes were minimal in lyophilized formulations. Antibody responses against EBOV-GP following three intramuscular immunizations in BALB/c mice were used to determine vaccine immunogenicity. EBOV-GP formulations were equally immunogenic in liquid and lyophilized forms. After lyophilization and reconstitution, adjuvanted vaccine formulations produced anti-EBOV-GP IgG antibody responses in mice similar to those generated against corresponding adjuvanted liquid vaccine formulations. More importantly, antibody responses in mice injected with reconstituted lyophilized vaccine formulations that had been incubated at 40 °C for 12 weeks prior to injection indicated that vaccine immunogenicity was fully retained after high-temperature storage, showing promise for future vaccine development efforts.
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Affiliation(s)
- Carly Fleagle Chisholm
- Department of Chemical and Biological Engineering, Center for Pharmaceutical Biotechnology, University of Colorado, Boulder, CO 80309, United States
| | - Taek Jin Kang
- Department of Chemical and Biological Engineering, Center for Pharmaceutical Biotechnology, University of Colorado, Boulder, CO 80309, United States; Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, Republic of Korea
| | - Miao Dong
- Department of Chemical and Biological Engineering, Center for Pharmaceutical Biotechnology, University of Colorado, Boulder, CO 80309, United States
| | - Kasey Lewis
- Department of Chemical and Biological Engineering, Center for Pharmaceutical Biotechnology, University of Colorado, Boulder, CO 80309, United States
| | - Madhuri Namekar
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, United States
| | - Axel T Lehrer
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, United States
| | - Theodore W Randolph
- Department of Chemical and Biological Engineering, Center for Pharmaceutical Biotechnology, University of Colorado, Boulder, CO 80309, United States.
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Min S, Jin Y, Hou CY, Kim J, Green JJ, Kang TJ, Cho SW. Bacterial tRNase-Based Gene Therapy with Poly(β-Amino Ester) Nanoparticles for Suppressing Melanoma Tumor Growth and Relapse. Adv Healthc Mater 2018; 7:e1800052. [PMID: 29888531 DOI: 10.1002/adhm.201800052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/23/2018] [Indexed: 01/06/2023]
Abstract
Here, a novel anticancer gene therapy with a bacterial tRNase gene, colicin D or virulence associated protein C (VapC), is suggested using biodegradable polymeric nanoparticles, such as poly(β-amino esters) (PBAEs) as carriers. These genes are meticulously selected, aiming at inhibiting translation in the recipients by hydrolyzing specific tRNA species. In terms of nanoparticles, out of 9 PBAE formulations, a leading polymer, (polyethylene oxide)4 -bis-amine end-capped poly(1,4-butanediol diacrylate-co-5-amino-1-pentanol) (B4S5E5), is identified that displays higher gene delivery efficacy to cancer cells compared with the leading commercial reagent Lipofectamine 2000. Interestingly, the B4S5E5 PBAE nanoparticles complexed with colicin D or VapC plasmid DNA induce significant toxicity highly specific to cancer cells by triggering apoptosis. In contrast, the PBAE nanoparticles do not induce these cytotoxic effects in noncancerous cells. In a mouse melanoma model of grafted murine B16-F10 cells, it is demonstrated that treatment with PBAE nanoparticles complexed with these tRNase genes significantly reduces tumor growth rate and delays tumor relapse. Moreover, increased stability of PBAE by PEGylation further enhances the therapeutic effect of tRNase gene treatment and improves survival of animals. This study highlights a nonviral gene therapy that is highly promising for the treatment of cancer.
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Affiliation(s)
- Sungjin Min
- Department of Biotechnology; Yonsei University; Seoul 03722 Republic of Korea
| | - Yoonhee Jin
- Department of Biotechnology; Yonsei University; Seoul 03722 Republic of Korea
| | - Chen Yuan Hou
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 04620 Republic of Korea
| | - Jayoung Kim
- Department of Biomedical Engineering; Translational Tissue Engineering Center; Institute for Nanobiotechnology; Johns Hopkins University School of Medicine; Baltimore MD 21231 USA
| | - Jordan J. Green
- Department of Biomedical Engineering; Translational Tissue Engineering Center; Institute for Nanobiotechnology; Johns Hopkins University School of Medicine; Baltimore MD 21231 USA
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 04620 Republic of Korea
| | - Seung-Woo Cho
- Department of Biotechnology; Yonsei University; Seoul 03722 Republic of Korea
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Sudheer PDVN, Yun J, Chauhan S, Kang TJ, Choi KY. Screening, expression, and characterization of Baeyer-Villiger monooxygenases for the production of 9-(nonanoyloxy)nonanoic acid from oleic acid. BIOTECHNOL BIOPROC E 2018. [DOI: 10.1007/s12257-017-0295-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Microbial strains are considered promising hosts for production of flavonoids because of their rapid growth rate and suitability for large-scale manufacturing. However, productivity and titer of current recombinant strains still do not meet the requirements of industrial processes. Genetically encoded biosensors have been applied for high-throughput screening or dynamic regulation of biosynthetic pathways for enhancing the performance of microbial strains that produce valuable chemicals. Currently, few protein sensor-regulators for flavonoids exist. Unlike the protein-based trans-regulating controllers, riboswitches can respond to their ligands faster and eliminate off-target effects. Here, we developed artificial riboswitches that activate gene expression in response to naringenin, an important flavonoid. RNA aptamers for naringenin were developed using SELEX and cloned upstream of a dual selectable marker gene to construct a riboswitch library. Two in vivo selection routes were applied separately to the library by supplementing naringenin at two different concentrations during enrichments to modulate the operational ranges of the riboswitches. The selected riboswitches were responsive to naringenin and activated gene expression up to 2.91-fold. Operational ranges of the riboswitches were distinguished on the basis of their selection route. Additionally, the specificity of the riboswitches was assessed, and their applicability as dynamic regulators was confirmed. Collectively, the naringenin riboswitches reported in this work will be valuable tools in metabolic engineering of microorganisms for the production of flavonoids.
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Affiliation(s)
- Sungho Jang
- Department
of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Korea
| | - Sungyeon Jang
- Department
of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Korea
| | - Yu Xiu
- Department
of Chemical and Biological Engineering, Center for Biotechnology and
Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- State
Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
- Beijing
Key Laboratory of Bioactive Substances and Functional Food, Beijing Union University, Beijing 100191, China
| | - Taek Jin Kang
- Department
of Chemical and Biochemical Engineering, Dongguk University, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Korea
| | - Sang-Hyeup Lee
- Department
of Life Chemistry, Catholic University of Daegu, Hayang-ro 13-13,
Hayang-eup, Gyeongsan, Gyeongbuk 38430, Korea
| | - Mattheos A. G. Koffas
- Department
of Chemical and Biological Engineering, Center for Biotechnology and
Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
- Department
of Biological Sciences, Center for Biotechnology and Interdisciplinary
Studies, Rensselaer Polytechnic Institutee, Troy, New York 12180, United States
| | - Gyoo Yeol Jung
- Department
of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Korea
- School
of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Korea
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10
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Chauhan S, Hou CY, Jung ST, Kang TJ. Detection and purification of backbone-cyclized proteins using a bacterially expressed anti-myc-tag single chain antibody. Anal Biochem 2017; 532:38-44. [PMID: 28600127 DOI: 10.1016/j.ab.2017.06.003] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 06/01/2017] [Accepted: 06/05/2017] [Indexed: 11/26/2022]
Abstract
A myc-tag and of which recognition by an antibody 9E10 has long been used for the detection and purification of recombinant proteins. We have previously expanded the application of the tag to the specific detection and purification of backbone-cyclized proteins. Here we sought a more practical way to using the 9E10 antibody by expressing its single chain antibody (scAb) form in Escherichia coli. The combined use of a strong T7 promoter and auto-induction strategy rather than early to mid-log induction of a Lac promoter resulted in the soluble over-expression of 9E10 scAb. However, the co-expression of a chaperone, Skp, was absolutely necessary for the activity even when the protein was expressed in a soluble manner. We could purify about 4 mg of 9E10 scAb from 1 l of culture, and the resulting scAb could be used to detect and purify the backbone-cyclized protein as the parental full-length 9E10. Moreover, the immunoaffinity resin prepared using 9E10 scAb could be regenerated several times after the elution of bound proteins using an acid, which added more value to the ready preparation of the active antibody in bacteria.
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Affiliation(s)
- Sushma Chauhan
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, South Korea
| | - Chen Yuan Hou
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, South Korea
| | - Sang Taek Jung
- Department of Bio and Nano Chemistry, Kookmin University, Seoul, 02707, South Korea
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 04620, South Korea.
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Lee KB, Hou CY, Kim CE, Kim DM, Suga H, Kang TJ. Inside Cover: Genetic Code Expansion by Degeneracy Reprogramming of Arginyl Codons (ChemBioChem 13/2016). Chembiochem 2016. [DOI: 10.1002/cbic.201600326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ki Baek Lee
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 100-715 South Korea
| | - Chen Yuan Hou
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 100-715 South Korea
| | - Chae-Eun Kim
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 100-715 South Korea
| | - Dong-Myung Kim
- Department of Fine Chemical Engineering and Applied Chemistry; Chungnam National University; Daejun 305-764 South Korea
| | - Hiroaki Suga
- Department of Chemistry; Graduate School of Science; The University of Tokyo; Tokyo 113-0033 Japan
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; Seoul 100-715 South Korea
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12
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Lee KB, Hou CY, Kim CE, Kim DM, Suga H, Kang TJ. Genetic Code Expansion by Degeneracy Reprogramming of Arginyl Codons. Chembiochem 2016; 17:1198-201. [PMID: 27151886 DOI: 10.1002/cbic.201600111] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Indexed: 11/11/2022]
Abstract
The genetic code in most organisms codes for 20 proteinogenic amino acids or translation stop. In order to encode more than 20 amino acids in the coding system, one of stop codons is usually reprogrammed to encode a non-proteinogenic amino acid. Although this approach works, usually only one amino acid is added to the amino acid repertoire. In this study, we incorporated non-proteinogenic amino acids into a protein by using a sense codon. As all the codons are allocated in the universal genetic code, we destroyed all the tRNA(Arg) in a cell-free protein synthesis system by using a tRNA(Arg) -specific tRNase, colicin D. Then by supplementing the system with tRNACCU , the translation system was partially restored. Through this creative destruction, reprogrammable codons were successfully created in the system to encode modified lysines along with the 20 proteinogenic amino acids.
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Affiliation(s)
- Ki Baek Lee
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 100-715, South Korea
| | - Chen Yuan Hou
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 100-715, South Korea
| | - Chae-Eun Kim
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 100-715, South Korea
| | - Dong-Myung Kim
- Department of Fine Chemical Engineering and Applied Chemistry, Chungnam National University, Daejun, 305-764, South Korea
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, 100-715, South Korea.
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14
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Shin J, Lee N, Song Y, Park J, Kang TJ, Kim SC, Lee GM, Cho BK. Efficient CRISPR/Cas9-mediated multiplex genome editing in CHO cells via high-level sgRNA-Cas9 complex. BIOTECHNOL BIOPROC E 2015. [DOI: 10.1007/s12257-015-0233-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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15
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Song Y, Lee BR, Cho S, Cho YB, Kim SW, Kang TJ, Kim SC, Cho BK. Determination of single nucleotide variants in Escherichia coli DH5α by using short-read sequencing. FEMS Microbiol Lett 2015; 362:fnv073. [PMID: 25934703 DOI: 10.1093/femsle/fnv073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2015] [Indexed: 12/16/2022] Open
Abstract
Escherichia coli DH5α is a common laboratory strain that provides an important platform for routine use in cloning and synthetic biology applications. Many synthetic circuits have been constructed and successfully expressed in E. coli DH5α; however, its genome sequence has not been determined yet. Here, we determined E. coli DH5α genome sequence and identified genetic mutations that affect its phenotypic functions by using short-read sequencing. The sequencing results clearly described the genotypes of E. coli DH5α, which aid in further studies using the strain. Additionally, we observed 105 single nucleotide variants (SNVs), 83% of which were detected in protein-coding regions compared to the parental strain E. coli DH1. Interestingly, 23% of the protein-coding regions have mutations in their amino acid residues, whose biological functions were categorized into two-component systems, peptidoglycan biosynthesis and lipopolysaccharide biosynthesis. These results underscore the advantages of E. coli DH5α, which tolerates the components of transformation buffer and expresses foreign plasmids efficiently. Moreover, these SNVs were also observed in the commercially available strain. These data provide the genetic information of E. coli DH5α for its future application in metabolic engineering and synthetic biology.
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Affiliation(s)
- Yoseb Song
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Bo-Rahm Lee
- Intelligent Synthetic Biology Center, Daejeon 305-701, Republic of Korea
| | - Suhyung Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Yoo-Bok Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Seon-Won Kim
- Division of Applied Life Science (BK21 Plus), PMBBRC, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea
| | - Sun Chang Kim
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea Intelligent Synthetic Biology Center, Daejeon 305-701, Republic of Korea
| | - Byung-Kwan Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea Intelligent Synthetic Biology Center, Daejeon 305-701, Republic of Korea
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16
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Cho S, Cho YB, Kang TJ, Kim SC, Palsson B, Cho BK. The architecture of ArgR-DNA complexes at the genome-scale in Escherichia coli. Nucleic Acids Res 2015; 43:3079-88. [PMID: 25735747 PMCID: PMC4381063 DOI: 10.1093/nar/gkv150] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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: 09/23/2014] [Accepted: 02/13/2015] [Indexed: 01/26/2023] Open
Abstract
DNA-binding motifs that are recognized by transcription factors (TFs) have been well studied; however, challenges remain in determining the in vivo architecture of TF-DNA complexes on a genome-scale. Here, we determined the in vivo architecture of Escherichia coli arginine repressor (ArgR)-DNA complexes using high-throughput sequencing of exonuclease-treated chromatin-immunoprecipitated DNA (ChIP-exo). The ChIP-exo has a unique peak-pair pattern indicating 5′ and 3′ ends of ArgR-binding region. We identified 62 ArgR-binding loci, which were classified into three groups, comprising single, double and triple peak-pairs. Each peak-pair has a unique 93 base pair (bp)-long (±2 bp) ArgR-binding sequence containing two ARG boxes (39 bp) and residual sequences. Moreover, the three ArgR-binding modes defined by the position of the two ARG boxes indicate that DNA bends centered between the pair of ARG boxes facilitate the non-specific contacts between ArgR subunits and the residual sequences. Additionally, our approach may also reveal other fundamental structural features of TF-DNA interactions that have implications for studying genome-scale transcriptional regulatory networks.
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Affiliation(s)
- Suhyung Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Yoo-Bok Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea
| | - Sun Chang Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Bernhard Palsson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA Center for Biosustainability, Technical University of Denmark, Hørsholm, Denmark
| | - Byung-Kwan Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
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17
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Choi JW, Yim SS, Lee SH, Kang TJ, Park SJ, Jeong KJ. Enhanced production of gamma-aminobutyrate (GABA) in recombinant Corynebacterium glutamicum by expressing glutamate decarboxylase active in expanded pH range. Microb Cell Fact 2015; 14:21. [PMID: 25886194 PMCID: PMC4335662 DOI: 10.1186/s12934-015-0205-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Gamma-aminobutylate (GABA) is an important chemical in pharmacetucal field and chemical industry. GABA has mostly been produced in lactic acid bacteria by adding L-glutamate to the culture medium since L-glutamate can be converted into GABA by inherent L-glutamate decarboxylase. Recently, GABA has gained much attention for the application as a major building block for the synthesis of 2-pyrrolidone and biodegradable polyamide nylon 4, which opens its application area in the industrial biotechnology. Therefore, Corynebacterium glutamicum, the major L-glutamate producing microorganism, has been engineered to achieve direct fermentative production of GABA from glucose, but their productivity was rather low. RESULTS Recombinant C. glutamicum strains were developed for enhanced production of GABA from glucose by expressing Escherichia coli glutamate decarboxylase (GAD) mutant, which is active in expanded pH range. Synthetic PH36, PI16, and PL26 promoters, which have different promoter strengths in C. glutamicum, were examined for the expression of E. coli GAD mutant. C. glutamicum expressing E. coli GAD mutant under the strong PH36 promoter could produce GABA to the concentration of 5.89±0.35 g/L in GP1 medium at pH 7.0, which is 17-fold higher than that obtained by C. glutamicum expressing wild-type E. coli GAD in the same condition (0.34±0.26 g/L). Fed-bath culture of C. glutamicum expressing E. coli GAD mutant in GP1 medium containing 50 μg/L of biotin at pH 6, culture condition of which was optimized in flask cultures, resulted in the highest GABA concentration of 38.6±0.85 g/L with the productivity of 0.536 g/L/h. CONCLUSION Recombinant C. glutamicum strains developed in this study should be useful for the direct fermentative production of GABA from glucose, which allows us to achieve enhanced production of GABA suitable for its application area in the industrial biotechnology.
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Affiliation(s)
- Jae Woong Choi
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
| | - Sung Sun Yim
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
| | - Seung Hwan Lee
- Department of Biotechnology and Bioengineering, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju, 500-757, Republic of Korea.
| | - Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 100-715, Republic of Korea.
| | - Si Jae Park
- Department of Environmental Engineering and Energy, Myongji University, 116 Myongji-ro, Cheoin-gu, Yongin, Gyeonggido, 449-728, Republic of Korea.
| | - Ki Jun Jeong
- Department of Chemical and Biomolecular Engineering (BK21 Plus Program), KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
- Institute for the BioCentury, KAIST, 335 Gwahagno, Yuseong-gu, Daejeon, 305-701, Republic of Korea.
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18
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Affiliation(s)
- Joan Lee
- Department
of Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Indong Jun
- Department
of Bioengineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Hyun-Ji Park
- Department
of Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Taek Jin Kang
- Department
of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea
| | - Heungsoo Shin
- Department
of Bioengineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Seung-Woo Cho
- Department
of Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
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19
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Kang TJ, Ho NAT, Pack SP. Buffer-free production of gamma-aminobutyric acid using an engineered glutamate decarboxylase from Escherichia coli. Enzyme Microb Technol 2013; 53:200-5. [DOI: 10.1016/j.enzmictec.2013.04.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 11/26/2022]
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20
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Pack SP, Kang TJ, Yoo YJ. Protein Thermostabilizing Factors: High Relative Occurrence of Amino Acids, Residual Properties, and Secondary Structure Type in Different Residual State. Appl Biochem Biotechnol 2013; 171:1212-26. [DOI: 10.1007/s12010-013-0195-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 03/12/2013] [Indexed: 11/29/2022]
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21
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Sudheer PDVN, Pack SP, Kang TJ. Cyclization tag for the detection and facile purification of backbone-cyclized proteins. Anal Biochem 2013; 436:137-41. [PMID: 23439382 DOI: 10.1016/j.ab.2013.02.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 02/08/2013] [Accepted: 02/11/2013] [Indexed: 11/27/2022]
Abstract
Backbone-cyclized proteins, with their characteristic stability toward denaturants such as heat and chemicals, are becoming increasingly significant in many applications. Intein-mediated protein cyclization is the most efficient and frequently used method of choice and has been successfully applied to various targets, achieving stable proteins. However, the detection and isolation of the cyclic protein from the linear one after cyclization is very difficult because the backbone-cyclized protein and the linear one (a by-product formed during the cyclization reaction), which originated from the same molecule, are almost identical in terms of their size. Thus, we first developed a split c-myc tag system; the active c-myc tag was formed only in the backbone-cyclized protein and not in the linear by-product from the inactive precursor, and this helps both the detection and purification of the backbone-cyclized proteins. This tag system, which we called a cyclization tag, was further engineered in its sequence to develop an engineered c-myc (e-myc) tag with enhanced efficiency in the backbone cyclization reaction while keeping its specificity toward the commercial antibody intact. Using two different proteins as models, we show that the cyclization tag developed here can be used as a specific tag for the backbone-cyclized protein, thereby facilitating detection and purification.
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Affiliation(s)
- Pamidimarri D V N Sudheer
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea
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22
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Lee KB, Kim HC, Kim DM, Kang TJ, Suga H. Comparative evaluation of two cell-free protein synthesis systems derived from Escherichia coli for genetic code reprogramming. J Biotechnol 2013; 164:330-5. [PMID: 23395618 DOI: 10.1016/j.jbiotec.2013.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 01/11/2013] [Accepted: 01/17/2013] [Indexed: 10/27/2022]
Abstract
Genetic codes can be reprogrammed to code for non-proteinogenic amino acids during protein synthesis. Technologically, these non-proteinogenic amino acids are incorporated into proteins by artificially charging them to suppressor-tRNAs that can reprogram the existing codons. Several methods and systems for genetic code reprogramming have been reported including methods for charging non-proteinogenic amino acids to tRNA molecules, codons for reprogramming, and systems for protein synthesis. However, there has been no systematic, comparative evaluation of cell-free protein synthesis systems in genetic code reprogramming for their efficiencies and robustness even with their potential usefulness in the field. Here we compare two cell-free protein synthesis systems, the crude S12 and PURE system, with the codon systems, non-proteinogenic amino acids, and the positions in the protein for reprogramming as variables. We show that the combined use of CCCG four-nucleotide codon that is newly developed in this study and the crude S12 system is the most reliable and robust method of choice, while the use of traditional UAG amber stop codon along with an RNA aptamer toward peptide release factor 1 can yield the most plentiful product with certain variations.
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Affiliation(s)
- Ki Baek Lee
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, Republic of Korea.
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23
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Kang T, Kwon NH, Lee JY, Park MC, Kang E, Kim HH, Kang TJ, Kim S. AIMP3/p18 controls translational initiation by mediating the delivery of charged initiator tRNA to initiation complex. J Mol Biol 2012; 423:475-81. [PMID: 22867704 DOI: 10.1016/j.jmb.2012.07.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 07/11/2012] [Accepted: 07/17/2012] [Indexed: 11/28/2022]
Abstract
Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs) are nonenzymatic scaffolding proteins that comprise multisynthetase complex (MSC) with nine aminoacyl-tRNA synthetases in higher eukaryotes. Among the three AIMPs, AIMP3/p18 is strongly anchored to methionyl-tRNA synthetase (MRS) in the MSC. MRS attaches methionine (Met) to initiator tRNA (tRNA(i)(Met)) and plays an important role in translation initiation. It is known that AIMP3 is dispatched to nucleus or nuclear membrane to induce DNA damage response or senescence; however, the role of AIMP3 in translation as a component of MSC and the meaning of its interaction with MRS are still unclear. Herein, we observed that AIMP3 specifically interacted with Met-tRNA(i)(Met)in vitro, while it showed little or reduced interaction with unacylated or lysine-charged tRNA(i)(Met). In addition, AIMP3 discriminates Met-tRNA(i)(Met) from Met-charged elongator tRNA based on filter-binding assay. Pull-down assay revealed that AIMP3 and MRS had noncompetitive interaction with eukaryotic initiation factor 2 (eIF2) γ subunit (eIF2γ), which is in charge of binding with Met-tRNA(i)(Met) for the delivery of Met-tRNA(i)(Met) to ribosome. AIMP3 recruited active eIF2γ to the MRS-AIMP3 complex, and the level of Met-tRNA(i)(Met) bound to eIF2 complex was reduced by AIMP3 knockdown resulting in reduced protein synthesis. All these results suggested the novel function of AIMP3 as a critical mediator of Met-tRNA(i)(Met) transfer from MRS to eIF2 complex for the accurate and efficient translation initiation.
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Affiliation(s)
- Taehee Kang
- Medicinal Bioconvergence Research Center, Seoul National University, Seoul 151-742, Korea
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Kang TJ, Suga H. Translation of a histone H3 tail as a model system for studying peptidyl-tRNA drop-off. FEBS Lett 2011; 585:2269-74. [DOI: 10.1016/j.febslet.2011.05.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 05/13/2011] [Accepted: 05/19/2011] [Indexed: 10/18/2022]
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Kang TJ, Hayashi Y, Suga H. Synthesis of the Backbone Cyclic Peptide Sunflower Trypsin Inhibitor-1 Promoted by the Induced Peptidyl-tRNA Drop-off. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006963] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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Kang TJ, Hayashi Y, Suga H. Synthesis of the backbone cyclic peptide sunflower trypsin inhibitor-1 promoted by the induced peptidyl-tRNA drop-off. Angew Chem Int Ed Engl 2011; 50:2159-61. [PMID: 21344575 DOI: 10.1002/anie.201006963] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2010] [Indexed: 11/07/2022]
Affiliation(s)
- Taek Jin Kang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, South Korea.
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Keum JW, Ahn JH, Kang TJ, Kim DM. Combinatorial, selective and reversible control of gene expression using oligodeoxynucleotides in a cell-free protein synthesis system. Biotechnol Bioeng 2009; 102:577-82. [PMID: 18767195 DOI: 10.1002/bit.22081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Herein we describe the methods for selective and reversible regulation of gene expression using antisense oligodeoxynucleotides (ODNs) in a cell-free protein synthesis system programmed with multiple DNAs. Either a complete shut down or controlled level of gene expression was attained through the antisense ODN-mediated regulation of mRNA stability in the reaction mixture. In addition to the primary control of gene expression, we also demonstrate that the inhibition of protein synthesis can be reversed by using an anti-antisense ODN sequence that strips the antisense ODN off the target sequence of mRNA. As a result, sequential additions of the antisense and anti-antisense ODNs enabled the stop-and-go expression of protein molecules. Through the on-demand regulation of gene expression, presented results will provide a versatile platform for the analysis and understanding of the complicated networks of biological components.
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Affiliation(s)
- Jung-Won Keum
- School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Seoul, Korea
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28
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Wang Z, Chang SH, Kang TJ. Cation complexation behavior of pyrene- and anthracene-appended new crown ether derivatives. Spectrochim Acta A Mol Biomol Spectrosc 2008; 70:313-7. [PMID: 17897872 DOI: 10.1016/j.saa.2007.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2007] [Revised: 08/06/2007] [Accepted: 08/13/2007] [Indexed: 05/17/2023]
Abstract
Pyrene- and anthracene-appended new crown ether derivatives have been synthesized by Schiff's base reaction, and cation complexation behavior was investigated by fluorescence spectroscopy measurements. Based on photo-induced electron transfer and intramolecular charge transfer mechanism, the host molecules emit stronger fluorescence in the presence of various cations Na(+), K(+), Rb(+), Cs(+) and NH(4)(+) since the complexation between guest cations and crown ether compounds inhibit partial electron transfer from the nitrogen atom to the chromophores and subsequently fluorescence is enhanced. The binding constants were estimated from the plots of the fraction of binding sites filled for crown ether compound as a function of free-ion concentration. Results show that 15-crown-5 derivatives exhibit higher binding ability with sodium cations while 18-crown-6 derivatives had higher affinity for potassium cations, which is consistent with the hole-size relationship of the crown ethers. Ammonium ion complexation caused largest fluorescence enhancement. It is understood that ammonium ion cannot only complex with crown ether, but also interact directly with the lone pair electrons of nitrogen atom in C=N bond so that electron transfer from the nitrogen atom to chromophores is further inhibited.
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Affiliation(s)
- Zhiping Wang
- Department of Chemistry, Daegu University, Gyeongsan 712-714, Republic of Korea
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Abstract
Here we report a ribozyme that catalyzes the 5'-nucleotidyl transfer reaction forming the 2'-5' phosphodiester bond. This ribozyme was retrieved as a sole sequence in the pool enriched for the 5'-triphosphate-dependent activities in incorporating ATP-gammaS. The originally selected ribozyme consisting of 109-nucleotide was miniaturized to 45-nucleotide M4 ribozyme via mutation studies, and based on this mini-ribozyme a trans-acting system was constructed. Interestingly, M4 ribozyme promiscuously accepts a variety of purine nucleotides. This remarkable ability of M4 ribozyme would lead us to the development of a new tool for the 5'-modification of RNAs with unique chemical groups.
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Affiliation(s)
- Taek Jin Kang
- Research Center for Advanced Science and Technology, The University of Tokyo, 153-8904 Tokyo, Japan
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30
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Kang TJ, Suga H. Ribosomal synthesis of nonstandard peptidesThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Systems and Chemical Biology, and has undergone the Journal's usual peer review process. Biochem Cell Biol 2008; 86:92-9. [DOI: 10.1139/o08-009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
It is well known that standard peptides, which comprise proteinogenic amino acids, can act as specific chemical probes to target proteins with high affinity. Despite this fact, a number of peptide drug leads have been abandoned because of their poor cell permeability and protease instability. On the other hand, nonstandard peptides isolated as natural products often exhibit remarkable pharmaco-behavior and stability in vivo. Although it is likely that numerous nonstandard therapeutic peptides capable of recognizing various targets could have been synthesized, enzymes for nonribosomal peptide syntheses are complex; therefore, it is difficult to engineer such modular enzymes to build nonstandard peptide libraries. Here we describe an emerging technology for the synthesis of nonstandard peptides that employs an integrated system of reconstituted cell-free translation and flexizymes. We summarize the historical background of this technology and discuss its current and future applications to the synthesis of nonstandard peptides and drug discovery.
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Affiliation(s)
- Taek Jin Kang
- Research Center for Advanced Science and Technology, University of Tokyo, 153-8904 Tokyo; and Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 113-8656 Tokyo, Japan
| | - Hiroaki Suga
- Research Center for Advanced Science and Technology, University of Tokyo, 153-8904 Tokyo; and Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 113-8656 Tokyo, Japan
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31
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Abstract
Here we report in vitro selection of a novel ribozyme that catalyzes the 5′-nucleotidyl transfer reaction forming the 2′–5′ phosphodiester bond. This ribozyme was retrieved as a sole sequence in the pool enriched for the 5′-triphosphate-dependent activities in incorporating ATP-γS. The originally selected ribozyme consisting of 109-nucleotide (nt) was miniaturized to 45-nt M4 ribozyme via a series of mutation studies, and based on this mini-ribozyme a trans-acting system was constructed. One of the most challenging tasks in our study was to determine the chemistry occurring at the 5′-ppp site. We utilized various analytical methods including MALDI-TOF analysis of the product generated by the trans-acting system and elucidated the chemistry to be 3′→5′ mononucleotide extension forming the 2′–5′ phosphodiester bond. Interestingly, M4 ribozyme promiscuously accepts a variety of purine nucleotides bearing 5′-mono-, di- and triphosphates as substrates. This remarkable ability of M4 ribozyme would lead us to the development of a new tool for the 5′-modification of RNAs with unique chemical groups.
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Affiliation(s)
- Taek Jin Kang
- Research Center for Advanced Science and Technology, The University of Tokyo, 153-8904 Tokyo, Japan and Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 113-8656 Tokyo, Japan
| | - Hiroaki Suga
- Research Center for Advanced Science and Technology, The University of Tokyo, 153-8904 Tokyo, Japan and Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 113-8656 Tokyo, Japan
- *To whom correspondence should be addressed. +81-3-5452-5495+81-3-5452-5495
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Kang TJ, Song HK, Ahn JH, Kim TW, Yoon YJ, Choi CY. Enhanced immunodetection of cell-free synthesized erythropoietin under denaturing conditions. Biotechnol Lett 2004; 26:641-4. [PMID: 15200173 DOI: 10.1023/b:bile.0000023022.60035.1e] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A monoclonal antibody produced by hydridoma cell line, ATCC HB8209, was used to detect and purify erythropoietin synthesized in a cell-free system. The antibody was raised against the N-terminal 20 residues of erythropoietin. It retained anti-erythropoietin activity in 6 M urea in which most of the cell-free synthesized erythropoietin became soluble and gave an enhanced activity of the antibody.
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Affiliation(s)
- Taek Jin Kang
- School of Chemical Engineering, College of Engineering, Seoul National University, Seoul 151-742, Korea
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Kang TJ, Woo JH, Song HK, Ahn JH, Kum JW, Han J, Choi CY, Joo H. A cell-free protein synthesis system as an investigational tool for the translation stop processes. FEBS Lett 2002; 517:211-4. [PMID: 12062439 DOI: 10.1016/s0014-5793(02)02625-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Using Escherichia coli cell-free protein synthesis system and aminoacylated amber suppressor tRNA, we successfully inserted an unnatural amino acid S-(2-nitrobenzyl)cysteine into human erythropoietin. Three different types of translation stop suppression were observed and each of the three types was easily discerned with SDS-PAGE. Optimal conditions were established for correct stop and programmed suppressions. Since this system differentiates proteins produced by misreading of codons from those produced by programmed suppression, we conclude that this cell-free translation system that we describe in this paper will be of a great use for future investigations on translation stop processes.
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Affiliation(s)
- Taek Jin Kang
- School of Chemical Engineering, College of Engineering, Seoul National University, Seoul, South Korea
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Chae GT, Lee SB, Kang TJ, Shin HK, Kim JP, Ko YH, Kim SH, Kim NH. Typing of clinical isolates of Mycobacterium leprae and their distribution in Korea. LEPROSY REV 2002; 73:41-6. [PMID: 11969125] [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: 02/24/2023]
Abstract
Although there is no genetic diversity in isolates of Mycobacterium leprae, the variance of tandem repeats in the rpoT gene was recently demonstrated. We have typed clinical isolates of M. leprae in Korea using difference of the tandem repeats in the rpoT gene. Among 69 patients, 65 Korean isolates (94.2%) demonstrated four copies of the 6 bp tandem repeat (GACATC) in the rpoT gene, and incidences of three copies were found in only two Koreans and two foreigners (2.9%, respectively).
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Affiliation(s)
- G T Chae
- Institute of Hansen's Disease, Department of Pathology, Catholic University of Korea, Seoul 137-701, Korea.
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Abstract
Near-field scanning optical microscopy (NSOM) is a high-resolution scanning probe technique capable of obtaining simultaneous optical and topographic images with spatial resolution of tens of nanometers. We have integrated time-correlated single-photon counting and NSOM to obtain images of fluorescence lifetimes with high spatial resolution. The technique can be used to measure either full fluorescence lifetime decays at individual spots with a spatial resolution of <100 nm or NSOM fluorescence images using fluorescence lifetime as a contrast mechanism. For imaging, a pulsed Ti:sapphire laser was used for sample excitation and fluorescent photons were time correlated and sorted into two time delay bins. The intensity in these bins can be used to estimate the fluorescence lifetime at each pixel in the image. The technique is demonstrated on thin films of poly(9,9'-dioctylfluorene) (PDOF). The fluorescence of PDOF is the results of both inter- and intrapolymer emitting species that can be easily distinguished in the time domain. Fluorescence lifetime imaging with near-field scanning optical microscopy demonstrates how photochemical degradation of the polymer leads to a quenching of short-delay intrachain emission and an increase in the long-delay photons associated with interpolymer emitting species. The images also show how intra- and interpolymer species are uniformly distributed in the films.
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Affiliation(s)
- E S Kwak
- Department of Chemistry and Biochemistry, Center for Nano- and Molecular Science and Technology, University of Texas at Austin, 78712-1167, USA
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36
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Abstract
Toll-like receptor 2 (TLR2) is critical in the immune response to mycobacterial infections and the mutations in the TLR2 have been shown to confer the susceptibility to severe infection with mycobacteria. To define this, we screened the intracellular domain of TLR2 in 131 subjects. Groups of 45 lepromatous and 41 tuberculoid leprosy (TT) patients and 45 controls were investigated. Ten subjects among the lepromatous leprosy (LL) patients had a band variant detected by single-stranded conformational polymorphism. DNA sequencing detected a C to T substitution at nucleotide 2029 from the start codon of the TLR2. The mutation would substitute Arg to Trp at amino acid residue 677, one of the conserved regions of TLR2. In our results, the mutation was involved in only LL, not TT and control. Thus, we suggest that the mutation in the intracellular domain of TLR2 has a role in susceptibility to LL.
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MESH Headings
- Amino Acid Sequence
- Drosophila Proteins
- Genetic Predisposition to Disease
- Humans
- Leprosy, Lepromatous/blood
- Leprosy, Lepromatous/genetics
- Leprosy, Lepromatous/immunology
- Leprosy, Tuberculoid/blood
- Leprosy, Tuberculoid/genetics
- Leprosy, Tuberculoid/immunology
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Membrane Glycoproteins/chemistry
- Membrane Glycoproteins/genetics
- Molecular Sequence Data
- Mutation
- Mycobacterium leprae
- Polymorphism, Single-Stranded Conformational
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Sequence Alignment
- Signal Transduction
- Toll-Like Receptor 2
- Toll-Like Receptors
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Affiliation(s)
- T J Kang
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 505 Banpo-Dong, Socho-Gu, 137-701, Seoul, South Korea
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Lee SB, Kim SK, Kang TJ, Chae GT, Chun JH, Shin HK, Kim JP, Ko YH, Kim NH. The prevalence of folP1 mutations associated with clinical resistance to dapsone, in Mycobacterium leprae isolates from South Korea. Ann Trop Med Parasitol 2001; 95:429-32. [PMID: 11454253 DOI: 10.1080/000349801300188447] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- S B Lee
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-Gu, Seoul, 137-701, South Korea
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Kang SH, Oh TJ, Kim RG, Kang TJ, Hwang SH, Lee EY, Choi CY. An efficient cell-free protein synthesis system using periplasmic phosphatase-removed S30 extract. J Microbiol Methods 2000; 43:91-6. [PMID: 11121607 DOI: 10.1016/s0167-7012(00)00206-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
An efficient cell-free translation system was developed by removal of phosphatase localized in the periplasmic space, which hampers the translation reaction by hydrolyzing ATP. S30 extract was prepared from the spheroplast of Escherichia coli, and as much as 40% of ATP-hydrolysis activity of phosphatases could be easily removed by the spheroplast formation. The reaction period of translation using phosphatase-removed S30 extract could be prolonged and protein synthesis was enhanced by more than 30%.
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Affiliation(s)
- S H Kang
- School of Chemical Engineering, College of Engineering, Seoul National University, 151-742, Seoul, South Korea
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Gostkowski ML, Curey TE, Okerberg E, Kang TJ, Vanden Bout DA, Shear JB. Effects of molecular oxygen on multiphoton-excited photochemical analysis of hydroxyindoles. Anal Chem 2000; 72:3821-5. [PMID: 10959968 DOI: 10.1021/ac000278+] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have examined the effects of dissolved molecular oxygen on multiphoton-excited (MPE) photochemical derivatization of serotonin (5HT) and related cellular metabolites in various buffer systems and find that oxygen has a profound effect on the formation efficiency of visible-emitting photoproducts. Previously, end-column MPE photoderivatization provided low mass detection limits for capillary electrophoretic analysis of hydroxyindoles, but relied on the use of Good's buffers to generate high-sensitivity visible signal. In the present studies, visible emission from 5HT photoderivatized in different buffers varied by 20-fold under ambient oxygen levels but less than 2-fold in the absence of oxygen; oxygen did not significantly alter the photoproduct excited-state lifetime (approximately 0.8 ns). These results support a model in which oxygen interferes with formation of visible-emitting photoproducts by quenching a reaction intermediate, an effect that can be suppressed by buffer molecules. Deoxygenation of capillary electrophoresis separation buffers improves mass detection limits for 5-hydroxyindoles fractionated in 600-nm channels by approximately 2-fold to < or =30000 molecules and provides new flexibility in identifying separation conditions for resolving 5HT from molecules with similar electrophoretic mobilities, such as the catecholamine neurotransmitters.
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Affiliation(s)
- M L Gostkowski
- Department of Chemistry and Biochemistry & The Institute for Cellular and Molecular Biology, University of Texas, Austin 78712, USA
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Kang TJ, Kang SH, Jung ST, Lee EY, Choi CY. A simple regression method for determining the quantity of translated protein in a cell-free protein synthesis system. J Biosci Bioeng 1999; 88:345-7. [PMID: 16232626 DOI: 10.1016/s1389-1723(00)80024-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/1999] [Accepted: 06/14/1999] [Indexed: 10/18/2022]
Abstract
A simple regression method for quantifying endogenous leucine in S30 extract was developed. This method enabled the quantity of translated protein in a cell-free protein synthesis system to be exactly determined.
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Affiliation(s)
- T J Kang
- Department of Chemical Technology, College of Engineering, Seoul National University, Seoul 151-742, Korea
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Abstract
A partial genomic DNA library of Chlamydomonas reinhardtii was screened with an (AC)11 probe for the presence of (CA/GT)n simple sequence repeats (SSRs). Based on the frequency of these repeats in the partial genomic library, we estimate that (CA/GT)n repeats occur at a rate of about one every 17.7 kb in the C. reinhardtii genome. Ten positive clones were sequenced and four polymerase chain reaction (PCR) primer sets flanking (CA/GT)n sequences were constructed for four loci. The PCR was used to specifically amplify these regions from multiple isolates of C. reinhardtii. All four loci were highly polymorphic in the C. reinhardtii isolates. A simple Mendelian inheritance pattern was found for all four loci, which showed 2:2 segregation in the tetrads resulting from a cross between C. reinhardtii and C. smithii. Our results suggest that these simple sequence repeat DNA loci will be useful for identity testing, population studies, linkage analysis, and genome mapping in Chlamydomonas.
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Affiliation(s)
- T J Kang
- Department of Botany, North Dakota State University, Fargo 58105-5517, USA
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Lim DY, Kang TJ, Hong SP, Chung CH, Choi CH, Lee SI, Park YW, Kwack JJ, Ki JD, Kim CW, Park CY. Influence of pentobarbital-Na on stimulation-evoked catecholamine secretion in the perfused rat adrenal gland. Korean J Intern Med 1997; 12:163-75. [PMID: 9439151 PMCID: PMC4531992 DOI: 10.3904/kjim.1997.12.2.163] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVES The present study was attempted to investigate the effects of pentobarbital-Na, one of the barbiturates which are known to depress excitatory synaptic transmission in the central nervous system at concentrations similar to those required for the induction and maintenance of anesthesia, on catecholamines (CA) secretion evoked by cholinergic stimulation and membrane-depolarization from the isolated perfused rat adrenal gland, and to clarify the mechanism of its action. METHODS Mature male Sprague-Dawley rats were anesthetized with thiopenal-Na (40 mg/kg, s.c.). The adrenal gland was isolated by the methods of Wakade. A cannula used for perfusion of the adrenal gland was inserted into the distal end of the renal vein. The adrenal gland was carefully removed from the animal and placed on a platform of a leucite chamber. RESULTS The perfusion of pentobarbital-Na(30-300 uM) into an adrenal vein for 20 min produced relatively dose-dependent inhibition in CA secretion evoked by ACh(5.32 mM), DMPP(100 uM for 1 min), McN-A-343(200 uM for 2 min), Bay-K-8644(10 uM) and high potassium(56 mM), while it did not affect the CA secretion of cyclopiazonic acid(10 uM). Also, in the presence of thiopental-Na (100 uM), CA secretory responses evoked by ACh, DMPP, McN-A-343 and high K+ were markedly depressed. Moreover, in adrenal glands preloaded with ketamine(100 uM for 20 min), which is known to be a dissociative anesthetic, CA secretion evoked by ACh, DMPP, McN-A-343 and high K+ were significantly attenuated. CONCLUSION Taken together, these experimental results suggest that pentobarbital-Na depresses CA release evoked by both cholinergic stimulation and membrane-depolarization from the isolated rat adrenal medulla and that this inhibitory activity may be due to the result of the direct inhibition of Ca++ influx into the chromaffin cells without any effect on the calcium mobilization from the intracellular store.
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Affiliation(s)
- D Y Lim
- Department of Pharmacology and Internal Medicine, College of Medicine, Chosun University, Kwangju, Korea
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Abstract
The present study was conducted to investigate the influence of arachidonic acid, which is known to be an important unsaturated fatty acid component of membrane phospholipids and to be liberated by phospholipase A2 action, on secretion of catecholamines (CA) from the isolated perfused rat adrenal glands and to clarify the mechanism of its action. Arachidonic acid (10 uM) perfused into an adrenal gland of the rat for 20 min caused a significant inhibition of CA secretion evoked by ACh (5.32 x 10(-3) M), DMPP (10(-4) M) and muscarine (10(-4) M) while it did not affect that induced by excess K+ (5.6 x 10(-2) M). Arachidonic acid, in the presence of ouabain (100 uM), an inhibitor of Na+, K(+) -ATPase, also produced a marked inhibitory effect of CA secretion evoked by ACh, DMPP and muscarine but did not modify the secretory effect of excess K+. The perfusion of arachidonic acid along with indomethacin (30 uM), which is an inhibitor of cyclooxygenase, for 20 min attenuated markedly CA secretory effect evoked by ACh, DMPP and muscarine while it did not influence that by excess K+. Prostaglandin F2 alpha perfused in a retrograde direction for 20 min inhibited greatly the CA secretion evoked by DMPP but did not affect the effect evoked by excess K+. All of arachidonic acid, ouabain, indomethacin and prostaglandin F2 alpha used in the present study did not affect the spontaneous basal release of CA in the perfused rat adrenal glands. Taken together, these experimental results suggest that arachidonic acid, as well as prostaglandin F2 alpha, cause the inhibitory action of CA secretion evoked by cholinergic receptor-mediated stimulation, but not by membrane depolarization, and also play a modulatory role in regulating CA secretion from the rat adrenal medulla.
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Affiliation(s)
- D Y Lim
- Department of Pharmacology, Chosun University Medical College, Kwangju, Korea
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Kang TJ. [Preliminary observations on the echocardiographic features of 84 cases of Keshan disease (author's transl)]. Zhonghua Nei Ke Za Zhi 1980; 19:442-5. [PMID: 7297262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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