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Singh M, Lee SC, Won K. Lignin phenolation by graft copolymerization to boost its reactivity. Int J Biol Macromol 2024; 266:131258. [PMID: 38556229 DOI: 10.1016/j.ijbiomac.2024.131258] [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: 10/29/2023] [Revised: 03/26/2024] [Accepted: 03/28/2024] [Indexed: 04/02/2024]
Abstract
Lignin is the most abundant phenolic biopolymer and a renewable resource of aromatics. It can be used as a phenol substitute in the synthesis of phenolic resins. However, lignin is not as reactive as phenol, so phenolation is generally carried out to improve lignin reactivity. In this work, we suggest a solution to circumvent the limitations of traditional phenolation (e.g., high temperature, strong acids/bases, limited reactivity, and phenol toxicity). We first attempt new lignin phenolation by graft copolymerization in which polymeric phenol, instead of toxic phenol, is introduced to lignin. Organosolv lignin from hardwood was modified with 2-bromoisobutyryl bromide to act as a lignin macroinitiator (L-Br). A protected phenolic monomer, 4-acetoxystyrene, was graft copolymerized onto L-Br using CuBr2/tris[2-(dimethylamino)ethyl]amine as a catalyst/ligand, after which the resultant lignin copolymer was deacetylated to produce lignin grafted with poly(4-hydroxystyrene). This poly-phenolation process was conducted at room temperature without the strong acids/bases and toxic phenol required in conventional phenolation. The poly-phenolated lignin was analyzed using 1H-, 13C-, and 31P NMR spectroscopy and gel permeation chromatography. This novel phenolation process enhanced the reactive sites of lignin more than tenfold. It also reduced the dark color of technical lignins significantly, thereby overcoming a serious obstacle to their applicability.
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Affiliation(s)
- Manisha Singh
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Sang Cheon Lee
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Keehoon Won
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea.
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Mari E, Duraisamy M, Eswaran M, Sellappan S, Won K, Chandra P, Tsai PC, Huang PC, Chen YH, Lin YC, Ponnusamy VK. Highly electrochemically active Ti 3C 2Tx MXene/MWCNT nanocomposite for the simultaneous sensing of paracetamol, theophylline, and caffeine in human blood samples. Mikrochim Acta 2024; 191:212. [PMID: 38509344 DOI: 10.1007/s00604-024-06273-9] [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: 11/20/2023] [Accepted: 02/22/2024] [Indexed: 03/22/2024]
Abstract
The facile fabrication is reported of highly electrochemically active Ti3C2Tx MXene/MWCNT (3D/1D)-modified screen-printed carbon electrode (SPE) for the efficient simultaneous electrochemical detection of paracetamol, theophylline, and caffeine in human blood samples. 3D/1D Ti3C2Tx MXene/MWCNT nanocomposite was synthesized using microwave irradiation and ultrasonication processes. Then, the Ti3C2Tx/MWCNT-modified SPE electrode was fabricated and thoroughly characterized towards its physicochemical and electrochemical properties using XPS, TEM, FESEM, XRD, electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry techniques. As-constructed Ti3C2Tx-MWCNT/SPE offers excellent electrochemical sensing performance with good detection limits (0.23, 0.57, and 0.43 µM) and wide linear ranges (1.0 ~ 90.1, 2.0 ~ 62.0, and 2.0-90.9 µM) for paracetamol, caffeine, and theophylline, respectively, in the human samples. Notably, the non-enzymatic electroactive nanocomposite-modified electrode has depicted a semicircle Nyquist plot with low charge transfer resistance (Rct∼95 Ω), leading to high ionic diffusion and facilitating an excellent electron transfer path. All the above results in efficient stability, reproducibility, repeatability, and sensitivity compared with other reported works, and thus, it claims its practical utilization in realistic clinical applications.
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Affiliation(s)
- Elancheziyan Mari
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-Ro 1-Gil, Jung-Gu, Seoul, 04620, Republic of Korea
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University (KMU), No. 100, Shiquan 1St Road, Sanmin District, Kaohsiung City, 807, Taiwan
| | - Murugesan Duraisamy
- School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300, Nibong Tebal, Puiau Pinang, Malaysia
| | - Muthusankar Eswaran
- School of Electronics and Automation (SoE), Kerala University of Digital Sciences, Innovation and Technology (Digital University Kerala), Thiruvananthapuram, Kerala, India
| | - Senthilkumar Sellappan
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology (VIT), Vellore City, India
| | - Keehoon Won
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-Ro 1-Gil, Jung-Gu, Seoul, 04620, Republic of Korea
| | - Pranjal Chandra
- Laboratory of Bio-Physio Sensors and Nanobioengineering, School of Biochemical Engineering, Indian Institute of Technology (BHU) Varanasi, Varanasi, Uttar Pradesh, India
| | - Pei-Chien Tsai
- Department of Computational Biology, Institute of Bioinformatics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, 602105, India
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical Univiersity, Kaohsiung City, 807, Taiwan
| | - Po-Chin Huang
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University (KMU), No. 100, Shiquan 1St Road, Sanmin District, Kaohsiung City, 807, Taiwan
- National Institute of Environmental Health Sciences, National Health Research Institutes (NHRI), Zhunan Town, Miaoli County, 35053, Taiwan
- Department of Medical Research, China Medical University Hospital (CMUH), China Medical University, Taichung City, Taiwan
| | - Yi-Hsun Chen
- Division of Gastroenterology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Yuan-Chung Lin
- Institute of Environmental Engineering, National Sun Yat-Sen University (NSYSU), Kaohsiung City, 804, Taiwan
| | - Vinoth Kumar Ponnusamy
- Research Center for Precision Environmental Medicine, Kaohsiung Medical University (KMU), No. 100, Shiquan 1St Road, Sanmin District, Kaohsiung City, 807, Taiwan.
- Department of Medical Research, Kaohsiung Medical University Hospital (KMUH), Kaohsiung City, 807, Taiwan.
- Department of Chemistry, National Sun Yat-Sen University (NSYSU), Kaohsiung City, 804, Taiwan.
- Department of Medical Research, China Medical University Hospital (CMUH), China Medical University, Taichung City, Taiwan.
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical Univiersity, Kaohsiung City, 807, Taiwan.
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Lee Y, Lee S, Kim S, Lee D, Won K. Solvent-free enzymatic synthesis and evaluation of vanillyl propionate as an effective and biocompatible preservative. Bioprocess Biosyst Eng 2023; 46:1579-1590. [PMID: 37682355 DOI: 10.1007/s00449-023-02921-1] [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: 06/27/2023] [Accepted: 08/16/2023] [Indexed: 09/09/2023]
Abstract
Preservatives are chemicals added to protect products against microbial spoilage, and thus are indispensable for pharmaceuticals, cosmetics, and foods. Due to growing concerns about human health and environments in conventional chemical preservatives, many companies have been seeking safe and effective alternatives that can be produced through environment-friendly processes. In this work, in order to develop effective and safe preservatives from plants, we attempt solvent-free lipase-catalyzed transesterification of vanillyl alcohol with ethyl propionate for the first time. The reaction product, vanillyl propionate was efficiently obtained in a high yield. Unlike vanillyl alcohol and ethyl propionate, vanillyl propionate showed antimicrobial activity. The minimal inhibitory concentration test showed that it exhibited high and broad antimicrobial activity against all the tested microorganisms (Gram-negative and Gram-positive bacteria, yeasts, and molds), which was overall comparable to that of propyl paraben, which is one of the most effective preservatives. It was also found to have even higher antioxidant capacity and biocompatibility with human cells than propyl paraben. Vanillyl propionate, which is a plant-based preservative produced through a green bioprocess, is expected to be successfully applied to various industries thanks to its high antimicrobial and antioxidant effect, and high biocompatibility.
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Affiliation(s)
- Yousun Lee
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Republic of Korea
- COSMAX, 255 Pangyo-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, 13486, Republic of Korea
| | - Sujin Lee
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Republic of Korea
| | - Sungjun Kim
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Republic of Korea
| | - Dogyeong Lee
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Republic of Korea
| | - Keehoon Won
- Department of Chemical and Biochemical Engineering, College of Engineering, Dongguk University-Seoul, 30 Pildong-ro 1-gil, Jung-gu, Seoul, 04620, Republic of Korea.
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Kim H, Kim S, Lee E, Won K, Jun S, Ahn M. Improving attention level through interactive neurofeedback game. IBRO Rep 2019. [DOI: 10.1016/j.ibror.2019.07.1391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Lee SK, Won K. Special Issue to Mark the Career and the Retirement of Professor Sun Bok Lee. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0100-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lee SC, Tran TMT, Choi JW, Won K. Lignin for white natural sunscreens. Int J Biol Macromol 2019; 122:549-554. [DOI: 10.1016/j.ijbiomac.2018.10.184] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022]
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Won K, Lee S, Choi J. Application of lignin as a natural active ingredient in sunscreens. N Biotechnol 2018. [DOI: 10.1016/j.nbt.2018.05.1156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Lee M, Won K, Kim EJ, Hwang JS, Lee HK. Comparison of stratum corneum thickness between two proposed methods of calculation using Raman spectroscopic depth profiling of skin water content. Skin Res Technol 2018; 24:504-508. [DOI: 10.1111/srt.12461] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2018] [Indexed: 11/28/2022]
Affiliation(s)
- M. Lee
- Skin Care DivisionAmorepacific Research & Development Center Yongin Korea
| | - K. Won
- Clinical LaboratoryKyung Hee University Skin Biotechnology Center Suwon Korea
| | - E. J. Kim
- Skin Care DivisionAmorepacific Research & Development Center Yongin Korea
| | - J. S. Hwang
- Department of Genetic EngineeringCollege of Life SciencesKyung Hee University Yongin Korea
| | - H. K. Lee
- Skin Care DivisionAmorepacific Research & Development Center Yongin Korea
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Choi J, Han S, Won K, Jun S. Effect of acoustic stimulation after sleep spindle activity. Sleep Med 2017. [DOI: 10.1016/j.sleep.2017.11.179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hill D, Lim H, Foong Y, Nelson V, Won K, Lazar M. OR043 Obesity disrupts tissue-protective macrophage populations in the adipose and lung. Ann Allergy Asthma Immunol 2017. [DOI: 10.1016/j.anai.2017.08.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mabekou SS, Lee SC, Dinh TH, Won K, Mitchell RJ. Enhanced sensitivity and responses to viologens from a whole-cell bacterial bioreporter treated with branched polyethyleneimines. J Appl Microbiol 2017; 123:1478-1487. [PMID: 28944557 DOI: 10.1111/jam.13592] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 05/17/2017] [Revised: 09/14/2017] [Accepted: 09/17/2017] [Indexed: 12/13/2022]
Abstract
AIMS Evaluate the use of polyethyleneimines (PEIs) as membrane permeabilizers to improve the responses and sensitivity of a bacterial bioreporter strain to viologens. METHODS AND RESULTS The responses from E. coli str. EBS, i.e., E. coli BW25113 carrying plasmid pSDS, when exposed to five different viologens were characterized, as were the toxicities of seven different PEIS, including two linear and five branched species. Based on these results, benzyl viologen led to the greatest responses, and 0·8-kDa branched PEI (BPEI) was the least toxic of the PEIs tested and, therefore, both were selected for the subsequent tests. The bioluminescence and relative responses from E. coli str. EBS exposed to various concentrations of 0·8 kDa BPEI identified 400 mg l-1 as the optimal concentration. Using this concentration, tests were performed with all five of the viologens. CONCLUSIONS The responses from E. coli str. EBS to the viologens were improved, with the maximum relative bioluminescence values increasing between 5·6 and 16·5-fold. The minimum detectable levels for four of the viologens were likewise improved 2- to 4-fold. SIGNIFICANCE AND IMPACT OF STUDY Improving bacterial membrane permeability in a controlled manner using BPEIs can improve biosensing of toxic compounds, as well as be used in biofuel and bioenergy applications where membrane permeability to a solute is important.
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Affiliation(s)
- S S Mabekou
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea
| | - S C Lee
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, Korea
| | - T H Dinh
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, Korea
| | - K Won
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul, Korea
| | - R J Mitchell
- School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Korea
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Abstract
Intelligent food packaging can provide consumers with reliable and correct information on the quality and safety of packaged foods. One of the key constituents in intelligent packaging is a colorimetric oxygen indicator, which is widely used to detect oxygen gas involved in food spoilage by means of a color change. Traditional oxygen indicators consisting of redox dyes and strong reducing agents have two major problems: they must be manufactured and stored under anaerobic conditions because air depletes the reductant, and their components are synthetic and toxic. To address both of these serious problems, we have developed a natural component-based oxygen indicator characterized by in-pack activation. The conventional oxygen indicator composed of synthetic and artificial components was redesigned using naturally occurring compounds (laccase, guaiacol, and cysteine). These natural components were physically separated into two compartments by a fragile barrier. Only when the barrier was broken were all of the components mixed and the function as an oxygen indicator was begun (i.e., in-pack activation). Depending on the component concentrations, the natural component-based oxygen indicator exhibited different response times and color differences. The rate of the color change was proportional to the oxygen concentration. This novel colorimetric oxygen indicator will contribute greatly to intelligent packaging for healthier and safer foods.
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Affiliation(s)
- Keehoon Won
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul , 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Nan Young Jang
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul , 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Junsu Jeon
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul , 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
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Hwang H, Moon SJ, Won K, Kim YH, Choi JW. Parameters affecting in vitro monolignol couplings during dehydrogenative polymerization in the presence of peroxidase and H2O2. J IND ENG CHEM 2015. [DOI: 10.1016/j.jiec.2014.12.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Affiliation(s)
- Sung Hee Kim
- Department of Microbial Engineering; Konkuk University; Seoul 143-701 South Korea
| | - Min Hoo Kim
- Department of Microbial Engineering; Konkuk University; Seoul 143-701 South Korea
| | - Ji Hyun Kim
- Department of Microbial Engineering; Konkuk University; Seoul 143-701 South Korea
| | - Saerom Park
- Department of Microbial Engineering; Konkuk University; Seoul 143-701 South Korea
| | - Hyungsup Kim
- Department of Textile Engineering; Konkuk University; Seoul 143-701 South Korea
| | - Keehoon Won
- Department of Chemical and Biochemical Engineering; Dongguk University; Seoul 100-715 South Korea
| | - Sang Hyun Lee
- Department of Microbial Engineering; Konkuk University; Seoul 143-701 South Korea
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Vu CHT, Won K. Leaching-resistant carrageenan-based colorimetric oxygen indicator films for intelligent food packaging. J Agric Food Chem 2014; 62:7263-7267. [PMID: 24979322 DOI: 10.1021/jf5014764] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Visual oxygen indicators can give information on the quality and safety of packaged food in an economic and simple manner by changing color based on the amount of oxygen in the packaging, which is related to food spoilage. In particular, ultraviolet (UV)-activated oxygen indicators have the advantages of in-pack activation and irreversibility; however, these dye-based oxygen indicator films suffer from dye leaching upon contact with water. In this work, we introduce carrageenans, which are natural sulfated polysaccharides, to develop UV-activated colorimetric oxygen indicator films that are resistant to dye leakage. Carrageenan-based indicator films were fabricated using redox dyes [methylene blue (MB), azure A, and thionine], a sacrificial electron donor (glycerol), an UV-absorbing photocatalyst (TiO2), and an encapsulation polymer (carrageenan). They showed even lower dye leakage in water than conventional oxygen indicator films, owing to the electrostatic interaction of anionic carrageenan with cationic dyes. The MB/TiO2/glycerol/carrageenan oxygen indicator film was successfully bleached upon UV irradiation, and it regained color very rapidly in the presence of oxygen compared to the other waterproof oxygen indicator films.
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Affiliation(s)
- Chau Hai Thai Vu
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul , 30 Pildong-ro 1-gil, Jung-gu, Seoul 100-715, Republic of Korea
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Kim MH, Park S, Kim YH, Won K, Lee SH. Immobilization of formate dehydrogenase from Candida boidinii through cross-linked enzyme aggregates. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.08.020] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vu CHT, Won K. Novel water-resistant UV-activated oxygen indicator for intelligent food packaging. Food Chem 2013; 140:52-6. [DOI: 10.1016/j.foodchem.2013.02.056] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 02/08/2013] [Accepted: 02/13/2013] [Indexed: 10/27/2022]
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Affiliation(s)
- Nan Young Jang
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; 30 Pildong-ro 1-gil Jung-gu Seoul 100-715 Republic of Korea
| | - Keehoon Won
- Department of Chemical and Biochemical Engineering; Dongguk University-Seoul; 30 Pildong-ro 1-gil Jung-gu Seoul 100-715 Republic of Korea
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Vu CHT, Won K. Bioinspired molecular adhesive for water-resistant oxygen indicator films. Biotechnol Prog 2013; 29:513-9. [DOI: 10.1002/btpr.1692] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 01/08/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Chau Hai Thai Vu
- Dept. of Chemical and Biochemical Engineering; Dongguk University-Seoul; 30 Pildong-ro 1-gil Jung-gu Seoul 100-715 Republic of Korea
| | - Keehoon Won
- Dept. of Chemical and Biochemical Engineering; Dongguk University-Seoul; 30 Pildong-ro 1-gil Jung-gu Seoul 100-715 Republic of Korea
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Moon SJ, Kwon M, Choi D, Won K, Kim YH, Choi IG, Choi JW. In vitro analysis of the monolignol coupling mechanism using dehydrogenative polymerization in the presence of peroxidases and controlled feeding ratios of coniferyl and sinapyl alcohol. Phytochemistry 2012; 82:15-21. [PMID: 22884779 DOI: 10.1016/j.phytochem.2012.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 04/03/2012] [Accepted: 07/10/2012] [Indexed: 05/27/2023]
Abstract
In this study, dehydrogenative polymers (DHP) were synthesized in vitro through dehydrogenative polymerization using different ratios of coniferyl alcohol (CA) and sinapyl alcohol (SA) (10:0, 8:2, 6:4, 2:8, 0:10), in order to investigate the monolignol coupling mechanism in the presence of horseradish peroxidase (HRP), Coprinus cinereus peroxidase (CiP) or soybean peroxidase (SBP) with H(2)O(2), respectively. The turnover capacities of HRP, CiP and SBP were also measured for coniferyl alcohol (CA) and sinapyl alcohol (SA), and CiP and SBP were found to have the highest turnover capacity for CA and SA, respectively. The yields of HRP-catalyzed DHP (DHP-H) and CiP-catalyzed DHP (DHP-C) were estimated between ca. 7% and 72% based on the original weights of CA/SA in these synthetic conditions. However, a much lower yield of SBP-catalyzed DHP (DHP-S) was produced compared to that of DHP-H and DHP-C. In general, the DHP yields gradually increased as the ratio of CA/SA increased. The average molecular weight of DHP-H also increased with increasing CA/SA ratios, while those of DHP-C and DHP-S were not influenced by the ratios of monolignols. The frequency of β-O-4 linkages in the DHPs decreased with increasing CA/SA ratios, indicating that the formation of β-O-4 linkages during DHP synthesis was influenced by peroxidase type.
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Affiliation(s)
- Sun-Joo Moon
- Department of Forest Sciences and Research Institute for Agriculture and Life Science, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
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Lee SH, Lee HJ, Won K, Park CB. Cover Picture: Artificial Electron Carriers for Photoenzymatic Synthesis under Visible Light (Chem. Eur. J. 18/2012). Chemistry 2012. [DOI: 10.1002/chem.201290069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
NAD analogues can be employed as artificial electron carriers for photoenzymatic synthesis under visible light. Four different NAD analogues that have a 3-substituted pyridine ring have been investigated. 3-Acetylpyridine adenine dinucleotide and 3-pyridinealdehyde adenine dinucleotide were photochemically reduced much more efficiently than NAD, while their reduced products showed coenzyme activity comparable to natural NAD.
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Affiliation(s)
- Sahng Ha Lee
- KAIST Institute for the BioCentury, Department of Materials Science and Engineering, Daejeon, Republic of Korea
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Kim MH, An S, Won K, Kim HJ, Lee SH. Entrapment of enzymes into cellulose–biopolymer composite hydrogel beads using biocompatible ionic liquid. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcatb.2011.11.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Park TJ, Kim YS, Hwang T, Govindaiah P, Choi SW, Kim E, Won K, Lee SH, Kim JH. Preparation and characterization of heparinized multi-walled carbon nanotubes. Process Biochem 2012. [DOI: 10.1016/j.procbio.2011.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Lee HJ, Lee SH, Park CB, Won K. Coenzyme analogs: excellent substitutes (not poor imitations) for electrochemical regeneration. Chem Commun (Camb) 2011; 47:12538-40. [PMID: 22003495 DOI: 10.1039/c1cc14313a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the first time, employment of nicotinamide coenzyme NAD analogs has overcome the limitations of NAD in electrochemical regeneration. It has been shown that NAD analogs, APAD and PAAD, were electrochemically reduced more efficiently than original NAD and that the stability of their reduced products was also much higher than NADH.
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Affiliation(s)
- Hye Jung Lee
- Department of Chemical and Biochemical Engineering, Dongguk University-Seoul, Seoul 100-715, Republic of Korea
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Kim JY, Shin EJ, Eom IY, Won K, Kim YH, Choi D, Choi IG, Choi JW. Structural features of lignin macromolecules extracted with ionic liquid from poplar wood. Bioresour Technol 2011; 102:9020-9025. [PMID: 21840709 DOI: 10.1016/j.biortech.2011.07.081] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 07/20/2011] [Accepted: 07/20/2011] [Indexed: 05/31/2023]
Abstract
1-Ethyl-3-methylimidazolium acetate ([Emim][CH₃COO]) was used for the extraction of lignin from poplar wood (Populus albaglandulosa), which was called to ionic liquid lignin (ILL) and structural features of ILL were compared with the corresponding milled wood lignin (MWL). Yields of ILL and MWL were 5.8±0.3% and 4.4±0.4%, respectively. The maximum decomposition rate (V(M)) and temperature (T(M)) corresponding to V(M) were 0.25%/ °C and 308.2 °C for ILL and 0.30%/ °C and 381.3 °C for MWL. The amounts of functional groups (OMe and phenolic OH) appeared to be similar for both lignins; approximately 15.5% and 6.7% for ILL and 14.4% and 6.3% for MWL. However, the weight average molecular weight (M(w)) of ILL (6347 Da) was determined to be 2/3-fold of that of MWL (10,002 Da) and polydispersity index (PDI: M(w)/M(n)) suggested that the lignin fragments were more uniform in the ILL (PDI 1.62) than in the MWL (PDI 2.64).
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Affiliation(s)
- Jae-Young Kim
- Department of Forest Sciences and Research Institute for Agriculture and Life Science, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-921, Republic of Korea
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Park K, Kim J, Do Y, Song H, Won K. Usefulness of preoperative F-18 FDG-PET/CT for detection of signet ring cell carcinoma of the stomach: Correlation with pathologic findings including immunohistochemical staining. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e14621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Kim J, Do Y, Park K, Kwon K, Song H, Won K, Kang Y. SUVmax of F-18 FDG-PET/CT in advanced gastric cancer with tubular adenocarcinoma: Correlation with pathologic findings including immunohistochemical staining. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e14566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Nam DH, Won K, Kim YH, Sang BI. A novel route for immobilization of proteins to silica particles incorporating silaffin domains. Biotechnol Prog 2010; 25:1643-9. [PMID: 19774662 DOI: 10.1002/btpr.261] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In the diatom Cylindrotheca fusiformis, modified peptides called silaffin polypeptides are responsible for silica deposition in vivo at ambient conditions. Recently, it was discovered that the synthetic R5 peptide, the repeat unit of silaffin polypeptide without post-translational modification, was capable of precipitating silica in vitro and at ambient conditions. Herein, chimeric proteins were generated by incorporating synthetic silaffin R5 peptides and related unmodified silaffin domains (R1-R7) from Cylindrotheca fusiformis onto green fluorescent protein (GFP) by recombinant DNA technology and their ability to cause silicification was also examined. GFP chimeric proteins showed silicification at very low concentrations (600-700 microg/mL) when compared with adding excess amounts of R5 peptides (10 mg/mL) as previously reported. Sensitive to pH conditions, only the GFP-R1 chimera showed silicification activity at pH 8.0. The protein immobilization efficiencies of these chimeras were unexpectedly high ranging from 75 to 85%, with the R1 silaffin-protein construct showing excellent immobilization efficiency and a constant molar ratio of silica to protein ranging from 250 to 350 over a wide pH range. The average silica particle sizes had a tendency to decrease as pH increased to basic conditions. This study demonstrated the production of nanoscale immobilized protein, fabricated via silaffin-fused proteins.
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Affiliation(s)
- Dong Hyun Nam
- Department of Chemical Engineering, Kwangwoon University, Nowon-gu, Seoul 139-701, South Korea
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Lee SH, Doan TTN, Won K, Ha SH, Koo YM. Immobilization of lipase within carbon nanotube–silica composites for non-aqueous reaction systems. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.molcatb.2009.10.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [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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Jung H, Kim JH, Yoon HH, Won K. Reconstitution of ferritins with organic and inorganic materials for various applications. J Biosci Bioeng 2009. [DOI: 10.1016/j.jbiosc.2009.08.435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Affiliation(s)
- Sahng Ha Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea
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Won K, Park MJ, Yoon HH, Kim JH. Immobilization of iron storage protein on a gold electrode based on self-assembled monolayers. Ultramicroscopy 2008; 108:1342-7. [DOI: 10.1016/j.ultramic.2008.04.088] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
Electrically conductive sol-gel matrices have been first introduced in order to enhance the efficiency of electrochemical NADH regeneration systems for biocatalysis. Vanadia-silica mixed gels as conductive sol-gels were synthesized using vanadium (V) oxytripropoxide (VOTP) and tetramethyl orthosilicate (TMOS) as precursors. Direct electrochemical reductions of NAD+ were carried out in the presence of vanadia-silica xerogels using unmodified platinum electrodes. Vanadia-silica gels from higher ratios of VOTP to TMOS could effectively improve electrochemical generations of NADH from NAD+. Direct electrochemical regenerations of NADH were coupled to the synthesis of l-glutamate from alpha-ketoglutarate catalyzed by glutamate dehydrogenases (GDH). In this case, vanadia-silica gels were used as matrices for enzyme encapsulation, as opposed to serving as additives. When GDH were entrapped in "nonconductive" silica gels, synthesized using only TMOS, in the control experiment, the initial supply of NADH exhausted quickly and a final conversion of 30% was obtained. However, the use of conductive vanadia-silica gels with encapsulated GDH resulted in complete conversion of alpha-ketoglutarate to l-glutamate. A turnover number of a cofactor was also enhanced 3-fold by the application of conductive vanadia-silica gels.
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Affiliation(s)
- Eulalia Siu
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, South Korea
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Song HK, Lee SH, Won K, Park JH, Kim JK, Lee H, Moon SJ, Kim DK, Park CB. Electrochemical regeneration of NADH enhanced by platinum nanoparticles. Angew Chem Int Ed Engl 2008; 47:1749-52. [PMID: 18224653 DOI: 10.1002/anie.200703632] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Hyun-Kon Song
- Division of Engineering, Brown University, Providence, RI 02912, USA
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Song HK, Lee S, Won K, Park J, Kim J, Lee H, Moon SJ, Kim D, Park C. Electrochemical Regeneration of NADH Enhanced by Platinum Nanoparticles. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200703632] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Lee JO, So HM, Jeon EK, Chang H, Won K, Kim YH. Aptamers as molecular recognition elements for electrical nanobiosensors. Anal Bioanal Chem 2008; 390:1023-32. [PMID: 17955221 PMCID: PMC2262919 DOI: 10.1007/s00216-007-1643-y] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [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: 07/03/2007] [Revised: 08/27/2007] [Accepted: 09/18/2007] [Indexed: 11/29/2022]
Abstract
Recent advances in nanotechnology have enabled the development of nanoscale sensors that outperform conventional biosensors. This review summarizes the nanoscale biosensors that use aptamers as molecular recognition elements. The advantages of aptamers over antibodies as sensors are highlighted. These advantages are especially apparent with electrical sensors such as electrochemical sensors or those using field-effect transistors.
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Affiliation(s)
- Jeong-O Lee
- Fusion-Biotechnology Research Center, Advanced Materials Division, Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong-gu, Daejeon, 305-343, South Korea.
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Jeon NY, Ko SJ, Lee YS, Kim BT, Won K, Lee H. Synthesis of optically pure halogenated phenyl 2-hydroxypropanones by lipase-catalyzed enantioselective transesterification. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcatb.2007.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Yoon DS, Won K, Kim YH, Song BK, Kim SJ, Moon SJ, Kim BS. Continuous removal of hydrogen peroxide with immobilised catalase for wastewater reuse. Water Sci Technol 2007; 55:27-33. [PMID: 17305120 DOI: 10.2166/wst.2007.016] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Hydrogen peroxide was continuously removed for wastewater reuse using an immobilised biocatalyst. A commercial catalase, which is an enzyme to decompose hydrogen peroxide to water and oxygen, was entrapped in chitosan beads. Hydrogen peroxide in aqueous solutions of varying pH, temperature and concentration was continuously removed through a reactor containing the catalase-entrapped chitosan beads at high efficiency for 24 h. Additional silicate coating of the chitosan beads resulted in significant improvements in the catalase performance under harsh conditions, which are often found in peroxide-based industrial processes. We expect that immobilisation of catalases can enhance their applicability for continuous degradation of hydrogen peroxide for wastewater reuse.
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Affiliation(s)
- D S Yoon
- Korea Research Institute of Chemical Technology, 100 Jang-dong, Yuseong-gu, Daejeon 305-343, Korea
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Park DW, Kim YH, Kim BS, So HM, Won K, Lee JO, Kong KJ, Chang H. Detection of tumor markers using single-walled carbon nanotube field effect transistors. J Nanosci Nanotechnol 2006; 6:3499-502. [PMID: 17252798] [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] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We have developed a biosensor capable of detecting carcinoembryonic antigen (CEA) markers using single-walled carbon nanotube field effect transistors (SWNT-FETs). These SWNT-FETs were fabricated using nanotubes produced by a patterned catalyst growth technique, where the top contact electrodes were generated using conventional photolithography. For biosensor applications, SU-8 negative photoresist patterns were used as an insulation layer. CEA antibodies were employed as recognition elements to specific tumor markers, and were successfully immobilized on the sides of a single-walled carbon nanotube using CDI-Tween 20 linking molecules. The binding of tumor markers to these antibody-functionalized SWNT-FETs was then monitored continuously during exposure to dilute CEA solutions. The observed sharp decrease in conductance demonstrates the possibility of realizing highly sensitive, label-free SWNT-FET-based tumor sensors.
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Affiliation(s)
- Dong-Won Park
- Department of Chemical Engineering, Chungbuk National University, Cheongju 500-712, Korea
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Jeon NY, Ko SJ, Won K, Kang HY, Kim BT, Lee YS, Lee H. Synthesis of alkyl (R)-lactates and alkyl (S,S)-O-lactyllactates by alcoholysis of rac-lactide using Novozym 435. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.07.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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So HM, Won K, Kim YH, Kim BK, Ryu BH, Na PS, Kim H, Lee JO. Single-walled carbon nanotube biosensors using aptamers as molecular recognition elements. J Am Chem Soc 2005; 127:11906-7. [PMID: 16117506 DOI: 10.1021/ja053094r] [Citation(s) in RCA: 339] [Impact Index Per Article: 17.8] [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: 11/28/2022]
Abstract
We report the real-time detection of protein using SWNT-FET-based biosensors comprising DNA aptamers as molecular recognition elements. Anti-thrombin aptamers that are highly specific to serine protein thrombin were immobilized on the sidewall of a SWNT-FET using CDI-Tween linking molecules. The binding of thrombin aptamers to SWNT-FETs causes a rightward shift of the threshold gate voltages, presumably due to the negatively charged backbone of the DNA aptamers. While the addition of thrombin solution causes an abrupt decrease in the conductance of the thrombin aptamer immobilized SWNT-FET, no noticeable change was observed with elastase.
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Affiliation(s)
- Hye-Mi So
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Daejeon 305-343, Korea
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Won K, Schautzer F, Krafczyk S, Kleine J, Büttner U, Noachtar S. Effects of carbamazepine and levetiracetam on gaze and posture control. Akt Neurol 2005. [DOI: 10.1055/s-2005-919328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lee YS, Hong JH, Jeon NY, Won K, Kim BT. Highly Enantioselective Acylation of rac-Alkyl Lactates Using Candida antarctica Lipase B. Org Process Res Dev 2004. [DOI: 10.1021/op0498722] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yeon Soo Lee
- Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseonggu, Daejon 305-343, South Korea
| | - Joo Hee Hong
- Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseonggu, Daejon 305-343, South Korea
| | - Nan Young Jeon
- Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseonggu, Daejon 305-343, South Korea
| | - Keehoon Won
- Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseonggu, Daejon 305-343, South Korea
| | - Bum Tae Kim
- Korea Research Institute of Chemical Technology, 100 Jangdong, Yuseonggu, Daejon 305-343, South Korea
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Lee SW, Won K, Lim HK, Kim JC, Choi GJ, Cho KY. Screening for novel lipolytic enzymes from uncultured soil microorganisms. Appl Microbiol Biotechnol 2004; 65:720-6. [PMID: 15365646 DOI: 10.1007/s00253-004-1722-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2004] [Revised: 07/02/2004] [Accepted: 07/09/2004] [Indexed: 10/26/2022]
Abstract
The construction and screening of metagenomic libraries constitute a valuable resource for obtaining novel biocatalysts. In this work, we present the construction of a metagenomic library in Escherichia coli using fosmid and microbial DNA directly isolated from forest topsoil and screened for lipolytic enzymes. The library consisted of 33,700 clones with an average DNA insert size of 35 kb. Eight unique lipolytic active clones were obtained from the metagenomic library on the basis of tributyrin hydrolysis. Subsequently, secondary libraries in a high-copy-number plasmid were generated to select lipolytic subclones and to characterize the individual genes responsible for the lipolytic activity. DNA sequence analysis of six genes revealed that the enzymes encoded by the metagenomic genes for lipolytic activity were novel with 34-48% similarity to known enzymes. They had conserved sequences similar to those in the hormone-sensitive lipase family. Based on their deduced amino acid similarity, the six genes encoding lipolytic enzymes were further divided into three subgroups, the identities among which ranged from 33% to 45%. The six predicted gene products were successfully expressed in E. coli and secreted into the culture broth. Most of the secreted enzymes showed a catalytic activity for hydrolysis of p-nitrophenyl butyrate (C(4)) but not p-nitrophenyl palmitate (C(16)).
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Affiliation(s)
- Seon-Woo Lee
- Biological Function Research Team, Korea Research Institute of Chemical Technology, 100 Jang-Dong, Yuseong-Gu, 305-343, Daejeon, South Korea.
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Dubey JP, Graham DH, De Young RW, Dahl E, Eberhard ML, Nace EK, Won K, Bishop H, Punkosdy G, Sreekumar C, Vianna MCB, Shen SK, Kwok OCH, Sumners JA, Demarais S, Humphreys JG, Lehmann T. MOLECULAR AND BIOLOGIC CHARACTERISTICS OF TOXOPLASMA GONDII ISOLATES FROM WILDLIFE IN THE UNITED STATES. J Parasitol 2004; 90:67-71. [PMID: 15040668 DOI: 10.1645/ge-110r] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [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: 11/10/2022] Open
Abstract
Toxoplasma gondii isolates can be grouped into 3 genetic lineages. Type I isolates are considered more virulent in outbred mice and have been isolated predominantly from clinical cases of human toxoplasmosis, whereas types II and III isolates are considered less virulent for mice and are found in humans and food animals. Little is known of genotypes of T. gondii isolates from wild animals. In the present report, genotypes of isolates of T. gondii from wildlife in the United States are described. Sera from wildlife were tested for antibodies to T. gondii with the modified agglutination test, and tissues from animals with titers of 1:25 (seropositive) were bioassayed in mice. Toxoplasma gondii was isolated from the hearts of 21 of 34 seropositive white-tailed deer (Odocoileus virginianus) from Mississippi and from 7 of 29 raccoons (Procyon lotor); 5 of 6 bobcats (Lynx rufus); and the gray fox (Urocyon cinereoargenteus), red fox (Vulpes vulpes), and coyote (Canis latrans) from Georgia. Toxoplasma gondii was also isolated from 7 of 10 seropositive black bears (Ursus americanus) from Pennsylvania by bioassay in cats. All 3 genotypes of T. gondii based on the SAG2 locus were circulating among wildlife.
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Affiliation(s)
- J P Dubey
- Animal Parasitic Diseases Laboratory, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Building 1001, Beltsville, Maryland 20705-2350, USA.
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