• Title, Summary, Keyword: Immobilization

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Immobilization of Proteins on Silicon Surfaces Using Chemical and Electrochemical Reactions of Nitrobenzenediazonium Cations (나이트로벤젠다이아조늄 양이온의 화학 및 전기화학 반응을 이용한 실리콘 표면상으로의 단백질 고정)

  • Kim, Kyu-Won;Haque, Al-Monsur Jiaul;Kang, Hyeon-Ju
    • Journal of the Korean Electrochemical Society
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    • v.13 no.1
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    • pp.70-74
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    • 2010
  • The immobilization of proteins on silicon surfaces using electrochemical reaction has been studied. Chemical deposition of nitrobenzendiazonium (NiBD) cations is employed to modify silicon surfaces. Electrochemical reduction of nitro-group to primary amine-group have been conducted on the modified surfaces to activate silicon surfaces for the protein immobilization. Attachment of gold nanoparticles was used to prove the reduction. The current method was applied to selective activation of a silicon nanowire and immobilize proteins on the selected nanowire. It has been demonstrated that the use of chemical and electrochemical reaction NiBD is efficient for the selective immobilization of proteins on silicon nanowire surfaces.

Simultaneous and Sequential Co-Immobilization of Glucose Oxidase and Catalase onto Florisil

  • Gul, Ozyilmaz;Tukel, S. Seyhan
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.960-967
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    • 2007
  • The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against $H_2O2$ inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and $30^{\circ}C$, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both $5^{\circ}C\;and\;25^{\circ}C$. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by $H_2O2$ and supplying additional $O_2$ to the reaction system.

Carbon Dioxide Sequestration of Enzyme Covalently Immobilized on Porous Membrane (공유결합으로 다공성 막에 고정화된 효소에 의한 이산화탄소 포집)

  • Park, Jin-Won
    • KSBB Journal
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    • v.28 no.4
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    • pp.225-229
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    • 2013
  • Bovine Carbonic anhydrase (BCA) was immobilized on a submicro-porous membrane through covalent immobilization. The immobilization was conducted on the porous membrane surface with the treatment of polyethyleneimine, glutaraldehyde, and the anhydrase, in sequence. The immobilization was confirmed using X-ray photon spectrometer. The pH values of carbon-dioxide saturated solution with buffer were monitored with respect to time to calculate the catalytic activities of hydration of carbon-dioxide for free and immobilized CA. The catalytic rate constant values for free CA, immobilized CA on polystyrene nanoparticles, and immobilized CA on a porous cellulose acetate membrane were 0.79, 0.67, and 0.56 $s^{-1}$, respectively. Reusability was studied up to 10 cycles of $CO_2$ sequestration. The activity for the CA immobilized on the membrane was kept to 95% after 10 cycles, and comparable to the CA on the nanoparticles. The stabilities for heat and storage were also investigated for the three cases. The results suggested that the CA immobilized the membrane had the least loss rate of the activity compared to the others. From this study, the porous membrane was feasible as a carrier for the CA immobilization in hydration and sequestration of carbon-dioxide.

Anti-Depressive Effects of OnDam-Tang with Addition of Linderae Radix (ODT-L) after Chronic Immobilization Stress in C57BL/6 Mice (우울증 유발 생쥐에서 온담탕가오약(溫膽湯加烏藥)의 항우울 효과)

  • Lee, Eun Hee;Jung, In Chul
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.4
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    • pp.403-410
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    • 2014
  • The purpose of this study was to examine the anti-depressive effects of OnDam-Tang with addition of Linderae Radix (ODT-L) on the animal model of depression induced by chronic immobilization stress. Depression model was made by chronic immobilization stress for 2 hours for 21 days. And we performed forced swimming test, analysis of the neurotransmitter and immunohistochemical staining, measured expression levels of serotonin in the brain. ODT-L has decreased immobilization time in forced swimming test. ODT-L has increased amount of melatonin in the brain. ODT-L has increased expression levels of serotonin in the brain. ODT-L prevented damage in the hippocampal region. ODT-L has reduced the expression level of CRF receptors in in hippocampus region. These results suggest that ODT-L may have anti-depressive effects on depression.

Ginsenoside Rb1 Modulates Level of Monoamine Neurotransmitters in Mice Frontal Cortex and Cerebellum in Response to Immobilization Stress

  • Lee, Sang-Hee;Hur, Jin-Young;Lee, Eun-Joo H.;Kim, Sun-Yeou
    • Biomolecules & Therapeutics
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    • v.20 no.5
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    • pp.482-486
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    • 2012
  • Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

Immobilization of α-amylase from Exiguobacterium sp. DAU5 on Chitosan and Chitosan-carbon Bead: Its Properties

  • Fang, Shujun;Chang, Jie;Lee, Yong-Suk;Hwang, Eun-Jung;Heo, Jae Bok;Choi, Yong-Lark
    • Journal of Applied Biological Chemistry
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    • v.59 no.1
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    • pp.75-81
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    • 2016
  • Glutaraldehyde was used as a cross-linking agent for immobilization of purified ${\alpha}$-amylase from Exiguobacterium sp. DAU5. Befitting concentration of glutaradehyde and cross-linking time is the key to preparation of cross-linking chitosan beads. Based on optimized immobilization condition for ${\alpha}$-amylase, an overall yield of 56% with specific activity of 2,240 U/g on chitosan beads and 58% with specific activity of 2,320 U/g on chitosan-carbon beads was obtained. The optimal temperature and pH of each immobilized enzyme activity were $50^{\circ}C$ and 50 mM glycine-NaOH buffer pH 8.5, respectively. Those retained more than 75 and 90% of its maximal enzyme activity at pH 7.0-9.5 and after incubation at $50^{\circ}C$ for 1 h, respectively. In addition, the immobilization product showed higher organic-solvent tolerance than free enzymes. The mode of hydrolyzing soluble starch revealed that the ${\alpha}$-amylase possessed high hydrolyzing activity. These results indicate that chitosan is good support and has broad application prospects of enzyme immobilization.

Immobilization of oxidative enzymes onto Cu-activated zeolite to catalyze 4-chlorophenol decomposition

  • Zol, Muhamad Najmi Bin;Shuhaimi, Muhammad Firdaus Bin;Yu, Jimin;Lim, Yejee;Choe, Jae Wan;Bae, Sungjun;Kim, Han S.
    • Membrane Water Treatment
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    • v.11 no.3
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    • pp.195-200
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    • 2020
  • In this study, a biocatalyst composite was prepared by immobilizing oxidoreductases onto Cu-activated zeolite to facilitate biochemical decomposition of 4-chlorophenol (4-CP). 4-CP monooxygenase (CphC-I) was cloned from a 4-CP degrading bacterium, Pseudarthrobacter chlorophenolicus A6, and then overexpressed and purified. Type X zeolite was synthesized from non-magnetic coal fly ash using acetic acid treatment, and its surfaces were coated with copper ions via impregnation (Cu-zeolite). Then, the recombinant oxidative and reductive enzymes were immobilized onto Cu-zeolite. The enzymes were effectively immobilized onto the Cu-zeolite (79% of immobilization yield). The retained catalytic activity of CphC-I after immobilization was 0.3423 U/g-Cu-zeolite, which was 63.3% of the value of free enzymes. The results of this study suggest that copper can be used as an effective enzyme immobilization binder because it provides favorable metalhistidine binding between the enzyme and Cu-zeolite.

Remediation of Groundwater contaminated MTBE using Micellar immobilization

  • 백기태;양지원
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.330-333
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    • 2002
  • Immobilization isotherms for methyl tort-buty1 ether (MTBE) in sodium dodecy1 sulfate(SDS) and cetylpyridinium chloride (CPC) were investigated for application to micellar enhanced remediation. Headspace solid-phase microextraction was used to analyze immobilization isotherms. Maximum partitioning coefficients of MTBE were 48 L/mol and 9 L/mol for SDS and CPC, respectively, The values decreased gradually as the MTBE mole fraction in the micelles increased.

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Electrokinetic 기법을 이용한 토양 중 납의 안정화

  • 조용실;김정환;한상재;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.351-354
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    • 2002
  • In this study, variation of electrochemical parameters and characteristics of lead immobilization due to phosphoric acid injection in soil were studied during electrokinetic remediation of lead contaminated soil. TCLP result showed about 100% of soil was satisfied TCLP regulation criteria. And injected ion from cathode reservoir by ionmigration was proportionate to concentration of phosphoric acid and elapsed time. Therefore, when removal is infeasible or not cost-effective, in situ immobilization method would be more effective.

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Molecular analysis of c-terminus structure for elucidating the stabilization effect of site-specific immobilization

  • Baek, Seung-Pil;Yu, Yeong-Jae
    • 한국생물공학회:학술대회논문집
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    • pp.886-889
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    • 2001
  • C-terminus specific immobilization often results in a increased structural stability resistant to various denaturation factors. In order to elucidate the immobilization effect on the c-terminus in molecular level, we made over 200 protein data set from Protein Data Bank(PDB), analyzed c-terminus structure of each protein, and investigated the structural relationship with the stabilizing factors such as hydrogen bond, ion pairs, cation pi, disulfide bond, solvation free energy, surface area, flexibility and so on.

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