• IMMUNE NETWORK
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• 제20권5호
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• pp.41.1-41.11
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• 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense single-stranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor - angiotensin converting enzyme 2 (ACE2) - on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene. The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.

• Membrane and Water Treatment
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• 제9권5호
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• pp.301-307
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• 2018

In this research work, synthesis of sugarcane bagasse/zinc aluminium biocomposite and apple peel/zinc aluminium biocomposite and their application for removal of Reactive Red-241 and Acid Orange-7, respectively, was studied using various parameters. At pH 2 the sorption was the highest for both dyes. The trend showed that the dye sorption declined by decreasing the biocomposite dose and enhanced by increasing the dye concentration and temperature. Equilibrium was achieved at 60 minutes for Reactive Red-241 onto sugarcane bagasse/zinc aluminium biocomposite and 90 minutes for Acid Orange-7 onto apple peel/zinc aluminium biocomposite.The research data was good fitted to pseudo-2nd-order kinetic model and Langmuir isotherm. FT-IR analysis was used to confirm the biosorption of the selected dyes at the surface of biosorbent through various binding sites. Surface morphology modification of both biocomposites before and after biosorption was inspected through SEM. Crystallinity of biocomposite was examined through XRD analysis. It was implied that sugarcane bagasse/ zinc aluminium biocomposite and apple peel/ zinc aluminium biocomposite are good adsorbents for dyes elimination from aqueous solutions.

• Membrane and Water Treatment
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• 제11권3호
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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.

• 분석과학
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• 제24권6호
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• pp.460-466
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• 2011

얇은 유리판 위에 정렬된 지질 이중막에 작용하는 항균성 펩타이드 magainin 2의 작용활성을 고체 핵자기 공명 분광법을 이용하여 조사하였다. 수화에 따른 지질 이중막의 파괴정도를 파악하기 위해 두 가지 수화 상태에서 실험이 이루어졌다. 95%의 상대 습도에서 수화된 지질 이중막에서는 약 15% 정도의 지질 이중막이 파괴되었으며, 완전히 수화된 지질 이중막에서는 약 20% 정도의 지질 이중막이 파괴되었다. 두 가지 시료 제조방법에 따른 지질 이중막 파괴 정도의 비교를 통해, 항균성 펩타이드의 지질 이중막 결합과정이 지질 이중막 파괴에 중요한 변수임을 알 수 있었다.

• Journal of Plant Biotechnology
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• 제42권4호
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• pp.277-283
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• 2015

Plant genome analyses, including Arabidopsis thaliana showed a large gene family of plant receptor kinases with various extracellular ligand-binding domain. Now intensively studies to understand physiological and cellular functions for higher plant receptor kinases in diverse and complex biological processes including plant growth, development, ligands perception including steroid hormone and plant-microbe interactions. Brassinosteroids (BRs) as a one of well know steroid hormone are plant growth hormones that control biomass accumulation and also tolerance to many biotic and abiotic stress conditions and hence are of relevance to agriculture. BRI1 receptor kinase, which is localized in plasma membrane in the cell sense BRs and it bind to a receptor protein known as BRASSINOSTEROID INSENSITIVE 1 (BRI1). Recently, we reported that BRI1 and its co-receptor, BRI1-ASSOCIATED KINASE (BAK1) autophosphorylated on tyrosine residue (s) in vitro and in vivo and thus are dual-specificity kinases. Other plant receptor kinases are also phosphorylated on tyrosine residue (s). Post-translational modifications (PTMs) can be studied by altering the residue modified by directed mutagenesis to mimic the modified state or to prevent the modification. These approaches are useful to not only characterize the regulatory role of a given modification, but may also provide opportunities for plant improvement.

• 한국환경과학회지
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• 제5권3호
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• pp.317-327
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• 1996

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Zinc-tolerant microorganism, such as Pseudomonas chlororaphis which possessed the ability to accumulate zinc, was isolated from industrial wastewaters polluted with various heavy metals. The characteristics of zinc accumulation in the cells, recovery of the zinc from the cells accumulating zinc, were investigated. Removal rate of zinc from the solution containing 100 mall of Zinc by zinc-tolerant microorganism was more than 90% at 48 hours after inoiulation of the microorganisms. A large number of the electron-dense granules were found mainly on thIn cell wall and membrane fractions, when determined by transmission electron microscope. Energy dispersive X- ray spectroscopy revealed that the electron-dense granules were zinc complex with the substances binding Heavy metals. The zinc accumulated into cells was not desorbed by distilled water, but more than 80% of the zinc accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at 55$0^{\circ}C$ amounted to about 21% of the dry weight of the cells. EDS analysis showed that the residues were comparatively pure zinc compounds containing more than 79% of zinc.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.54-60
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• 2015

Papiliocin, from the swallowtail butterfly, Papilio xuthus, shows high bacterial cell selectivity against Gram-negative bacteria. Recently, we designed a 22mer analog with N-terminal helix from $Lys^3$ to $Ala^{22}$, PapN. It shows outstanding antimicrobial activity against Gram-negative bacteria with low toxicity against mammalian cells. In this study, we determined the 3-D structure of PapN in 300 mM DPC micelle using NMR spectroscopy and investigated the interactions between PapN and DPC micelles. The results showed that PapN has an amphipathic ${\alpha}$-helical structure from $Lys^3$ to $Lys^{21}$. STD-NMR and DOSY experiment showed that this helix is important in binding to the bacterial cell membrane. Furthermore, we tested antibacterial activities of PapN in the presence of salt for therapeutic application. PapN was calcium- and magnesium-resistant in a physiological condition, especially against Gram-negative bacteria, implying that it can be a potent candidate as peptide antibiotics.

• Annals of Clinical Neurophysiology
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• 제3권1호
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• pp.21-25
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• 2001

Background & Object : Myasthenia gravis(MG) is an autoimmune disease due to binding of antibody to acetylcholine receptors on the muscle membrane. It is well known that other autoimmune diseases infrequently accompany myasthenia gravis. The aim of this study was to evaluate the clinical significance of associated autoimmune diseases(AAD) and compare prognosis between MG with AAD and MG without AAD. Method : A total of 65 MG patients(24 men and 41 women) were enrolled at this study. From the clinical records of these patients, we investigated the clinical characteristics and prognosis of MG with AAD and compared these data with those of MG without other such diseases. Results : AAD were found in 10 of 65 cases(15%). 9 cases of 10 MG with AAD were generalized MG type. The most common disease was thyroid disorder. The rate of AAD was higher in thymic abnormal patients. There was no significant remission rate difference between MG with AAD and MG without AAD, but the percentage of patients experienced crisis was higher in MG with AAD. Conclusion : The occurrence of AAD may suggest a more generalized autoimmune disturbance that could be associated with a less favorable prognosis.

• Journal of Microbiology and Biotechnology
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• 제10권5호
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• pp.707-713
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• 2000

Myasthenia gravis (MG) is caused mainly by autoantibodies directed against acetylcholine receptors located in the postsynaptic muscle cell membrane. Using in vitro selection techniques, we isolated an RNA containing 2'-fluoro pyrimidines that can specifically and avidly ($K_d$ ~25 nM) bind rat monoclonal antibody called mAb198, which recognizes the main immunogenic region on the acetylcholine receptors. This RNA can act as a very effective decoy and block mAb198 binding to the receptors in vitro. Furthermore, this RNA decoy can prevent the antigenic modulation of the acetylcholine receptor caused by mAb198 in human muscle cell cultures with and $IC_{50} $of approximately $2.4{\mu}M$. These results indicate that the RNA selected in this study is a more potent decly inhibitor of myashthenic antibodies than the previously identified RNA with 2'-amino pyrimidines [11]. Moreover, this RNA cross-reacts with autoantibodies from patients with MG and can protect human cells from the effects of these antibodies. These observations have important implications for developing an antigen-specific treatment of autoimmune diseases including MG, which is based on decoy RNAs selected in vitro.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.967-973
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• 2020

The fungal cell wall is a major target of antifungals. In this study, we report the antifungal activity of an ethanol extract from Aucklandia lappa against Candida albicans. We found that the extract caused cell wall injury by decreasing chitin synthesis or assembly and (1,3)-β-D-glucan synthesis. A sorbitol protection assay demonstrated that the minimum inhibitory concentration (MIC) of the A. lappa extract against C. albicans cells increased eight-fold from 0.78 to 6.24 mg/ml in 72 h. Cell aggregates, which indicate damage to the cell wall or membrane, were commonly observed in the A. lappatreated C. albicans cells through microscopic analysis. In addition, the relative fluorescence intensities of the C. albicans cells incubated with the A. lappa extract for 3, 5, and 6 h were 92.1, 84.6, and 79.8%, respectively, compared to the controls, estimated by Calcofluor White binding assay. This result indicates that chitin content was reduced by the A. lappa treatment. Furthermore, synthesis of (1,3)-β-D-glucan polymers was inhibited to 84.3, 79.7, and 70.2% of that of the control treatment following incubation of C. albicans microsomes with the A. lappa extract at a final concentration equal to its MIC, 2× MIC, and 4× MIC, respectively. These findings suggest that the A. lappa ethanol extract may aid the development of a new antifungal to successfully control Candidaassociated disease.