• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.844-850
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• 2000

The specific binding and internalization of viral particles is an essential step for the successful infection of viral pathogens. In the case of the hepatitis B virus (HBV), virions bind to the host cell via the preS domain of the viral surface antigen and are subsequently internalized by endocytosis. HBV-preS specific receptors are primarily expressed on hepatocytes, however, viral DNA and proteins have also been detected in extrahepatic sites, suggsting that celluar recepators for HBV may also exist on extrahepatic cells. Recently, an EBV-transformed B-cell line was identified onto which the preS region binds in a receptor-ligand specific manner. In this study, this specific interaction was further characterized, and the binding region within the preS protein was locaized. Also the internalization after host cell attachment was visualized and analyzed by fluorescence-labeled HBV-preS1 proteins using confocal microscopy. Energy depletion by sodium azide treatment effectively inhibited the internalization of the membrane-bound preS1 ligands, thereby indicating an energy-dependent receptor-mediated endocytotic pathway. Accordingly, the interaction of HBV-pres! with this specific B-cell line may serve as an effective model for an infection pathway in extrahepatic cells.

• Parasites, Hosts and Diseases
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• v.42 no.4
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• pp.169-174
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• 2004

This study was carried out to find out specific proteins from different organs of Clonorchis sinensis. Crude extract, organ-specific and excretory-secretory (ES) proteins were analyzed by immunoblot with infected human sera. The bands of 7- and 17 -kDa were main component of intestinal fluid and ES protein and commonly found in all organ-specific proteins. The 17-kDa protein was observed from ES antigen, intestinal fluid, eggs and sperms, 26- and 28-kDa proteins were from the uterus, vitellaria, and ovary, and 34-, 37-, 43- and 50-kDa proteins were mainly from the testis and sperms. Serum of mice immunized with sperms reacted to the 50-kDa protein by immunoblotting and immunohistochemical staining showed a positive reaction at the seminal receptacle and seminiferous tubule. The present results show that the 7-kDa protein is a common antigen of every part or organ of C. sinensis, but different organs express their specific antigenic protein bands.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.15 no.3
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• pp.191-199
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• 2011

In this paper, we adopt a position specific scoring matrix as an abstraction of amino acid type to derive two new statistical potentials for protein structure prediction, and investigated its effect on the quality of the potentials compared to that derived using residue specific amino acid identity. For stringent test of the potential quality, we carried out folding simulations of 91 residue A chain of protein 2gpi, and found unexpectedly that the abstract amino acid type improved the quality of the one-body type statistical potential, but not for the two-body type statistical potential which describes long range interactions. This observation could be effectively used when one develops more accurate potentials for structure prediction, which are usually involved in merging various one-body and many-body potentials.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1223-1227
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• 2010

In this study, the orientational behavior of thermotropic liquid crystals (LC) supported on a film of protein receptors was examined. Avidin was roller printed and covalently immobilized onto the surface of gold using NHS/EDC chemistry. The orientation of nematic 4-cyano-4'-pentylbiphenyl (5CB) was found to be parallel to the plane of the printed avidin surface before incubation with a solution of biotin. However, protein-receptor complexation induced a random orientation of 5CB, where protein-receptor complexes disturbed the nanoscale topography of the printed protein surface. Atomic force microscopy and ellipsometry was used to confirm printing and the specific interaction of proteins. These results demonstrate that the combination of LC and roller printing can be used to detect specific interactions between biomolecules by manipulating the orientational behavior of LC to the printed protein surfaces.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.313-315
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• 2004

The coat protein gene of Korean isolate of Ricer stripe virus (RSV-Kr) was cloned and its nucleotide sequence was determined. Total RNA was extracted from infected leaves and RSV viral RNA was detected by using RT-PCR with specific primer of coat protein gene. The result of RT-PCR showed a specific band. Purified RT-PCR products of coat protein gene were ligated into the pGEM-T Easy plasmid vector and cloned cDNA was obtained for nucleotide sequence determination. Coat protein gene of RSV-Kr consisted of 969 bp long encoding a protein of 322 amino acids. RSV-Kr showed 94%-99% sequence identities to that of Japanese- and Chinese isolates.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.38-43
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• 2016

Novel and specific recognition elements are of central importance in the development of a pathogen detection method. Here, we describe a simple method for identifying the cell-wall binding domain (CBD) from a sequenced bacterial genome employing homology search for phage lysin genes. A putative CBD (CPF369_CBD) was identified from a genome of Clostridium perfringens type strain ATCC 13124, and its function was studied with the CBD-GFP fusion protein recombinantly expressed in Escherichia coli. Fluorescence microscopy showed the specific binding of the fusion protein to C. perfringens cells, which demonstrates the potential of this method for the identification of novel bioprobes for specific detection of pathogenic bacteria.

• The Microorganisms and Industry
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• v.14 no.1
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• pp.22-28
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• 1988

DNA 클로닝과 조작기술의 발전은 어떤 유전자의 특정한 위치에 선택적으로 돌연변이를 도입할 수 있는 site-specific mutagenesis 기술을 창출해 내었다. 이 기술로 DAN 염기의 치환, 결실, 삽입등을 클론된 유전자에 직접 도입할 수가 있게 되어 생체의 유전자 조작이나 유전자의 산물인 단백질의 구조와 기능을 의도적으로 변화시키는 protein engineering에 광범위하게 이용되고 있다. Protein engineering은 주로 단백질의 촉매 및 생리활성의 증가, 효소의 특성및 기질 특이성의 변화, 단백질 구조의 안정화 및 내염성 증가, 분자량의 감소, 효소및 생리활성 단백질의 구조의 안정화및 내열성 증가 등에 활용되고 있으며 산업적 유용성이 큰새로운 단백질의 창조에도 기여할 것으로 기대를 모으고 있다. Site-specific mutagenesis 기술로 현재 가장 널리 이용되는 것이 in vitro상에서 수행하는 oligonucleotide-directed site specific mutagenesis이다. 이 방법은 생화학적으로 합성한 특정한 염기서열을 가진 oligonucleotide들을 일종의 mutagen으로 사용하거나 효소적 DNA 합성을 위한 primer로 사용하여 클론된 DNA의 염기서열을 선택적으로 개조하거나 혹은 다른 조작을 하는 것이다. 여기서는 돌연변이율을 높이는 여러가지 개량된 방법들이 나왔으며 그중의 몇가지를 소개하였다.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.177-181
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• 1998

This study was carried out to investigate activity difference in the superoxide dismutase (SOD) and peroxidase (POD) of tomato callus transformed with Agrobacterium containing the GUS gene. Than those of other two tomato cultivars, the hypocotyl explant of JA101 was shown to have higher POD and SOD specific activity of 23 unit/mg protein and 2,156 unit/mg protein, respectively. Relatively high frequency of callus formation was obtained from the hypocotyl explant on MS medium containing 1 mg/L 2,4-D for 30 days and its POD(47 unit/mg protein) and SOD (95,786 unit/mg protein) specific activities were higher than other 2,4-D concentration. The hypocotyl explant and callus cocultivated with Agrobacterium for 72 hours were transferred to MS medium supplemented with 1 mg/L 2,4-D, 30 mg/L kanamycin, 30 g/L sucrose and 4 g/L Gelrite. The hypocotyl explants transferred to the medium formed callus with 45.5% effeciency after 8 weeks. The transformation efficiency confirmed by GUS assay was 21.6%. POD specific activity of the transformed callus (54 unit/mg protein) were somewhat lower than the non-transformed callus (64 unit/mgg protein) and SOD specific activity of the transformed callus (30,300 unit/mg protein) were also lower than the non-transformed callus (37,077 unit/mg protein). However there was no significant difference in POD and SOD isozyme patterns between the transformed and the non-transformed calluses. From these results, it revealed that there was no difference of antioxidant enzyme activities between the transformed callus and the non-transformed callus in tomato.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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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.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.299-303
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• 1997

The effects of partial replacement of flour with isolated soy protein (ISP) on sponge cake quality were investigated. The replacement did not cause any significant changes in physical characteristics of sponge cakes including specific gravity, specific volume and expansion ratio. As the level of ISP replacement increased, the sponge cakes were darker in color, harder, chewier and drier than control groups. The textural characteristics (hardness, cohesiveness, springiness, gumminess and chewiness) of the sponge cakes also increased as the level of flour replacement increased. Up to 15％ of the flour could be replaced by ISP without diminishing the sponge cake quality.