• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.63-69
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• 1997

Erythropoietin (EPO) is a glycoprotein that mediates the growth and differentiation of erythroid progenitors. In order to produce recombinant human erythropoietin in tobacco plant, the EPO genomic DNA (5.4 kb) was cloned into plant expression vectors, pBI$\Delta$GUS121, pBD$\Delta$GUS121 and pPEV-1, and introduced in Nicotiana tabacum (var. Xanthi) via Agrobacterium tumefaciens-mediated transformation. After selection on MS media containing kanamycin (Km), 10 Km-resistant plants were obtained per each construct. The correct integration of EPO genomic DNA in the genome of transgenic plant was confirmed by polymerase chain reaction (PCR). Northern blot showed that transcripts of 1.8 kb length were produced in leaves of the plants, but there was no difference of mRNA amount according to promoter number and 5'-untranslated sequence (UTS). The proteins obtained from leaves of transgenic plants were immunologically detected by Western blot using rabbit anti-human EPO polyclonal antibody. The expressed protein appeared as smaller band of apparent mass of 30 kDa as compared to the EPO protein from human urine (37 kDa), suggesting that the modification (glycosylation) system in tobacco plant might be different from that of mammalian cells.

• BMB Reports
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• v.32 no.3
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• pp.317-319
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• 1999

A leucine aminopeptidase has been isolated from the culture medium of the soil fungus, Aspergillus flavus. The enzyme was found to be a glycoprotein, as judged by electrophoresis analysis and the subsequent staining by the periodic acid-Schiff's reagent. Carbohydrate moieties could be cleaved by N-glycosidase, but not by O-glycosidase, indicating that the glucans are linked to the asparagine residue in the protein. Removal of N-glucans was observed without prior denaturation of the protein, implying that the N-glycosidic linkage is exposed and accessible to glycosidase. When the activity of native or deglycosylated enzyme was measured in the presence of various metal ions, removal of carbohydrates increased the aminopeptidase activity of the enzyme.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1339-1344
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• 2013

We have synthesized several glycosyl ergosterols and 5,6-dihydroergosterols (DHE) and examined their effects on production of nitric oxide (NO) and iNOS protein expression in LPS-treated RAW264.7 macrophage cells. Our results showed that DHE derivatives inhibited production of NO and iNOS protein expression more strongly than ergosterol derivative. Especially, DHE-Glc exhibited most potent inhibitory activity without cytotoxicity up to the concentration of $100{\mu}M$.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.306-311
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• 2002

O-linked N-acetylglucosamine (O-GlcNAc) is an abundant posttranslationally modified compound in eukaryotic cells. Human O-GlcNAc transferase (OGT) was produced as a maltose binding protein (MBP) fusion protein, which showed significant catalytic activity to modify recombinant Sp1, transcription factor. To facilitate the production of O-GlcNAc modified proteins, instead of using the tedious in vitro glycosylation reaction or expression in eukaryotic cells, a MBP-fusion OGT expression vector (pACYC184-MBPOGT) was constructed using pACYC184 plasmid, which could coexist with general prokaryotic expression vectors containing ColE1 origin. By cotransforming pACYC184-MBPOGT and pGEX-2T vectors into Escherichia coli BL21, intracellular O- GlcNAcylated proteins could be obtained by a simple purification procedure. It is expected that this may be a useful tool for production of O-GlcNAc modified proteins.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.1-5
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• 2014

This study was performed to determine the whitening effect of organic solvent extracts from the centipede, Scolopendra subspinipes mutilans. We prepared different concentrations (50%, 70% and 100%) of ethanol, methanol, 100% ethyl acetate and water extracts. We tested melanin inhibitory effect and tyrosinase activity using B16/F10 melanoma cell. As a result, treatment of organic solvent extracts is decreased the biosynthesis of melanin and tyrosinase activity to 36 ~ 86%. Especially the 70% ethanol extracts was the most effective in B16/F10 melanoma cells. In the study on melanogenic protein expression, 70% ethanol extracts of Scolopendra subspinipes mutilans blocked glycosylation of tyrosinase. Therefore this result suggests that 70% ethanol extracts could be developed as skin whitening agents.

• Journal of the Korean Wood Science and Technology
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• v.33 no.4 s.132
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• pp.45-52
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• 2005

The manganese peroxidase (mnp5) from white-rot fungus Phanerochaete chrysosporium has been heterologously expressed in the methylotrophic yeast Pichia pastoris. The majority of the rMnP5 (recombinant MnP5) produced by P. pastoris exhibited an approximate molecular mass 45 kDa considerably larger than that of the predicting mnp5 due to two glycosylation sites of mnp5. After site direct mutation treatment, the effect of N-linked hyperglycosylation was examined by enzyme activity. Analysis by sodium dodesyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie Brilliant Blue (CBB) staining revealed a major protein band with a molecular mass of 37 kDa. Enzyme activity of M-rMnP5 (mutant recombinant MnP5) was similar to that of rMnP5, indicating that hyperglycosylation did not affect the active site. In this work, active mnp5 was successfully expressed in P. pastoris, suggesting that P. pastoris has potential capability of producing active heme-containing proteins.

• Journal of Life Science
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• v.17 no.11
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• pp.1497-1504
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• 2007

To investigate the function and secretion of human thrombopoietin (TPO) in mammalian cells, hTPO cDNA was cloned using human liver cDNA, and recombinant hTPO (rec-hTPO) was produced in CHO cell lines. In addition, six N-linked glycosylation sites were substituted for Ala to elucidate the role of each carbohydrate chain. To analyze the biological activity, rec-hTPO protein was injected subcutaneously. Blood was withdrawn for platelet determination. The metabolic clearance rate (MCR) was also analyzed at the 1, 4, 10 and 24 hr after tail vein injection. Wild-type TPO (WT) was efficiently secreted into the medium. However, a hTPO mutant with 116 deleted nucleotides detected by PCR cloning was not secreted. The N-linked glycosylation sites had nearly the same expression quantity as rec-hTPO WT apart from mutants 3 and 4. The glycosylation site of mutant 4 appeared to be an indispensable site for hTPO secretion. Also characterized was the biological activity through an injection with rec-hTPO (10 ng) to ICR mice (7 weeks). The result of the blood analysis showed a considerable increase in the platelet number six days after He injection. To analyze the pharmacokinetics, rec-hTPO was injected into the tail vein (5 ng). The result was 200 pg/ml 1hr after this injection. Following this, it dramatically decreased and virtually disappeared 10 hours after the injection. Thus, rec-hTPO may be a treatment for thrombopenia by the production of the high active rec-hTPO. In addition, hTPO can permit the development of potent new analogues that stimulate the platelet value.

• Journal of Life Science
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• v.28 no.11
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• pp.1379-1385
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• 2018

Glycans are attached to proteins as in glycoproteins and proteoglycans. They are found on the exterior surface of cells. O- and N-linked glycans are very common in eukaryotic cells but may also be found in prokaryotes. The interaction of cell surface glycans with complementary glycan binding proteins located on neighboring cells, other cell types, pathogens like virus, or bacteria is crucial in biologically and biomedically important processes like pathogen recognition, cell migration, cell-cell adhesion, development, and infection. Their implication in pathological condition, suggests an important role for glycans as disease markers. In addition, a great amount of research has been shown that appropriate glycosylation of a recombinant therapeutic protein is critical for product solubility, stability, pharmacokinetics and pharmacodynamics, bioactivity, and safety. Besides, cancer-associated glycosylation changes often involve sialic acid in glycan branch which play important roles in cell-cell interaction, recognition and immunological response. This review aims at giving a comprehensive overview of the glycan's biological function and describing the relevance among the glycosylation, disease diagnosis and treatment methods. Furthermore, the high-throughput analytic methods available to measure the profile changing patterns of glycan in the blood serum as well as possible underlying biochemical mechanisms.

• Parasites, Hosts and Diseases
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• v.42 no.2
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• pp.57-60
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• 2004

A highly specific antigenic protein of 31 kDa from plerocercoid of Spirometra mansoni (sparganum) was obtained by gelatin affinity and Mono Q anion-exchange column chromatography. The purified 31 kDa protein was subjected to N-glycan enzymatic digestion for structural analysis. The relative electrophoretic mobility was analyzed by SDS-PAGE, before and after digestion. On SDS-PAGE after enzymatic digestion, the 31 kDa protein showed a molecular shift of approximately 2 kDa, which indicated the possession of complex N-linked oligosaccharides (N-glycosidase F sensitive) but not of high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H, non-sensitive). Chemically periodated 31 kDa protein showed statistically non-significant changes with human sparganosis sera by enzyme linked immunosorbent assay (ELISA). Therefore, the dominant epitopes of the 31 kDa molecule in human sparganosis were found to be mainly polypeptide, while N-glycans of the antigenic molecule in sparganum was minimal in anti-carbohydrate antibody production.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.355-361
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• 2006

Porcine epidemic diarrhea virus (PEDV) strain Chinju99, which was previously isolated from piglets suffering from severe diarrhea was used to characterize the membrane (M) protein gene to establish the molecular information, and the results will be useful in elucidating concepts related to molecular pathogenesis and antigenic structures of PEDV isolates. The Chinju99 M gene generated by reverse transcription and polymerase chain reaction (RT-PCR) consisted of 681 bases containing 22.3% adenine, 22.3% cytosine, 23.1% guanine and 32.3% thymine nucleotides, and the GC content was 45.4%. It had some nucleotide mismatches from M gene of other PEDV strains, such as CV777, Br1/87, KPEDV-9, JMe2, JS2004-2 and LJB-03 with 97-99% nucleotide sequence homology to these strains. Also, it encoded a protein of 226 amino acids, which had some mismatches from those of CV777, Br1/87, KPEDV-9, JMe2, JS20004-2 and LJB-03, as the amino acid sequence homology showed a 97-98% to these strains. The Chinju99 had a very close relationship to the Japanese strain JMe2 for the nucleotide and amino acid sequences of the M gene. The amino acids predicted from Chinju99 M gene consisted of mostly hydrophobic residues and contained three potential sites for asparagine (N)-linked glycosylation, two serine (S)-linked phosphorylation sites by protein kinase C, and two S- or threonine (T)-linked phosphorylation sites by casein kinase II.