• BMB Reports
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• v.38 no.5
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• pp.526-532
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• 2005

A lectin with in-vitro anticancer activity against established human cancer cell lines has been purified by affinity chromatography on asialofetuin-linked amino activated silica beads from the tubers of Arisaema tortuosum, popularly known as Himalayan Cobra lily, a monocot plant from the family Araceae. The bound Arisaema tortuosum lectin (ATL) was eluted with glycine-HCl buffer, pH 2.5. ATL was effectively inhibited by asialofetuin, a complex desialylated serum glycoprotein as well as by N-acetyl-D-lactosamine, a disaccharide. It gave a single band corresponding to a subunit molecular weight of 13.5 kDa in SDS-PAGE, pH 8.8 both under reducing and non reducing conditions. When subjected to gel-filtration on Biogel P-200, it was found to have a molecular weight of 54 kDa, suggesting a homotetramer structure, in which individual polypeptides are not bound to each other with disulfide bonds. ATL is a glycoprotein with 0.9% carbohydrate content, stable up to $55^{\circ}C$ and at pH 2 to 10. The lectin had no requirement for divalent metal ions i.e. $Ca^{2+}$ and $Mn^{2+}$ for its activity. However, as reported for other monocot lectins, ATL gave multiple bands in isoelectric focusing and Native PAGE, pH 8.3. The lectin was found to inhibit in vitro proliferation of human cancer cell lines HT29, SiHa and OVCAR-5.

• Journal of Plant Biology
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• v.38 no.3
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• pp.251-258
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• 1995

The soluble acid invertase ($\beta$-D-fructofuranoside fructohydrolase, EC 3.2.1.26) was isolated and characterized from the hypocotyls of mung bean (Phaseolus radiatus L.). The enzyme was purified to apparent homogeneity by consecutive step using diethylaminoethyl (DEAE)-cellulose anion exchange, Concanavalin (Con) A affinity and Sephacryl S-300 chromatography. The overall purification was about 148-fold with a yield of about 15%. The finally purified enzyme exhibited a specific activity of about 139 $\mu$mol of glucose produced mg-1 protein min-1 at pH 5.0 and appeared to be a single protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and nondenaturing PAGE. The enzyme had the native molecular weight of 70 kD and subunit molecular weight of 70 kD as estimated by Sephadex G-200 chromatography and SDS-PAGE, respectively, suggesting that the enzyme was composed of a monomeric protein. On the other hand, the enzyme appeared to be a glycoprotein containing N-linked high mannose oligosaccharide chain on the basis of its ability to bind to the immobilized C on A. The enzyme had a Km for sucrose of 1.8 mM at pH 5.0 and maximum activity around pH 5.0. The enzyme showed highest enzyme activity with sucrose as substrate, but the activity was slightly measured with raffinose and cellobise. No activity was measured with maltose and lactose. These results indicate the soluble acid invertase is a $\beta$-fructofuranosidase.

• Journal of Plant Biology
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• v.35 no.2
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• pp.99-106
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• 1992

The endosperm protein, vicilin, of ginseng (Panax ginseng C.A. Meyer) was purified by ammonium sulfate precipitaion, gel permeation and ion exchange column chromatography. Vicilin is a glycoprotein composed of 2 subunits with molecular masses of 55,000 (large subunit) and 44,000 (small subunit). The anti-vicilin antibody was raised in rabbit, and purified by DEAE Affi-Gel Blue affinity chromatography. The endosperm cells of the seed were reacted with this anti-vicilin antibody and colloidal gold conjugated secondary antibody. Gold particles were labelled on the elaborating granules of Golgi complex, electron-dense granules and protein bodies in the endosperm cells. These results indicated that the vicilin, which was synthesized in rough endoplasmic reticulum and transported to Golgi, was elaborated in saccules of the Golgi and then transported into protein bodies by electron-dense granules.anules.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.556-561
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• 2010

Lactoferrin is an 80-kDa iron-binding glycoprotein that is found in high concentrations in human milk. Human lactoferrin (hLF) has several beneficial biological activities including immune system modulation and antimicrobial activity. In the present study, we devolved a method of hLF expression through introducing the hLF gene construct into Oriza sativa cv. Nakdong using the Agrobacterium-mediated transformation system. The expression of the hLF gene under the control of the rice glutelin promoter was detected in the seeds of transgenic rice plants. Transformed rice plants were selected on media containing herbicide(DL-phosphinothricin) and the integration of hLF cDNA was confirmed by Southern blot analysis. The expression of the full length hLF protein from the grains of transgenic rice plants was verified by Western blot analysis. The lactoferrin expression levels in the transformed rice grains determined by enzyme-linked immunosorbant assay accounted for approximately 1.5% of total soluble protein. Taken together, these data indicate that rice grains expressing hLF can be directly incorporated into infant formula and baby food.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.546-552
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• 2022

Epidermal cell adhesion molecule (EpCAM) is a tumor-associated antigen (TAA), which has been considered as a cancer vaccine candidate. The EpCAM protein fused to the fragment crystallizable region of immunoglobulin G (IgG) tagged with KDEL endoplasmic reticulum (ER) retention signal (EpCAM-FcK) has been successfully expressed in transgenic tobacco (Nicotiana tabacum cv. Xanthi) and purified from the plant leaf. In this study, we investigated the ability of the plant-derived EpCAM-FcK (EpCAM-FcK^P) to elicit an immune response in vivo. The animal group injected with the EpCAM-FcK^P showed a higher differentiated germinal center (GC) B cell population (~9%) compared with the animal group injected with the recombinant rhEpCAM-Fc chimera (EpCAM-Fc^M). The animal group injected with EpCAM-FcK^P (~42%) had more differentiated T follicular helper cells (Tfh) than the animal group injected with EpCAM-Fc^M (~7%). This study demonstrated that the plant-derived EpCAM-FcK fusion antigenic protein induced a humoral immune response in mice.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.65.2-65
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• 2003

To protect the plant against several soil-borne pathogens, we are currently constructing disease-resistant transgenic root stock for the growth of cucurbitaceae vegetable plants, watermelon and gourd. We made a watermelon cDNA library from Cladosporium cucumerinum-Infected leaves for substractive hybriazation and differential screening. We isolated the several pathogen inducible cDNA clones, such as caffeoyl-CoA-methyltransferase, LAA induced protein, receptor-like kinase homolog, hydroxyproline-rich glycoprotein, catalase, calmodulin binding protein, mitochondrial ATPase beta subunit, methyl tRNA synthetase and WRKY transcription factors. We previously obtained CaMADS in pepper and galactinol synthase ( CsGolS) in cucumber that were confirmed to be related with disease-resistance. CaMADS and CsGolS2 were transformed into the inbred line 'GO701-2' gourd, the inbred line '6-2-2' watermelon and the Kong-dye watermelon by Agrobacterium tumerfaciens LBA4404. Plant growth regulators (zeatin, BAP and IAA) were used for shoot regeneration and root induction for optimal condition. Putative transgenic plants were selected in medium containing 100mg/L kanamycin and integration of the CaMADS and CsGO/S2 into the genomic DNA were demonstrated by the PCR analysis. We isolated major soil-borne pathogens, such as Monosporascus cannonballus, Didymella bryoniae, Cladosporium cuvumerinum from the cultivation area of watermelon or root stock, and successfully established artificial inoculation method for each pathogen. This work was supported by a grant from BioGreen 21 program, Rural Development Administration, Republic of Korea.

• The Plant Pathology Journal
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• v.36 no.4
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• pp.323-334
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• 2020

Lysin motif (LysM) proteins are reported to be necessary for the virulence and immune response suppression in many herbaceous plant pathogens, while far less is documented in woody plant pathogens. In this study, we preliminarily characterized the molecular function of a LysM protein LtLysM1 in woody plant pathogen Lasiodiplodia theobromae. Transcriptional profiles revealed that LtLysM1 is highly expressed at infectious stages, especially at 36 and 48 hours post inoculation. Amino acid sequence analyses revealed that LtLysM1 was a putative glycoprotein with 10 predicted N-glycosylation sites and one LysM domain. Pathogenicity tests showed that overexpressed transformants of LtLysM1 displayed increased virulence on grapevine shoots in comparison with that of wild type CSS-01s, and RNAi transformants of LtLysM1 exhibited significantly decreased lesion length when compared with that of wild type CSS-01s. Moreover, LtLysM1 was confirmed to be a secreted protein by a yeast signal peptide trap assay. Transient expression in Nicotiana benthamiana together with protein immunoblotting confirmed that LtLysM1 was an N-glycosylated protein. In contrast to previously reported LysM protein Slp1 and OsCEBiP, LtLysM1 molecule did not interact with itself based on yeast two hybrid and co-immunoprecipitation assays. These results indicate that LtLysM1 is a secreted protein and functions as a critical virulence factor during the disease symptom development in woody plants.

• Proceedings of the Plant Resources Society of Korea Conference
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• v.18 no.1
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• pp.41-51
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• 2005

We examined whether extracts from 14 local citrus spp. on Jeju Island (Korea) contained chemosensitizing activity that would increase the cytotoxic effect of vincristine(VCR) in drug-resistant cancer cells. We report that methanol extracts from fruits and flowers of some species had a chemosensitizing effect that reversed P-glycoprotein (Pgp)-mediated multidrug resistance (MDR). Using drug-sensitive AML-2/WT and drug-resistant AML-2/D100 in the absence of VCR in human acute myelogenous leukemia cells we found that fruit or flower extracts alone generally had low cytotoxicity $(IC_{50}>200\;{\mu}g/ml)$. In studies examining the effect of extracts on 120 ng/ml VCR cytotoxicity in drug-resistant AML-2/D100 cells, we found that immature fruit extracts had greater chemosensitizing activity than either extracts from mature fruit or flower. Of the 14 species examined, the immature fruit extract from Inchangkyool (Citrus ichangiensis) showed the hishest chemosensitizing index(CI) valus. Immature fruit extracts of Hongkyool(C. tachibana), Byungkyool(C. platymamma), Cheongkyool(C. nippokoreana) and Jinkyool (C. sunki) also strongly potentiated VCR cytotoxicity in AML-2/D100 cells. The chemosensitizing effect of peel extracts was 2-10-fold that of whole fruit extracts from Hongkyool (C. tachibana), Byungkyool (C. platymamma) and Inchangkyool (C. inchangiensis). The CI values for flower extracts were higher than those for mature fruit extracts, but lower than those for immature fruit extracts. These results indicate that immature citrus fruits contain compounds that do not exert their activity solely through cytotoxicity. In particular, Incahngkyool (C. inchangiensis), Byungkyool(C.platymamma), Cheongkyool(C. nippokoreana) and Hongkyool (C. tahibana) may be useful sources of chemosensitizing compounds.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.130-138
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• 2010

Orchid fleck virus (OFV) is an unassigned plant virus in the family Rhabdoviridae. OFV was isolated from Cymbidium sp. showing oval necrotic lesions on their leaves in Korea, and designated as OFV-NHHS1. The complete nucleotide sequence of the RNA1 (6,413 nt) (GenBank accession no. AB516442) and RNA2 (6,001 nt) (GenBank accession no. AB516441) was determined in this study. RNA1 and RNA2 contained five and one ORF respectively. RNA1 encodes nucleocapsid (N) of 49 kDa, ORF2 of 26 kDa, ORF3 of 38 kDa, ORF4 of 20 kDa and glycoprotein (G) of 61 kDa proteins, whereas RNA2 encodes a single polymerase of 212 kDa. OFV-NHHS1 shared extremely high similarity of 98.6-100% and 98.9-99.6% in nucleotidle and amino acid sequences with a Japanese isolate, OFV-so, respectively. However, the N, G and L of OFV-NHHS1 revealed 6.9-19.3%, 7.3-12.0%, and 13.4-26.6% identities to those of 29 Rhabdoviruses, respectively. To survey the infection rate of OFV in commercial orchids in Korea, 51 Cymbidium sp., 10 Phalaenopsis sp., 22 Oncidium sp. and 21 Dendrobium sp. plants that showed typical viral symptoms were collected. RT-PCR with specific primers for detection of Cymbidium mosaic virus (CymMV), ORSV and OFV showed high infection rate by ORSV alone and double infection by ORSV and CymMV. One of the orchids tested was infected with OFV. This is the first report of the complete nucleotide sequences of OFV isolated in Korea.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.442-448
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• 2006

Human lactoferrin (hLf) is an iron-binding glycoprotein that has been considered to play many biological roles in the human, including the stimulation of the immune system, antimicrobial and anti-inflammatory effects, and regulation of iron absorption. We generated transgenic Siberian ginseng (Acanthopanax senticosus) cell cultures producing a functional hLf protein using the signal peptide sequence from the endoplasmic reticulum and driven by an oxidative stress-inducible SWPA2 promoter which is highly expressed in plant cell cultures. The production of hLf increased proportionally to cell growth and showed a maximal level (up to 3.6% of total soluble protein) at the stationary phase in suspension cultures. Full-length hLf protein was identified by immunoblot analysis in transgenic cell cultures of Siberian ginseng. Recombinant hLf (rhLf) was purified from suspension cells of Siberian ginseng by ammonium sulfate precipitation, cation-exchange and gel filtration chromatography. N-terminal sequences of rhLf were identical to native hLf (nhLf). The overall monosaccharide composition of rhLf showed the presence of plant specific xylose while sialic acid is absent. Antibacterial activity of purified rhLf was higher than that of nhLf. Taken together, we anticipate that medicinal Siberian ginseng cultured cells, as demonstrated by this study, will be a biotechnologically useful source for commercial production of functional hLf not requiring further purification.