• Parasites, Hosts and Diseases
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• v.41 no.2
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• pp.89-96
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• 2003

Among the panel of monoclonal antibodies (mAb) against Toxoplasma gondii, mAb of Tg621 (Tg621) clone blotted 38 kDa protein which localized in the cytoplasm of tachyzoites by immunofluorescence microscopy The protein was not released into the parasitophorous vacuole during or after invasion. The cDNA fragment encoding the protein was obtained by screening a T. gondii cDNA expression library with Tg621. The full length cDNA sequence was completed with 5’-RACE as 1,592 bp, which contained open reading frame of 942 bp. The deduced amino acid sequence of Tg621 consisted of a polypeptide of 313 amino acids, with significant homology to ribosomal P proteins (RPP) of other organisms especially high to those of apicomplexan species. The expressed and purified TgRPP was assayed in western blot with the sera of toxoplasmosis patients and normal sera, which resulted in the 74.0% of positive reactions in toxoplasmosis patients whereas 8.3% in normal group. Therefore, the antibody formation against TgRPP in toxoplasmosis patients was regarded as specific for T. gondii infection and suggested a potential autoantibody.

• Parasites, Hosts and Diseases
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• v.53 no.3
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• pp.335-339
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• 2015

Cryptosporidium andersoni ATP-binding cassette (CaABC) is an important membrane protein involved in substrate transport across the membrane. In this research, the nucleotide binding domain (NBD) of CaABC gene was amplified by PCR, and the eukaryotic expression vector of pEGFP-C1-CaNBD was reconstructed. Then, the recombinant plasmid of pEGFP-C1-CaNBD was transformed into the mouse intestinal epithelial cells (IECs) to study the iron transportation function of CaABC. The results indicated that NBD region of CaABC gene can significantly elevate the transport efficiency of $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $HCO_3{^-}$ in IECs (P<0.05). The significance of this study is to find the ATPase inhibitors for NBD region of CaABC gene and to inhibit ATP binding and nutrient transport of CaABC transporter. Thus, C. andersoni will be killed by inhibition of nutrient uptake. This will open up a new way for treatment of cryptosporidiosis.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.167-173
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• 1984

The cellabiase (${\beta}$-glucosidase) gene in a Cellulomonas sp. CS1-1 was cloned into E. coli HB101 using the vector plasmid pBR322, and the expression of the gene in E. coli studied. The chromosomal DNA of the cellulomonas was digested by seveal restriction enzymes, each of which has only one cleaving site in plasmid pBR322. The recombinant plasmid, pSB2, created with Sal I frament, was expressed for the cellobiase gene in E. coli. The recombiant plasmid was estimated to contain 6.4 Kb foreign DNA at the Sal I site of plasmid pBR322 and the inserted DNA was mapped by single and double digestion with several enzymes. E. coli HB101(pSB2) has slowly grown in a mineral liquid medium containing cellobiose as a sole carbon source. The cellobiase activity in the transformed E. coli was 132 units per liter, which is equivalent to one twenty fifth of that in doner strain Cellulomonas sp. CS1-1. The transforned cell with plasmid containing cellulase gene grow well in the LB mediuns. The synthesis of cellobiase in the strain, E. coli HB101 (pSB2), was inhibited by glucose and at high concentration of cellobiose, and induced by cellobiose at low concentration.

• Journal of Microbiology
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• v.34 no.2
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• pp.151-157
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• 1996

By PCR amplification using the sequence of the previously cloned shiga-like toxin II DNA, a gene encoding it has been cloned from an isolate of healthy Korean native bovine feces, Escherichia coli KSC109. The nucleotide sequence s included tow open reading frames coding for 319 and 89 amino acids corresponding to A and B subunits, respectively. Comparison of the nucleotide and predicted amino acid sequences of newly cloned gene (slt-II) with those of others in the SLT-II family revealed completely identical homology with SLT-II cloned previously from bacteriophabe DNA of E. coli 933 derived from a patient with hemorrhagic colities. In addition, the sequence homology of SLT-II with SLT-II variant form bovine was more than 95% at both the nucleotide and protein levels. Overexpression of SLT-II recombinant gene by induction with IPTG using an E, coli hostvector, system was conducted and the correctly processed products with active mature form exhibited 1000-fold higher cytotoxycity for Vero cells than that form original strain.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.375-381
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• 2014

Transgenic potato was generated to express recombinant 5 repeated ${\beta}$-amyloid ($A{\beta}$) peptides, potential antigens to be applied as a preventive accine for Alzheimer's disease using Agrobacterium mediated transformation. The $A{\beta}$ peptides were fused to the human IgG Fc fragment enhancing protein and KDEL, which is the endoplasmic reticulum (ER) retention signal ($5A{\beta}$-FcK). The $5A{\beta}$-FcK, was expressed under the control of the duplicated 35S promoter. PCR analysis confirmed the presence of the transgene in several transgenic potato lines. Southern blot analysis showed only a single gene copy number in transgenic line 22, whereas multiple gene copy numbers were shown for transgenic lines 31 and 44. Northern blot analysis showed that line 22 had stronger mRNA levels when compared to lines 31 and 44. Immunoblot analysis confirmed that the $5A{\beta}$-FcK protein was expressed in the transgenic potato plant. These results indicate that $5A{\beta}$ fused to Fc can be expressed in potato plants.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2000.06a
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• pp.64-75
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• 2000

During the last three decades considerable advances has been made in goat embryo production and transfer technology. The Korean native black goat is the most useful domestic ruminant in this country for biological investigation and application because it has a lot of merits such as relatively short generation period(1 vs 2 year for a cow), easy of handling, well adaptation, high fertility, convenient and inexpensive. This article covers the methods of superovulation, estrus synchronization, embryo collection and transfer techniques, pregnancy diagnosis and subsequent pregnancy and kidding rates for the production of transgenic Korean native black goats. More than one hundred goat kids have been produced as a result of our transgenic goat project via microinjection of foreign gene into pronuclei, in vitro culture, transfer of various stages of fresh and frozen-thawed microinjected embryos into oviducts or uteri of recipient does. We have got two transgenic goats carrying a transgene targeting the expression of recombinant human granulocyte colony stimulating factor(hG-CSF) to the mammary gland so far. Since collection and transfer of embryos in this species is usually accomplished by laparotomy, exteriorization of the reproductive tract for surgical embryo collection leads to the formation of post-operative adhesions. Nonsurgical or laparoscopic technique to reduce adhesions from repeated surgeries has great advantages in improving embryo production and transfer especially from valuable donors. We will discuss this later.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.557-560
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• 2006

The epoxide hydrolase (EH) of Aspergillus niger LK was expressed to high levels in Escherichia coli based on codon usage. E. coli, Rosetta (DE3)PLysS, containing a large number of tRNAs for rare-codons was employed as a host strain. The recombinant E. coli expressing A. niger EH showed an enhanced enantioselective hydrolysis activity toward racemic styrene oxide. Enantiopure (S)-styrene oxide with a high enantiopurity of 99% ee was obtained from racemic substrates.

• KSBB Journal
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• v.17 no.6
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• pp.577-581
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• 2002

In an attempt to produce recombinant proteins using the pollen enriched in some plant species, a 1.7 kb DNA encoding urease subunit B (UreB) amplified by PCR from Helicobacter pylori urease gene cluster in pH808 plasmid was cloned to be expressed under CaMV35S promoter in lily (Lilium longiflorum) pollen tubes elongated in vitro. Lily pollen at early germinating stage was transformed with the ureB DNA using Agrobacterium via vacuum infiltration and, incubated for a full pollen tube growth 16 - 24 h in the dark in the presence of kanamycin. DNA integration and expression in the transgenic pollen were analyzed by the standard molecular techniques and the results suggest that the pollen in vitro may be employed as a protein factory in a disposable fashion.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.311-318
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• 1991

The DNA fragment representing for Pseudorabies gp50 and gp60(Shope) was cloned by recombinant techniques. The viral DNA was extracted from the infected cells and digested with Bam HI. The 6.8 Kb of Bam HI fragment was isolated from agarose gel and further digested with Nde I followed by Klenow treatment. The blunt ended 4.9Kb fragment was cloned into pTZ18R plasmid vector. The upstream region of gp50 was further manipulated to remove its 5' promoter region and create EcoRl site for possible eukaryotic expression system. The result of partial sequencing of cloned DNA indicated that Shope strain showed 95% homology with gp50 of Rice strain.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.165-169
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• 1997

Two gentamicin resistance R plasmids, pGM5 and pGM6, containing aacC2 gene were selected from environmental isolates. The gentamicin resistance determinants of R plasmids were cloned into the BamHI site of pUC18. Restriction enzyme map of inserted region of recombinant plasmids, pSYS and pSY6, and PCR results indicated that Tn3 sequence was located upstream of gentamicin resistance gene. Based on the restriction maps and susceptibility tests, it was concluded that the sequence of bla and 3' inverted repeat of Tn3 play a important roles in the expression of gentamicin resistance gene.