• BMB Reports
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• 제45권3호
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• pp.133-140
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• 2012

Cancers claim millions of lives each year. Early detection that can enable a higher chance of cure is of paramount importance to cancer patients. However, diagnostic tools for many forms of tumors have been lacking. Over the last few years, studies of chimeric RNAs as biomarkers have emerged. Numerous reports using bioinformatics and screening methodologies have described more than 30,000 expressed sequence tags (EST) or cDNA sequences as putative chimeric RNAs. While cancer cells have been well known to contain fusion genes derived from chromosomal translocations, rearrangements or deletions, recent studies suggest that trans-splicing in cells may be another source of chimeric RNA production. Unlike cis-splicing, trans-splicing takes place between two pre-mRNA molecules, which are in most cases derived from two different genes, generating a chimeric non-co-linear RNA. It is possible that trans-splicing occurs in normal cells at high frequencies but the resulting chimeric RNAs exist only at low levels. However the levels of certain RNA chimeras may be elevated in cancers, leading to the formation of fusion genes. In light of the fact that chimeric RNAs have been shown to be overrepresented in various tumors, studies of the mechanisms that produce chimeric RNAs and identification of signature RNA chimeras as biomarkers present an opportunity for the development of diagnoses for early tumor detection.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.275-279
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• 2005

Insect cell transformants, stably expressing human $GFP_{uv}-{\beta}1$, 3-N-acetylglucosaminyltransferase 2 $({\beta}3GnT2)$ as the green fluorescent protein $(GFP_{uv})-fused$ protein, were efficiently isolated on Western blot by the quantification of the densitometric intensity of the fusion protein. From almost 150 transformants containing the fusion gene linked to three different types of signal sequence, two transformants, Tn-pXme4a and -pX28a, were successfully selected, showing 8.3 and 8.6 mU/mL ${\beta}3GnT$ activity, respectively. This method requires a screening time almost one-half that required in the isolation of stably transformed cells with high expression levels, and at the same time allows the handling a large number of transformants.

• 한국수정란이식학회지
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• 제26권4호
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• pp.287-296
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• 2011

Mammalian fertilization is a complex cascade process consisting of sperm migration through the female reproductive tract, physiological changes to sperm such as sperm capacitation and acrosome reaction, and sperm-egg interaction in the oviduct in vivo. On the other hand, in vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the body: in vitro. IVF has been used for a variety of purposes in reproductive biotechnology for human and animals. The discovery of sperm capacitation in 1951 promoted the development of IVF technology. In the initial stage of IVF, sperm capacitation in preincubation medium was shown to be essential to fuse with eggs. Besides, sperms should detour some of the in vivo regulations for IVF. This review introduces a general mammalian fertilization process, including sperm capacitation, removal of cumulus matrix, acrosome reaction, and sperm-egg fusion and focuses on the roles of key biochemical molecules, signal mechanisms, and genes involved during IVF and novel results of sperm-oocyte interaction elucidated in various gene-knockout mice models.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.511-519
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• 2009

A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.738-744
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• 2003

The gene ADH encoding NAD-dependent alcohol dehydrogenase from Bacillus stearothennophilus was cloned and overexpressed as a GST fusion protein at a high level in Escherichia coli. The expressed fusion protein was purified simply by glutathione affinity chromatography. GST fusion protein was then cleaved by thrombin, while soluble enzyme was further purified by glutathione affinity chromatography. The recombinant enzyme had the same elctrophoretic mobility as the native enzyme from Bacillus stearothennophilus. The recombinant enzyme catalyzed the oxidation of a number of alcohols and exhibited high activities towards secondary alcohols. The $K_m\;and\;V_{max}$ values of the recombinant enzyme for ethanol were 5.11 mM and 61.35 U/mg, respectively. Pyridine and imidazole notably inhibited the enzymatic activity. The activity of the recombinant enzyme optimally proceeded at pH 9.0 and $70^{\circ}C$. The midpoint of the temperature-stability curve for the recombinant enzyme was approximately $68^{\circ}C$, and the enzyme was not completely inactivated even at $85^{\circ}C$. The recombinant enzyme showed a high resistance towards denaturing agents (0.05% SDS, 0.1 M urea). Therefore, due to its stability and relatively broad substrate specificity, the recombinant enzyme could be utilized in bio-industrial processes and biosensors.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.274-280
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• 1991

Effects of IPTG induction on cell growth and production of ${\beta}$-galactosidase-preS2 fusion protein (${\beta}$gal-preS2) were studied in a defined medium using a recombinant Escherichia coli JM109/pCMHB30. IPTG was added (0.2 mM) to induce the cloned-gene expression in the early-, mid-, and late-log growth phases. The most serious decreases in growth rate and plasmid stability were observed for the induction in the early-log growth phase. The expression level of ${\beta}$gal-preS2 attained by the induction in the mid-log phase was about 0.51 mg fusion protein/mg total cellular protein, which was 2- and 5-fold improvement over the levels obtained with the inductions in the early- and late-log phases. Formation of acidic byproducts including acetate and pyruvate showed different profiles during the fermentation period for each cases of induction; pyruvate was the major byproduct for the induction in the early-log phase while acetate production became more significant for the cases of inductions in the mid- and late-log phases.

• BMB Reports
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• 제29권5호
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• pp.462-467
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• 1996

Acetolactate synthase (ALS, EC 4.1.3.18) is the first common enzyme in the biosynthesis of leucine, isoleucine, and valine. It is the target enzyme for several classes of herbicides, including the sulfonylureas, the imidazolinones, the mazolopyrimidines, the pyrimidyl-oxy-benzoates, the pyrimidyl-thio-benzens, and the 4,6-dimethoxypyrimidines. An amino-terminal fragment of the sulfonylurea-resistant ALS gene (SurB) from Nicotiana tabaccum was cloned into the bacterial expression vector pGEX-2T. The resulting recombinant plasmid pGEX-ALS1 was used to transform Escherichia coli strain BL21, and the tobacco ALS was expressed in the bacteria as a protein fused with glutathione S-transferase (GST). Polyclonal antibodies against the fusion product (GST-ALS) were produced, and the sensitivity of GST-ALS with the rabbit anti-GST-ALS IgG was up to 50 ng. This antibody was used for Western blot analysis of the partially purified ALS from barley shoots. The results suggest that the polyclonal antibody produced in this study can be used to detect plant ALS.

• Animal cells and systems
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• 제1권1호
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• pp.63-69
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• 1997

We have previously reported that NF-kB is involved in the regulation of nitric oxide synthase gene expression during differentiation of chick embryonic myoblasts. However, how NF-kB is timely activated during myogenesis remains elusive. One of the most prominent events in myogenesis is myoblast membrane fusion, which is accompanied with massive cytoskeletal reorganization. Here we show that the activity of NF-kB markedly increases in L6 rat myogenic cells that have just initiated morphological changes by treating nocodazole, a microtubule-disrupting agent. Furthermore, the induction of NF-kB activation was closely correlated with the myoblast fusion. In addition, a variety of agents that disrupt microtubules stimulated the myoblast fusion as well as the induction of NF-kB activation. In contrast, taxol, a microtubule-stabilizing agent, suppressed the induction of NF-kB activation and inhibited spontaneous differentiation of L6 cells as well. In addition, we found that the NF-KB in the cells consists of p50/p65 heterodimers. These results support the idea that reorganization of microtubule at early stages of differentiation plays a role as a signal for NF-KB activation during myogenesis.

• 한국잠사곤충학회지
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• 제35권1호
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• pp.36-42
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• 1993

Bacillus thruingiensis subsp. kurstaki HD-1의 내독소단백질 유전자인 CryIA(a)의 N-말단 부분과 B.tk HD-73의 내독소단백질 유전자인 CryIA(c)의 C-말단 부분의 융합에 따른 독성발현 여부에 관하여 조사하였다. 융합생산물인 pSK3, pSK4 및 pSK5의 플라스미드는 각각 4.5kb, 4.8kb 그리고 5.5kb로 구성되어 있다. 형질전환체의 내독소단백질에 대한 Western blotting은 SK4 및 SK5가 77-kDa 그리고 105-kDa에서 B.t k HD-1 항체에 대하여 반응을 나타내었다. 독성검정의 공시충인 배추좀나방 및 담배나방을 사용한 결과 pSK5를 포함하는 형질전환체만이 각각 96% 및 97%의 높은 치사율을 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권4호
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• pp.576-584
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• 2017

Objective: To generate recombinant Bacillus subtilis (B. subtilis) engineered for expression of porcine ${\beta}-defensin-2$ (pBD-2) and cecropin P1 (CP1) fusion antimicrobial peptide and investigate their anti-bacterial activity in vitro and their growth-promoting and disease resisting activity in vivo. Methods: The pBD-2 and CP1 fused gene was synthesized using the main codons of B. subtilis and inserted into plasmid pMK4 vector to construct their expression vector. The fusion peptide-expressing B. subtilis was constructed by transformation with the vector. The expressed fusion peptide was detected with Western blot. The antimicrobial activity of the expressed fusion peptide and the recovered pBD-2 and CP1 by enterokinase digestion in vitro was analyzed by the bacterial growth-inhibitory activity assay. To analyze the engineered B. subtilis on growth promotion and disease resistance, the weaned piglets were fed with basic diet supplemented with the recombinant B. subtilis. Then the piglets were challenged by enteropathogenic Escherichia coli (E. coli). The weight gain and diarrhea incidence of piglets were measured after challenge. Results: The recombinant B. subtilis engineered for expression of pBD-2/CP1 fusion peptide was successfully constructed using the main codons of the B. subtilis. Both expressed pBD-2/CP1 fusion peptide and their individual peptides recovered from parental fusion peptide by enterokinase digestion possessed the antimicrobial activities to a variety of the bacteria, including gram-negative bacteria (E. coli, Salmonella typhimurium, and Haemophilus parasuis) and grampositive bacteria (Staphylococcus aureus). Supplementing the engineered B. subtilis to the pig feed could significantly promote the piglet growth and reduced diarrhea incidence of the piglets. Conclusion: The generated B. subtilis strain can efficiently express pBD-2/CP1 fusion antimicrobial peptide, the recovered pBD-2 and CP1 peptides possess potent antimicrobial activities to a variety of bacterial species in vitro. Supplementation of the engineered B. subtilis in pig feed obviously promote piglet growth and resistance to the colibacillosis.