• Journal of Plant Biotechnology
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• 제42권3호
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• pp.180-185
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• 2015

'여봉'과 '매향' 딸기 식물체로부터 잎 절편을 형질전환 재료로 이용하였다. CaMV 35S promoter에 모넬린 유전자가 연결된 pGA482-pS1D 벡터가 들어있는 아그로박테리움 EHA105 균주를 매개로 형질전환을 수행하였다. 공동 배양 후 잎 절편체로부터 캘러스 형성과 식물체 재분화율은 '여봉' 품종이 '매향' 품종보다 높았으며 이들 형질전환 식물체는 정상적으로 생육하여 개화하였다. PCR 및 Southern blot 분석을 통해 1-2 카피의 모넬린 유전자가 형질전환 딸기 식물체에 도입되었음을 확인하였으며, Northern blot 분석을 통하여 두 품종에서 모두 모넬린 유전자가 발현됨을 확인하였다. 비록 장기간 계대배양된 이들 딸기 형질전환 식물체에서는 모넬린 유전자가 escape 되는 경향을 보였지만, 본 연구에서 확립된 형질전환 시스템은 딸기의 유전적 개량을 위한 새로운 기회를 제공할 수 있을 것이다.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1949-1954
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• 2007

A simple way to prevent protein hyperglycosylation in Hansenula polymorpha was found. When glucose oxidase from Aspergillus niger and carboxymethyl cellulase from Bacillus subtilis were expressed under the control of an inducible methanol oxidase (MOX) promoter using methanol as a carbon source, hyperglycosylated forms occurred. In contrast, MOX-repressing carbon sources (e.g., glucose, sorbitol, and glycerol) greatly reduced the extent of hyperglycosylation. Carbon source starvation of the cells also reduced the level of glycosylation, which was reversed to hyperglycosylation by the resumption of cell growth. It was concluded that the proteins expressed under actively growing conditions are produced as hyperglycosylated forms, whereas those under slow or nongrowing conditions are as short-glycosylated forms. The prevention of hyperglycosylation in the Hansenula polymorpha expression system constitutes an additional advantage over the traditional Saccharomyces cerevisiae system in recombinant production of glycosylated proteins.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.224-229
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• 2009

Human lactoferrin is an iron-binding glycoprotein with many biological activities, including the protection against microbial and virus infection and stimulation of the immune system. We introduced a human lactoferrin (hLf) cDNA under the control of 35S promoter into sweet potato by particle bombardment. Transgenic plants were regenerated via somatic embryogenesis. Transgenic plants were produced typical tuberous roots in soil. PCR, Southern and northern analyses confirmed that the hLf cDNA was incorporated into the plant genome and was properly expressed in plants. Western blot analysis showed that the 80 kDa full length hLf protein was produced in transgenic tuberous roots. Overall results indicated that sweet potato would be an excellent host to produce human therapeutic proteins.

• 대한화학회지
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• 제59권2호
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• pp.188-193
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• 2015

• BMB Reports
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• 제51권12호
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• pp.609-610
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• 2018

Glycosylation is one form of protein modification and plays a key role in protein stability, function, signaling regulation and even cancer. NleB and SseK are bacterial effector proteins and possess glycosyltransferase activity, even though they have different substrate preferences. NleB/SseKs transfer the GlcNAc sugar to an arginine residue of host proteins, leading to reduced $NF-{\kappa}B-dependent$ responses. By combining X-ray crystallography, NMR, molecular dynamics, enzyme kinetic assays and in vivo experiments, we demonstrated that a conserved HEN (His-Glu-Asn) motif in the active site plays a key role in enzyme catalysis and virulence. The lid-domain regulates the opening and closing of the active site and the HLH domain determines the substrate specificity. Our findings provide evidence for the enzymatic mechanism by which arginine can be glycosylated by SseK/NleB enzymes.

• Journal of Microbiology and Biotechnology
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• 제34권7호
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• pp.1443-1451
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• 2024

Weizmannia coagulans can be used as a starter strain in fermented foods or as a probiotic. However, it is salt-sensitive. Here, W. coagulans genomes were compared with the genomes of strains of Bacillus species (B. licheniformis, B. siamensis, B. subtilis, and B. velezensis) that were isolated from fermented foods and show salt tolerance, to identify the basis for the salt-sensitivity of W. coagulans. Osmoprotectant uptake (Opu) systems transport compatible solutes into cells to help them tolerate osmotic stress. B. siamensis, B. subtilis, and B. velezensis each possess five Opu systems (OpuA, OpuB, OpuC, OpuD, and OpuE); B. licheniformis has all except OpuB. However, W. coagulans only has the OpuC system. Based on these findings, the opuA and opuB operons, and the opuD and opuE genes, were amplified from B. velezensis. Expression of each of these systems, respectively, in W. coagulans increased salt-tolerance. W. coagulans expressing B. velezensis opuA, opuD, or opuE grew in 10.5% NaCl (w/v), whereas wild-type W. coagulans could not grow in 3.5% NaCl. The salt resistance of B. subtilis was also increased by overexpression of B. velezensis opuA, opuB, opuD, or opuE. These results indicate that the salt-susceptibility of W. coagulans arises because it is deficient in Opu systems.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.427-427
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• 2005

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1716-1722
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• 2018

Immunosuppressive drugs are used to make the body less likely to reject transplanted organs or to treat autoimmune diseases. In this study, five immunosuppressive drugs including two glucocorticoids (dexamethasone and prednisolone), one calcineurin inhibitor (cyclosporin A), one non-steroid anti-inflammatory drug (aspirin), and one antimetabolite (methotrexate) were tested for their effects on viral proliferation using feline foamy virus (FFV). The five drugs had different cytotoxic effects on the Crandell-Ress feline kidney (CRFK) cells, the natural host cell of FFV. Dexamethasone-pretreated CRFK cells were susceptible to FFV infection, but pretreatment with prednisolone, cyclosporin A, aspirin, and methotrexate showed obvious inhibitory effects on FFV proliferation, by reducing viral production to 29.8-83.8% of that of an untreated control. These results were supported by western blot, which detected viral Gag structural protein in the infected cell lysate. As our results showed a correlation between immunosuppressive drugs and susceptibility to viral infections, it is proposed that immune-compromised individuals who are using immune-suppressive drugs may be especially vulnerable to viral infection originated from pets.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1482-1486
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• 2003

In order to compare effects of feeding systems on rumen fermentation characteristics and nutrient digestion, steers were fed either total mixed ration (TMR) or separate concentrate-roughage ration (CR). Total tract digestibility of nutrients was higher in steers receiving TMR. Especially, DM, ADF and NDF in TMR were digested to a greater extent than those in CR. Rumen pH was not influenced by the feeding systems. Holstein steers on TMR had higher ruminal $NH_3$-N than those on CR. Feeding system did not alter VFA production but TMR feeding resulted in lower A/P ratio. TMR feeding tended to increase the number of bacteria and protozoa in the rumen fluid. Also steers fed TMR generally had higher fiber degrading enzyme activities, which might be the result of increased number of cellulolytic microbes in the rumen of animals on TMR. Our results indicate that TMR may provide more favorable condition for nutrient digestion both in the rumen and in the total tract of steers.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1505-1516
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• 2016

The detection of food pathogens is an important aspect of food safety. A range of detection systems and new analytical materials have been developed to achieve fast, sensitive, and accurate monitoring of target pathogens. In this review, we summarize the characteristics of selected nanomaterials and their applications in food, and place focus on the monitoring of biological and chemical contaminants in food. The unique optical and electrical properties of nanomaterials, such as gold nanoparticles, nanorods, quantum dots, carbon nanotubes, graphenes, nanopores, and polydiacetylene nanovesicles, are closely associated with their dimensions, which are comparable in scale to those of targeted biomolecules. Furthermore, their optical and electrical properties are highly dependent on local environments, which make them promising materials for sensor development. The specificity and selectivity of analytical nanomaterials for target contaminants can be achieved by combining them with various biological entities, such as antibodies, oligonucleotides, aptamers, membrane proteins, and biological ligands. Examples of nanomaterial-based analytical systems are presented together with their limitations and associated developmental issues.