• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.640-646
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• 2017

In this study, we elucidated anti-cancer activity and potential molecular mechanism of 70% ethanol extracts from Taxilli Ramulus (Taxillus chinensis (DC.) Danser) (TR-E70) against human colorectal cancer cells. Anti-cell proliferative effect of TR-E70 was evaluated by MTT assay. The effect of TR-E70 on the expression of cyclin D1 in the protein and mRNA level was evaluated by Western blot and RT-PCR, respectively. TR-E70 suppressed the proliferation of human colorectal cancer cell lines, HCT116 and SW480. Although TR-E70 decreased cyclin D1 expression in protein and mRNA level, decreased level of cyclin D1 protein by TR-E70 more dramatically occurred than that of cyclin D1 mRNA. Cyclin D1 downregulation by TR-E70 was attenuated in presence of MG132. In addition, TR-E70 phosphorylated threonine-286 (T286) of cyclin D1. TR-E70-mediated cyclin D1 degradation was blocked in presence of LiCl as an inhibitor $GSK3{\beta}$ but not PD98059 as an ERK1/2 inhibitor and SB203580 as a p38 inhibitor. Our results suggest that TR-E70 may downregulate cyclin D1 as one of the potential anti-cancer targets through $GSK3{\beta}$-dependent cyclin D1 degradation. From these findings, TR-E70 has potential to be a candidate for the development of chemoprevention or therapeutic agents for human colorectal cancer.

• Biomedical Science Letters
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• v.8 no.4
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• pp.211-215
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• 2002

The baculovirus/Sf9 cell expression can be employed as a powerful system for producing large amounts of the human erythrocyte glucose transporter, GLUT1 heterologously In order to exploit the system further, it is necessary to develop a convenient method for demonstrating that the transporter expressed in insect cells is biologically active. To achieve this, we have expressed the human CLUT1 in insect cells and photolabelled the expressed protein with [$^3$H] cytochalasin B, a potent inhibitor of the human erythrocyte glucose transporter. Subsequently, the labelled proteins were analysed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Membranes labelled with [$^3$H] cytochalasln B in the presence of L-Glucose yielded a single sharp peak of labelling of apparent $M_r$ 45,000 on SDS/polyacrylamide gels. The mobility of this peak corresponded exactly to that of the band detected by anti-glucose transporter antibodies on Western blots of membranes prepared from insect cells infected with recombinant virus. In addition, the sharpness of the radioactive peak provides further evidence for the conclusion that the expressed protein is much less heavily and heterogeneously glycosylated than its erythrocyte counterpart. No peak of labelling was seen with the membranes prepared from non-infected Sf9 cells. Furthermore, the incorporation of label into this peak was completely inhibited by the presence of 500 mM-D-Glucose during tile photolabelling procedure, showing the stereoselectivity of the labelling. These evidences clearly show that human glucose transporter expressed in insect cells exhibits native-like biological activity, and that photolabelling with [$^3$H] cytochalasin B can be a convenient means for analysing the biological activity of the transport protein expressed in insect cells.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.177-182
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• 2009

The glycosylated human MINPP (multiple inositol polyphosphate phosphatase), which was recombinantly over-expressed by using industrial host, Pichia pastoris, showed the phytase activity against phytate ($InsP_6$) and the enzyme activity of the unglycosylated counterpart was decreased to 30%. The optimal phytase activity occurred at pH 7.4. The human MINPP showed high substrate specificity for $InsP_6$ with little activity on other organic phosphate conjugates such as para-nitrophenylphosphate (pNPP), ATP, and ribose-1-phosphate (R-1-P). The phosphatase activity against 2,3-bisphosphoglycerate (2,3-BPG) by human MINPP was increased to 1.2-fold in the presence of stimulator, 1 mM 2-phosphoglycolate (2-PG) but the phytase activity against $InsP_6$ was not affected by addition of 1 mM 2-PG. The phosphatase activity against 2,3-BPG by human MINPP was not increased in the presence of 2 mM $Mg^{2+}$ or 100 mM $Cl^-$.

• BMB Reports
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• v.28 no.5
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• pp.427-432
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• 1995

Ganglioside GM3 and sialidase activities in human fetal liver have been investigated. Gangliosides were extracted from fetal livers by the Folch-Suzuki method and analyzed by high-performance thin layer chromatography (HPTLC). GM3 increased, but lactosylceramide (LacCer) decreased predominantly over the developmental stages. Sialidase in human fetal liver was mainly localized in the lysosomal fraction and its activity was high in the earlier stages of development. The optimum pH for this enzyme was 4.3~4.4. Sialidase was more active with the ganglioside mixture than with GM3, sialyllactose or fetuin. Fetal liver sialidase was still active (20% activity) in the presence of 25% methanol. These results suggested that the changes of the ganglioside GM3 and sialidase activity may be involved in the regulation of cell growth in human fetal liver during development.

• Animal cells and systems
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• v.2 no.2
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• pp.243-248
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• 1998

We have partially sequenced glutaminyl cyclases from several mammalian and one avian species and found that the two cysteine residues of the human glutaminyl cyclase are completely conserved. The mammalian glutaminyl cyclase has been reported to possess reactive thiols (Busby, Jr, et aI., 1987, J BioI Chern 262, 8532-8536). Mutagenesis of these cysteine residues, however, resulted in only a slight decrease in enzyme activity. Likewise, the recombinant human enzyme was completely resistant to attempted chemical modification of the putative reactive thiols. Although the human glutaminyl cyclase did not appear to have reactive thiols, it was sensitive to diethylpyrocarbonate and acetylimidazole, indicating the presence of functionally important histidine and tyrosine residues which could act as acid/base catalysts. Almost identical deuterium solvent isotope effect (1.2 vs 1.3) upon the reaction by the human and papaya enzymes, respectively, provides an evidence both animal and plant glutaminyl cyclases catalyze pyroglutamyl-peptide formation by intramolecular cyclization.

• Journal of the Korea Convergence Society
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• v.13 no.4
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• pp.203-211
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• 2022

Due to the Corona-19 pandemic, online education has grown worldwide and it is now being predicted that online education will dominate the future of education. This study examines, as characteristics of the human factor, the effect of self-efficacy; as system factors influencing learners' satisfaction with online learning and behavioral intention to use online learning, this study examines perceived social presence and perceived teaching presence. Participating in this study were 236 students who filled out an online survey in return for course credits. Study findings suggest that individuals with high social presence and teaching presence will have higher satisfaction with online learning and higher behavioral intention to use online learning than those with low social presence and teaching presence. The study also found that individuals with high self-efficacy have higher satisfaction with online learning and higher behavioral intention to use online learning than those with low self-efficacy. This study provides theoretical implications as well as practical implications for e-learning educators when it comes to enhancing students' satisfaction with online learning and behavioral intention to use online learning.

• CELLMED
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• v.1 no.1
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• pp.3.1-3.4
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• 2011

Emerging infectious diseases are usually a public concern. The presence of new emerging infectious diseases is a topic to be reported on and discussed about in medicine. Several new emerging infectious diseases have occurred within the present decade. In this specific review, the author briefly reviews the important new emerging human viral infections that first appeared in Asia during the present decade, 2001 - 2010.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.154-155
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• 2001

Cyclooxygenase-2 (COX-2) is an inducible enzyme expressed in response to a variety of proinflammatory agents and cytokines. COX-2 expression has been shown to be elevated in several different types of human cancer. The presence of oncogenic ras has been associated with constitutive induction of COX-2 in certain H-ras transformed cells, and COX-2 overexpression confers resistance to apoptosis.(omitted)

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.1
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• pp.103-109
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• 2015

This paper introduces a multi-purpose smart fusion sensor. Normally, this type of sensor can contribute to energy savings specifically related to lighting and heating/air conditioning systems by detecting individuals in an office building. If a fire occurs, the sensor can provide information regarding the presence and location of residents in the building to a management center. The system consists of four sensors: a thermopile sensor for detecting heat energy, an ultrasonic sensor for measuring the distance of objects from the sensor, a fire detection sensor, and a passive infrared sensor for detecting temperature change. The system has a wireless communication module to provide the management center with control information for lighting and heating/air conditioning systems. We have also demonstrated the usefulness of the proposed system by applying it to a real environment.

• Korean Journal of Pharmacognosy
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• v.9 no.4
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• pp.157-167
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• 1978

Atherosclerosis is associated with the presence of extracellular lipid droplets and large fatty deposits, both of which are to be covered at the surface mainly by zwitterionic phospholipids. The development of atherosclerosis is often associated with the accumulation of calcium. Furthermore, the presence of glycosaminoglycans directly underlying fatty deposits in human aorta has been demonstrated. Also, the possible involvement of the interaction between sulfated polysaccharide and lipoprotein in the development of atherosclerosis has been suggested in view of the presence of both low density lipoproteins and glycosaminoglycans, as well as their complexes, in atherosclerotic aortas. Therefore interactions of sulfated polysaccharides with low density lipoproteins which serve as a vehicle for cholesterol and cholesterol ester and with zwitterionic phospholipids have been studied extensively by a number of workers to provide mechanisms. In this paper, the mechanism of the interaction of sulfated polysaccharides with low density lipoproteins and the mechanism of the interaction between sulfated polysaccharides and zwitterionic phospholipids are reviewed. The possibility of the occurence of these interactions in the body are also considered.