• Journal of Microbiology and Biotechnology
• /
• v.16 no.5
• /
• pp.673-677
• /
• 2006

A perfusion culture of transgenic Nicotiana tabacum cell suspensions, transformed to express recombinant glucuronidase (GUS), was successfully performed in a 5-1 stirred tank bioreactor. With 0.1 $day^{-1}$ of perfusion rate, the maximum dry cell weight (DCW) reached to 29.5 g/l in 16 days, which was 2.1-fold higher than the obtained in batch culture (14.3 g/l). In terms of the production of GUS, the volumetric activity could be increased up to 12.8 U/ml by using perfusion, compared with 4.9 U/ml in batch culture. The specific GUS activities in both perfusion and batch cultures were maintained at similar levels, 200-400 U/g DCW. Consequently, a perfusion culture could be a good strategy for the enhanced production of recombinant proteins in a plant cell culture system.

• Environmental Engineering Research
• /
• v.19 no.1
• /
• pp.41-45
• /
• 2014

The peels of Carya cathayensis Sarg. (PCCS) were treated under subcritical water conditions ($130^{\circ}C$ to $280^{\circ}C$ for 0 to 120 min). The extract from PCCS included reducing sugar, proteins, and compounds with radical scavenging activity. Addressing the reducing sugar that is a resource of bioethanol, we could maximize the reducing sugar under the subcritical water ($190^{\circ}C$ for 60 min) and obtain 0.24 g/g-sample together with 9.7 units/mg-sample of radical scavenging activity. The obtained extract was estimated to correspond to 1 L of bioethanol/100 g-sample. It was therefore considered that the treatment by subcritical water could yield reducing sugar and natural compounds with radical scavenging activity.

• Archives of Pharmacal Research
• /
• v.17 no.3
• /
• pp.199-203
• /
• 1994

Several lines evidence indicate that microtubule depolymerization initiates DNA synthesis or enhances the effects of serum or purified growth factors in many types of fibroblasts. Yet little is known about the intracellular events responsible for the mitogenic effect of microtubule disrupting agents. The effects of antitubulin agents on DNA synthesis in sparse and dense cultures in the presence or absence of serum and possible involvement of G-proteins in their mitotic action were examined. In these studies, colchicine by itself appeared to be mitogenic only for confluent quiesecent human lung fibroblasts. In sparse culture, however, colchicine inhibited serum-stimulated DNA synthesis. Colcemid, another antitubulin agent, showed similar effects of growth inhibition and stimulation in sparse and confluent cultures while lumicolhicine, inactive colchicine, did not. The mitogenic effect of two antitubulin agents, colchicine and colcemid, was partially inhibited by pertussis toxin. These data suggest that microtubular integrity is associated with the expression of either negative or positive control on DNA synthesis and mitogenic effect of antitubulin agents may be partially mediated by pertussis toxin-sensitive G protein.

• The Korean Journal of Zoology
• /
• v.30 no.4
• /
• pp.371-378
• /
• 1987

The fractions of serum proteins, the levels of serum immunoglobulins and the positive rate of HBs Ag were investigated in Korean patients with Down's syndrome. Mean concentrations (g/dl) of serum protein, albumin, a1,-globulin fraction, a2-globulin fraction, $\beta$-globulin fraction and Y-globulin fraction were 7.80$\pm$1.44, 3.89$\pm$0.74, 0.26$\pm$0.09, 0.80$\pm$0. 18, 1.00토0.29 and 1.85$\pm$0.64, respectively. Mean concentrations(mg/dl) of IgG, IgA and IgM were 1,682.17$\pm$600.26, 247.39$\pm$180.86 and 170.87$\pm$79.90, respectively. The positive rate of HBs Ag was 21.74% These results revealed higher levels of Y-globulin fraction, IgG and positive rate of HBs Ag in patients with Down's syndrome than in normal population.

• Proceedings of the PSK Conference
• /
• 2003.04a
• /
• pp.222.1-222.1
• /
• 2003

The signal transduction pathway leading to the activation of the p70s6k plays an important role in the progression of cells from G0/G1 to S phase of the cell cycle but remains incompletely characterized. We investigated the role of the Rho family G protein Rac1 in H2O2-mediated p70s6k activation. Transient expression of a dominant negative mutants of the small GTP-binding proteins Rac1 (Rac1N17) and Cdc42(Cdc42N17) showed reduced levels of slower migration on Western blots of one-dimensional SDS-PAGE in p70s6k and ERK1/2 by PDFG stimulation. (omitted)

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1994.11a
• /
• pp.143-145
• /
• 1994

Chimeric fusion proteins involving IgG have proven valuable in studying protein-protein interactions and may possess therapeutic applications as well. For example, three receptor subtypes for the natriuretic peptides, when fused to the Fc portion of human IgG ${\gamma}$ chain, were quantitatively and qualitatively indistinguishable from the native receptor, thus allowing detailed structure-function studies of the receptor. In an attempt to block human immunodeficiency virus infectivity with soluble derivatives of CD4, a CD4/IgG Fc chimeric molecule was shown to increase the plasma half life of soluble CD4 and possessed the added advantage of IgG Fc-mediated placental transfer. In the case of the KGFR, this approach provided a framework for dissection of its ligand binding domains and made it possible to demonstrate that high affinity binding sites for two ligands, aFGF and KGF, reside within different receptor Ig-like domains. Chimeric molecules fused to immunoglobulins would have the advantages of secretion from transfected cells as well as detection and purification from medium utilizing Staphylococcus aureus Protein A. In addition, where highly related receptors make their discrimination very hard due to the difficulties in generating specific immunochemical probes, IgG fusion protein with tailor-made specificities confers particular advantages to elucidate patterns of receptor distribution and expression. The approach described here may have general applications in defining ligand-receptor interactions as well as searching for specific agonists and antagonists of receptor function.

• Advances in Traditional Medicine
• /
• v.6 no.1
• /
• pp.45-52
• /
• 2006

The methanol extracts of the roots, root bark and stem of Berberis tinctoria, were investigated for their hepatoprotective activity against carbon tetrachloride $(CCl_4)$ induced toxicity in freshly isolated rat hepatocytes, HEp-G2 cells and animal models. The methanol extracts were able to significantly normalise the levels of aspartate amino transferase, alanine aminotransferase, alkaline phosphatase, triglycerides, total proteins, albumin, total bilirubin and direct bilirubin, which were altered due to $CCl_4$ intoxication in freshly isolated rat hepatocytes and also in animal models. The anti-hepatotoxic effect of the methanol extracts in vitro were observed at $600\;-\;1,000\;{\mu}g/ml$ concentrations. A dose dependent increase in the percentage viability was observed when $CCl_4$ exposed HEp-G2 cells were treated with different concentrations of the methanol extracts. The highest percentage viability of HEp-G2 was observed at a concentration of $1,000\;{\mu}g/ml$. The results from the present investigations also indicate good correlation between the in vivo and in vitro studies.

• The Korean Journal of Physiology
• /
• v.24 no.2
• /
• pp.353-362
• /
• 1990

Fluoride (F-), a known stimulator of G-protein, induced strong contraction in rabbit trachealis muscle. $AlCl_3\;(5{\sim}20\;{\mu}M)$, which is required for G-protein stimulation by $F^-$, potentiated the contractile response to $F^-$. $Ca^{2+}-removal$ and verapamil, a calcium channel blocker, inhibited the fluoroaluminate-induced contraction. Fluoroaluminate increased $^{45}Ca$ influx in the absence and presence of verapamil. In heparin-loaded muscle high $K^+-induced$ contraction was not affected, but acetylcholine and fluoroaluminate-induced contractions were inhibited. The fluoroaluminate-induced contraction was partially relaxed by isoproterenol, a stimulator of adenylate cyclase. Pertussis toxin partially inhibited fluoroaluminate-induced contraction and potentiated isoproterenol-induced relaxation in the presence of fluoroaluminate, but had no effect on acetylcholine-induced contraction and the isoproterenol-induced relaxation in the presence of acetylcholine. These results suggest that fluoroaluminate has the ability to stimulate at least two putative G-proteins in rabbit trachealis muscle; One causes $Ca^{2+}$ influx through the potential-operated $Ca^{2+}$ channel and the other induces intracellular $Ca^{2+}$ release by the increase of inositol-1, 4, 5-triphosphate.

• Fisheries and Aquatic Sciences
• /
• v.24 no.1
• /
• pp.1-9
• /
• 2021

Human prostate cancer is the second most frequently diagnosed cancer worldwide, and its incidence rate continues to increase. Advanced prostate cancer is more difficult to treat than early forms due to its chemotherapy resistance. There is need for more effective agents that can inhibit the progression of advanced prostate cancer. Demethoxyfumitremorgin C (DMFTC) was isolated from the fermentation extract of the marine fungus Aspergillus fumigatus. Antiproliferative activity of DMFTC against human prostate cancer PC3 cells was examined through cell cycle analysis by flow cytometry, the fluorescent nuclear imaging analysis with propidium iodide (PI), and proteins expression related to cell cycle arrest and apoptosis were investigated via Western blotting. DMFTC inhibited PC3 cells growth through G1 phase cell cycle arrest and apoptosis induction. It activated the tumor suppressor p53 and the Cdk inhibitor p21, which regulate the cell progression into the G1 phase. Additionally, PI-positive late apoptotic non-viable cells were increased and the expression levels of the G1-positive downstream regulators cyclin D, cyclin E, Cdk2, and Cdk4 were decreased by DMFTC treatment. These results suggest that DMFTC induces G1 arrest and apoptosis induction through regulation of p53/p21-dependent cyclin-Cdk complexes, and it may be a useful therapeutic agent for the treatment of human advanced prostate cancer.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.2
• /
• pp.285-290
• /
• 1997

The insulin-like growth factors(IGFs) are bound to several binding proteins(IGFBPs) that appear to regulate IGF transport, receptor binding, and its action. The concentration of these peptides are altered by catabolic conditions. To determine IGF-I and IGFBP levels in noninsulin-dependent diabetes mellitus (NIDDM), sera was obtained from 5 patients and 7 controls. Serum levels of IGF-I in NIDDM were lower than those in either of the controls. By western immunoblot analysis, especially IGFBP-1 levels are increased, whereas IGFBP-3 levels decreased and their fragments was increased in NIDDM serum. IGFBP-3 proteolytic activity in NIDDM sera was inhibited by phenylmethylsulfonylfluoride (PMSF), aprotinin, and ethylenediaminetetraacetic acid(EDTA). This pattern of inhibition was consistent with a metal-dependent serine protease. By gelatin zymography, these proteolytic enzymes were identified as the size of 97 and 69 kDa. IGFBP-1, which is primarily insulin regulated, was increased in NIDDM and may modulate circulating IGF-I levels by regulating capillary passage of IGF-I. IGFBP-3 proteolysis markedly reduces its affinity for the IGFs, particularly for IGF-I. This accelerates their kinetics of dissociation, thereby increasing the proportions of IGF-I in free form and its availability to the cells.