• Applied Biological Chemistry
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• v.35 no.1
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• pp.14-22
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• 1992

A series of new N-[1-(benzotriazol-1-yl)aryl]arylamine derivatives were synthesized and their antifungal activities $(pI_{50})$ in vitro against Pyricularia oryzae, Fusarium oxysporum f. sp. sesami, Valsa ceratosperma and Botrytis cinerea were dertermined by the agar medium dilution method. From the results of the quantitative structure-activity relationships $(QSAR_S)$ analysis, $hydrophobicity({\pi})$, $electronic({\Sigma\sigma})$ and molar $refractivity({\Sigma}M_R)$ parameter of X & Y-substituents on the phenyl group were also shown to be important factor in determining the variation in the antifungal activity. 4-Bromo group substituents (1d & 2b) were the most effective compounds and the $half-life(T_{1/2})$ on the hydrolysis of X(1) at netural pH was about 1.5 day. Molecular orbital(MO) functions of substrate compound, linear free energy relationships$(LFER_S)$ on the antifungal reactivity arid the results of molecular design were also discussed.

• The Korean Journal of Zoology
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• v.27 no.4
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• pp.199-212
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• 1984

A cytoplasmic endoprotease, named protease Ci, has been partially purified by classical chromatographic procedures. This enzyme degrades insulin, glucagon and bovine growth hormone to trichloroacetic acid-soluble materials, but shows little or no hydrolysis of bovine serum albumin, casein or globin. It has a molecular weight of about 120,000 as determined by gel filtration on Sephadex G200, and it appears to be consisted of two identical subunits having molecular weight of 54,000 when estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Protease Ci has an optimum pH of 7.5, and has an isoelectric point of 5.5. This enzyme is a metalloprotease, since it is inhibited by o-phenanthroline and can be activated by the addition of divalent metal cations, such as $Mn^++$ and $Co^++$. Protease ci is inhibited by p-hydroxymercuribenzoic acid, but not by either of leupeptin or Ep475 which are specific inhibitors of sulfhydryl protease. It is distinct from protease Pi, a perplasmic insulin degrading enzyme, since protease Ci is localized to the cytoplasm. The physiological function of protease Ci is presently unknown.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.6
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• pp.437-443
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• 2020

Biological phosphorus removal is accomplished by exposing PAO(phosphorus accumulating organisms) to anaerobic-aerobic conversion conditions. In the anaerobic condition, PAO synthesize PHB(polyhydroxybutyrate) and simultaneously hydrolysis of poly-p resulting phosphorus(Pi) release. In aerobic condition, PAO uptake phosphorus(Pi) more than they have released. In this study, cyanobacteria Synechococcus sp., which is known to be able to synthesize PHB like PAO, was exposed to anaerobic-aerobic conversion. If Synechococcus sp. can remove excess phosphorus by the same mechanism as PAO, synergistic effects can occur through photosynthesis. Moreover, Synechococcus sp. is known to be capable of synthesizing PHB using inorganic carbon as well as organic carbon, so even if the available capacity of organic carbon decreases, it was expected to show stable phosphorus removal efficiency. In 6 hours of anaerobic condition, phosphorus release occurred in both inorganic and organic carbon conditions but SPRR(specific phosphorus release rate) of both conditions was 10 mg-P/g-MLSS/day, which was significantly lower than that of PAO. When converting to aerobic conditions, SPUR(specific phosphorus uptake rate) was about 9 mg-P/g-MLSS/day in both conditions, showing a higher uptake rate than the control condition showing SPUR of 6.4 mg-P/g-MLSS/day. But there was no difference in terms of the total amount of removal. According to this study, at least, it seems to be inappropriate to apply Synechococcus sp. to luxury uptake process for phosphorus removal.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.108-109
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• 2013

Mitochondria play key roles in the production of cell's energy. Their dominant function is the synthesis of adenosine 5'-triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi) through the oxidative phosphorylation. Evaluation of drug-induced mitochondrial toxicity has become increasingly important since mitochondrial dysfunction has recently been implicated in numerous diseases including cancer and diabetes mellitus. Mitochondrial functions have been monitored via oxygen consumption, mitochondrial membrane potential, and more importantly via ATP synthesis since ATP synthesis is the most essential function of mitochondria. Various analytical methods have been employed to investigate ATP synthesis in mitochondria, including high performance liquid chromatography (HPLC), bioluminescence technique, and pH measurement. However, most of these methods are based on destructive analysis or indirect monitoring through the enzymatic reaction. Infrared absorption spectroscopy (IRAS) is one of the useful techniques for real-time, label-free, and direct monitoring of biological reactions [1,2]. However, the strong water absorption requires very short path length in the order of several micrometers. Transmission measurements with thin path length are not suitable for mitochondrial assays because solution handlings necessary for evaluating mitochondrial toxicity, such as rapid mixing of drugs and oxygen supply, are difficult in such a narrow space. On the other hand, IRAS in the multiple internal reflection (MIR) geometry provides an ideal optical configuration to combine solution handling and aqueous-phase measurement. We have recently reportedon a real-time monitoring of drug-induced necrotic and apoptotic cell death using MIR-IRAS [3,4]. Clear discrimination between viable and damaged cells has been demonstrated, showing a promise as a label-free and real-time detection for cell-based assays. In the present study, we have applied our MIR-IRAS system to mitochondria-based assays by monitoring ATP synthesis in isolated mitochondria from rat livers. Mitochondrial ATP synthesis and hydrolysis were in situ monitored with MIR-IRAS, while dissolved oxygen level and solution pH were simultaneously monitored with O2 and pH electrodes, respectively. It is demonstrated that ATP synthesis and hydrolysis can be monitored by the IR spectral changes in phosphate groups in adenine nucleotides and MIR-IRAS is useful for evaluating time-dependent drug effects of mitochondrial toxicants.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.375-377
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• 2000

It is now generally accepted that a phosphoinositide cycle is involved in the transduction of a variety of signals in plant cells. In animal cells, the hydrolysis of phosphatidyl-4,5-bisphosphate catalysed by phosphatidylinositol - specific phospholipase C yields to D-myo-inositol - 1,4,5-trisphosphate and diacylglycerol, which are well known second messengers. The binding of InsP$_3$to a receptor located on the endoplasmic reticulum triggers a calcium release from the endoplasmic reticulum. We have detected and partially characterised key components of phosphoinositide signaling. First, tobacco microsomal fraction and plasma membrane PI-PLC. Consecutively, using a radioligand binding assay we have identified a $Ca^{2+}$ -dependent high affinity InsP$_3$binding site in microsomal membrane fraction vesicle preparation and then we have measured inositol-1,4,5-trisphosphate induced calcium release from tobacco microsomal fraction. These findings suggest that phosphoinositide signaling system is present and operates in the tobacco suspension culture.e.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1757-1760
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• 2005

A series of 6-alkyloxyl-3,4-dihydro-2(1H)-quinoliones (5a-5n) were synthesized through nitration, reduction, diazotization, hydrolysis and alkylation from 3,4-dihydro-2(1H)-quinolione. Their structures were characterized by IR, $^1H$-NMR and MS. The anticonvulsant activity was evaluated by the Maximal electroshock test (MES) and the subcutaneous pentylenetetrazole (Metrazole) test (sc-Met). The neurotoxicity was measured by the Rotarod test (Tox). The result showed that 6-hexyloxy-3,4-dihydro-2 (1H)-quinolinone (5c) was potent in anti-MES and anti-scMet test with $ED_{50}$ of 24.0 mg/kg and 21.2 mg/kg, respectively, albeit its $TD_{50}$ (67.6 mg/kg) revealed the high neurotoxicity. 6-Benzyloxy-3,4-dihydro-2(1H)-quinolinone (5f) was less effective against MES induced seizure with $ED_{50}$ of 29.6 mg/kg, but no neurotoxicity was observed even under 300 mg/kg. Its Protective index (PI) was greater than 10 preferable to Phenytoin, Carbamazepin, Phenobarbital and Valproate.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.95-104
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• 2019

Background: Oxidized low-density lipoprotein (ox-LDL) causes vascular endothelial cell inflammatory response and apoptosis and plays an important role in the development and progression of atherosclerosis. Ginsenoside compound K (CK), a metabolite produced by the hydrolysis of ginsenoside Rb1, possesses strong anti-inflammatory effects. However, whether or not CK protects ox-LDL-damaged endothelial cells and the potential mechanisms have not been elucidated. Methods: In our study, cell viability was tested using a 3-(4, 5-dimethylthiazol-2yl-)-2,5-diphenyl tetrazolium bromide (MTT) assay. Expression levels of interleukin-6, monocyte chemoattractant protein-1, tumor necrosis factor-${\alpha}$, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 were determined by enzyme-linked immunosorbent assay and Western blotting. Mitochondrial membrane potential (${\Delta}{\Psi}m$) was detected using JC-1. The cell apoptotic percentage was measured by the Annexin V/ propidium iodide (PI) assay, lactate dehydrogenase, and caspase-3 expression. Apoptosis-related proteins, nuclear factor $(NF)-{\kappa}B$, and mitogen-activated protein kinases (MAPK) signaling pathways protein expression were quantified by Western blotting. Results: Our results demonstrated that CK could ameliorate ox-LDL-induced human umbilical vein endothelial cells (HUVECs) inflammation and apoptosis, $NF-{\kappa}B$ nuclear translocation, and the phosphorylation of p38 and c-Jun N-terminal kinase (JNK). Moreover, anisomycin, an activator of p38 and JNK, significantly abolished the anti-apoptotic effects of CK. Conclusion: These results demonstrate that CK prevents ox-LDL-induced HUVECs inflammation and apoptosis through inhibiting the $NF-{\kappa}B$, p38, and JNK MAPK signaling pathways. Thus, CK is a candidate drug for atherosclerosis treatment.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.21-28
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• 2000

A new fourty six 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenylpro- pionamide derivatives were synthesized and the herbicidal activities against rice plant and barnyard grass with pre-emergence in down land were measured. The structure activity relationships (SAR) between the activities and physicochemical parameters of the substituted(X) N-phenyl group in substrates were analyzed and discussed by Free- Wilson and Hansch method from the basis on the former study (Sung. et. al., 1999). The conditions of selective herbicide activity both the barnyard grass and rice plant are shown that the optimal hydrophobicity, $({\pi})_{opt.}=1.34$ and electron donating with field effect (F<0) of meta and ortho, para-substituted mono or disubstituent on the N-phenyl ring were found to contribute significantly. The herbicidal activities against barnyard grass are roughly the same as the results in up land whereas damage to rice plant in down land more increase than that of up land. Degradation products in water are 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)propionic acid ((A)) (obs. pKa=4.35 & obs. logP=4.77) and 6-chloro-2-benzoxazolone (B) (obs. pKa=8.40 & obs. logP=2.90). These results were supposing that the hydrolysis product of substrates, (A) is comparatively absorbed in rice plant but not in barnyard grass. And it is assumed from the SAR equations that the 2,6-dimethyl-4-methoxymethyl group substituent ($pI_{50}=5.41$, 3g/ha) is selected as the most highest herbicidal activity against barnyard grass in green house.

• Journal of fish pathology
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• v.18 no.1
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• pp.67-80
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• 2005

Phosphoinositide-specific phospholipase $C\delta$ $PLC\delta$) plays an important role in many cellular responses and is involved in the production of second messenger. The present study was conducted to obtain the biochemical characteristics of the expressed recombinant $PLC\delta$ in E. coli cloned from Misgurnus mizolepis and partially purified $PLC\delta$ enzymes from liver tissues of M. mizolepis (wild ML-$PLC\delta$). The ML $PLC\delta$ gene was cloned and expressed under the previous report (Kim et al., 2004), and purified the recombinant protein by successive chromatography using $Ni^{2+}$-NTA affinity column and gel iltration FPLC column. The wild ML-$PLC\delta$ protein was solublized with 2 M KCI and purified by successive chromatography on open heparin-Sephagel and analytical TSKgel heparin-5PW. Both the recombinant and wild ML-$PLC\delta$ form of protein showed a concentration-dependent PLC activity to phosphatidylinositol 4,5-bis-phosphate (PIP$_2$) or phosphatidylinositol (PI). Its activity was absolutely $Ca^{2+}$- dependant, which was similar to mammalian $PLC\delta$ isozymes. Maximal PI-hydrolytic activations of recombinant and wild ML- TEX>$PLC\delta$ was at pH 7.0 and pH 7.5, respectively. In addition, the enzymatic activities of recombinant and wild ML-$PLC\delta$ were increased in concentration-dependent manner by detergent, such as sodium deoxycholate SDC), phosphatidylethanolamine (PE) and phosphatidylcholine (PC). The activities decreased in contrast by a polyamine, such as spermine. Western blotting showed that several types of $PLC\delta$ isozymes exist in various organs. Taken together our results, it suggested that the biochemical characteristics of ML-$PLC\delta$ are similar with those of mammalian $PLC\delta1$ and ${\delta}3$ isozymes.

• Journal of Life Science
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• v.30 no.9
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• pp.826-833
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• 2020

Phospholipase C gamma (PLCγ) has critical roles in receptor tyrosine kinase- and non-receptor tyrosine kinase-mediated cellular signaling relating to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P₂] to produce inositol 1,4,5 trisphosphate (IP₃) and diacylglycerol (DAG), which promote protein kinase C (PKC) and Ca²⁺ signaling to their downstream cellular targets. PLCγ has two isozymes called PLCγ1 and PLCγ2, which control cell growth and differentiation. In addition to catalytically active X- and Y-domains, both isotypes contain two Src homology 2 (SH2) domains and an SH3 domain for protein-protein interaction when the cells are activated by ligand stimulation. PLCγ also contains two pleckstrin homology (PH) domains for membrane-associated phosphoinositide binding and protein-protein interactions. While PLCγ1 is widely expressed and appears to regulate intracellular signaling in many tissues, PLCγ2 expression is restricted to cells of hematopoietic systems and seems to play a role in the regulation of immune response. A distinct mechanism for PLCγ activation is linked to an increase in phosphorylation of specific tyrosine residue, Y783. Recent studies have demonstrated that PLCγ mutations are closely related to cancer, immune disease, and brain disorders. Our review focused on the physiological roles of PLCγ by means of its structure and enzyme activity and the pathological functions of PLCγ via mutational analysis obtained from various human diseases and PLCγ knockout mice.