• Proceedings of the KSCN Conference
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• 2004.05a
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• pp.437.1-437
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• 2004

The protein, called PTP1B (protein tyrosine phosphatase 1B), joins a list of enzymes that mice are associated with obesity. The purpose of this study was to investigate the effects of PTP1B inhibitors and taurine on blood lipid profiles in adolescents obesity model rats. Three week-old thirty-six male Sprague-Dawley rats were randomly assigned to six groups (high fat diet group; HFD group, high fat diet ＋ taurine group; HF＋TR group, high fat diet＋PTP1B inhibitor A group; HF＋A group, high fat diet＋PTP1B inhibitor B; HF＋B group, high fat diet＋PTP1B inhibitor A＋taurine group; HF＋A＋TR group, high fat diet ＋ PTP1B inhibitor B＋taurine group; HF＋B＋TR group).(omitted)

• Korean Journal of Bronchoesophagology
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• v.6 no.2
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• pp.201-203
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• 2000

The PTP (Press-Through-Pack) has been widely used as a packing material for tablets and capsules. But esophageal foreign bodies attributed to the PTP may cause injury to esophageal mucous membrane, potentially inducing severe complications such as hemorrhage, perforation, etc. We report three cases of PTP foreign bodies in esophagus with reference to recent literature.

• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.3119-3121
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• 2014

• Journal of Life Science
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• v.18 no.3
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• pp.403-408
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• 2008

In this study, we compared with 80% ethanol extracts from peel of Poncirus trifoliata (PTP) and peel of Citrus junos (CJP) against antioxidant and immune activities. Total phenolics and flavonoids contents in PTP extracts were $60.75{\pm}1.15$ and $33.75{\pm}0.15$ mg/l00 g, respectively, and those were lower than CJP extracts. Antioxidant activities of PTP were increased with the more concentration, and were similar to CJP. Antioxidant activities of PTP were increased with increasing of concentration, and were similar to those of CJP. The NO production in macrophage cell lines were increased in a dose-dependent manner, until 5 mg/ml of CJP and 1 mg/ml of PTP compared with control cells, but decreased at higher concentrations. The proliferation of mouse spleen cells were increased in a dose-dependent manner, until 1 mg/ml of CJP and PTP compared with control cells but decreased at higher concentrations. The NO production in macrophage cell lines treated with PTP and CJP were increased in a dose-dependent manner, compared with untreated control cells until the concentrations of $1{\sim}5$ mg/ml (CJP) and 1 mg/ml (PTP) but decreased at higher concentrations than that. The proliferation of mouse spleen cells treated with PTP and CJP were increased in a dose-dependent manner, compared with untreated control cells until the concentration of 1 mg/ml but decreased at higher concentrations than that.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1479-1484
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• 2008

Protein tyrosine phosphatase (PTP) 1B is the superfamily of PTPs and a negative regulator of multiple receptor tyrosine kinases (RTKs). Inhibition of protein tyrosine phosphatase 1B (PTP1B) has been proposed as a strategy for the treatment of type 2 diabetes and obesity. Recently, it has been reported that amentoflavone, a biflavonoid extracted from Selaginella tamariscina, inhibited PTP1B. In the present study, docking model between amentoflavone and PTP1B was determined using automated docking study. Based on this docking model and the interactions between the known inhibitors and PTP1B, we determined multiple pharmacophore maps which consisted of five features, two hydrogen bonding acceptors, two hydrogen bonding donors, and one lipophilic. Using receptor-oriented pharmacophore-based in silico screening, we searched the biflavonoid database including 40 naturally occurring biflavonoids. From these results, it can be proposed that two biflavonoids, sumaflavone and tetrahydroamentoflavone can be potent allosteric inhibitors, and the linkage at 5',8''-position of two flavones and a hydroxyl group at 4'-position are the critical factors for their allosteric inhibition. This study will be helpful to understand the mechanism of allosteric inhibition of PTP1B by biflavonoids and give insights to develop potent inhibitors of PTP1B.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1206-1211
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• 2013

The selective inhibition of PTP1B has been widely recognized as a potential drug target for the treatment of type 2 diabetes and obesity. In the course of screening for PTP1B inhibitory fungal metabolites, the organic extracts of several fungal species isolated from marine environments were found to exhibit significant inhibitory effects, and the bioassay-guided investigation of these extracts resulted in the isolation of fructigenine A (1), cyclopenol (2), echinulin (3), flavoglaucin (4), and viridicatol (5). The structures of these compounds were determined mainly by analysis of NMR and MS data. These compounds inhibited PTP1B activity with 50% inhibitory concentration values of 10.7, 30.0, 29.4, 13.4, and 64.0 ${\mu}M$, respectively. Furthermore, the kinetic analysis of PTP1B inhibition by compounds 1 and 5 suggested that compound 1 inhibited PTP1B activity in a noncompetitive manner, whereas compound 5 inhibited PTP1B activity in a competitive manner.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.135-136
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• 2001

The Tk-ptp gene encoding a protein tyrosine phosphatase (PTPase) from the hyperthermophilic archaeon Thermococcus kodakaraensis KODI was cloned and sequenced. Sequence analysis indicated that Tk-ptp encoded a protein consisting 147 amino acid residues (16,953 Da). The wild type and the mutants were expressed in Escherichia coli cells as His-tagged fusion proteins and examined for enzyme characteristics. Tk-PTP possessed two unique features that were not found in eucaryal and bacterial counterparts. First, the recombinant Tk-PTP showed the phosphatase activity not only for the phosphotyrosine but also phosphoserine. Second, the conserved Asp (Asp-63), which was considered to be a critical residue, was not involved in catalysis. In order to know a specific substrate for Tk-PTP, C93S mutant was used to trap substrate protein. Proteins of 120, 60 and 53 kDa were isolated specifically from KODI cell lysates by affinity chromatography with Tk-PTP-C93S. It is suggested that these proteins are tyrosine-phosphorylated substrates of Tk-PTP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.127-129
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• 1997

The high pretilt angles in nematic liquid crystals (NLCs) have been generated on robbed polythiophene (PTP) surfaces with alkyl chain lengths. The pretilt angle of the NLC was observed on unidirectionally rubbed PTP surfaces with alkyl chains with more than 9 carbon atoms. We obtained the Pretilt angle of 15~40$^{\circ}$ on rubbed PTP surfaces with 10 carbon atoms in the a1ky1 chain. Also, the pretilt angles of 65~80$^{\circ}$ of NLC were obtained on rubbed PTP surfaces with 11 and 12 carbon atoms in the alkyl chain. We suggest that this high pretilt angle generation in NLC is due to the surface-excluded volume effect by the alkyl chain lengths between. the LCs and the PTP surfaces. Finally, we conclude the odd-even effect on rubbed PTP surfaces is clearly contributed to the pretilt angle generation.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.4
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• pp.230-233
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• 2007

Protein tyrosine phosphatase 1B (PTP1B) acts as a negative regulator of insulin signaling, and selective inhibition of PTP1B has served as a potential drug target for the treatment of type 2 diabetes. As part of our searching for PTP1B inhibitors from natural products, the extracts of marine microorganisms were screened for the inhibitory effects on the activity of protein tyrosine phosphatase 1B (PTP1B). Among the tested 304 extracts, 29 extracts exhibited inhibition rate ranging 40.1 - 83.6 % against PTP1B at the concentration level of $30{\mu}g/mL$.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3912-3914
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• 2013