• Journal of Nutrition and Health
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• v.22 no.6
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• pp.497-506
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• 1989

To investigate the effect of levels of dietary protein and age on bone metabolism 40% and 5% casein were fed to the rats of 2 & 13 months of age for 12 weeks. High protein groups showed higher bone weight and Ca content than low protein groups and urinary Ca loss was increased in high protein groups but the difference disappeared gradually. A significant increase in urinary hydroxyproline excretion was noted in high protein groups of both age. Another short term study was undertaken to study if the above effect was related with renal function or PTH. Extremely high and low protein diets(60%, 6%) were fed to the rats of different ages(6wks, 6mos.) for 2 weeks, Urinary Ca excretion was significantly increased in high protein groups of young and aged rats and GFR was increased as well. There was no difference in serum iPTH levels between low and high protein groups, but it was elevated in aged rats. Alkaline phosphatase activity was higher in young rats, reflecting faster bone formation. The observed hypercalciuria in high protein groups, especially in aged rats, seems to be related to higher GFR, and PTH dose not appear to be a major mediator.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.370-377
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• 2001

Flounder brain cytosol contains protein inhibitors that markedly inhibit the activity of partially purified brain membrane phospholipase D (PLD) which is dependent on phosphatidylinositol 4,5-bisphosphate ($PIP_2$) but insensitive to ADP-ribosylation factor (ARF), The PLD inhibitors have been enriched through several chromatographic steps and characterized with respect to size and mechanism of inhibition. Sequential chromatography of the brain cytosol yielded six inhibitor fractions, Two (IIA and IIB) of six inhibitor fractions showed the $PIP_2$-phosphatase activities. IIA was identified as synaptojanin, a nerve terminal protein that has known to be a member of the inositolpolyphosphate 5-phosphatase family, by immunoblot analysis. IIB showed an apparent molecular mass of 158 kDa by Superose 12 gel filtration chromatography and was immunologically distinct from synaptojanin. IIB hydrolyzed $PIP_2$, yielding only phosphatidylinositol phosphate (PIP) as product, suggesting that IIB hydrolyzes only one phosphate from either the 4- or 5-position of PI (4,5)$P_2$. These studies demonstrate that the existence of multiple $PIP_2$-phosphatases have been implicated in the negative regulation of $PIP_2$-dependent PLD activity within flounder brain.

• Journal of Life Science
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• v.9 no.2
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• pp.160-168
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• 1999

Butyrate is one of the short-chain fatty acids that are present in the colon of mammals in millimolar concentration as a result of microbial anaerobic fermentation of dietary fiber, undigested starch, and proteins. In this study, sodium butyrate was examined in HT29 cell, human colonic cancer cell line, on cell viability, alkaline phosphatase activity, PLC-${\gamma}$1 expression and complex sphingolipid biosynthesis. Treatment with butyrate showed that the decrease of cell adhesion and viability was time-dependent. Sodium butyrate also induced to increase the activity of alkaline phosphatase which is a differentiation marker enzyme and decrease the expression of PLC-${\gamma}$1. Biosynthesis of sphingomyelin and galactosylceramide by butyrate treatment were decreased so fast but ceramide was increased 680dpm/mg protein% more than untreated group on first day and then decreased fast. In addition, acid ceramidase and neutral ceramidase activity were inhibited early stage by sodium butyrate. These results suggest that sodium butyrate causes cell differentiation or cell growth arrest of HT29 cell accompanied by early increase of ceramide content and alkaline phosphatase activity and decrease of galactosylceramide content and PLC-r1 expression.

• Biomolecules & Therapeutics
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• v.12 no.4
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• pp.228-234
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• 2004

Brazilin shows hypoglycemic effect in diabetic animals through enhancement of glucose metabolisms in insulin responsive tissues. One of the major mechanisms of brazilin to enhance glucose metabolism is stimulation of glucose transport in adipocytes. In this study, the essential molecular moiety of brazilin for the stimulation of glucose transport was investigated. We found that brazilin undergoes a structural change in physiological buffer and produces hydrogen peroxide. Methylation of hydroxyl group of brazilin or addition of catalase along with brazilin resulted in the complete inhibition of brazilin-induced glucose transport in adipocytes. Because hydrogen peroxide increases glucose transport by inhibition of phosphatases, we examined the effect of brazilin on phosphatase activity. Brazilin inhibited phosphatases in a wide range of activity, and protein phosphatase 1 and 2A were also inhibited. These results suggest that the production of hydrogen peroxide by oxidation of catechol hydroxyl group of brazilin mediates glucose transport through inhibition of phosphatases which otherwise decrease glucose transport in adipocytes.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.28-33
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• 2014

Background: Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present. Methods: Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme. Results and Conclusion: Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammaranetype triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 ($IC_{50}$) values of $29.08{\mu}M$, $21.27{\mu}M$, $28.12{\mu}M$, and $26.59{\mu}M$, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.

• The Korean Journal of Food & Health Convergence
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• v.5 no.3
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• pp.21-33
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• 2019

The incidence of both obesity and Type 2 Diabetes Mellitus( DM) is increasing proportionately so that causes of deaths from these has overtaken from that of malnourishment. Hence it has been recommended to treat the 2 in parallel considering the role of diabesity on health. Important causes of T2DM are insulin resistance (IR) and /or inadequate insulin secretion. Protein tyrosine phosphatase 1B(PTPIB) has a negative impact in insulin signaling pathways and hence plays crucial role inT2DM,since its overexpression might induce IR. Thus PTPIB is considered a therapeutic target for both obesity and T2DM, there has been a search for novel ,promising natural inhibitors. We conducted a pubmed search for articles related to PTPIB inhibitors from natural causes be it marine sources or other natural sources. Out of 988 articles we selected 100 articles for review. Thus various bioactive molecules isolated from marine organisms that can acts as PTPIB Inhibitors and thus possess antidiabetic activity both in vitro/ in vivo studies ,besides products from fruits like Chinese raspberry or curcumin used as routine spices are described with their chemical classes, structure-activity relationships and potency as assessed by IC 50 values are discussed. More work is required to make this a reality.

• 대한약리학회:학술대회논문집
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• 2006.10a
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• pp.92.2-92.2
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• 2006

• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.90-96
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• 1994

Changes in haemolymph proteins, hydrolases such as esterase(EST), acid phosphatase(ACP) and alkaline phosphatase(ALP) , and inorganic ion(Na+, K+ and Cl- ) contents were induced by the injection of Bacillus thuringiengis into haemocoel of the last instar larva of Heliothis assulta. Protein concentration of haemolymph was increased until 24 hrs after injection, and decreased thereafter. Among the 8 basic protein bands identified through acid - polyacrylamide gel electrophoresis(PAGE), 2 bands(bands a and b) became stronger by the bacterial infection. Activities of EST and ALP increased until 12 hrs after injection and then fell down, whereas ACP activity was decreased continuously with time after injection. Contents of inorganic ions were all increased by the bacterial injection, showing slow rate of increase in the chloride ion, but rapid in the sodium and potassium ions.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.237-242
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• 1992

In order to clone the gene coding for alkaline phosphatase in the yeast Kluyveromyces fragilis, a genomic library was constructed using the yeast-E. coli shuttle vector pHN114 as a cloning vector. From the genomic library, a clone carrying the gene was isolated and the plasmid was designated as pSKH101. A restriction enzyme map was made using this plasmid. Subcloning experiments and complementation studies showed that alkaline phosphatase was active only in the original 3.1 kb insert. Southern hybridization analysis confirmed that the cloned DNA fragment was derived from K. fragilis genomic DNA. Using a minicell experiment, the product of the cloned gene was identified as a protein with a molecular weight of 63 KDa. A 0.6 kb HindIII fragment, which showed promoter activity, was isolated using the E. coli promoter-probe vector pKO-1.

• Journal of Life Science
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• v.21 no.7
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• pp.1032-1038
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• 2011

Recently identified Ciona intestinalis voltage sensor-containing phosphatase (Ci-VSP) consists of an ion channel-like transmembrane domain (VSD) and a phosphatase-like domain. Ci-VSP senses the change of membrane potential by its VSD and works as a phosphoinositide phosphatase by its phosphatase domain. In this study, we present the construction of His-tagged phosphatase-like domain of Ci-VSP, its recombinant expression and purification, and its enzymatic activity behavior in order to examine the biochemical behavior of phosphatase domain of Ci-VSP without interference. We found that Ci-VSP(248-576)-His can be eluted with an elution buffer containing 25 mM NaCl and 100 mM imidazole during His-tag purification. In addition, we found the proper measurement condition for kinetics study of Ci-VSP(248-576)-His against p-nitrophenyl phosphate (pNPP). We measured the kinetic constant of Ci-VSP(248-576)-His at $37^{\circ}C$, pH 5.0 or 5.5, under 30 min of reaction time, and less than $2.0\;{\mu}g$ of protein amount. With these conditions, we acquired that Ci-VSP(248-576)-His has $K_m$ of $354{\pm}0.143\;{\mu}M$, $V_{max}$ of $0.0607{\pm}0.0137\;{\mu}mol$/min/mg and $k_{cat}$ of $0.359{\pm}0.009751\;min^{-1}$ for pNPP dephosphorylation. Therefore, we produced a pure form of Ci-VSP(248-576)-His, and this showed a higher activity against pNPP. This purified protein will provide the road to a structural investigation on an interesting protein, Ci-VSP.