• Title/Summary/Keyword: Small G protein

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Screening of Inhibitory Activity of Plant Extracts against Farnesyl Protein Transferase (식물추출물의 파네실 전달효소 저해활성 검색)

  • Kang, Hyun-Mi;Lee, Seung-Ho;Ryu, Shi-Yong;Son, Kwang-Hee;Yang, Deok-Cho;Kwon, Byoung-Mog
    • Korean Journal of Pharmacognosy
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    • v.34 no.1 s.132
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    • pp.91-99
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    • 2003
  • Ras proteins play an important role in intracellular signal transduction pathways involved in cell growth and the mutated twas genes have been found in thirty percent of human cancers. Ras proteins (H-, K- and N-Ras) are small guanine nucleotide binding proteins that undergo a series of posttranslational modifications including the farnesylation onto cysteine 186 at C-terminal of Ras by farnesyl protein transferase (FPTase). This is a mandatory process for retention of transforming ability. Therefore, inhibitors of FPTase have a promising to be effective antitumor agents. In our screening program for FPTase inhibitors, the methanol extracts of 193 plants were screened for the inhibitory activity against FPTase partially purified from the rat brain. Extracts of 7species plants including Areca catechu, Saururus chinensis, Curcuma longa, Artemisa princeps, Paeonia suffruticosa, Spatholobus suberectus, Cinnamomum cassia, Cinnamomum japonicum inhibited more than 60% of FPTase activity at a concentration of $100\;{\mu}g/ml$.

Bioconversion of Straw into Improved Fodder: Preliminary Treatment of Rice Straw Using Mechanical, Chemical and/or Gamma Irradiation

  • Helal, G.A.
    • Mycobiology
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    • v.34 no.1
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    • pp.14-21
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    • 2006
  • Crude protein (CP) content of mechanically ground rice straw into small particles by an electric grinder and reducing value (RV) and soluble protein (SP) in the culture filtrate were lower than that of the chopped straw into $5{\sim}6\;cm$ lengths when both ground and chopped straws were fermented with Aspergillus ochraceus, A. terreus or Trichoderma koningii, at steady conditions. The reduction rate of RV, SP and CP was 22.2, 2.4, 7.3%; 9.1, 4.9, 8.5% or 0.0, 0.0, 3.6% for the three fungi, respectively. Chemical pretreatment of straw by soaking in $NH_{4}OH$ for a day caused significant increase in CP of the fermented straw than the other alkali and acidic pretreatments. Gamma irradiation pretreatment of dry and wet straw with water, specially at higher doses, 100, 200 or 500 kGy, caused significant increase in RV and SP as CP in the fermented straw by any of these fungi. Chemical-physical combination pretreatment of rice straw reduced the applied dose of gamma irradiation required for increasing fermentable ability of fungi from 500 kGy to 10 kGy with approximately the same results. Significant increases in RV and SP of fermented straw generally occurred as the dose of gamma irradiation for pretreated straw, which combined with $NH_{4}OH$, gradually rose. Whereas, the increase percentage in CP of fermented straw that was pretreated by $NH_{4}OH-10\;kGy$ was 12.4%, 15.4% or 8.6% for A. ochraceus, A. terreus or T. koningii, respectively.

Molecular Size and Distribution of Zinc-binding Ligands in Rat Pancreatic Tissue

  • Kwun, In-Sook;Donald Oberleas
    • Preventive Nutrition and Food Science
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    • v.2 no.3
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    • pp.219-224
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    • 1997
  • The pancreas is an important organ in the maintenance of zine homeostasis. The pancreatic tissue used in this study was obtained from rats fed varying levels of dietary Ca nd phytate followed by intraperitoneal {TEX}${65}^Zn${/TEX} injection. THe objective of this study was to determine the molecular size and distribution of compounds that may represent zinc-binding complexes in pancreatic tissue homogenates. The supernatant of the homogenized pancreatic tissue was separated using a Sephadex G-75 column with Tris buffer at pH 8.1. All subfractions were assayed for zinc, protein and {TEX}${65}^Zn${/TEX} activity. The elution of subfractions from pancreatic tissue homogenates showed a prominent peak corresponding to the high molecular weight protein standard (>66kd). A sall molecular weigth protein (<6.5kd), that was absorbed at 280nm, was also present: prominently in low Ca group, however not much as in high Ca group. These small compounds may combine weakly with zinc in pancreatic tissue an serve as zinc-binding ligands in pancreatic/biliary fluid. In the duodenum, these ligands dissociate zinc into an ionic form which becomes vulnerable to phytate complexation.

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GPR48 Promotes Multiple Cancer Cell Proliferation via Activation of Wnt Signaling

  • Zhu, Yong-Bin;Xu, Lin;Chen, Ming;Ma, Hai-Na;Lou, Fang
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.8
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    • pp.4775-4778
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    • 2013
  • The key signaling networks regulating cancer cell proliferation remain to be defined. The leucine-rich repeat containing G-protein coupled receptor 48 (GPR48) plays an important role in multiple organ development. In the present study, we investigated whether GPR48 functions in cancer cells using MCF-7, HepG2, NCI-N87 and PC-3 cells. We found that GPR48 overexpression promotes while its knockdown using small interfering RNA oligos inhibits cell proliferation. In addition, Wnt/${\beta}$-catenin signaling was activated in cells overexpressing GPR48. Therefore, our results indicated that GPR48 activates Wnt/${\beta}$-catenin signaling to regulate cancer cell proliferation.

A NOTE ON THE REMOVAL OF PHYTATE IN SOYBEAN MEAL USING Aspergillus usami

  • Ilyas, A.;Hirabayasi, M.;Matsui, T.;Yano, H.;Yano, F.;Kikishima, T.;Takebe, M.;Hayakawa, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.8 no.2
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    • pp.135-138
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    • 1995
  • Soybean meal was fermented by Aspergillus usami in order to reduce phytate content. Aflatoxin B1 was not detected in the fermented soybean meal. The contents of crude protein, crude fiber, ether extract and crude ash were slightly increased following fermentation with a concomitant reduction in nitrogen free extract. Though the fermentation partly degraded proteins in the soybean meal, there was small difference in amino acid composition between the soybean meal and the fermented soybean meal. The results showed that the fermentation did not affect nutritional value of protein in soybean meal. Approximately 55% of phosphorus extracted by trichloroacetic acid was inositol hexaphosphate (phytate) in the soybean meal. The content of inositol tetra to hexaphosphates was not detected in the fermented soybean meal. These results indicated that the fermentation almost completely eliminated phytate in soybean meal. Phytase activity was not detected in the unfermented soybean meal. However, the enzyme activity in the fermented soybean meal was 167.7 U/g. When the fermented soybean meal in supplemented in formula feeds, phytase in the fermented soybean meal might partly degrade the phytate in other ingredients in the digestive tract. The fermented soybean meal is possibly used as a phytate-free protein source of feed, which contains high available phosphorus.

Studies on the Development of Food Resources from Waste Seeds V. Chemical Composition of Water-melon Seed (폐기종실(廢棄種實)의 식량자원화(食糧資源化)에 관(關)하여 제(第)5보(報) : 수박씨의 화학적(化學的) 조성(組成))

  • Yoon, Hyung Sik;Kwon, Joong Ho;Hwang, Joo Ho;Bae, Man Jong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.3
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    • pp.207-211
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    • 1983
  • An attempt was made to find out the possibility of utilizing water-melon seed as resources of food fats and protein. The water-melon seed contained 40.40% of crude fat and 28.36% of crude protein. The lipid fraction obtained by silicic acid column chromatography was composed of about 97.35% neutral lipid, and the main components of neutral lipid by thin layer chromatography were triglyceride(50.40%), diglyceride(21.84%) and sterol(11.48%). The predominant fatty acids of total and major lipid classes were linoleic acid(55.30-67.85%), palmitic acid(12.07-28.12%) and oleic acid(9.06-16.40%), whereas stearic acid and linolenic acid were detected as small amounts. The salt soluble protein of watermelon seed was highly dispersible in 0.02M sodium phosphate buffer containing about 0.7M $MgSO_4$, and the extractability of seed protein was about 27%. Glutamic acid and arginine were major amino acids, and the essential amino acids such as lysine, threonine, valine, methionine, isoleucine, leucine and phenylalanine were also detected. The electrophoretic analysis showed 6 bands in water-melon seed protein, and the collection rate of the main protein fraction purified by sephadex G-100 and G-200 was 52.4%. The amino acids of the main fraction protein were also mainly composed of glutamic acid and arginine. The molecular weight for the main protein of the water-melon seed was estimated to be 120,000.

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An Analysis of Association for Essential Proteins in Protein-Protein Interaction Network (단백질 상호작용 네트워크에서 구조적 특징과 필수 단백질의 연관성 분석)

  • Kang, tae-ho;Ryu, jae-woon;Lee, yoon-kyoung;Yeo, myung-ho;Jung, young-su;Kwon, mi-hyeong;Yoo, jae-soo;Kim, hak-yong
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.842-845
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    • 2008
  • The protein interaction network contains a small number of highly connected protein, denoted hub and many destitutely connected proteins. Recently, several studies described that a hub protein is more likely to be essential than a non-hub protein. This phenomenon called as the centrality-lethality rule. This rule is widely credited to exhibit the importance of hub proteins in the complex network and the significance of network architecture as well. To confirm whether the rule is accurate, we investigated all protein interaction DBs of yeast in the public sites such as Uetz, Ito, MIPS, DIP, SGD, and BioGRID. Interestingly, the protein network shows that the rule is correct in lower scale DBs (e.g., Uetz, Ito, and DIP) but is not correct in higher scale DBs (e.g., SGD and BioGRID). We are now analyzing the features of networks obtained from the SGD and BioGRD and comparing those of network from the DIP.

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Evaluation of Quality Characteristics for Gochujang Produced by Small- and Medium-scale Manufacturers (전국 중소업체 생산 고추장의 품질 특성 평가)

  • Lee, Seul;Jo, Jeon Ho;Yoo, Seon Mi;Park, Bo Ram;Han, Hye Min;Kim, Ha Yun
    • Korean Journal of Food Science and Technology
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    • v.46 no.3
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    • pp.309-314
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    • 2014
  • To improve the standardized quality of gochujang produced by major companies, the quality characteristics of 29 gochujang samples produced by regional small- and medium-scale manufacturers were determined. The average moisture content, crude protein content, pH, acidity, and salinity of gochujang from regional manufacturers were found to be 34.32-45.53%, 5.07-5.68%, 4.61-4.92, 3.30-3.72%, and 9.93-16.14%, respectively. The contents of reducing sugar, amino type N, and capsaicinoids were found to be 16.81-29.81%, 191.72-660.55 mg%, and 32.49-79.58 mg/kg, respectively, and the ${\alpha}$- and ${\beta}$-amylase activity were 2.52-4.15 and 26.36-36.47 U/g, respectively. These values varied significantly across regional manufacturers. In addition, overall, gochujang had a range of 23.93-55.64% moisture content, 4.01-7.30% crude protein content, 105.47-1092.00 mg% amino type N content, and 8.74-181.50 mg/kg capsaicinoid content. These results indicate that the quality characteristics of gochujang showed a wide distribution but met the Korean Industrial Standards. Therefore, these data can be used for quality control of gochujang.

Development of animal protein(feed for fry) utilizing the rumen ciliates (제1위 섬모충(rumen ciliates)을 이용한 동물성 단백질(치어용 사료) 개발)

  • Jee, Cha-ho;Hyun, Gong-yool
    • Korean Journal of Veterinary Research
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    • v.35 no.2
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    • pp.327-336
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    • 1995
  • This study was carried out to develop the animal protein(feed for fry) that was isolated, purified and lyophilized the rumen ciliates from the healthy rumen contents which have $10^5-10^6/g$ ciliates and were discarded in abattoirs. The rumen ciliates are non-pathogenic, anaerobic and the weight of this protozoa is 2% of rumen content. The rumen protozoan and bacterial proteins both have a biological value for rats of 80-81, which is higher than the 72 of brewer's yeasts. Furthermore, the true digestibility and net protein utility of the protozoan protein are 91 and 73, much higher than those of bacterial(74 and 60) or yeast(84 and 60) proteins. The amino acids of rumen protozoa is nutritionally superior than the others. The size of rumen ciliates is $30-200{\times}20-110{\mu}m$ and so we had isolated and purified the rumen ciliates from the rumen contents by the physical methods. The purified rumen protozoa was lyophilized with freezing dryer. The results of this experiment were as follows : 1. Population dynamics of protozoan ciliates in slaughtered rumens; % of samples which small ciliates were predominated was 82.5%(52/63) and that of large ciliates was 17.5%(11/63). 1) predominant species of small ciliates were Entodinium ovinum and E nanellum. 2) predominant species of large ciliates were Epidinium ecaudatum and Diploplastron affine. 2. The lyophilized rumen ciliates which were isolated and purified from 1 kg of rumen content at the pH 6.2-6.8 was about 7.0 gram. 3. The nutrient analysis of lyophilized rqmen ciliates(LRC) was as follows: 1) Proximate analysis of the LRC and the composition of fry feed; moisture 8.05%(below 10.0), protein 35.37%(45), fat 5.39%(4.5), fiber 1.23%(below 2.5), ash 2.25%(below 15.0), Ca 0.26%(below 2.0), P 0.14%(below 1.1), energy 4,608.11(fish meal 5000 cal/g) 2) Amino acids (% in crude protein) of the LRC and the rotifer(Brachionus plicatilis); Arg 5.19%(4.50), His 2.50%(1.55), Ile 5.29%(3.45), Leu 8.11%(5.85), Lys 10.34%(6.15), Met 2.25% (0.85), Phe 5.66%(3.80), Thr 5.14% (3.45), Val 4.18%(3.90), Ala 4.13%(3.35), Asp 13.26%(8.25), Glu 16.62%(9.20), Gly 4.23%(3.10), Pro 3.25%(5.05), Ser 4.85%(3.85), Tyr 5.04%(3.05) 3) Fatty acids(% in fat) of the LRC and the rotifer(biological feed ; Brachionus plicatilis); myristic acid(C14:0) 3.27%(0.3), myristoleic acid(C14:1) 0.83%(-), palmitic acid(C16:0) 39.11% (23.5), palmitoleic acid(C16:1) 2.81%(2.0), stearic acid(C18:0) 9.36%(5.6), oleic acid(C18:1) 25.54%(3.5), linoleic acid(C18:2) 15.05%(32.9), linolenic acid(C18:3) 1.74%(9.8). Judging from the above investigated results, the analytical data of proximate analysis, amino acids, fatty acids of the purified and lyophilized rumen protozoa are reasonable for the feed of freshwater fishes(fry and fingerling). But it was disappointed of our expectation that the crude protein of lyophilized rumen ciliates contains low percentage, it was thought that because of the small ciliates(starch digester) in beef cattle rumens which were administered the concentrated feed, is much difficult to isolate and purify than the large ciliates(fiber digester).

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The Mechanism of Action of Ghrelin and Motilin in the Pacemaker Potentials of Interstitial Cells of Cajal from the Murine Small Intestine

  • Kim, Jeong Nam;Kim, Byung Joo
    • Molecules and Cells
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    • v.42 no.6
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    • pp.470-479
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    • 2019
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that exhibit periodic spontaneous depolarization in the gastrointestinal (GI) tract and generate pacemaker potentials. In this study, we investigated the effects of ghrelin and motilin on the pacemaker potentials of ICCs isolated from the mouse small intestine. Using the whole-cell patch-clamp configuration, we demonstrated that ghrelin depolarized pacemaker potentials of cultured ICCs in a dose-dependent manner. The ghrelin receptor antagonist [D-Lys] GHRP-6 completely inhibited this ghrelin-induced depolarization. Intracellular guanosine 5'-diphosphate-${\beta}$-S and pre-treatment with $Ca^{2+}$-free solution or thapsigargin also blocked the ghrelin-induced depolarization. To investigate the involvement of inositol triphosphate ($IP_3$), Rho kinase, and protein kinase C (PKC) in ghrelin-mediated pacemaker potential depolarization of ICCs, we used the $IP_3$ receptor inhibitors 2-aminoethoxydiphenyl borate and xestospongin C, the Rho kinase inhibitor Y-27632, and the PKC inhibitors staurosporine, Go6976, and rottlerin. All inhibitors except rottlerin blocked the ghrelin-induced pacemaker potential depolarization of ICCs. In addition, motilin depolarized the pacemaker potentials of ICCs in a similar dose-dependent manner as ghrelin, and this was also completely inhibited by [D-Lys] GHRP-6. These results suggest that ghrelin induced the pacemaker potential depolarization through the ghrelin receptor in a G protein-, $IP_3$-, Rho kinase-, and PKC-dependent manner via intracellular and extracellular $Ca^{2+}$ regulation. In addition, motilin was able to depolarize the pacemaker potentials of ICCs through the ghrelin receptor. Therefore, ghrelin and its receptor may modulate GI motility by acting on ICCs in the murine small intestine.