• Title/Summary/Keyword: Small G protein

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Seasonal Changes in Concentrations of Proteins and Lipids in Growing Goat Oocytes

  • Sangha, G.K.;Bhatia, H.;Khera, K.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.1
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    • pp.36-40
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    • 2007
  • Proteins and lipids not only provide a source of energy to the cell, but also play vital roles in modifying the physical properties and function of the biological membranes. In the present study, we investigated the biochemical constituents, viz. proteins and lipids, in growing oocytes of goat antral follicles during summer and winter seasons. Goat genitalia in phosphate buffered saline (pH 7.4) were brought to the laboratory within one hour of slaughter under aseptic conditions at $37^{\circ}C$. Oocytes were aspirated from normal small (<3 mm in diameter) and large (>3 mm) follicles and pooled for biochemical estimations. A significant increase in the amount of protein and lipid was observed with the growth of the oocyte. The amount of protein varied non-significantly with the season, while the amount of lipid varied significantly. The amounts of phospholipid, cholesterol, free fatty acid, and triglyceride increased with the growth of the oocyte, but no significant effect of season in these constituents was observed. Lysolecithin, sphingomyelin, and sterols were the polar lipids identified in both oocytes prepared from small follicles (small oocytes) as well as large follicles (large oocytes). In addition, the small oocytes also contained phosphatidyl serine, while large oocytes contained phosphatidyl glycerol phosphate and phosphatidyl inositol. Among non-polar lipids, triglycerides and long chain alcohols appear only in small oocytes and not in large oocytes. Monoglycerides, 1,2-diglycerides, 1,3-diglycerides and o-dialkyl glycerol ethers, fatty acids, fatty acid methyl esters, and wax esters were identified in both small and large oocytes. Information on biochemical composition of growing oocytes is relevant to oocyte and embryo competence, culture and cryopreservation.

Fed-batch Culture of Recombinant E.coli for the Production of Penicillin G Amidase (Penicillin G Amidase생산을 위한 재조합 대장균의 유가배양에 관한 연구)

  • Lee, Sang-Mahn
    • Microbiology and Biotechnology Letters
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    • v.36 no.4
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    • pp.314-319
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    • 2008
  • Penicillin G amidase (PGA, benzylpenicillinaminohydrolase, EC 3.5.1.11) is industrially important enzyme which converts penicillin G to 6-aminopenicillanic acid (6-APA) and phenylacetic acid (PAA). The PGA in E. coli ATCC 11105 is secreted into the periplasm after removing signal sequences and becomes heterodimer which composed of two subunits, small subunit (24 kDa) and large subunit (65 kDa). In this study, the PGA gene was obtained from E. coli ATCC 11105 using PCR (polymerase chain reaction) technique. The active PGA was successfully secreated into periplasm in E. coli BL2 1(DE3) harboring pET-pga plasmid. The optimized fed-batch fermentation, consisting of a three-step shift of culture temperature from $37^{\circ}C$ to $22^{\circ}C$, gave a productivity of 19.6 U/mL with a cell growth of 62 O.D. at 600 nm.

Vasoactive Intestinal Polypeptide Inhibits Pacemaker Activity via the Nitric Oxide-cGMP-Protein Kinase G Pathway in the Interstitial Cells of Cajal of the Murine Small Intestine

  • Kim, Byung Joo;Lee, Jae Hwa;Jun, Jae Yeoul;Chang, In Youb;So, Insuk;Kim, Ki Whan
    • Molecules and Cells
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    • v.21 no.3
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    • pp.337-342
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    • 2006
  • Interstitial cells of Cajal (ICCs) are pacemaker cells that activate the periodic spontaneous depolarization (pacemaker potentials) responsible for the production of slow waves in gastrointestinal smooth muscle. The effects of vasoactive intestinal polypeptide (VIP) on the pacemaker potentials in cultured ICCs from murine small intestine were investigated by whole-cell patch-clamp techniques. Addition of VIP (50 nM-$1{\mu}M$) decreased the amplitude of pacemaker potentials and depolarized resting membrane potentials. To examine the type of receptors involved in ICC, we examined the effects of the $VIP_1$ agonist and found that it had no effect on pacemaker potentials. Pretreatment with $VIP_1$ antagonist ($1{\mu}M$) for 10 min also did not block the VIP (50 nM)-induced effects. On the other hand exposure to 1H-(1,2,4)oxadiazolo(4,3-A)quinoxalin-1-one (ODQ, $100{\mu}M$), an inhibitor of guanylate cyclase, prevented VIP inhibition of pacemaker potentials. Similarly KT-5823 ($1{\mu}M$) or RP-8-CPT-cGMPS ($10{\mu}M$), inhibitors of protein kinase G (PKG) blocked the effect of VIP (50 nM) on pacemaker potentials as did N-nitro-L-arginine (L-NA, $100{\mu}M$), a non-selective nitric oxide synthase (NOS) inhibitor. These results imply that the inhibition of pacemaker activity by VIP depends on the NO-cGMP-PKG pathway.

Platform Technologies for Research on the G Protein Coupled Receptor: Applications to Drug Discovery Research

  • Lee, Sung-Hou
    • Biomolecules & Therapeutics
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    • v.19 no.1
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    • pp.1-8
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    • 2011
  • G-protein coupled receptors (GPCRs) constitute an important class of drug targets and are involved in every aspect of human physiology including sleep regulation, blood pressure, mood, food intake, perception of pain, control of cancer growth, and immune response. Radiometric assays have been the classic method used during the search for potential therapeutics acting at various GPCRs for most GPCR-based drug discovery research programs. An increasing number of diverse small molecules, together with novel GPCR targets identified from genomics efforts, necessitates the use of high-throughput assays with a good sensitivity and specificity. Currently, a wide array of high-throughput tools for research on GPCRs is available and can be used to study receptor-ligand interaction, receptor driven functional response, receptor-receptor interaction,and receptor internalization. Many of the assay technologies are based on luminescence or fluorescence and can be easily applied in cell based models to reduce gaps between in vitro and in vivo studies for drug discovery processes. Especially, cell based models for GPCR can be efficiently employed to deconvolute the integrated information concerning the ligand-receptor-function axis obtained from label-free detection technology. This review covers various platform technologies used for the research of GPCRs, concentrating on the principal, non-radiometric homogeneous assay technologies. As current technology is rapidly advancing, the combination of probe chemistry, optical instruments, and GPCR biology will provide us with many new technologies to apply in the future.

Colostrum Protein Isolate Increases Gut and Whole Body Growth and Plasma IGF-I in Neonatal Pigs

  • Van Barneveld, R.J.;Dunshea, F.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.24 no.5
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    • pp.670-677
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    • 2011
  • The growth rate of the young pig is generally much less than it's potential and may be constrained by endocrine status as well as nutrient intake. Growth factors are present in relatively high quantities in colostrum and play an important part in gut development. It is possible that supplementation of colostrum protein isolate may stimulate gut and whole body growth in the pig. Eight male and 8 female (Large Whitex${\times}$Landrace) piglets were weaned at 1 d of age after each pig had obtained colostrum from their dam, and were trained to consume one of two liquid diets. The two diets were based on either a colostrum protein isolate (n = 4 males and 4 females) or whey protein concentrate (n = 4 males and 4 females) and were formulated to contain equal levels of crude protein and amino acids. Pigs were fed their diets ad libitum for 28 days after which time 12 pigs were euthanised and various tissues and organs weighed. Pigs were bled for IGF-I analyses at 21 and 28 days of age. Daily gain was higher in pigs consuming the colostrum isolate (171 vs. 216 g/d, p = 0.010), particularly between 2 and 4 weeks of age (212 vs. 298 g/d, p = 0.010). Pigs tended to consume more of the liquid feed containing colostrum isolate (25.5 vs. 29.1 kg, p = 0.074) and gained more live weight per unit of liquid feed (0.203 vs. 0.223 g/g, p = 0.056). There were no effects of sex on growth performance. Pigs consuming the diet supplemented with colostrum isolate had higher (p<0.05) full gut weight (445 vs. 554 g, p = 0.026), empty gut weight (356 vs. 463 g, p = 0.008), stomach weight (42.2 vs. 54.4 g, p = 0.001), small intestine weight (222 vs. 275 g, p = 0.025) and large intestine weight (63.7 vs. 98.0 g, p = 0.005). Plasma IGF-I (99 vs. 150 ng/ml, p<0.001) and IGF-II (265 vs. 406 ng/ml, p<0.001) were higher in pigs fed colostrum isolate. Pigs consuming colostrum protein isolate ate more, grew faster and had higher plasma IGF-I concentrations than pigs consuming a diet with similar macronutrient content but devoid of growth factors.

Probing α/β Balances in Modified Amber Force Fields from a Molecular Dynamics Study on a ββα Model Protein (1FSD)

  • Yang, Changwon;Kim, Eunae;Pak, Youngshang
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1713-1719
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    • 2014
  • 1FSD is a 28-residue designed protein with a ${\beta}{\beta}{\alpha}$ motif. Since this protein displays most essential features of protein structures in such a small size, this model protein can be an outstanding system for evaluating the balance in the propensity of the secondary structures and the quality of all-atom protein force fields. Particularly, this protein would be difficult to fold to its correct native structure without establishing proper balances between the secondary structure elements in all-atom energy functions. In this work, a series of the recently optimized five amber protein force fields [$ff03^*$, $f99sb^*$-ildn, ff99sb-${\phi}^{\prime}$-ildn, ff99sb-nmr1-ildn, ff99sb-${\Phi}{\Psi}$(G24, CS)-ildn] were investigated for the simulations of 1FSD using a conventional molecular dynamics (MD) and a biased-exchange meta-dynamics (BEMD) methods. Among those tested force fields, we found that ff99sb-nmr1-ildn and ff99sb-${\Phi}{\Psi}$(G24, CS)-ildn are promising in that both force fields can locate the native state of 1FSD with a high accuracy (backbone rmsd ${\leq}1.7{\AA}$) in the global free energy minimum basin with a reasonable energetics conforming to a previous circular dichroism (CD) experiment. Furthermore, both force fields led to a common set of two distinct folding pathways with a heterogeneous nature of the transition state to the folding. We anticipate that these force fields are reasonably well balanced, thereby transferable to many other protein folds.

Study on Biochemical Constituents of Caprine Ovarian Follicular Fluid after Superovulation

  • Mishra, O.P.;Pandey, J.N.;Gawande, P.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.12
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    • pp.1711-1715
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    • 2003
  • The experiment was designed on 42 non pregnant Black Bengal goat. Out of which 18 were subjected to a superovulatory treatment comprising of eCG and hCG for embryo transfer study. The remaining 24 goats received no treatment and served as control for parameter studied as well as recipient for embryo transfer studies. Important biochemical constituents such as acid and alkaline phosphatase, total protein and cholesterol and inorganic phosphorus were estimated in the follicular fluid of control and treated group and the values were separately recorded for small medium and large size follicle. The results indicated a significant effect on acid phosphotase activity due to size of follicle. The value increased progressively from small to medium and from medium to large follicles. Alkaline phosphotase activity showed reverse trend. Alkaline phosphotase decreased progressively as size increased. The concentration of inorganic phosphorus did not reveal any significant difference between the control and treatment groups and also between the different size follicles. The concentration of protein decreased significantly from small to medium and from medium to large, although no difference was observed between the control and treatment groups. The concentration of Cholesterol in the follicular fluid indicated a significant increase from small to medium and to large follicle. Here also no difference was observed due to treatment. Similar in the composition of follicular fluid in the respect of above mentioned constituents indicated no of super ovulatory treatment on follicular fluid composition.

Suppression of CDK2 expression by siRNA induces cell cycle arrest and cell proliferation inhibition in human cancer cells

  • Long, Xiang-E.;Gong, Zhao-Hui;Pan, Lin;Zhong, Zhi-Wei;Le, Yan-Ping;Liu, Qiong;Guo, Jun-Ming;Zhong, Jiu-Chang
    • BMB Reports
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    • v.43 no.4
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    • pp.291-296
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    • 2010
  • Cyclin-dependent kinase 2 (CDK2) is a member of serine/threonine protein kinases, which initiates the principal transitions of the eukaryotic cell cycle and is a promising target for cancer therapy. The present study was designed to inhibit cdk2 gene expression to induce cell cycle arrest and cell proliferation suppression. Here, we constructed a series of RNA interference (RNAi) plasmids which can successfully express small interference RNA (siRNA) in the transfected human cells. The results showed that the RNAi plasmids containing the coding sequences for siRNAs down-regulated the cdk2 gene expression in human cancer cells at the mRNA and the protein levels. Furthermore, we found that the cell cycle was arrested at G0G1 phases and the cell proliferation was inhibited by different siRNAs. These results demonstrate that suppression of CDK2 activity by RNAi may be an effective strategy for gene therapy in human cancers.

A Study on the Change of Thiamine and Riboflavin Value in the Organs of Rats (장기내(臟器內) Thiamine 과 Riboflavin 함량(含量) 변동(變動)에 대(對)한 연구(硏究) - 전아(餞餓), 고당질식(高糖質食), 고조백질식(高蚤白質食) 및 Vitamin E 첨가(添加) 유식(裕食)에 의(依)한 영향(影響)에 대(對)하여 -)

  • Lee, Ky-Dong
    • Journal of Nutrition and Health
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    • v.1 no.2
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    • pp.93-105
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    • 1968
  • The variations of both thiamine and riboflavin value in the organs, viz. liver, small intestine, spleen and kidney of the rats were measured for observing some metabolic changes in the animals during fasting and feeding different quality of diets without V-E supplement. The animal used for the experiment was adult female ablino rat from a pure strain, weighing 225-280g. The animals were divided into 6 groups; the control group, the high carbohydrate diet group, the high carbohydrate diet with V-E group, the high protein diet group, the high protein diet with V-E group, and fasting group. The result obtained are summarized as follows; 1. The thiamine contents in the liver were once increased during early stage of starvation compared with the control group, thereafter they were decreased on the 8 days fasting while the contents in the small intestine and spleen were decreased during 1 to 8 days fasting. 2. The riboflavin contents in the liver and kidney were increased during starvation and the content in the small intestine was no marked change compared with control group. 3. The thiamine contents in the liver and small intestine during feeding the high carbohydrate with V-E supplement diet group were lower than that of the diet without V-E group and the content in the spleen was increased by feeding V-E enriched high carbohydrate diet. 4. The thiamine contents in the liver, small intestine and spleen during feeding the V-E supplemented diets were lower than that of the non-supplemented one's. 5. The riboflavin contents in the liver, small intestine, and kidney were increased during feeding the high carbohydrate diet compared to the control group, and they were decreased during feeding the V-E enriched high carbohydrate diet. 6. The riboflavin contents in each organ were increased during feeding the high protein diet compared to the control group, and they were much increased during 20 to 30 days of feeding the V-E supplemented high protein diet. 7. Therefore, as the above results showed, the variation of thiamine value in the each organs were not markedly changed during feeding different quality of the diets. The thiamine and riboflavin contents in the each organ in the V-E enriched high carbohydrate diet group were lower than without V-E supplemented one's The riboflavin contents in each organ were increased during feeding the high protein diet compared with the control group and the centents were increased during 20 to 30 days of the feeding V-E enriched high protein diet.

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Isolation and sequence analysis of a small cryptic plasmid from Lactobacillus farciminis KCTC3681 (Lactobacillus farciminis로부터 미지의 작은 플라스미드의 분리와 염기서열 분석)

  • Lee, Eun-Mo;Choi, Shin-Geon
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.53-57
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    • 2008
  • From the extensive screening for small cryptic plasmid among about 23 lactic acid bacteria (LAB), 2.4 kb of cryptic plasmid was isolated from Lactobacillus farciminis strain KCTC 3681 and named as pLF24. The plasmid pLF24 was a circular molecule of 2,396 base-pairs in length with a G+C content of 38%. Two protein-coding sequences could be predicted. ORF1 and ORF2 showed homologies to plasmids of gram-positive bacteria. The replication protein coded by ORF2 and the plus origin, were similar to replication regions of other gram-positive bacteria as shown in plasmids such as pLH2, pLS141-1 and pLC2. The nucleotide sequence of pLF24 was deposited into Genbank data base with an accession number of EU429343. The newly isolated plasmid can be used for construction of shuttle vector in Lactobacillus bacteria.

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