• Journal of Biomedical Engineering Research
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• v.8 no.2
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• pp.199-204
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• 1987

ABA type block copolymers composed of r benzyle L-glutamate as the A component and poly(ethylene glycol) as the B components were obtained. Platelet adhesion on their sunfaces was investigated by a column elusion method to examine the effects of microdomain and secondary structure. The number of platelets adhered from whole blood and plasma rich platelet was smaller for the block copolymer systems than for the homopolymers. In the block copolymer system, the number of platelets adrered on their surfaces increased with increasing the content of PEG, that is, with decreasing of a-helix of block copolymers. A thick thrombus formation on the PBLG homopolymer was observed than block copolymer by scanning electron micrographs. The platelets adhesion increased with increasing the critical surface tension of the block copolymer.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.71-81
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• 1988

Glutamate and aspartate may evoke an increase in membrane permeability to monovalent cations and $Ca^{++}$. However, it is uncertain whether $Ca^{++}$ influx is mediated by voltage dependent $Ca^{++}$ channels or by excitatory amino acid activated channels. In addition, the influences of excitatory amino acids on $Ca^{++}$ uptake by neuronal tissues as well as the responses of their actions to extracellular $Mg^{++}$ concentration are different. $K^{+}$ induced $Ca^{++}$ uptake by synaptosomes was dependent on extracellular $Mg^{++}$ up to 5 mM and at concentration of 10 mM, $Ca^{++}$ influx was rather reduced. In $Na^{+}$ rich media, glutamate-and aspartate-induced $Ca^{++}$ uptake was increased by $Mg^{++}$ in a dose independent manner. However, the response for NMDA was inhibited by $Mg^{++}$ at concentrations above 2 mM. $K^+$-and glutamate-induced $Ca^{++}$ influx s were inhibited by 2,4-dinitrophenol, chlorprom-azine and verapamil but not by tetraethylammonium chloride. Tetrodotoxin effectively inhibited the action of glutamate but did not affect that of $K^+$. The response for MNDA was inhibited by 2, 4-dinitrophenol and tetrodotoxin, slightly inhibited by verapamil, and not affected by tetraethylammonium chloride. In $Na^{++}$ rich medium, depolarizing action of glutamate, aspartate and MNDA on synaptosomes was not demonstrated, whereas these agents stimulated $Ca^{++}$ uptake and caused $Ca^{++}$ influx induced depolarization at mitochondria. On the other hand, the activities of synaptosomal ATPases were not affected by excitatory amino acids at 5 mM. The results suggest that glutamate or NMDA induced $Ca^{++}$ influx at synaptosomes exhibits different responses for extracellular $Mg^{++}$ Ex citatory amino acids induced $Ca^{++}$ influx at synaptosomes may be associated with increased permeability of membrane for $Na^{++}$ and $Ca^{++}$ except $K^{++}$ and membrane depolarization due to increased ionic permeability.

• Journal of Life Science
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• v.33 no.1
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• pp.1-7
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• 2023

Intracellular cargo transport is mediated by molecular motor proteins, such as kinesin and cytoplasmic dynein. Kinesins make up a large subfamily of molecular motors. Kinesin-1 is a plus-end-directed molecular motor protein that moves various cargoes, such as organelles, protein complexes, and mRNAs, along a microtubule track. It consists of the kinesin superfamily protein (KIF) 5A, 5B, and 5C (also called kinesin heavy chains) and kinesin light chains (KLCs). Kinesin-1 interacts with many different binding proteins through its carboxyl (C)-terminal region of KIF5s and KLCs, but their binding proteins have not yet been fully identified. In this study, a yeast two-hybrid assay was used to identify the proteins that interact with the KIF5A specific C-terminal region. The assay revealed an interaction between KIF5A and glutamate-rich 4 (ERICH4). ERICH4 bound to the KIF5A specific the C-terminal region but did not interact with the C-terminal region of KIF5B or KIF3A (a motor protein of kinesin-2). In addition, KIF5A did not interact with another isoform, ERICH1. Glutathione S-transferase (GST) pull-downs showed that KIF5A interacts with GST-ERICH4 and GST-ERICH4-amino (N)-terminal but not with GST-ERICH4-C or GST alone. When co-expressed in HEK-293T cells, ERICH4 co-localized with KIF5A and co-immunoprecipitated with KIF5A and KLC but not KIF3B. Together, our findings suggest that ERICH4 is capable of binding to KIF5A and that it may serve as an adaptor protein that links kinesin-1 with cargo.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.326-336
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• 2016

Saccharomyces cerevisiae is one of the most employed cell factories for the production of bioproducts. Although monomeric hexose sugars constitute the preferential carbon source, this yeast can grow on a wide variety of nitrogen sources that are catabolized through central nitrogen metabolism (CNM). To evaluate the effects of internal perturbations on nitrogen utilization, we characterized strains deleted or overexpressed in GLT1, encoding for one of the key enzymes of the CNM node, the glutamate synthase. These strains, together with the parental strain as control, have been cultivated in minimal medium formulated with ammonium sulfate, glutamate, or glutamine as nitrogen source. Growth kinetics, together with the determination of protein content, viability, and reactive oxygen species (ROS) accumulation at the single cell level, revealed that GLT1 modulations do not significantly influence the cellular physiology, whereas the nitrogen source does. As important exceptions, GLT1 deletion negatively affected the scavenging activity of glutamate against ROS accumulation, when cells were treated with H₂O₂, whereas Glt1p overproduction led to lower viability in glutamine medium. Overall, this confirms the robustness of the CNM node against internal perturbations, but, at the same time, highlights its plasticity in respect to the environment. Considering that side-stream protein-rich waste materials are emerging as substrates to be used in an integrated biorefinery, these results underline the importance of preliminarily evaluating the best nitrogen source not only for media formulation, but also for the overall economics of the process.

• Advances in Traditional Medicine
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• v.9 no.3
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• pp.225-231
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• 2009

The present study deals with the amelioration by Lagerstroemia speciosa Linn. leaf extract against hepatotoxicity induced by carbon tetrachloride ($CCl_4$), which was evaluated in terms of serum marker enzymes like serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase, alkaline phosphatase, serum total bilirubin, total protein levels along with concomitant hepatic and antioxidants like superoxide dismutase, catalase, glutathione, glutathione peroxidase and lipid peroxidation enzymes were monitored. These biochemical parameters altered by the single dose level of $CCl_4$ (0.75 ml/kg body weight, i.p). Pre treatment with L. speciosa prior to the administration of $CCl_4$, at the doses of 50 and 250 mg/kg. body weight/day, p.o. for 7 days, significantly restored all the serum and liver tissue parameters near to the normal levels, respectively. Silymarin was used as a reference standard, prior to the administration of $CCl_4$ to rats. These findings indicate the protective potential of L. speciosa against hepato toxicity which possibly involve mechanism related to its ability of selective inhibitors of (reactive oxygen species like antioxidants brought about significant inhibition of TBARS suggesting possible involvement of $O_2{\cdot}-$, $HO_2{\cdot}$, and ${\cdot}OH$. In conclusion, the amelioration may be attributed to the synergistic effects of its constituents rather than to any single factor as the leaves are rich in tannins, sterols, flavonoids, saponins etc.

• Food Science of Animal Resources
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• v.33 no.3
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• pp.377-389
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• 2013

Gamma-amino butyric acid (GABA) is a kind of pharmacological and biological component and its application is wide and useful in Korea specially, becoming aging society in the near feature. GABA is request special dose for the purposed biological effect but the production of concentrated GABA is very difficult due to low concentration of glutamic acid existed in the fermentation broth. To increase GABA concentrate using fermentation technology, high content of glutamic acid is required. For this reason, various strains which have the glutamic acid decarboxylase (GAD) and can convert glutamic acid to GABA, were isolated from various fermented foods. Most of GABA producing strains are lactic acid bacteria isolated from kimchi, especially added monosodium glutamate (MSG) as a taste enhancer. Optimizing the formulation of culture media and the culture condition, GABA conversion yield and amounts were increased. Finally GABA concentration of fermentation broth in batch or fed batch fermentation reached 660 mM or 1000 mM, respectively. Furthermore formulation of culture media for GABA production developed commercially. Many studies about GABA-rich product have been continued, so GABA-rich kimchi, cheese, yogurt, black raspberry juice and tomato juices has been also developed. In Korea many biological effects of GABA are evaluated recently and GABA will be expected to be used in multipurpose.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.79-86
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• 2011

The contents of free amino acid in cabbage cultivars originated from China and Korea were measured to determine the quality for taste and nutrition. The experimental variables were season (spring-sowing and fall-sowing), leaf position (inside and outside), and the cabbage color (green and red). Eighteen free amino acids were detected at the range of 0-38 mg/g dry weight. The most abundant amino acid was serine(0-128 mg/g). Alanine, aspartate, glutamate, asparagine, histidine, and proline were relatively rich at 2-12 mg/g dry weight. Glycine were significantly increased in spring-sowing cabbages by 2-fold but proline was reversely decreased by 7-fold. The inside parts of cabbages contained significantly more alanine, glutamate, glycine, isoleucine, serine, and valine than the outside ones. The higher contents of isolecuine, leucine, proline, and valine were observed in the red cabbages than the green ones. The significant cross effects of season-color and position-color were also observed, indicating the red and the green cabbages were differently affected by season and tissue position.

• Journal of Microbiology and Biotechnology
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• v.30 no.1
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• pp.109-117
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• 2020

Cre recombinase is widely used to manipulate DNA sequences for both in vitro and in vivo research. Attachment of a trans-activator of transcription (TAT) sequence to Cre allows TAT-Cre to penetrate the cell membrane, and the addition of a nuclear localization signal (NLS) helps the enzyme to translocate into the nucleus. Since the yield of recombinant TAT-Cre is limited by formation of inclusion bodies, we hypothesized that the positively charged arginine-rich TAT sequence causes the inclusion body formation, whereas its neutralization by the addition of a negatively charged sequence improves solubility of the protein. To prove this, we neutralized the positively charged TAT sequence by proximally attaching a negatively charged poly-glutamate (E12) sequence. We found that the E12 tag improved the solubility and yield of E12-TAT-NLS-Cre (E12-TAT-Cre) compared with those of TAT-NLS-Cre (TAT-Cre) when expressed in E. coli. Furthermore, the growth of cells expressing E12-TAT-Cre was increased compared with that of the cells expressing TAT-Cre. Efficacy of the purified TAT-Cre was confirmed by a recombination test on a floxed plasmid in a cell-free system and 293 FT cells. Taken together, our results suggest that attachment of the E12 sequence to TAT-Cre improves its solubility during expression in E. coli (possibly by neutralizing the ionic-charge effects of the TAT sequence) and consequently increases the yield. This method can be applied to the production of transducible proteins for research and therapeutic purposes.

• Nutrition Research and Practice
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• v.3 no.2
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• pp.95-101
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• 2009

It has been reported that dietary polyunsaturated fats (PUFA) increase liver injury in response to ethanol feeding. We tested the hypothesis that diets rich in linoleic acid (18:2n-6) would affect acute liver injury after acetaminophen injection and that protein restriction might exacerbate the liver injury. We examined effects of feeding diets with either 15% (wt/wt) corn oil or 14% beef tallow and 1% corn oil for six weeks with either 6 or 20 g/100 g protein on acute hepatotoxicity. After the feeding period, liver injury was induced by injecting either with 600 mg/kg body weight acetaminophen suspended in gum arabic-based vehicle, or with vehicle alone during fasting status. Samples of liver and plasma were taken for analyses of hepatic glutathione (GSH) levels and liver-specific enzymes [(Glutamate-pyruvate transaminase (GPT) and glutamate-oxaloacetate transaminase (GOT)], respectively. Whereas GSH level was significantly lower in only group fed 15% corn oil with 6 g/100 g protein among acetaminophen-treated groups, activities of GPT and GOT were significantly elevated in all groups except the one fed beef tallow with 20 g/100 g protein, suggesting low protein might exacerbate drug-induced hepatotoxicity. The feeding regimens changed the ratio of 18:2n-6 to oleic acid (18:1n-9) in total liver lipids approximately five-fold, and produced modest changes in arachidonic acid (20:4n-6). We conclude that diets with high 18:2n-6 promote acetaminophen-induced liver injury compared to diets with more saturated fatty acids (SFA). In addition, protein restriction appeared to exacerbate the liver injury.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.187-188
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• 2016

열대열 말라리아(Plasmodium falciparum, P. falciparum, P. f) 신속진단키트의 경우, P. falciparum에 특이적인 단백질로써 Histidine Rich Protein 2 (PfHRP2)가 사용되고 있다. 그러나 최근 연구에서 남아메리카와 중앙아메리카를 중심으로 pfhrp2/pfhrp3 유전자가 결여된 P. falciparum 열원충이 나타나는 것으로 보고된 바 있다. 본 연구에서는 생물정보학을 기반으로 PfHRP2 항원 단백질을 대체할 수 있는 새로운 P. falciparum 특이 항원 단백질을 선정하고자, PlasmoDB에서 5,777개의 P. falciparum 관련 단백질 리스트를 얻었다. 이후 NCBI BLAST를 통해 단백질 아미노산 서열을 분석하고 정상인에게 존재하지 않으며, 동시에 다른 말라리아 열원충(P. vivax, P. ovale, P. malariae, P. knowlesi)에도 존재하지 않는 P. falciparum 특이 아미노산 서열을 가진 단백질 15개를 추출하였다. IEDB analysis를 이용하여 에피토프, 수용성, 베타-턴, 접근성, 유연성, 면역원성을 분석하여 높은 평균값을 갖는 상위 3개 단백질을 선별하였다. KEGG pathway와 EMBL-EBI를 통해 선별된 3개 단백질의 혈액내 검출 가능성 및 아미노산 서열의 보존성을 분석하여 최종적으로 Glutamate-Rich Protein (GLURP)을 선정하였다. AIDA를 통해 단백질 아미노산 서열을 이용한 3차 구조 예측으로 GLURP의 구조 및 항체와의 결합을 도식화하였다. 최종적으로 선정한 GLURP는 pfhrp2/pfhrp3 유전자 결여 P. falciparum까지 특이적으로 진단이 가능하여 차세대 P. falciparum 특이 신속진단키트 개발에 도움이 될 수 있을 것으로 기대한다.