• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1530-1532
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• 2001

The displacement current measuring system used for detecting the dynamic behavior of monolayers at the air-water interface is described. It basically consists of a film balance, a pair of electrodes connected to each other through a sensitive ammeter. Here, one electrode is suspended in air and the other electrode is placed in the water. With Maxwell-displacement-current-measuring method, the phase transitons of Poly-$\gamma$-benzyl p-glutamate (PBDG) on a water surface were detected. Measured surface pressure, displacement current and dipole moment of monolayers of PBDG on the water surface. Also, we measured that compression velocity(30, 40, 50[mm/min]) when the sample spread volume was about 400[ul]. From the result, it is known that current is generated in the range of high surface pressures as compression velocity become faster.

• Asian Journal of Turfgrass Science
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• v.12 no.4
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• pp.189-194
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• 1998

The effect of proline, glutamine, aspartic acid and their combinations on callus induction and embriogenic callus formation from 3 creeping bentgrass (Agrostis palustris) cv. Regent, Mariner, Cato and 1 colonial bentgrass (Agrostis tenuis) cv. Tiger was estimated in both light and dark condition. The addition of amino acids to the growth medium did not have a significant stimulatory effect on the induction of embryogenic callus, instead, they were inhibitory, particularly at higher concentration (40 mM). But supplement of amino acids at lower concentrations (5 or 10mM) to basal medium was beneficial in inhibiting the formation of hairy outgrowth on the surface of embryogenic callus.

• Journal of Plant Biology
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• v.34 no.4
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• pp.253-260
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• 1991

Spirodela polyrhiza and Lemna aequinoctialis often occurred at the sites of high ammonium concentration and at the sites of high nitrate concentration, respectively. We investigated the different distribution between two species in relation to the type of nitrogen sources and their concentrations. Our experiments showed that L. aequinoctialis grew faster than S. polyrhiza in nitrate media with lower than 15 mM concentration. The nitrate uptake was also faster in L. aequinoctialis than in S. polyrhiza. However, neither differences in growth nor in uptake patterns between these two species were observed in ammonium media. Glutamine synthetase (GS), glutamate dehydrogenase (GDH) and glutamate synthetase (GOGAT) activities were higher in L. aequinoctialis. In particular, nitrate reductase activity (NRA) in L. aequinoctialis was 12.1 times as high as that in S. polyrhiza. These results showed that the two species responded varyingly to the types of nitrogen sources and their concentrations. Therefore, the difference in geographic distribution between the two species appeared to reflect the interspecific differences in enzyme activities and, subsequently, nitrogen absorption abilities.

• Journal of the Korean Magnetic Resonance Society
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• v.4 no.2
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• pp.133-139
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• 2000

The strategy to incorporate [$^{15}$ N]-labeled amino acids were discussed. Instead of using specific auxotrophic strains for selective labeling, the prototrophic strain, BL2l(DE3), was used with a plasmid, pLysS, and found to be very effective for several amino acids including alanine, lysine, leucine, and threonine. Isoleucine, valine, glutamine, and tyrosine were also found to be effective despite some diffusion into other amino acids. Interesting result was obtained when [$^{15}$ N]-labeled glycine was tried: only glycines were labeled when amino acid mixture was added in the growth medium, and serines were co-labeled when amino acids were omitted. These results can be used as a guideline when selective labeling strategy is considered, and when the resulting data are interpreted.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2542-2548
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• 2009

Direct methylation behaviors of 20 amino acids with tetramethylammonium hydroxide (TMAH) were studied under diluted conditions with silica. Amino acid concentration was controlled by dilution with silica ($SiO_2$) and the molar ratios of amino acid/silica were 0.20, 0.50, and 2.0. The molar ratios of amino acid/TMAH (0.51 - 4.64) also varied. It was found that arginine, asparagine, aspartic acid, cysteine, glutamic acid, and glutamine did not generate any directly methylated pyrolysis products, whereas alanine, glycine, isoleucine, leucine, methionine, phenylanaline, valine, and proline generated all the directly methylated pyrolysis products. Tri- and tetra methylated products of lysine consisted of two types. Histidine and threonine hardly generated the partly methylated products. Mono- and dimethylated products of serine, tryptophan, and tyrosine were not observed. Relative intensities of the methylated products varied with the amino acid concentration, TMAH concentration, and pyrolysis temperature. Direct methylation behaviors of amino acids were explained by the structural characteristics of amino acids.

• Asian Journal of Turfgrass Science
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• v.8 no.1
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• pp.13-18
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• 1994

$CO_2$와 질소동화작용에 있어서의 잎과 줄기간의 세포간 관계가 잔디군락의 자연 환경 상태하에서 자라는 Portulaca oleracea 에서 조사되었다. 기공이 줄기에서는 관찰되지 않는 반면 잎에서는 $1cm^2$당 3,275개가 나타났다. 어린 쇠비름 잎의 기공의 조헝운 범에누누 높고 낮에는 낮다. 최고 활성을 갖는 마디의 순서는 위에서 아래로 떨어짐에 따라 변화한다.P.oleracea 의 줄기조직은 CMA의 최고 활성을 나타내었으나 잎에서는 CMA의 활성이 나타나지 않았다. 빠른 산의 성화는 새벽에 원줄기에서 보여지나 줄기는 서서히 증가하는 것 밖에 관찰되지 않는다. RuPB carboxy-lase의 활성은 거의 관찰 되지 않는다. 특히 잎새에서의 PEP carboxylase의 활성은 이른 아침에 줄기에서는 낮고 잎에서는 매우 높음을 보여준다. 이런 결과는 새벽에 열려진 기공을 통과할$CO_2$가 PEP carboxylase에 의해 잎에서 동화되고 $C_4$생산물이 줄기로 이동함을 나타낸다. Nitrate 축적과 nitrate reductase, nitrite reductase, glutamine symithetase, gluamate symthase, glutamade dehydrogenase의 농도는 잎보다 줄기에서 더 높았고 밤보다 낮에 더 높다. 이것은 뿌리를 통해 흡수된 nitrate의 상당한 양이 줄기에서 동화되고 줄기 조직을 통해 잎으로 이동되어 거기에서 감소된다.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.1
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• pp.40-43
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• 1998

The glycosylation pattern of Erythropoietin (EPO), produced by recombinant CHO cells, was studied using the simple and rapid technique of 'Lectin-blotting'. In this experiment we used three different kinds of lectins, MAA(Maackia amurensis agglutinine), RCA(Ricinus communis agglutinine), and DSA(Datura stramonium agglutinine), which bind to the terminal sialic acid, galactose, and the N-acetyllactosamine chain respectively. The lectin-blotting technique was used to analyze the carbohydrate structure of EPO produced in the presence of two physiologically active chemical compounds, ammonium and chloroquine. The effect of the ammonium ion on the glycosylation of EPO was studied because it accumulated in the medium mainly as a by-product of glutamine matabolism. Ammonium chloride significantly inhibited the sialylation of the terminal galactose residue at concentrations of 8mM or more. Chloroquine, a potent inhibitor of glycosylation, inhibited terminal sialylation at concentrations of 100 and 200 $\mu$M, and at a concentration of 300 $\mu$M, also inhibited Nacetyllactosamine chain synthesis.

• Archives of Pharmacal Research
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• v.18 no.2
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• pp.75-78
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• 1995

The analysis method nad stability test of antineoplaston A10, a new anticancer drug candidate, were established. A10 and phenylacetyl- L-glutamine, one of the degradation products, can be detected by high-performance liquid chromatography. The degradation kinetics of antineoplaston A10 in aqueous solutions from pH 1 to 10 buffers were carried out at 40, 50 and 60.deg.C. Pseudo-first order kinetics were obtained throughout the entire pH ranges studied. The pH-rate profiles showed that antineoplaston A10 was very unstable in alkaline conditions and most stable at pH 4.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.247-252
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• 2010

The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000) through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were increased to sugar concentration, L-glutamine acid, vitamin C content and lycopine content than those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines.

• Microbiology and Biotechnology Letters
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• v.51 no.4
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• pp.551-554
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• 2023

We report the draft genome sequence of Sporobolomyces phaffii RJAF-17, a basidiomycetous yeast strain producing lipoamino acid surfactants, N-palmitoyl leucine and N-parmitoleyl glutamine. The annotation and classification of protein-coding genes provided the basic information for the genome of strain RJAF-17, including prediction of abundant genes as well as detection of genes involved in the biosynthesis of lipoamino acids. With the molecular importance of lipoamino acids as promising alternatives to chemical surfactants, the genomic information of strain RJAF-17 can help us understand the role of biomolecules in yeasts and explore possibilities of large-scale synthesis for industrial applications.