• Title/Summary/Keyword: $^{15}N$ labeling

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Nitrogen Patitioning at Low Temperature in Fall-Sowing Species I. Uptake of exogenous N and remobilization of endogenous N (추파 청예작물의 저온 조건하에서 질소의 분배에 관한 연구 I. 외인성 질소의 흡수 및 내인성 질소의 전이)

  • Kim, Tae-Hwan;Kim, Byung-Ho
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.17 no.3
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    • pp.249-256
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    • 1997
  • A pulse-chase labeling of $^{15}N$ on winter rye (Scale cereale) and forage rape (Brassica napus) grown at $15^{\circ}C$ and $25^{\circ}C$ was carried out to determine the effects of low temperature on the uptake exogenous N and the remobilization of endogenous N. The growth rate of leaves and roots depressed at $5^{\circ}C$. AAer 9 days at $5^{\circ}C$, nitrogen content of leaves decreased to 20% on the average while that of roots increased to 12% compared with the plants grown at $25^{\circ}C$. Total content of $NO_3$- uptake 60m medium was 23.0 and 43.5 mg Nlplant, respectively, for winter rye and forage rape grown at $5^{\circ}C$ during 9 days. These values were corresponded to 59.3 and 26.1% lower uptake than those of $25^{\circ}C$. A large part of 1 5 ~ was distributed into leaves throughout time course in both of two species. The content of $^{15}N$ in leaves of winter rye at day 6 increased to 166 and 296 $\mu^{15}$N/plant compared with the initial value (day 0) in the plants grown at $5^{\circ}C$and $25^{\circ}C$ , corresponding to 90 and 163 $\mu$g N of remobilization h m roots into leaves during the fist 6 days. From 7 to 9 days, 75 and 52 $\mu$gN of outflow 6om leaves were occurred at $5^{\circ}C$ and $25^{\circ}C$. However, little remobilization of endogenous N was estimated in forage rape throughout the entire time course regardless of temperature treatment. Comparing two species studied, winter rye was much sensitively influenced by low temperature on the uptake of exogenous N and the remobilization of endogenous N.

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Remobilization of Nitrogen Reserves and Analysis of Xylem Exudate during Regrowth of Alfalfa (Medicago sativa) (알팔파의 예취 후 재생시 저장질소의 재이동과 목부 삼출액의 분석)

  • 김태환
    • Journal of Plant Biology
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    • v.36 no.4
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    • pp.363-370
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    • 1993
  • Experiments with non-nodulated alfalfa (Medicago sativa L. cv, Europe) plants grown in hydroponic cuiture, were carried out to estimate the remobiJization of nitrogen (N) reserves and to investigate the transported forms of reduced soluble-N in xylem during regrowth following shoot removal. Endogenous N remobilization were estimated by $^{15}N$ labelling and amino acids in xylem sap were analysed. The, $^{15}N$ contents of ~egr9wing leaves and stems increased as a result of remobilization of N reserves mainly from root ,system, Regrowing leaves were a stronger sink than regrowing stems, with about tWo-thirds of remobilized 15N being recoved in leaves. Endogenous N in lateral roots accounted for about 46% of the total N reserves used for regrowth, while tap roots accounted for 23%, About 72% of total endogenous N remobilized to regrowing shoot, occurred during the first 10 days of regrowth, The outflow of reduced soluble-N (mainly amino acids) was greater than that of protein-N, while the latter was the largest storage pool in tap root and lateral roots. It is suggested that amino acids-N was the most readily avaiable form of N reserves. Asparagine, which repre5ented about 75% of amino acids-N in xylem sap, was the main transported form of reduced N. Its relative contents, during the first 10 days of regrowth, decreased from 75% to 59%. This decline was accompanied by compensatory increase in the relative contents of asparatate and glutamine.

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Kit Preparation and Biodistribution of $Bz-MAG_3$ (benzoylmercaptoacetylglycylglycylglycine) for Renal Imaging (신장기능영상용 방사성의 약품 $Bz-MAG_3$(Benzoylmercaptoacetylglycylglycylglycine) 의 키트화 및 체내분포)

  • Kim, Young-Ju;Jeong, Jae-Min;Cho, Jung-Hyuk;Chang, Young-Soo;Lee, Dong-Soo;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.30 no.3
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    • pp.367-371
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    • 1996
  • The $MAG_3$ is a tubular excreting radiopharmaceutical for renal image. We synthesized benzoyl $MAG_3\;(Bz-MAG_3)$ and made a kit for labeling with $^{99m}Tc$. We checked the labeling efficieny of $^{99m}Tc$ labeled $MAG_3$ and biodistribution. Labeling efficieny was checked by TLC-SG (acetonitrile/$H_2O$=2/1). After injecting of 1 mCi of $^{99m}Tc-MAG_3$ to ICR-mice, $T_{max}(min),\;T_{1/2}(min)$ were obtained in the renogram. Sequential images (30sec, 2min, 5min, 10min, 15min, 20min) of $^{99m}Tc-MAG_3$ were compared with those of commercial $^{99m}Tc$-DTPA (Du Pont Merck Pharmaceutical Co.) kit. 1) The $R_f$ value of synthesized $^{99m}Tc-MAG_3$ was 0.78 and labeling efficiency was $97.5{\pm}1.9%$ (n=10). 2) The dynamic images of the $^{99m}Tc-MAG_3$ were better than those of the $^{99m}Tc$-DTPA. 3) The $T_{max}(min.)$ and $T_{1/2}(min.)$ of $^{99m}Tc-MAG_3$ (n=10) were $1.5{\pm}0.5$ (left), $1.4{\pm}0.4$ (right), and $4.3{\pm}1.4$ (left), $4.8{\pm}2.0$ (right), respectively. The $T_{max}(min.)$ and $T_{1/2}(min.)$ of $^{99m}Tc$-DTPA (n=7) were $2.7{\pm}1.6$ (left), $2.7{\pm}1.6$ (right), and $3.8{\pm}1.7$ (left), $4.5{\pm}2.7$ (right), respectively. The quaility of image and labeling efficiency of the synthesized $Bz-MAG_3$ kit were excellent, that it was supposed to be used in routine clinical work.

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Uptake, Assimilation and Translocation of Ammonium or Nitrate in Italian Ryegrass

  • Kim, Tae-Hwan;Lee, Bok-Rye;Jung, Woo-Jin;Kim, Dae-Hyun;Chung, Soon-Ju;Kim, Kil-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.4
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    • pp.303-308
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    • 2001
  • To investigate the partitioning of newly absorbed N derived from NO$_3$- and NH$_4$$^{+}$, 6 mM $K^{15}$ NO$_3$ or 3 mM ($^{15}$ NH$_4$)$_2$ was fed continuously in Italian ryegrass (Lolium multiflrum L.) for 7 days. Nitrogen metabolites (nitrate, amino acid, soluble- and insoluble protein) were analyzed at the end of $^{15}$ N feeding. Dry weight in shoot, stubble and root was not significantly different between NO$_3$$^{[-10]}$ and NH$_4$$^{+}$ feeding. Total nitrogen content in all three organs was significantly higher in NH$_4$$^{+}$ than NO$_3$$^{[-10]}$ feeding. Sum on N content in reduced N fractions (amino acids + proteins) in shoot, stubble and roots in NH$_4$$^{+}$ feeding increased by 13.3, 12.5 and 35.4 %, respectively, compared to NO$_3$$^{[-10]}$ feeding. The Relative Specific Activity (RSA, percentage of newly absorbed $^{15}$ N relative to total N in a sample) values of amino acids and insoluble proteins were significantly higher in NH$_4$$^{+}$ feeding. Total amount of newly absorbed $^{15}$ N in NO$_3$$^{[-10]}$ and NO$_3$$^{[-10]}$ feeding was 52.3 and 69.5 mg/plant on dry matter basis, respectively. In both NH$_4$$^{+}$ and NO$_3$$^{[-10]}$ grown plants, most of the N was allocated to the shoot, 67.5% in NH$_4$$^{+}$ feeding and 58.8% NO$_3$$^{[-10]}$ feeding, respectively. The $^{15}$ N amount incorporated in the reduced N compounds (amino acids and proteins) in NH$_4$$^{+}$ grown plants significantly increased by 74.8% compared to NO$_3$$^{[-10]}$ grown plants. The increase of the $^{15}$ N amount assimilated to amino acids in NH$_4$$^{+}$ grown plants was remarkably higher in roots as more than 7.25 times compared to NO$_3$$^{[-10]}$ feeding. These results indicated that Italian ryegrass was much efficiently utilized NH$_4$$^{+}$-N for the synthesis of reduced N compounds.reduced N compounds.

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Monitoring of Genetically Modified Bean Sprouts at Traditional Markets in Seoul and a Survey of Perception of Traditional Market Merchants and High School Students on Genetically Modified Organisms (서울 일부지역 재래시장의 유전자재조합 콩나물의 판매실태 및 상인과 일부 고등학생의 유전자재조합 식품에 대한 인식도 조사)

  • Choi, Seul-Ki;Lim, Jung-Hoon;Shin, Jee-Seong;Jeong, Jin-An;Joung, Hyo-Jee
    • Korean Journal of Community Nutrition
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    • v.15 no.5
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    • pp.679-686
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    • 2010
  • The purpose of this study is to monitor genetically modified bean sprouts at traditional markets in Seoul and to investigate perception of traditional market merchants and high school students on genetically modified organisms (GMOs). We analyzed 30 bean sprouts that were selected at 11 traditional markets in Seoul using the method of polymerase chain reaction (PCR). Also, we compared perception of GMOs between merchants (n = 30) and students (n = 126). Knowledge test about GMOs was performed by students. The result of PCR, 16.7% of bean sprouts were confirmed as GM bean sprouts (n = 5). Students had significantly more exposure to information about GMOs than merchants (p < 0.05). Major information sources about GMOs were from mass media (television, newspaper and radio). About half of subjects were not aware that they eat GMOs and GMOs are sold to consumers. Only 17.3% of subjects had constant eating intent for GMOs after perceiving foods that he/she usually eats are GMOs. 51.3% of subjects had willingness to purchase GMOs if GMOs have same quality and lower cost than natural foods. 37.2% of subjects thought that GMOs would be harmful to humans. Students had more positive perception of GMOs' side effects than merchants (p < 0.01). There was no merchant who knew labeling of GMOs. 19.1% of students knew labeling of GMOs. Students' mean percentage of correct answers of six questions about GMOs was 45.2%. Therefore, providing adequate information about GMOs is needed for consumer's choice whether to purchase GMOs or not.

Expression and Purification of a Cathelicidin-Derived Antimicrobial Peptide, CRAMP

  • Park Eu-Jin;Chae Young-Kee;Lee Jee-Young;Lee Byoung-Jae;Kim Yang-Mee
    • Journal of Microbiology and Biotechnology
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    • v.16 no.9
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    • pp.1429-1433
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    • 2006
  • Application of recombinant protein production and particularly their isotopic enrichment has stimulated development of a range of novel multidimensional heteronuclear NMR techniques. Peptides in most cases are amenable to assignment and structure determination without the need for isotopic labeling. However, there are many cases where the availability of $^{15}N$ and/or $^{13}C$ labeled peptides is useful to study the structure of peptides with more than 30 residues and the interaction between peptides and membrane. CRAMP (Cathelicidin-Related AntiMicrobial Peptide) was identified from a cDNA clone derived from mouse femoral marrow cells as a member of cathelicidin-derived antimicrobial peptides. CRAMP was successfully expressed as a GST-fused form in E. coli and purified using affinity chromatography and reverse-phase chromatography. The yield of the CRAMP was 1.5 mg/l 1. According to CD spectra, CRAMP adopted ${\alpha}$-helical conformation in membrane-mimetic environments. Isotope labeling of CRAMP is expected to make it possible to study the structure and dynamic properties of CRAMP in various membrane systems.

Oxidation-Induced Conformational Change of a Prokaryotic Molecular Chaperone, Hsp33, Monitored by Selective Isotope Labeling

  • Lee, Yoo-Sup;Ryu, Kyoung-Seok;Lee, Yuno;Kim, Song-Mi;Lee, Keun-Woo;Won, Hyung-Sik
    • Journal of the Korean Magnetic Resonance Society
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    • v.15 no.2
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    • pp.137-145
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    • 2011
  • Hsp33, a prokaryotic molecular chaperone, exerts holdase activity in response to oxidative stress. In this study, the stepwise conformational change of Hsp33 upon oxidation was monitored by NMR. In order to overcome its high molecular weight (33 kDa as a monomer and 66 kDa as a dimer), spectra were simplified using a selectively [$^{15}N$]His-labeled protein. All of the eight histidines were observed in the TROSY spectrum of the reduced Hsp33. Among them, three peaks showed dramatic resonance shifts dependent on the stepwise oxidation, indicating a remarkable conformational change. The results suggest that unfolding of the linker domain is associated with dimerization, but not entire region of the linker domain is unfolded.

Ki-67 Labeling Indices in 'Classic' versus 'Blastoid' Mantle Cell Lymphomas - Proposed Cutoff Values for Routine Diagnostic Workup

  • Pervez, Shahid;Haroon, Saroona;Awan, Dreema
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6591-6594
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    • 2015
  • Background: Mantle-cell lymphoma (MCL) is a unique entity of peripheral B-cell lymphoma that has a discrete morphologic, immunologic, and genetic phenotype, with more common 'classic' and less frequent 'blastoid' and 'pleomorphic' variants, associated with an aggressive clinical course. The aim of this study was to analyze proliferation (Ki-67) indices of 'classic' (c-MCL) and 'blastoid' (b-MCL) variants of a cohort of MCL and to suggest cut off values for the Ki-67 proliferation index in these two subsets. Materials and Methods: MCL cases diagnosed over $4{\frac{1}{2}}$ years at Section of Histopathology, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi were retrieved and reviewed. Ki-67 labelling was scored and analysed. Results: A total of 90 of cases of MCL were scrutinized. Mean age ${\pm}SD$ was $60.2{\pm}12.5$ years and the male to female ratio was 4:1, with 67 (75%) cases of c-MCL and 23 (25%) cases of b-MCL. Most samples were lymph node biopsies (n=68), whereas the remainder were from various extranodal sites The mean Ki-67 proliferation index was $29.5%{\pm}14.4%$ in classic variants and $64.4{\pm}15.2%$ for the blastoid variant, the difference being statistically significant (p = 0.029). Conclusions: It was concluded that differential cut-off values of Ki-67 labeling may be used in more objective way to reliably classify MCL into classic or blastoid variants by diagnostic pathologists. We propose a < 40 proliferative index to be suggestive of c-MCL and one of > 50 for the blastoid variant.

NMR Studies on the Structure of Human Annexin I

  • Han, Hee-Yong;Bang, Keun-Su;Na, Doe-Sun;Lee, Bong-Jin
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.182-182
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    • 1996
  • Annexin I is a member of the annexin family of calcium dependent phospholipid binding proteins and has anti-inflammatory activity by inhibiting phospholipase A$_2$ (PLA$_2$). Recent X-ray crystallographic study of annexin I identified six Ca$\^$2+/ binding bites, which was different types (type II, III) from the well-known EF-hand motif (type I). In this work, the structure of annexin I was studied at atomic level by using $^1$H, $\^$15/N and $\^$l3/C NMR(nuclear magnetic resonance) spectroscopy, and the effect of Ca$\^$2+/ binding on the structure of annexin I was studied, and compared with that of Mg$\^$2+/ binding, When Ca$\^$2+/ was added to annexin I, NMR peak change was occured in high- and low-field regions of $^1$H-NMR spectra. NMR peak change by Ca$\^$2+/ binding was different from that by Mg$\^$2+/ binding. Because annexin I is a larger protein with 35 kDa molecular weight, site-specific (amide-$\^$15/N, carbonyl-$\^$l3/C) labeling technique was also used. We were able to detect methionine, tyrosine and phenylalanine peaks respectively in $\^$13/C-NMR spectra, and each residue was able to be assigned by the method of doubly labeling annexin I with [$\^$13/C] carbonyl-amino acid and [$\^$15/N] amide-amino acid. In $\^$l3/C-NMR spectra of [$\^$13/C] carbonyl-Met labeled annexin I, we observed that methionine residues spatially located near Ca$\^$2+/ binding Sites Were Significantly effected by Ca$\^$2+/ binding. From UV spectroscopic data on the effect of Ca$\^$2+/ binding, we knew that Ca$\^$2+/ binding sites of annexin I have cooperativity in Ca$\^$2+/ binding. The interaction of annexin I with PLA$_2$ also could be detected by using heteronuclear NMR spctroscopy. Consequently, we expect that the anti-inflammatory action mechanism of annexin I may be a specific protein-protein interaction. The residues involved in the interaction with PLA$_2$ can be identified as active site by assigning NMR peaks effected by PLA$_2$ binding.

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