• Title/Summary/Keyword: HHL

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Protein structure analysis : Pharmacophore study for new insecticide target AnCE using the substrate of ACE, HHL molecule (단백질의 구조연구 : ACE의 기질 HHL을 이용한 신규 살충제 표적 AnCE에 대한 약리단 연구)

  • Lee, Jung-Kyung;Kim, Kyeong-Yee
    • The Korean Journal of Pesticide Science
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    • v.9 no.3
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    • pp.191-198
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    • 2005
  • Hippuryl-L-histidyl-L-leucine (Hip-L-His-L-Leu, HHL) is the known substrate of ACE, which used often in inhibition kinetic study to design new inhibitor. Here we use HHL molecule as a template to predict pharmacophore which can interact with residues in active site of AnCE, new potential insecticide target protein. To explain physicochemical properties related to molecular geometry and conformational change in reaction field as well as electron density of atoms associated to pharmacophores, geometry optimization, NMR chemical shifts and natural population analysis were performed by ab initio and DFT method. Calculated NMR chemical shifts showed good agreement with the experimental ones and obtained electron densities were used for analyzing pharmacophores of corresponding atoms. Finally, we could extract aye pharmacophores related to hydrophobic aliphatic and aromatic site, hydrogen bonding donor and acceptor site and Zn binding site from the HHL molecule.

Expression of Antihypertensive Peptide, His-His-Leu, as Tandem Repeats in Escherichia coli

  • Jeong, Do-Won;Shin, Dong-Seok;Ahn, Chang-Won;Song, In-Sang;Lee, Hyong-Joo
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.952-959
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    • 2007
  • His-His-Leu (HHL), a tripeptide derived from a Korean soybean paste, is an angiotensin-I-converting enzyme (ACE) inhibitor. We report here a method of producing this tripeptide efficiently by expressing tandem multimers of the codons encoding the peptide in E. coli and purifying the HHL after hydrolysis of the peptide multimers. The HHL gene, tandemly multimerized to a 40-mer, was ligated with ubiquitin as a fusion gene (UH40). UH40 was inserted into vector pET29b; the UH40 fusion protein was then produced in E. coli BL21. The recombinant UH40 protein was purified by cation-exchange chromatography with a yield of 17.3mg/l and analyzed by matrixassisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry and protein N-terminal sequencing. Leucine aminopeptidase was used to cleave a 405-Da HHL monomer from the UH40 fusion protein and the peptide was purified using reverse-phase high-performance liquid chromatography (HPLC) on a C18 HPLC column, with a final yield of 6.2mg/l. The resulting peptide was confirmed to be HHL with the aid of MALDI-TOF mass spectrometry, glutamine-TOF mass spectrometry, N-terminal sequencing, and measurement of ACE inhibiting activity. These results suggest that our production method is useful for obtaining a large quantity of recombinant HHL for functional antihypertensive peptide studies.

Structural Studies of Copper(II)-Hippuryl-L-histidyl-L-leucine(HHL) Complex by NMR Methods

  • Lee Seong-Ran;Jun Ji-Hyun;Won Ho-Shik
    • Journal of the Korean Magnetic Resonance Society
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    • v.10 no.1
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    • pp.115-125
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    • 2006
  • Hippuryl-L-histidyl-L-leucine(HHL) is widely used as a substrate of angiotensin converting enzyme(ACE) cleaving the neurotransmitter angiotensin(I) to the octapeptide angiotensin(II). The structure of the substrate molecules should provide information regarding the geometric requirements of the ACE active site. For the purpose of determination of in vivo reaction, metallo(Cu, Zn)-HHL complexes were synthesized and the degree of complex formation were identified by MALDITOF, ESI mass spectrometric analysis. Tn addition, the pH-dependent species distribution curves were obtained by potentiometric titration. Nitrogen atoms of imidazole ring and oxygen atom of caboxylate groups in the peptide chain were observed to be participated in the metal complex formation. After purification of complexes further structural characterization were made by utilizing UV-Vis, electrochemical methods and NMR. Complete NMR signal assignments were carried out by using 2D-spectrum techniques COSY, TOCSY, NOESY, HETCOR. A complex that two imidazole and carboxylate groups are asymmetrically participating to coordination mode was predicted to the solution-state structure of $Cu(II)-HHL_2$ based on $^{13}C-NMR$ signal assignment and NOE information.

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The effect of word length on f0 intervals: Evidence from North Kyungsang children

  • Kim, Jungsun
    • Phonetics and Speech Sciences
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    • v.7 no.1
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    • pp.107-116
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    • 2015
  • The present experiment investigated the effect of word length on the length of f0 intervals for North Kyungsang children. In order to find out the lengths of the f0 intervals, the f0 values at the midpoints of vowels in words were measured. F0 estimates were computed as intervals consistent with the logarithmic scale corresponding to the number of syllables in the words. The results indicated that the mean f0 intervals in words of different lengths showed a significant difference for the HH in HH vs. HHL and the LH in LH vs. LLH for North Kyungsang children. Adult speakers from the North Kyungsang region significantly differed only within the HH in HH vs. HHL. Adult speakers made a noticeable contribution in this characteristic from the children. The result of the adult study was presented to confirm whether the children used a North Kyungsang dialect. With respect to individual speaker differences, the North Kyungsang children showed more or less consistent patterns in quantile-quantile plots for the HH vs. HHL, but for the HL vs. LHL and LH vs. LLH, there were more variations than for the HH vs. HHL. The individual speakers' variation was the largest for the HL vs. LHL and the smallest for HH vs. HHL. Considering these results, the effect of word length on f0 intervals tended to show pitch accent-type-specific characteristics in the process of prosodic acquisition.

Growth and photoluminescence of the strained ZnTe/ZnMnTe single quantum well (스트레인을 받는 ZnTe/ZnMnTe 단일양자우물의 성장과 광발광 특성)

    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.6
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    • pp.269-269
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    • 2002
  • ZnTe/ZnMnTe single quantum well of high quality was grown by hot-wall epitaxy, in which ZnMnTe layer was used as a barrier. It was found that ZnTe well layer was under severe strain. Very sharp luminescent peaks of the heavy-hole exciton (el-hhl) and the light-hole exciton (el-lhl) were observed from the photoluminescence (PL) measurement. As the well layer thickness increases, the peaks associated with excitons of (el-hhl) and (el-lhl) were shifted toward the lower energy side. The temperature dependence of the PL peak intensity was well explained by the thermal activation theory.

Growth and photoluminescence of the strained ZnTe/ZnMnTe single quantum well (스트레인을 받는 ZnTe/ZnMnTe 단일양자우물의 성장과 광발광 특성)

  • 최용대
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.12 no.6
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    • pp.267-271
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    • 2002
  • ZnTe/ZnMnTe single quantum well of high quality was grown by hot-wall epitaxy, in which ZnMnTe layer was used as a barrier. It was found that ZnTe well layer was under severe strain. Very sharp luminescent peaks of the heavy-hole exciton (el-hhl) and the light-hole exciton (el-lhl) were observed from the photoluminescence (PL) measurement. As the well layer thickness increases, the peaks associated with excitons of (el-hhl) and (el-lhl) were shifted toward the lower energy side. The temperature dependence of the PL peak intensity was well explained by the thermal activation theory.

Intonational Pattern Frequency of Seoul Korean and Its Implication to Word Segmentation

  • Kim, Sa-Hyang
    • Speech Sciences
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    • v.15 no.2
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    • pp.21-30
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    • 2008
  • The current study investigated distributional properties of the Korean Accentual Phrase and their implication to word segmentation. The properties examined were the frequency of various AP tonal patterns, the types of tonal patterns that are imposed upon content words, and the average number and temporal location of content words within the AP. A total of 414 sentences from the Read speech corpus and the Radio corpus were used for the data analysis. The results showed that the 84% of the APs contained one content word, and that almost 90% of the content words are located in AP-initial position. When the AP-initial onset was not an aspirated or tense consonant, the most common AP patterns were LH, LHH, and LHLH (78%), and 88% of the multisyllabic content words start with a rising tone in AP-initial position. When the AP-initial onset was an aspirated or tense consonant, the most common AP patterns were HH, HHLH, and HHL (72%), and 74% of the multisyllabic content words start with a level H tone in AP-initial position. The data further showed that 84.1% of APs end with the final H tone. The findings provide valuable information about the prosodic pattern and structure of Korean APs, and account for the results of a previous study which showed that Korean listeners are sensitive to AP-initial rising and AP-final high tones (Kim, 2007). This is in line with other cross-linguistic research which has revealed the correlation between prosodic probability and speech processing strategy.

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Characterization of a Phenazine and Hexanoyl Homoserine Lactone Producing Pseudomonas aurantiaca Strain PB-St2, Isolated from Sugarcane Stem

  • Mehnaz, Samina;Baig, Deeba Noreen;Jamil, Farrukh;Weselowski, Brian;Lazarovits, George
    • Journal of Microbiology and Biotechnology
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    • v.19 no.12
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    • pp.1688-1694
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    • 2009
  • A novel strain of fluorescent pseudomonad (PB-St2) was isolated from surface-sterilized stems of sugarcane grown in Pakistan. The bacterium was identified as Pseudomonas aurantiaca on the basis of 16S rRNA gene sequence analysis and results from physiological and biochemical characteristics carried out with API50 CH and QTS 24 bacterial identification kits. Assays using substrate-specific media for enzymes revealed lipase and protease activities but cellulase, chitinase, or pectinase were not detected. The bacterium was unable to solubilize phosphate or produce indole acetic acid. However, it did produce HCN, siderophores, and homoserine lactones. In dual culture assays on agar, the bacterium showed antifungal activity against an important pathogen of sugarcane in Pakistan, namely Colletotrichum falcatum, as well as for pathogenic isolates of Fusarium oxysporium and F. lateritium but not against F. solani. The antifungal metabolites were identified using thin-layer chromatography, UV spectra, and MALDI-TOFF spectra and shown to be phenazine-1-carboxylic acid (PCA), 2-hydroxyphenazine (2-OH-PHZ), and N-hexanoyl homoserine lactone (HHL) (assessed using only TLC data). The capacity of this bacterium to produce HCN and 2-OH-PHZ, as well as to inhibit the growth of C. falcatum, has not been previously reported.

Changes of Serum Lipid Profiles after Eating Lycii Fructus in Rats Fed High Fat Diet (구기자 섭취에 의한 고지방식이를 하는 흰쥐의 혈중 지질상태 변화)

  • 김희선
    • Journal of Nutrition and Health
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    • v.31 no.3
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    • pp.263-270
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    • 1998
  • The purpose of this study was to investigate the effect of Lycii fructus on the serum lipid in rats fed high fat diet. We compared the effects of L. fructus and L.fructus water extract both adminstered with high fat diets on rats that had previously been on high fat or standard diets. Two separate experiments were conducted for 6 weeks. respectively. In experiment I, 4 groups of rats were fed experimental diets consisting of either \circled1 6 weeks of a standard diet(control), \circled2 6 weeks of a high-fat diet(HHC), \circled3 3 weeks of a high-fat diet followed by 3 weeks of a high-fat diet containing L. fructus(HHL) or \circled4 6 weeks of a high-fat diet with L. fructus extract in place of water for the last 3 weeks (HHT). In the second set of experiments, a high-fat diet (SHC), high-fat diet containing L.fructus(SHL) or high-fat diet with L. fructus extract in place of water (SHT) were fed for 3 weeks after 3 weeks of standard diet feeding. Rats fed L. fructus diet consumed more diets than high-fat diets. THe results of experiment I showed significant decreases(p<0.05) in serum triglyceride(TB) and low density lipoprotein-cholesterol (LDL-C) levels with L. fructus feedings, but did not show andy changes in total cholesterol (TC) level. High density lipoprotein-cholesterol (HDL-C) level was increased significantly(p<0.05) with L. fructus feedings. Therefore, the ration of LDL-C to HDL-C(LDL-C/HDL-C) which is used as an atherosclerosis index was significantly (p<0.05) low, while the HDL-c/TC ration was significantly(p<0.05) high with L.fructus intake. However, no significant were found in serum cholesterols and TG levels in experimentII. The results of these experiments indicate that , regardless of the feeding from, L. fructus can be beneficial in lowering serum TG and LDL-C levels for habitual high-fat diet intakers. L.fructus also seems to be effective in elevating serum HDL-C level, theregy having beneficial effects on atherosclerosis by influencing the serum lipoprotein profile.

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Hardware Abstraction Architecture for Low Cost Flash Memories in Wireless Sensor Nodes (무선 센서 노드상의 저가형 플래시 메모리를 위한 하드웨어 추상화 구조)

  • Kim, Chang-Hoon;Kwon, Young-Jik
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.2
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    • pp.72-80
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    • 2009
  • In this parer, we propose a hardware abstraction architecture(HAA) for low cost flash memories that can be applicable to wireless sensor nodes. The proposed HAA consists of three layers. The three layers are 1) HHL(Hardware Interlace Layer), HAL(Hardware Adaption Layer), and HPL(Hardware Presentation Layer), where HIL provides a platform independent interlace to applications of upper layers, HAL performs hardware resource management, program status control, and generation of logical instructions as main core of the HAA, and HPL initializes hardware and communicates data between MCU and flash memory. We implemented our HAA on AT45DB flash memory, and the HAA used 4,384 bytes program memory and 195 bytes data memory respectively. Since the proposed HAA is composed of well defined three layers and shows a low utilization of memory, it can provides a high efficiency in terms of flexibility, scalability, and re-usability, and thus the HAA is well suited for wireless sensor nodes.