• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.2001-2006
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• 2005

Glycoproteins and glycolipids play key roles in intracellular reactions between cells and their environments at the membrane surface. For better understanding of the nature of these events, it is necessary to know threedimensional structures of those carbohydrates, involved in them. Since carbohydrates contain many hydroxyl groups which can serve both as hydrogen bond donors and acceptors, hydrogen bond is an important factor stabilizing the structure of carbohydrate. DMSO is an aprotic solvent frequently used for the study of carbohydrates because it gives detailed insight into the intramolecular hydrogen bond network. In this study, conformational properties and the hydrogen bonds in $\beta$-lactose in DMSO are investigated by NMR spectroscopy and molecular dynamics simulations. NOEs, temperature coefficients, deuterium isotope effect, and molecular dynamics simulations proved that there is a strong intramolecular hydrogen bond between O3 and HO2' in $\beta$-lactose and also OH3 in $\beta$-lactose may form an intermolecular hydrogen bond with DMSO.

• BMB Reports
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• 제53권2호
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• pp.94-99
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• 2020

Brain cytoplasmic 200 RNA (BC200 RNA) is proposed to act as a local translational modulator by inhibiting translation after being targeted to neuronal dendrites. However, the mechanism by which BC200 RNA inhibits translation is not fully understood. Although a detailed functional analysis of RNA motifs is essential for understanding the BC200 RNA-mediated translation-inhibition mechanism, there is little relevant research on the subject. Here, we performed a systematic domain-dissection analysis of BC200 RNA to identify functional RNA motifs responsible for its translational-inhibition activity. Various RNA variants were assayed for their ability to inhibit translation of luciferase mRNA in vitro. We found that the 111-200-nucleotide region consisting of part of the Alu domain as well as the A/C-rich domain (consisting of both the A-rich and C-rich domains) is most effective for translation inhibition. Surprisingly, we also found that individual A-rich, A/C-rich, and Alu domains can enhance translation but at different levels for each domain, and that these enhancing effects manifest as cap-dependent translation.

• 한국수정란이식학회지
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• 제29권2호
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• pp.119-125
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• 2014

Although the majority of surviving pigs cloned by somatic cell nuclear transfer (SCNT) appear to be physiologically normal, there is a general lack of detailed hemato-physiologic studies for the period of early adulthood to substantiate this claim. In the present study, we investigated variation in blood chemistry and endocrinological parameters between mesenchymal stem cells (MSCs) derived from cloned and normal age-matched female and male miniature pigs. Cloned females and males showed normal ranges for complete blood count assessments. Biochemical assessments showed that ${\gamma}$-GGT, ALT and cholesterol levels of male and female clones were significantly (P<0.05 or P<0.01, respectively) higher than that of age-matched control miniature pigs. Variations in insulin and IGF-1 were higher in female clones than in male clones and controls. Thus, although female and male cloned miniature pigs may be physiologically similar to normal animals, or at least within normal ranges, a greater degree of physiological and endocrinological variation was found in cloned pigs. The above variation must be taken into account before considering cloned female or male miniature pigs for various biomedical applications.

• 대한임상검사과학회지
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• 제48권4호
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• pp.275-279
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• 2016

Dengue fever is a vector borne disease caused by a dengue virus. It is an RNA virus of the family flaviviridae, with different serotypes. Herein, we report our attempt to carry out a sensitivity comparison of immunodiagnostic assays for dengue fever in dengue positive patients. Blood samples from 189 volunteers were collected. To determine the sensitivity of the NS1 test, two different types of tests-immunochromatographic tri-line test and rapid dengue test (RDT)-as well as IgM and IgG capture ELISA were performed. The result of RDT has shown that 59.7% of volunteers were IgM positive and 50.2% were IgG positive. Conversely, the results from capture ELISA shows 79.8% and 59.7% for IgM and IgG, respectively. The sensitivity of the capture ELISA test for IgM and IgG was higher than that of immunochromatographic tri-line rapid test, but the specificity was lower. Therefore, to confirm dengue fever, we recommend performing more detailed, investigative tests since a single test may not be sufficient.

• 공업화학
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• 제16권1호
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• pp.9-14
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• 2005

펜톤 반응(2가 철+과산화수소)은 오늘날 환경기술분야에서 응용 가능성이 높아 큰 주목을 받고 있으며, 그 원리를 응용한 새로운 기술들이 활발하게 연구되고 있다. 하지만 다양한 응용 연구에도 불구하고, 그 화학반응의 상세한 메커니즘은 아직도 명확히 밝혀지지 않았으며 연구자들 사이에 여전히 논쟁이 진행되고 있다. 지금까지 학계에서는 펜톤 반응에서 생성되는 (산화)반응성이 큰 화학종으로 수산화 라디칼 또는 고가 산화철 복합체가 제시되어 왔는데, 본고에서는 이러한 논의들의 핵심적인 내용을 비판적으로 정리, 고찰하고자 하였다.

• 한국자기공명학회논문지
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• 제3권1호
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• pp.44-51
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• 1999

An enzyme derived conformational changes of cobalamine is thought to be important in the homolytic cleavage of Co-C bond which is the first step of catalytic Cl-cycle of coenzyme B12-dependent enzymes. Modern 2D-NMR and NMR-based distance geometric studies were carried out to determine the 3D structure of corrin ring. Homonuclear and heteronuclear correlation NMR experiments were performed for complete 1H-NMR signal assignments. Distances between numerous proton pairs were deduced based on the NOE cross peak intensities and subsequently used as input into the distance geometry program for the 3D structure determination. The detailed 3D structure from the present NMR-based analysis was compared with the result from X-ray crystallographic study, which revealed greater conformational changes occur in benzimidazole group and sugar ring than in macrocyclic corrin and tetrapyrrole. In addition, the distance geometry used in this study was found to be quite useful for NMR-based structure determination of medium-sized molecules that give poor NOE effects arising from their intermediate tumbling rate ($\omega$$\tau$c 1.0).

• Macromolecular Research
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• 제17권6호
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• pp.365-377
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• 2009

In this feature article, we briefly review the new methods we have utilized recently in the investigation of morphology and phase behavior of block copolymers. We first describe the chromatographic fractionation method to purify block copolymers from their side products of mainly homopolymers or block copolymer precursors inadvertently terminated upon addition of the next monomer in the sequential anionic polymerization. The chromatographic method is extended to the fractionation of the individual block of diblock copolymers which can yield the diblock copolymer fractions of different composition and molecular weight, which also have narrower distributions in both molecular weight and composition. A more detailed phase diagram could be constructed from the set of block copolymer fractions without the need of acquiring many block copolymers each prepared by anionic polymerization. The fractions with narrow distribution in both molecular weight and composition exhibit better long-range ordering and sharper phase transition. Next, epitaxial relationships between two ordered structures in block copolymer thin film is discussed. We employed the direct visualization method, transmission electron microtomography(TEMT) to scrutinize the grain boundary structure.

• 대한화학회지
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• 제36권3호
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• pp.345-350
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• 1992

Ln$(NO_3)_3$/DMF 상자성 용액의 양성자 선-나비와 화학적이동을 240 K부터 380 K 사이에서 측정하였다. 이들 데이터로부터 DMF 분자의 CHO기에 대한 배위구 교환속도와 열역학 교환파라미터를 추출하였다. 1/$T_2$ 와 ${\Dellta}{\omega}$ 데이터의 온도의존성을 자세하게 분석하고 고찰하여 결과를 정리하였다. 분석의 결과를 살펴보면 짝짓지 않은 전자 스핀이 몇몇 $Ln^{3+}$이온에서 첫 배위구를 넘어 퍼지면서 bulk 용매의 DMF 분자로 스칼라이완의 기여를 제공하는 것 같다.

• International Journal of Advanced Culture Technology
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• 제8권2호
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• pp.165-175
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• 2020

The purpose of this study is to examine whether the visual materials presented in the science textbooks coincide with those visual materials that are preferred the most by students. After analyzing the visual materials presented in the unit "Molecular Motion and Change of State" of science textbooks for the first grade of middle school, questionnaires by teaching-learning process are made. Thereafter, students are requested to select those types of visual materials that were preferred by them by process and describe their reasons for the selection. According to the results of the survey of students' perception, students at the high science achievement level prefer those visual materials that were presented conceptually and implicatively, while students at the low science achievement level prefer concrete and detailed visual materials. Except for the learning motivation process, the proportion of non-preferred visual materials is higher in the remaining processes and those visual materials that were presented in the science textbooks are much different from those visual materials that were preferred by students.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.967-971
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• 1994

The stability constants, log K of the 1 : 1 complexation for IA ions, $Ag^+$, and $Tl^+$ with a series of podands having different aromatic end-groups (I-IV) have been determined conductometrically in methanol at 25.0 $^{\circ}$C. Exceptionally the equivalent conductivity, ${\lambda}_{eq}\;of\;Li^+\;and\;Na^+$ were increased by the addition of I, because the complexed ions are less mobile than solvated ions. The order of log K values for I was $Ag^+{\gg}Tl^+>K^+>Na^+>Rb^+>Cs6+>Li^+$. The log K sequence of the podands for the certain cations was I>II>III${\geq}$IV. And every podands except IV showed the maximum selectivity for $Ag^+$ among the cations. These results were discussed in terms of the aromatic end-group effects, such as hetero-donor atoms or conformational changes by ${\pi}-{\pi}$ stacking interactions. The detailed conformations of ${\pi}-{\pi}$ stacking were also discussed by the observations of upfield shifts of some aromatic protons upon complexation from $^1H$ NMR spectra.