3-MCPD의 생식˙발생독성에 관한 연구

곽승준(Seung Jun Kwack),김순선(Soon Sun Kim),최요우(Yo Woo Choi),이규식(Gyu Seek Rhee),손경희(Kyung Hee Sohn),이이다(Rhee Da Lee),채수영(Soo Young Chae),정용현(Yong-Hyun Chung1),유일재(Il Je Yu1),박귀례(Kui Lea Park) 한국독성학회 2004 Toxicological Research Vol.20 No.2

3-Monochloro-1,2-propanediol(3-MCPD) is a toxic compound, often present in different foods containing acid hydrolyzed(AH) protein, like seasonings and savory food products. The purpose of the present study was to investigate the effects of 3-MCPD on male fertility, sperm and testosterone secretion. In vivo male fertility test was performed for observing the adverse effects of 3-MCPD on the function of male reproductive system and pregnancy outcome. 0.01, 0.05, 0.25, 1 and 5 mg/kg b.w. of 3-MCPD was given daily by gavage to groups of 15 adult male SD rats for 4 weeks. At the end of pre-treatment period, males were mated overnight with normal females. Following morning, males demonstrating successful induction of pregnancy were sacrificed on that day to assess sperm parameters and histopathology of reproductive organs. The resulting pregnant females were sacrificed on day 20 of gestation to evaluate pregnancy outcome. As a result, four-week paternal administration with 3-MCPD resulted in adverse effects on male fertility and pregnancy outcome without remarkable histopathological changes in testes and epididymides; sperm motility, copulation index and fertility index were markedly decreased in the treated group and numbers of live fetuses showed steep dose-response curves. Also, spermatogenesis was investigated in this experiment. However, no<br/> effect was observed on production of sperm in testes treated with 3-MCPD for 4 weeks. Hormone assay was performed for observing the effects of 3-MCPD on testosterone and luteinizing hormone (LH) in blood and testes of male SD rats and cultured primary Leydig cell. In result, significant changes of related hormones did not observed by treatment of 3-MCPD. These results indicated that paternal treatment with 3-MCPD induced spermatotoxic effect, which caused an antifertility on male.

Optimal Shape Design of Dielectric Micro Lens Using FDTD and Topology Optimization

Young-Seek Chung,이병제,김성철 한국광학회 2009 Current Optics and Photonics Vol.13 No.2

In this paper, we present an optimal shape design method for a dielectric microlens which is used to focus an incoming infrared plane wave in wideband, by exploiting the finite difference time domain (FDTD) technique and the topology optimization technique. Topology optimization is a scheme to search an optimal shape by adjusting the material properties, which are design variables, within the design space. And by introducing the adjoint variable method, we can effectively calculate a derivative of the objective function with respect to the design variable. To verify the proposed method, a shape design problem of a dielectric microlens is tested when illuminated by a transverse electric (TE)-polarized infrared plane wave. In this problem, the design variable is the dielectric constant within the design space of a dielectric microlens. The design objective is to maximally focus the incoming magnetic field at a specific point in wideband.

A stable solution of time domain electric field integral equation using weighted Laguerre polynomials

Chung, Young-Seek,Lee, Yoonju,So, Joonho,Kim, Joonyeon,Cheon, Chang-Yul,Lee, Byungje,Sarkar, Tapan K. Wiley Subscription Services, Inc., A Wiley Company 2007 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.49 No.11

<P>In this article, we propose a new stable solution for the time domain electric field integral equation (TD-EFIE) for arbitrarily shaped conducting structures, which utilizes weighted Laguerre polynomials as temporal basis functions, which means that the unknown surface currents are expanded by these basis functions. The proposed algorithm is based on the Galerkin's scheme that involves separate spatial and temporal testing procedures. By introducing the temporal testing procedure, the conventional marching-on in time procedure can be replaced by a recursive relation between the different orders of the weighted Laguerre polynomials. In this article, by deriving the integral formulation using the weighted Laguerre polynomials, we solve for the surface current density as the unknown directly. To verify the accuracy of the proposed method, we have compared the results with the inverse discrete Fourier transform of the frequency domain solutions for the electric field integral equation. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2789–2793, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22835</P>

포화 특성 해석을 위한 복소 고조파 유한 요소해석법

정용식(Chung Young-Seek),박관수(Park Gwan-Soo),한송엽(Hahn Song-Yop) 대한전기학회 1990 대한전기학회 학술대회 논문집 Vol.1990 No.7

The Purification and Characterization of a Bacillus stearothermophilus Methionine Aminopeptidase ( MetAP )

Lee, Young Seek,Chung, Il Yup,Chung, Jae Min 생화학분자생물학회 1989 BMB Reports Vol.35 No.2

Methianine aminopeptidase (MetAP) catalyzes the removal of an amino-terminal methionine from a newly synthesized polypeptide. The enzyme was purified to homogeneity from Bacillus stearothermophilus (KCTC 1752) by a procedure that involves heat precipitation and four sequential chromatographs (including DEAE-Sepharose ion exchange, hydroxylapatite, Ultrogel AcA 54 gel filtration, and Reactive red 120 dye affinity chromatography). The apparent molecular masses of the enzyme were 81,300 Da and 41,000 Da, as determined by gel filtration chromatography and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), respectively This indicates that the enzyme is comprised of two identical subunits. The MetAP specifically hydrolyzed the N-terminal residue of Met-Ala-Ser that was used as a substrate, and exhibited a strong preference for Met-Ala-Ser over Leu-Gly-Gly, Leu-Ser-Phe, and Leu-Leu-Tyr. The enzyme has an optimal pH at 8.0, an optimal temperature at 80℃, and pI at 4.1. The enzyme was heat-stable, as its activity remained unaltered when incubated at 80℃ for 45 min. The Km and Vmax values of the enzyme were 3.0 mM and 1.7 mmol/min/㎎, respectively. The B. stearothermophilus MetAP was completely inactivated by EDTA and required Co^(2+) ion(s) for activation, suggesting the metal dependence of this enzyme.

Suppression of Egr-1 transcription through targeting of the serum response factor by oncogenic H-Ras

Shin, Soon Young,Bahk, Young Yil,Ko, Jesang,Chung, Il-Yup,Lee, Young Seek,Downward, Julian,Eibel, Hermann,Sharma, Prem M,Olefsky, Jerrold M,Kim, Young-Ho,Lee, Bonghee,Lee, Young Han Wiley (John WileySons) 2006 The EMBO journal Vol.25 No.5

<P>The transcription factor Egr-1 functions as a key regulator in cellular growth, differentiation, and apoptosis. The loss of Egr-1 expression is closely associated with tumor development, although the molecular mechanism behind the suppression of Egr-1 is largely unknown. In this report, we show that growth factor-induced transcriptional activation of Egr-1 gene is downregulated by chronic expression of oncogenic H-Ras in NIH3T3 fibroblasts. Our results demonstrate that phosphoinositide 3-kinase (PI3K) signaling is necessary for oncogenic H-Ras-mediated reduction of Egr-1 gene expression. Aberrant activation of PI3K signaling by oncogenic Ras decreased the level of serum response factor (SRF) protein through the acceleration of proteolysis, which resulted in decreased SRF binding to the serum response element (SRE) sites within the Egr-1 promoter, leading to the suppression of Egr-1 transcription. Inhibition of PI3K signaling restored the downregulation of SRF and Egr-1 expression caused by oncogenic Ras. Our findings suggest a novel signaling mechanism by which prolonged activation of oncogenic H-Ras can trigger the loss of tumor suppressor Egr-1 through the PI3K pathway in NIH3T3 fibroblast model cell lines.</P>

실험동물의 발생이상 용어집

김종춘(Jong-Choon Kim),양영수(Young-Su Yang),안태환(Tai-Hwan Ahn),김성호(Sung-Ho Kim),정수연(Soo-Youn Chung),이규식(Gyu-Seek Rhee),정나영(Na-Young Chung),정문구(Moon-Koo Chung) 한국독성학회 2006 Toxicological Research Vol.22 No.3

This paper presents the first version of a Korean glossary of terms for structural developmental abnormalities in common laboratory animals, mainly rats, mice and rabbits. This is a translation of the glossary entitled Terminology and Developmental Abnormalities in Common Laboratory Mammals that was edited by the International Federation of Teratology Societies (IFTS) Committee on International Harmonization of Nomenclature in Developmental Toxicology. The purpose of the Korean glossary is to provide a common vocabulary that will reduce confusion and ambiguity in the description of developmental effects, particularly in submissions to regulatory agencies worldwide. The glossary contains a primary term or phrase, a definition of the abnormality, and notes, where appropriate. Selected synonyms or related terms, which reflect a similar or closely related concept, are noted. Non-preferred terms are indicated where their usage may be incorrect. Modifying terms used repeatedly in the glossary (e.g., absent, branched) are listed in Appendix A, and syndrome names are generally excluded from the glossary, but are listed separately in Appendix B. The glossary is organized into broad sections for external, visceral, and skeletal observations, then subdivided into regions, structures, or organs in a general overall head to tail sequence. Numbering is sequential, and not in any regional or hierarchical order. Uses and misuses of the glossary are discussed. Updates of the Korean glossary are planned based on the comments received.

Construction of a Transcriptome-Driven Network at the Early Stage of Infection with Influenza A H1N1 in Human Lung Alveolar Epithelial Cells

Chung, Myungguen,Cho, Soo Young,Lee, Young Seek The Korean Society of Applied Pharmacology 2018 Biomolecules & Therapeutics(구 응용약물학회지) Vol.26 No.3

We aimed to understand the molecular changes in host cells that accompany infection by the seasonal influenza A H1N1 virus because the initial response rapidly changes owing to the fact that the virus has a robust initial propagation phase. Human epithelial alveolar A549 cells were infected and total RNA was extracted at 30 min, 1 h, 2 h, 4 h, 8 h, 24 h, and 48 h post infection (h.p.i.). The differentially expressed host genes were clustered into two distinct sets of genes as the infection progressed over time. The patterns of expression were significantly different at the early stages of infection. One of the responses showed roles similar to those associated with the enrichment gene sets to known 'gp120 pathway in HIV.' This gene set contains genes known to play roles in preventing the progress of apoptosis, which infected cells undergo as a response to viral infection. The other gene set showed enrichment of 'Drug Metabolism Enzymes (DMEs).' The identification of two distinct gene sets indicates that the virus regulates the cell's mechanisms to create a favorable environment for its stable replication and protection of gene metabolites within 8 h.

Escherichia coli로 부터 Methionine Aminopeptidase의 분리정제

정승식,이영식 漢陽大學校 基礎科學硏究所 1994 基礎科學論文集 Vol.13 No.-

Methionine aminopeptidase (MAP, EC 3.4.1.1)는 단백질 생합성 과정중에서 amino terminal의 N-formyl methionine residue을 제거하는 효소이다. MAP의 정체를 위하여 70% Ammonium Sulfate fractionation 후에 DEAE-Cellulose를 이용한 Ion-Exchange chromatography와 Sephacryl S-200을 이용한 Gel Filtration chromatography를 시도하였다. MAP는 분자량이 30Kd정도인 것으로 밝혀져 있으며, 그 활성에는 cobalt metal ion에 대한 의존성을 갖고 있다. 효소의 반응성 대한 최적 온도는 30℃이며, 100mM potassium phosphate buffer 하에서 pH 7.5에서 최적활성도를 나타내었으며, Km 값은 ?? mM이었다. Cobalt 이외의 2가 양이온들의 영향은 작았다. Methionine aminopeptidase (MAP, EC 3.4.1.1) is a N-terminal methionine removing enzyme from newly synthesized protein in protein biosynthesis. MAP was partially purified to about 5 folds on DEAE-Cellulose Ion-Exchange chromatography and Sephacryl S200 Gel Filtration chromatography. MAP was separated at 0.1M NaCl concentration by Ion-Exchange chromatography. The molecular weight of MAP was 30Kda, and monomeric enzyme, and other divalent cation effects was less than cobalt ion. This enzyme was measured at 30℃, 100mM potassium phosphate buffer, and pH 7.5. The Km value was ?? mM.

The Purification and Characterization of Bacillus subtilis Tripeptidase(PepT)

Chung,Il Yup,Park,Yong Seek,Kim,Hyo Joon,Yong,Whan-Mi,Cha,Myung Hoon,Lee,Young Seek The Korea Science and Technology Center 1999 BMB Reports Vol.32 No.3

A tripeptidase (PepT) was purified to homogeneity from Bacillus subtilis through four sequential chromatographies including DEAE-Sepharose ion exchange, hydroxylapatite, mono-Q FPLC ion exchange, and Superose-12 FPLC gel filtration. The apparent molecular mass of the enzyme was 49,200 Da and 51,400 Da as determined by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography, respectively, and the enzyme exists in a monomeric form. The physico-chemical properties of the enzyme were as follows: optimum pH at 7.5, optimum temperature at 60℃, and pI at 4.9. The Km and Vmax values of the enzyme were 4.3 mM and 2.5 mmol/min/mg, respectively, with Met-Ala-Ser as substrate. The B. subtilis PepT requires Co²+ ion(s) for activation, while it is inactivated by EDTA and 1,10-phenanthroline, suggesting that it is a metalloprotein. The enzyme was not inhibited by any of serine protease, aspartic protease, or leucine amino-peptidase inhibitors. The enzyme showed comparable activities towards four different substrates including Met-Ala-Ser, Leu-Gly-Gly, Leu-Ser-Phe, and Leu-Leu-Tyr. The amino terminal sequences of PepT determined by Edman degradation was found to be MKEEIIERFTTYVXV and turned out to be identical to that of PepT deduced from a cloned B. subtilis pepT.