Regulation of Metabolic Flux in Saccharomyces cerevisiae for the Production of Ceramide

김세경 인하대학교 대학원 2010 국내박사

The first sphingolipid was discovered by Johann Thudichum more than a hundred years ago in brain tissue. Since then many species of sphingolipid have been identified and characterized chemically. The specific physiological functions of sphingolipids have been identified only in the past two decades. Recently, the sphingolipid represented by ceramide and sphingosine has been researched as signal transfer materials and its role in induction of apoptosis in cells. It has been also studied regarding to cell-to-cell signaling including acceptor on the cell membrane represented by sphingosine 1-phosphate and sphingosylphosphoryl-choline. Ceramide can be obtained from natural resources. However, ceramide from animal sources has met difficulties due to bovine spongiform encephalopathy and prevention campaigns to stop the use of animal ingredients. Ceramide extracted from plants has a form of cerebroside and has not been produced sufficiently. Recently, ceramide production using microorganisms has been gaining interest. Yeasts are adequate for the production of ceramide due to their fast growth, non-toxicity, and simplicity in gene manipulation. The presence of ceramide has been detected in only two yeasts; Saccharomyces cerevisiae and Candida utilis. In this study ceramide production from S. cerevisiae was investigated. The variation of ceramide production due to the regulation of genes and expression of enzymes in sphingolipid the metabolic pathway was studied. For optimal condition of ceramide production, S. cerevisiae was grown in a batch culture and ceramide was extracted by solvent extraction. The ceramide content was analyzed by HPLC by using ELSD. The cellular content of ceramide was measured at different growth phases: exponential phase, early stationary phase, and late stationary phase which was 12 hours and 24 hours after cells entered the stationary phase. After 20 hours of cell growth the glucose was depleted completely and after 32 hours the viable cell count of the cells started to decrease. The highest ceramide content was 2.01 mg ceramide/g cell from S. cerevisiae at 32 hours of cell growth, which was 12 hours after entering the stationary phase. Effect of expression of individual genes in the sphingolipid synthesis pathway on the biosynthesis of ceramide was examined. Six genes that are directly related to the synthesis of ceramide were selected and cloned in S. cerevisiae. The maximum production of ceramide (9.8 mg ceramide/g cell) was obtained when the tsc10 gene responsible for 3-ketosphinganine reductase was amplified. Real time RT-PCR analysis showed that the increase in ceramide content was proportional to the increase in the tsc10 gene expression level, which was 4.56 times higher than that of the control strain. Effect of regulation of expression of enzymes in sphingolipid synthesis pathway was investigated. Two types of plasmid were used: one was pESC-URA, a high copy number plasmid and the other was YCplac, a low copy number plasmid. Six genes involved in the expression of four enzymes on sphingolipid pathway were cloned into pESC-URA which has two cloning sites or YCplac22 and YCplac33. In investigation using high copy number plasmid, the highest ceramide production (10.52 mg ceramide/g cell) was obtained when tsc10 gene responsible for 3-ketosphinganine reductase was amplified. The concentration of ceramide was 4.82 times higher than that of control strain S. cerevisiae SCE. High production of ceramide was also obtained from S. cerevisiae SCEL2,1 (10.08 mg ceramide/g cell) and S. cerevisiae SCEG1C1 (9.88 mg ceramide/g cell). S. cerevisiae SCEL2,1 contain lcb2 and lcb1 which encode palmitoyltransferase and S. cerevisiae SCEG1C1 contain lag1 and lac1 which encode ceramide synthase, respectively. Though the expression level of sur2 gene that encodes dihydrosphingosine C-4 hydroxylase increased 11.76 times, the ceramide production was lower compared to S. cerevisiae with other genes. For the investigation of ceramide production using low copy number plasmid, YCplac22 and YCplac33 were used. The plasmids are low copy number plasmids and retain higher stability. The production of ceramide by S. cerevisiae with YCplac22 and YCplac33 were lower than that of S. cerevisiae with pESC-URA plasmid. The highest ceramide production was 4.69 mg ceramide/g cell in S. cerevisiae SCyT10 that contain tsc10 gene. However, the production of the cell was 50% of S. cerevisiae SCYT10 and S. cerevisiae SCET10 that contain tsc10 gene in high copy number plasmids. Ceramide is a natural bioactive compound that stimulates and regulates the physiological functions of human skin. It is originally abundant in human skin, however, the amount decreases according to the age, health, and environment. Ceramide is a major lipid component of lamellar structure and present in the intercellular spaces of the stratum corneum. The lamellar structure provides the barrier function of the epidermis. It is well known that ceramide plays an essential role in structure of human skin and maintaining water permeability function of the skin. S. cerevisiae is an adequate microorganism for the production of ceramide due to fast growth, non-toxicity, and simplicity in gene manipulation. In this study important genes on sphingolipid pathway were cloned in S. cerevisiae by using plasmids. The expression of individual genes or set of genes for the expression of enzymes involved in sphingolipid synthesis pathway was regulated for higher ceramide production. The results of this study can be used to enhance the production of ceramide which is one of major active ingredients of cosmeceuticals. The ceramide production through regulation of metabolic flux in metabolic pathway and search of the relationship of genes will be valuable sources in the understanding of signal transfer and metabolic pathway of ceramide biosynthesis.

항공사의 전략적 인적자원관리가 조직유효성에 미치는 영향-국내 K항공사를 중심으로-

김세경 한국항공대학교 일반대학원 2015 국내석사

유럽향 이동형 TV 방송 DVB-T가 포함된 다기능 네비게이션 시스템 개발

김세경 수원대학교 일반대학원 2009 국내석사

In this thesis, a novel multi-functional navigation system is developed including DVB-T - the European broadcasting standard - and Bluetooth technology. There are many data transmission rates in DVB-T standard, so the broadcasting companies can make many different choices based upon their business models and the amount of budget allocated for the investment. Bluetooth technology has developed from the research on interface between cell phones and other electronics around them, and it is superior to IrDA in terms of transmission distance, ability to overcome obstacles, power consumption, and transmission rate. The system that will be embodied has the Atlas-III main-platform with built-in GPS Baseband. The reset and overall power of main-platform will be controlled by using micro-controller (ATMEGA48) due to the fact that Atlas-III requires rather complicated power and reset sequences. This system uses many different RF technologies within identical PCB; the main focus of the research was on the full performance-capacity of the system with clear separation of RF equipments, guaranteeing no interference between the equipments and the establishment of the ground. Based on this research and through the convergence (RDS/TMC) of different RF technologies, a distinctive system will be constructed; on the other hand, by focusing on one RF technology, a more perfected system will be constructed.

자기통제력에 관련된 변인에 대한 메타분석

김세경 경성대학교 2014 국내박사

지역특산음식 선택속성이 고객만족과 행동의도에 미치는 영향 : 강릉특산음식마을 방문객을 중심으로

김세경 가톨릭관동대학교 2017 국내석사

ABSTRACT The Effect of Attribute Selection of Local Specialty Food on the Customer Satisfaction and Behavioral Intention -Focusing on Visitors to Gang-neung Specialty Food Town- Kim, Se-Kyoung Department of Hotel Culinary & Food Service Management Graduate School Catholic Kwan-dong University (Supervised by Professor Yoon, Deok-Ihn) This study aimed to analyze the relationship among local specialty food selection attributes, customer satisfaction and behavioral intention of consumers trying out local specialty food by discussing the effect of local specialty food selection attributes on customer satisfaction and behavioral intention. After identifying concept of each variable, structural relationship of variables was examined by literature review to perform empirical analysis. For empirical analysis, 249 surveys were collected from consumers who have tried out local specialty food through local specialty food villages and local festivals of Gangneung between September 24th and October 5th of 2016. Survey analysis was performed using SPSS 20.0 program, and frequency analysis was used to find out general characteristics and conditions of the samples. Exploratory factor analysis and reliability analysis were performed on the measured variables. In addition, correlation analysis was done before testing of hypothesis to find the relationship among variables, and simple regression analysis and multiple regression analysis were performed for testing of hypothesis. The results of this study can be summarized as follows. First, among local specialty food selection attributes, food taste ad quality factor, human service factor, physical service factor and image factor had positive effect on customer satisfaction. Convenience factor did not have positive effect on satisfaction. This implies that taste and quality of food, human service, physical service such as surrounding environment, and image such as reputation can improve customer satisfaction when trying out local specialty food. Second, among local specialty food selection attributes, food taste and quality factor and image factor had positive effect on behavioral intention. Human service factor, physical service factor and convenience factor did not have significant effect. This means that taste and quality of local specialty food and image of local specialty restaurant have positive impact on behavioral intention of customers, and taste and quality of food and image of restaurant should be actively reflected on marketing activities. On the other hand, it would be necessary to further increase competency of restaurants by diagnosing and improving problems found in relation to human service factor, physical service factor and convenience factor, thereby providing higher level of service. Third, customer satisfaction showed positive effect on behavioral intention. Therefore, it is necessary to establish a marketing strategy that focuses on customers showing high satisfaction to increase their behavioral intention. Such marketing strategy should try to maximize customer satisfaction so that consumers who try out local specialty food can come back later. This requires high level of food taste and quality and service. Based on the implications of this study, business operators in the four local specialty food villages need to place voluntary efforts to continue developing local specialty food and come up with effective marketing strategies. In addition, food experience activities using local specialty food, familiarization tours with local tourist products through the use of the 6th industry, and increased promotion activities on SNS can be taken into consideration.

高壓下의 親核性 置換反應에 關한 速度論的 硏究 : 피리딘류와 치환된 염화벤조일류의 반응속도론

김세경 漢陽大學校 1992 국내박사

지역특산품 구매동기가 긍정적소비감정, 관광만족 및 재구매의도에 미치는 영향 : 신뢰를 조절변수로

김세경 가톨릭관동대학교 2019 국내박사

This study aims to identify the mediating effect of trust between the impact of motivation for local specialty purchase on positive consumption emotion, tour satisfaction, and repurchase intention and the impact of positive consumption emotion and tour satisfaction on repurchase intention. Based on the results, this study seeks to propose an effective marketing strategy using local specialties. This study used books, previous research papers, and academic journals for literature review which started from existing theory, set and tested hypothesis through observation and analysis, and drew conclusion using the deduction of syllogism. For empirical analysis, this research conducted a survey for 30 days from July 15, 2015 to August 30, 2018 and analyzed the data using the SPSS 21.0 for Windows statistical package. Frequency analysis was performed to identify the general characteristics of the sample, and explorative factor analysis and reliability analysis were performed on the measured variables. Also, this study conducted correlation analysis to identify the relationship among research variables before the hypothesis test as well as simple regression analysis, multiple regression analysis, and parameter analysis to test the hypothesis. The analysis results can be summarized as follows. First, the analysis results for the impact of motivation to purchase local specialties on positive consumption emotion showed diversion had positively (+) significant impact on positive consumption emotion. Among the motivation to purchase local specialties, product orientation, cultural factor, and self-desire had a positively (+) significant impact on positive consumption emotion. Second, from the analysis on the impact of the motivation to purchase local specialty on tour satisfaction, diversion and product orientation, cultural factor, and self-desire among the motivation to purchase local specialties had a positively (+) significant impact on tour satisfaction. Third, positive consumption emotion had a positively (+) significant impact on tour satisfaction, and fourth, positive consumption emotion had a positively (+) significant impact on repurchase intention. Fifth, tour satisfaction had a positively (+) significant impact on repurchase intention as seen in the analysis result. Sixth, the result of mediating regression analysis on trust between positive consumption emotion and repurchase intention through the regression analysis showed significance probability change was not statistically significant and was thus rejected. Seventh, the mediating regression analysis result of trust between tour satisfaction and repurchase intention showed that significance probability change was not statistically significant and was thus rejected. In this study on tourists who have purchased local specialties, a motivation for local specialty purchase is divided into diversion, product orientation, cultural factor, and self-desire. The motivation to purchase local specialties have impacts on the positive consumption emotion, tour satisfaction, and repurchase intention, and positive consumption emotion and tour satisfaction on local specialties had impact on intention to repurchase local specialties. Also, trust did not have a mediating effect between positive consumption emotion and intention to repurchase local specialties as well as between the tour satisfaction and the intention to repurchase local specialties. In a research by Ki-sang Nam et al (2015) on the relationship between the types and attitude of regional common brand and purchase intention, consumers’ trust did not have a mediating effect. Since local specialties are consumed based on a trust such as nostalgia for hometown or attachment for countryside, local specialties that arouse nostalgia for hometown or attachment for countryside must be purchased consciously by consumers in order to maximize their intention to repurchase local specialties. It is also necessary to establish a marketing strategy to expand and distribute specialty stores for tourists to easily purchase local specialties in any tourist sites instead of trying to find designated stores. The study results have practical significance as they provided opportunities to understand the impact of motivation to purchase local specialties on positive consumption emotion, tour satisfaction, and repurchase intention as well as the mediating effect of trust. This study hopes to contribute to the development of various local specialties through the production of agro-fishery and livestock goods in different regions. It also seeks to help revitalize regional economies by generating additional incomes through tourists and leading them to the active sales of local specialties.

公程管理電算化Model開發에 關한 硏究

김세경 成均館大學校 1980 국내석사

악성 골종양 환자에 발생한 BRONJ의 임상적 고찰

김세경 경북대학교 대학원 2011 국내석사

PURPOSE : Through the analysis of serological values and clinical aspects of the cancer patients with malignant bone tumor in Korea, we'd like to find out the way of BRONJ diagnosis and the method of BRONJ treatment. MATERIAL and METHOD : Among those who were referred to the Department of Oral and Maxillofacial surgery in Kyungpook University Dental Hospital and who met the BRONJ criteria of American Association of Oral and Maxillofacial Surgeons (AAOMS), twenty-one cancer patients(12 of multiple myeloma, 7 of breast cancer, and 2 of prostate cancer) are selected. And 5 factors(erythrocyte sedimentation rate: ESR, c-reactive protein: CRP, alkaline phosphatease: ALP, osteocalcin: OCN, c-termainal cross-link telopeptide: CTX) were measured and compared with those of normal values. RESULTS : 1. Among the patients with malignant bone tumor, the BRONJ occurred more frequently in patients with multiple myeloma(12persons, 57.1%). The average time to BRONJ was 35.0±19.0 months. The risk factors of BRONJ were the extraction(14 persons, 67%) and improper denture use(4 persons, 20%). 2. Mandible was more susceptible to BRONJ than maxilla, as posterior was to anterior. When BRONJ was diagnosed, BRONJ stage of the selected patients were stage I(2 persons, 9%), stage II(13 persons, 62%), and stage III(6 persons, 29%). 3. The differences between the recurred patients and non-recurred patients in the values of ESR, CRP, and CTX were not noticed. But the statement is not statistically convincing, as the number of selected patients was not large enough. The higher the stage of BRONJ, the lower the value of CTX. 4. During the treatment of BRONJ, some patients discontinued the use of BPs and the others didn't. The investigation was made in order to find out the differences between two groups. The result showed no differences in the aspect of disease and/or recurrence frequencies (p>0.05). It is a matter for consideration that drug holiday to BRONJ patients should be necessary. CONCLUSION : Among the cancer patients with malignant bone tumor, BRONJ occurred more frequently in patients with multiple myeloma and was more susceptible to mandible than maxilla. During the treatment of BRONJ, some patients discontinued the use of BPs and the others didn't. The investigation was made in order to find out the differences between two groups. The result showed no differences in the aspect of disease and/or recurrence frequencies (p>0.05). The differences between the recurred patients and non-recurred patients in the values of ESR, CRP, and CTX were not noticed. But the statement is not statistically convincing, as the number of selected patients was not large enough.

Notes on Dualizing Complexes of a Commutative Noetherian Local Ring : 可換 Noetherian 局所環의 雙對複體에 關한 小考

김세경 全南大學校 大學院 1992 국내박사

본 論文의 1章과 2章에서는 單位元을 갖는 可換 Notherian 局所環의 경우에 R.Y.Sharp (定義 1.5), J.E.Hall (定義 2.8), P.Robert (定義 2.6)에 의해 定義된 雙對複體의 槪念이 同値槪念이라는 것을 定理 2.9에서 證明하고, 3章의 Proposition 3.5 에서 Gorenstein 環의 CM 準同型 像은 階數가 1인 Gorenstein 加群을 갖는다는 것을 證明 하고, Bass問題에 대한 다음 定理들을 證明 하였다. 定理 3.9 (A, m) 을 1次元 可換 Noetherian 局所環 이라 하고, k=A/m 이라 하자. 0아닌 유한생성 A-加群 M이 存在하여 injdim_A(M) < ∞ 이면, A는 Cohen-Macaulay環 이다. 定理 3.10 (A, m) 을 2次元 可換 Noetherian 局所環 이라 하고, k=A/m 이라 하자 0아닌 유한생성 A-加群 M이 存在하여 1) injdim_A(M) < ∞ 이고 2) M이 k-벡터空間 이거나 Supp(M) ≠ { m } 이면, A는 Cohen-Macaulay 環 이다. 定理 3.11 A가 有限次元 Gorenstein 局所環 B의 準同型 像 이고 rad(0:_B A)=rad(0:_B B) 라 하자. 0아닌 有限生成 A-加群 M이 存在하여 injdim_A(M) < ∞ 이면, A는 Cohen-Macaulay 環 이다. In this thesis, we will prove that the concepts of dualizing complex introduced respectively by R.Y.Sharp (Definition 1.5), by J.E.Hall (Definition 2.8), and by P.Robert (Definition 2.6) are equivalent (Theorem 2.9), and that every CM homomorphic image of a Gorenstein ring has a Gorenstein module of rank 1 (Proposition 3.5). And we will give very elementary proofs of Bass Conjecture on a 1-dimensional commutative Noetherian local ring and on a 2-dimensional commutative Noetherian local ring under certain conditions (Theorem 3.9, Theorem 3.10, and Theorem 3.11). Theorem 3.9. Let (A, m) be a commutative Noetherian local ring of dimA = 1 and of it's residue field A/m = k. If A has a finitely generated module M such that injdim_AM < ∞, then A is a Cohen-Macaulay ring. Theorem 3.10. Let (A, m) be a commutative Noetherian local ring with its residue field A/m = k and let dimA = 2. Suppose that A has a finitely generated module M satisfying the following two conditions. (1) injdim_AM < ∞. (2) M is a k-vector space or SuppM □{m}. Then A is a Cohen-Macaulay ring. Theorem 3.11. Let A be a homomorphic image of a finite dimensional Gorenstein local ring B and rad(0 :_B B) = rad(0 :_B A). If there exists a nonzero finitely generated A-module M such that injdim_AM < ∞, then A is a Cohen-Macaulay ring.