가원 (歌園) : 신년축사 (新年祝詞) / 학생 (學生) 이회석 (李會錫)

이회석 조선불교월보사 1913 朝鮮佛敎月報 Vol.12 No.-

Structure-based Mutational Studies of D-3-hydroxybutyrate Dehydrogenase for Substrate Recognition of Aliphatic Hydroxy Acids with a Variable Length of Carbon Chain

이회석,나정걸,이진원,연영주 한국생물공학회 2019 Biotechnology and Bioprocess Engineering Vol.24 No.4

Native 3-hydroxybutyrate dehydrogenase from Alcaligenes faecalis can catalyze the reversible reduction of acetoacetate, a four carbon chain oxo acid. This enzyme has been engineered to enable the reduction of levulinic acid, with one carbon longer than acetoacetate. In this study, the native and engineered enzymes were subjected to the catalysis of oxo acids with a carbon chain length of 3 to 8, in order to examine the capability of the enzyme to work on various platform chemicals. The engineered enzyme could reduce the C7 and C8 oxo acids whereas the wild-type had no activity on these substrates. Docking simulation has indicated Tyr155 and Ser142 are key residues for the catalysis. In addition, stable hydrogen bond formation between Gln196 and the substrates affects the turnover rate. Mutation sites in the engineered enzyme were focused on creating larger active site volume for substrates with extended chain lengths. Both qualitative and quantitative structural basis for the enzyme substrate specificity on alpha, beta, gamma and omega hydroxy acids could be elucidated.

Enzymatic synthesis of nylon precursors by 4-aminobutyrate aminotransferase and 6-oxohexanoate dehydrogenase

이회석,양영헌,연영주,박현준 한국생물공학회 2024 Biotechnology and Bioprocess Engineering Vol.29 No.1

6-Aminocaproic acid and adipic acid are the key value-added chemical precursors in the pharmaceutical, solvent and polyamide industry, including nylon-6, and nylon-6, 6. An enzymatic interconversion of the two precursors can provide a convenient and eco-friendly biosynthetic route to each of the precursors and thus, require analysis of the reaction process. Herein, an in vitro enzymatic method was employed to convert the two precursors while most studies so far have focused on the whole cell bioconversion to investigate the process. 4-Aminobutyrate aminotransferase was utilized to mediate the reactions between 6-aminocaproic acid and the intermediate 6-oxohexanoic acid with the aid of pyridoxal 5’-phosphate and amine donor/acceptor. 6-Oxohexanoate dehydrogenase was utilized for the reaction from 6-oxohexanoic acid to adipic acid with NADP + . A range of reaction conditions were investigated including the type of amine donor, pH conditions, the concentrations of enzyme and amine donor/acceptor. The optimum condition resulted in 78% yield for the reaction from 6-oxohexanoic acid to 6-aminocaproic acid. The yield for the one-pot, two-step enzymatic cascade from 6-aminocaproic acid via 6-oxohexanoate intermediate to adipic acid was 88%, which was higher than the yield for each individual step in the cascade, with 31% and 32%, for the fi rst and second step, respectively. Furthermore, structural analysis on the active site of the 4-aminobutyrate aminotransferase docked with a range of amine donors implicates the optimal donor is glutamate in accordance with the experimental data and suggests enzyme engineering possibilities for more readily available donors to facilitate the industrial application of the process.

중추신경계를 침범한 한국인 고셔병 환자의 임상적 특성과 유전자 분석

최회석,김성환,Hiroyuki Ida,김현주 대한소아청소년과학회 2000 Clinical and Experimental Pediatrics (CEP) Vol.43 No.5

목 적 : 신경계를 침범한 한국인 고셔병 환자의 임상적 특징 및 자연력을 파악하고 유전자 분석이 한국인 고셔병 환자의 신경계 침범 유무의 결정에 유용한지를 알기 위해 본 연구를 시행하였다.방 법 : 아주대학교병원 한국 고셔병 환자 모임에등록된 환자들 중 신경계 증상을 동반한 제 Ⅱ형 및 Ⅲ형 환자 13명의 의무기록을 토대로 발병연령, 초기증상, 임상양상, 임상신경생리검사 소견, 뇌 자기공명영상촬영 소견 및 임상경과 등을 분석하였다. 유전자 분석은 신경계 침범증상이 있는 고셔병 환자 7례 및 신경계 침범증상이 없는 고셔병 환자 8례에서 중합 효소 연쇄반응법(PCR) 및 중합효소 연쇄반응-단일쇄 다형성법(PCR-SSCP)을 시행하였다.결 과 : 한국인 고셔병 환자 46례 중 제 Ⅱ형은 6례(13%), 제 Ⅲ형은 7례(15%)였다. 제 Ⅱ형 환자들은 전형적인 임상양상을 보이다 급격히 진행해 모두가 2세 이전에 사망하였다. 제 IIIa형 환자는 모두 간질 발작으로 증상이 시작되었고 1례를 제외하고 대부분 현재 생존하고 있다. 제 IIIa형 환자는 모두 뇌파 검사상 미만성 다발성 극파 및 광 과민성을 보였으며 일부는 간질발작이 유도되었다. 7례의 신경계 침범증상이 있는 고셔병 환자에서 유전자 검색이 시행되어 L444P/L444P(2례), F213I/F213I(1례), F213I/?(1례), 및 N 188S/?(1례)와 같은 유전자 변이가 발견되었다. 반면 신경계 침범증상이 없는 8례의 제 I형 고셔병 환자에서는 L444P/?(4례), L444P/F213I(1례), F213I/ ?(2례)와 같은 유전자 변이가 발견되었다. Purpose : We performed the study to determine the clinical characteristics and natural history of Gaucher disease with CNS involvement in Korea as well as to determine whether gene analysis would be helpful in the identification of neuronopathic Gaucher disease. Methods : We described the initial symptom, clinical manifestations, age of onset, clinical neurophysiologic findings and brain MRI findings from the medical records of 13 patients with neuronopathic Gaucher disease identifed from the Korean Gaucher Disease Patient Registry. Mutation analysis was performed in 7 cases of neurono pathic Gaucher disease patients by PCR or PCR-single strand conformation polymorphism(SSCP). Results : Among 46 cases of Korean Gaucher disease, type Ⅱ was found in 6 cases(13%) and type Ⅲ was found in 7 cases(15%). Type II Gaucher disease showed typical clinical features, and those patients expired in less than 2 years of age. All the type IIIa patients presented epileptic seizure as an initial symptom and most of the patients survived. All the type IIIa patients revealed epileptiform activity and photoparoxysmal response. Mutation analysis in neuronopathic Gaucher disease patients revealed L444P/L444P(2 cases), F213I/F213I(1 case), F213I/?(1 case) and N188S/?(1 case). However, mutation analysis in type I Gaucher disease revealed L444P/?(4 cases), F213I/?(2 cases) and L444P/F213I(1 case). Conclusion : The clinical characteristics and natural history of Korean Gaucher disease is similar to those of Jewish Gaucher disease. Brain MRI, clinical neurophysiologic study and gene analysis are not helpful in the identification of neuronopathic Gaucher disease. Regular neurologic examinations are the only method to determine CNS involvement in Gaucher disease.

SDI 정책리포트 : 2010년 1/4분기 서울지역 소비자 및 기업 체감경기 전망

박회석 서울시정개발연구원 2010 SDI 정책리포트 Vol.59 No.-

배제 정보를 이용한 효율적인 한국어 형태소 분석기

임회석(Heui-Seok Lim),윤보현(Bo-Hyun Yun),임해창(Hae-Chang Rim) 한국정보과학회 1995 정보과학회논문지 Vol.22 No.6

The existing Korean morphological analyzers generate all the possible candidates only to accept the correct candidates, creating significant amount of implausible candidates. Hence the string processing time and the dictionary access frequency in analyzing a word are aggravated. To lower the above inefficiency, this paper proposes the efficient Korean morphological analyzer using exclusive information, which represents the exclusive relation between specific phoneme, specific syllable, specific string and each part of speech. We discuss how it can reduce the implausible candidates in analyzing a word. The result of the experiment showed that Korean morphological analyzer using exclusive information decreased the dictionary access frequency about 40.16% in comparison with others by reducing the implausible candidates. 모든 형태소 결합을 찾아내는 기존의 한국어 형태소 분석 방법은 후보 생성 과정에서 불필요한 분석 후보를 생성하여 문자열 처리 시간과 사전 탐색 횟수를 가중시키는 단점이 있다. 본 논문은 이러한 비효율성을 감소시키기 위하여 배제 정보(Exclusive Information)를 이용한 효율적인 한국어 형태소 분석 방법을 제안한다. 배제 정보는 음소, 음절, 문자열 각각과 특정 품사와의 배제 관계를 나타내는 정보이다. 배제 정보를 이용한 형태소 분석 시스템은 필요 없는 분석 후보 생성을 감소시키므로 효율적인 분석을 수행한다. 한국어 어절 약 30만개에 대해서 실험한 결과, 본 논문에서 제시한 배제 정보를 이용한 한국어 형태소 분석 시스템은 분석 후보의 생성을 줄임으로 기존의 시스템보다 사전 탐색 횟수를 약 40.16% 감소시킬 수 있었다.

대학생활 적응척도의 요인구조 분석 -관광관련 전공 학생을 중심으로-

박회석 ( Hee Seok Park ) 관광경영학회 2010 관광경영연구 Vol.43 No.-

This study investigated the factor structure of RSACQ(Revised Student Adaption to College Questionnaire) using SPSS 11.5 and AMOS 4.5 program that supply estimation method for data. The participants consisted of 277 tourism major`s students aged 18-51. The results showed that student`s adaption accessed by RSACQ has for factors. individual and emotional adaption, scholastic adaption, adaption of university`s general environment and social adaption. This strengths of this study include the application of more rigorous questionnaire methodology than has been used in previous studies. Also, this result that tourism major`s students accessed by RSACQ has four factors is possible to used in clinical settings as well as future researches.

Erucamide from Radish Leaves Has an Inhibitory Effect Against Acetylcholinesterase and Prevents Memory Deficit Induced by Trimethyltin

김초롱,김회석,최수정,김재겸,김민철,김윤정,신동훈 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.8

In this study, we investigated a potent acetylcholinesterase inhibitor that was isolated from radish leaf (Raphanus sativus L.) extracts. Through sequential fractionation of radish leaf extract, the active constituent was identified as cis-13-docosenamide (erucamide). To validate the potency, erucamide derived from radish leaves was supplemented in diets and then fed to trimethyltin (TMT)-exposed mice. Specifically, mice had free access to a control diet or diets containing different concentrations of erucamide for 3 weeks, followed by an injection of TMT (2.5 mg/kg body weight). Our results showed that pretreatment of mice with erucamide (20 and 40 mg/kg body weight per day) significantly attenuated the TMTinduced learning and memory deficits that were assessed by Y-maze and passive avoidance tests. These findings suggest that radish leaves, and possibly its isolated erucamide, may have preventive effects against memory deficits related to Alzheimer’s disease by modulation of cholinergic functions.

이유자돈 사료에 유기태 아연 (Zn-Met)의 적정 첨가 수준에 관한 연구

안성호,임회석,백인기 中央大學校 食糧資源硏究所 2002 食糧資源硏究所 論文集 Vol.14 No.1

An experiment was conducted to study the effects of supplementary Zn-methionine chelate on the performance of the weanling pigs. Thirty six, 18 in each sex, 5 wk old 3-way crossbred (YxLxD) pigs were assigned to 6 treatments which were control, control + 100, 200, 400, 600 or 800 ppm Zn of methionine chelate treatment respectively. Three pigs were housed in a raised floor pen and 2 pens were assigned to each treatment. Individual pig weight and feed intake of each pen were recorded weekly for 4 wks. Average daily feed intakes (ADFI) and average daily gains (ADG) were significantly (P<0.05) different among treatments. Zn-Met-100 treatment showed highest ADG but other Zn-Met treatments showed lower ADG than the control. ADFI was highest in the control. There were no significant differences in feed conversion ratio and serum APase activity among treatments. Serum IgG concentrations were significantly (P<0.05) different among treatments. All Zn-Met treatments showed higher IgG concentration than the control. The levels of Zn in serum and feces increased linearly as the level of Zn increased but the levels of Fe and Cu in serum and feces were not significantly affected by treatments. It was concluded that supplementation of Zn-Met at the level exceeding 100ppm Zn may not have beneficial effects on the performance of weaning pigs.

e-러닝: m-러닝 2 ; 멀티미디어를 이용한 심상 기반 영어 어휘 학습 방법

유지호 ( Ji Ho Yoo ),임회석 ( Heui Seok Lim ) 한국컴퓨터교육학회 2011 한국컴퓨터교육학회 학술발표대회논문집 Vol.15 No.2

정보화로 인해 교육현장에서도 멀티미다어의 활용이 가속화되고 있으며, 다양한 교수-학습도구들이 등장하고 있다. 또한, 이를 이용한 교수-학습방법 역시 응용 및 확산되어 그 효과성 역시 검증하고자 하려는 노력이 진행중이다. 그러나 기존 교수자 중심의 텍스트 기반 교수-학습의 연장선상에서는, 학습자 중심의 멀티 미디어 교수-학습 환경측면을 이해하려는 데에는 한계가 있다. 즉, 멀티미다어가 활용되는 환경을 이해하고 다양한 도구들이 가진 장점들을 융합할 수 있으며, EFL 상황에서의 효율성이 요구되는 영어 어휘 학습을 체제적으로 분석할 수 있다. 이를 통해서, 교수-학습의 향상을 목표로 하는 심상 형성 활동을 통한 영어 어휘 학습 방법을 설계ㆍ개발하고자 한다.