Molecular Characteristics of Cysteinyl Groups of Metallothionein by 5,5'-Dithiobis(2-nitrobenzoic acid)

김봉섭,권훈정,최명언,고은희,Kim, Bong-Sub,Kwon, Hoon-Jeong,Choi, Myung-Un,Koh, Eun-Hie 생화학분자생물학회 1987 한국생화학회지 Vol.20 No.3

In the previous study of the reaction of the cysteinyl groups of metallothionein (MT) with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) (Korean Biochem. J. (1984) 17, 288-298), it was found that the DTNB titrable cysteinyl groups were markedly affected either by the presence of metal or by the changes of protein conformation. In order to clarify these phenomena, we prepared the a fragment (4-metal cluster) of MT-I and examined the DTNB reaction. The ratio of 1.7 was obtained as the DTNB titrable cysteinyl groups to the bound metal ions. Thus these data support the notion that only one type of cysteinyl groups may interact with DTNB, mainly simply coordinated cysteinyl groups. Furthermore, we investigated the effects of var ous disulfides on the DTNB reaction rates to explore the microenvironment around the cysteinyl groups. Disulfides tested were cystamine, 2-hydroxyethyl disulfide, dimethyl disulfide, and 3,3'-dithiodipropanoic acid. The DTNB reaction rate of MT-I was enhanced by cystamine and 2-hydroxyethyl disulfide, but that of the a fragment was inhibited by both disulfides. Others had no effects on the DTNB reaction of MT. Therefore, the DTNB titrable cysteinyl groups of MT seem to be located in a hydrophilic and negatively charged microenvironment. 메탈로사이오닌과 5,5'-dithiobis(2-nitrobenzoate) (DTNB)의 반응연구에 의하면 (Korean Biochem. J. (1984) 17, 288-289), DTNB에 의하여 적정되는 cysteinyl기의 수는 금속의 존재나 메탈로사이오닌의 구조에 영향을 받는다. 이것을 더 연구하기 위해 메탈로사이오닌의 $\alpha$ fragment를 분리하여 DTNB와 반응시켰다. DTNB로 적정가능한 cysteinyl기의 수와 금속이온수의 비는 1.7이었다. 이것은 메탈로사이오닌 내의 cysteinyl키 중 simply coordinate된 것만이 DTNB와 반응함을 뒷받침 해준다. 더 나아가 cysteinyl 거의 분자내 환경을 알기 위해 disulfide 의 영향을 살펴보았다. Cystamine, 2,2'-dihydroxyethyl disulfide, 3,3'-dithiodipropanoic acid, dimethyl disulfide 동의 disulfide가 사용 되었다. 메탈로사이오닌-I의 경우에는 cystamine과 2,2'-hydroxyethyl disulfide에 의하여 반응속도가 증가하였으나 $\alpha$ fragment의 경우에는 감소하였다. 다른 두 disulfide는 반응속도에 영향을 마치지 않았다. 따라서 DTNB와 반응하는 메탈로사이오닌의 cysteinyl기는 그 미세환경이 음성전하를 띠고 친수성의 위치에 처해 있다고 추정된다.

나노인덴테이션과 주사탐침현미경을 이용한 박막 재료의 특성평가

김봉섭,윤존도,김종국,Kim, Bong-seob,Yun, Jon-do,Kim, Jong-kuk 한국재료학회 2003 한국재료학회지 Vol.13 No.9

Surface and mechanical properties of thin films with submicron thickness was characterized by nanoindentation with Berkovich and Vickers tips, and scanning probe microscopy. Nanoindention was made in a depth range of 15 to 200 nm from the surface by applying tiny force in a range from 150 to $9,000 \mu$N. Stiffness, contact area, hardness, and elastic modulus were determined from the force-displacement curve obtained. Reliability was first tested by using fused quartz, a standard sample. Elastic modulus and hardness values of fused quartz measured were the same as those reported in the literature within two percent of error. Mechanical properties of ITO thin film were characterized in a depth range of 15∼200nm. As indentation depth increased, elastic modulus and hardness decreased by substrate effect. Ion beam deposited DLC thin films were indented in a depth range of 40∼50 nm. The results showed that the DLC thin film using benzene and bias voltage 0∼-50 V has elastic modulus and hardness value of 132 and 18 GPa respectively. Pure DLC thin films showed roughnesses lower than 0.25 nm, but silicon-added DLC thin films showed much higher roughness values, and the wavy surface morphology.

고분자농약

김봉섭 한국고분자학회 2001 고분자 과학과 기술 Vol.12 No.6

산업별 재무요소가 ESG 환경 등급에 미치는 영향 분석

김봉섭,현석 사단법인 한국융합기술연구학회 2023 아시아태평양융합연구교류논문지 Vol.9 No.11

본 연구는 2020년부터 2022년까지 환경 등급을 확보한 한국의 상장기업을 대상으로, 각 산업별로 전년도의 재무요소가 환경 등급에 어떠한 영향을 미치는지를 실증적으로 분석하였다. 표준산업 분류코드를 기반으로 산업을 구분하였으며, 제조업, 전문 과학 및 기술 서비스업, 도매 및 소매업, 금융 및 보험업, 정보통신업, 건설업, 운수 및 창고업의 7개 산업을 분석대상으로 하였다. 자료수가 불충분한 농업 임업 및 어업 등 9개 산업은 분석대상에서 제외하였다. 분석 결과 각 산업별로 환경 등급에 영향을 미치는 요소가 다르게 나타났다. 특히, 제조업, 전문 및 과학 서비스업, 도소매업에서는 재무 및 인적변수가 환경 등급에 유의미한 영향을 미쳤으며, 정보통신업에서는 인적변수의 영향이 유의하였다. 또한, 성과가 우수한 기업과 높은 환경 평가를 받는 기업 간에는 긍정적인 상관관계가 확인되었다. 이를 통해 기업이 해당 산업에서 뛰어난 성과를 달성하고 충분한 자원을 확보하면 환경 문제에 더 큰 관심을 가질 수 있음을 제시하였다. 환경 분야는 유럽 공급망 규제 및 기후 급변으로 인해 최근들어 중요성이 부각되는 분야로, 한국에서는 대기업 중심으로 활동이 전개되고 있다. 환경 등급 또한 ESG 등급에 비해 국내에서는 연구가 더딘 분야로, 본 연구가 기업 환경 등급 연구에 대한 단초가 되기를 기대한다. The study investigates how financial factors in the preceding year influence environmental ratings. We categorized domestic companies listed in the stock market, which received environmental ratings from 2020 to 2022, according to industry using the Standard Industrial Classification Code. The study analyzed seven industries, including manufacturing, professional science and technology services, wholesale-retail, finance-insurance, information-communications, construction, and transportation-warehousing. Nine industries with insufficient data, including agriculture-forestry-fishing, were excluded from the analysis.The findings indicate that the variables that influence environmental ratings vary by industry. In the manufacturing, professional, technical services, wholesale, and retail industries, both financial and human factors played significant roles. Conversely, in the information and communication industry, human factors were the primary determinants. Overall, the empirical analysis indicates a correlation between high performing companies and favorable ratings in future environmental assessments. These findings suggest that companies can prioritize environmental focus when they excel in their industries and have sufficient resources available. The environmental field is a field that has recently gained importance due to European supply chain regulations and rapid climate change, and in Korea, activities are centered around large corporations. Environmental ratings are also an area with rare research in Korea compared to ESG ratings, and we hope that this study will serve as a starting point for research on corporate environmental ratings.

Cure Behavior and Mechanical Interfacial properties of Tetrafunctional Epoxy/Poly(ε-caprolactone) Blend System

김봉섭,박수진,이재락,김승학 한국고분자학회 2001 한국고분자학회 학술대회 연구논문 초록집 Vol.2001 No.10

이동전화의 프레즌스 효과 연구

김봉섭,김정미 한국언론학회 2009 한국언론학회 학술대회 발표논문집 Vol.2009 No.6-5

이승만정부의 해외유학인재 정책

김봉섭 재외한인학회 2014 在外韓人硏究 Vol.34 No.-

균류키토산의 균체생산에서 기질농도 최적화에 관한 연구

김봉섭,서명교,노종수,이용희,이국의 한국환경보건학회 2003 한국환경보건학회지 Vol.29 No.3

In the process of producing chitosan from crustacean shell, the use of excessive acid and alkli is causing the problems of environmental pollution and of production cost. In this study, one way to solve these problems is to cultivate fungi, then, to extract chitosan from the cell wall. By means of flask incubation and batch cultivation, the optimum cultivation conditions for mass production of continuous cultivation was found. Four strains used for the production of fungal chitosan were Gongronella butleri IF08080, Absidia coerulea IF05301, Rhizopus delemar IF04775, Mucor tuberculisporus IF09256. In flask incubation to select strain of producing much chitosan by means of experiment of the effect of initial pH, Absidia coerulea IFO 5301 had highest yield in FCs, 258.1 $\pm$ 47.3 mg/200 $m\ell$l at pH 6.5. In flask incubation under the optimum cultivation condition, temperature 27$^{\circ}C$, culture time 6days, glucose 2%, peptone 1%, (NH$_4$)$_2$ SO$_4$ 0.5%, $K_2$HPO$_4$ 0.1 %, Nacl 0.1 %, MgSO$_4$ㆍ7$H_2O$ 0.05%, CaCl$_2$ㆍ2$H_2O$ 0.01 %, the yield of DCW brought the highest yields. In batch bioreactor, the optimum cultivation condition was that cell suspended solution was 70 $m\ell$, aeration rate 0.5 l/min, agitation rate 800 rpm, culture time 36 hr. In continuous bioreactor, the optimum substrate flow rate was 4 ι/day.

재외동포 관련 연구동향과 향후 과제

김봉섭 전남대학교 글로벌디아스포라연구소 2008 전남대학교 세계한상문화연구단 국내학술회의 Vol.2008 No.8

붉은대게 폐각으로부터 키토산의 제조 및 물리화학적 특성

김봉섭,박광식,주옥수,서명교,허종화 한국환경보건학회 2001 한국환경보건학회지 Vol.27 No.1

Chitosans were prepared from red crab chitin under various alkali treatment conditions(different alkali concentrations, reaction times and temperatures) and theirphysicochemical properties were investigated. The nitrogen content and deacetylation degree of red crab chitin were 6.15% and 22.17A%, respectively. By the IR spectra, red crab and reference chitin showed the sharp bands at 1650 CM-1/ and 1550 CM-1/, which are characteristic of chitin. The nitrogen contents of prepared chitosans ranged from 6.19~7.48%. Thedeacetylation degree was increased from 63~76% and 48~78% with increasing reaction time and temperature, whereas viscosity was decreased. The nitrogen content and yield of red crab chitosan perpared from chitin with 50% NaOH, 1:25(w/v) for 3.0 hr at 120CM-1 / were 7.26% and 85.0%, respectively. and viscosity, deacetylation degree and molecular weight, 67.0 mPa.s, 75.0% and 6.5x105 Dalton, respectively. From the IR spectra, the amide absorption bands of red crab and reference chitosan became very weak, similarly. And at solid state 13C-NMR spectra, C=O(carbonyl carbon) signals absent, whereas CH3(methyl carbon) was residues. Chemical shift of 13C-NMR spectra of red crab and reference chitosans were in good agreement with slight experimental deviation.