S-C2 : Cellular Signal Transduction and Properties of PI - specific Phospholipase C ( PLase C ) in Bovine Brain

조기승,유성호,서판길,이기영,이서구 한국생화학분자생물학회 (구 한국생화학회) 1987 추계학술대회집 Vol.- No.-

生化學의 오늘과 來日

조기승 漢陽大學校文理科大學 化學科 1974 化脈 Vol.- No.4

電氣 가오리 Acetylcholinesterase 酵素의 特性에 關한 硏究

曺基勝 漢陽大學校 環境科學硏究所 1982 環境科學論文集 Vol.3 No.-

남해안에서 나는 전기가오리의 발전기관으로부터 Acetylcholinesterase 를 추출 정제하였다. Sepharose 4B Affinity Column Chromatography 에 의해 정제한 결과 예민한 단일 peak를 나타냈고, Specific activity 는 2,700으로 68배의 정제도를 나타냈다. Acetylcholinesterase의 최적 pH는 7.3 과 7.6 사이로 이 pH 전후에서는 활성도의 감소추세를 보였고, 여러 가지 Buffer 용액에 대한 효소활성도를 시험한 결과 시험한 Buffer 용액 중 Tris-HCI Buffer 용액이 가장 높은 활성도를 보였다. 25℃ 에서 여러 안정제에 대한 효과를 보았을 때, 0.01% Casein 과 0.05 M Mgcl₂를 함유한 Tric-HCI Buffer 용액에서 효소활성도가 가장 안정함을 보여 Casein 과 ?? 이 안정효과가 있음을 확인하였다. Acetylcholinesterase는 매우 낮은 농도의 유기인산화합물인 parathion 과 같은 농약에 매우 민감한 저해현상을 나타냈다. Acetylcholinesterase was extracted and purified from electric organs of Electrophorus Japonica inhabited a southern coast. Acetylcholinesterase showed a single sharp peak by affinity column chromatography and has a specific activity, 2,700, representing a 68 fold purification over the homegenate. The optimum pH range of this enzyme was between from 7.3 to 7.6, and decreased outside this pH range. In the several buffer solutions tested, the highest enzyme activity was obtained with Tris-HCI buffer. It is certified that 0.01% casein and 0.05M Mgcl₂have a stabilizing effect on enzyme activity at 25℃ in Tris-HCI buffer. Acetylcholinesterase was inhibited sensitively by a low concentration of organic phosphorus compound, suchas, parathion.

사람의 적혈구막의 Palmitoylcarnitine과 Palmitoyl-CoA : Carnitine Palmitine Palmitoyltransferase의 역할에 관한 연구

조기승,정진성,Cho, Key-Seung,Chung, Jin- Sung 생화학분자생물학회 1982 한국생화학회지 Vol.15 No.3

An enzyme, palmitoyl-CoA: carnitine palmitoyltransferase (E.C. 2.3.1.21) was confirmed to catalyze reversively the formation and hydrolysis of $^{14}C$ -palmitoylcarnitine in human erythrocyte membrane. The optimum pH range of this enzyme was between from pH 7.2 to pH 7.4, and decreased rapidly outside of this pH range. In the several buffer systems tested, the highest enzyme activity was obtained with Tris-HCl buffer. As a cofactor, 5 ${\mu}moles$ of $Mg^{2+}$ ion significantly stimulated the enzyme activity in the experimental conditions. Palmitoylcarnitine formed from this enzyme system or synthesized from other chemical method has activated significantly the membrane bound enzymes, such as adenosine triphosphatase (ATPase) and Glucose-6-Phosphatase (G-6-Pase). 사람의 적혈구막에서 palmitoyl-CoA: carnitine palmitoyltransferase에 의해 $^{14}C$-palmitoylcarnitine이 가역적으로 생성 및 가수분해 됨을 확인하였다. 이 효소의 최적 pH 범위는 pH 7.2에서 pH 7.4 근방으로, 이 pH 범위 외에서는 급속한 효소활성도의 감소를 나타냈다. 몇가지의 완충용액을 시험하여 보았을때 Tris-HCI buffer가 가장 높은 효소활성도를 보였으며, 조요소로서 5 ${\mu}mole$의 $Mg^{2+}$이온이 동일 실험조건하에서 효소의 활성도를 굉장히 증가시켰다. 이 효소계에 의해서나 흑은 화학적인 합성에 의해 만들어진 palmitoyl. carnitine은 세포막에 부착되어 있는 효소인 ATPase나 G-6-Pase와 같은 효소를 상당히 활성화 시켰다.

The Mechanism of Acyl Phosphatidyl Glycerol Biosynthesis in Escherichia coli B and B/r

조기승,홍승덕,장정순,이강석,Cho, Key-Seung,Hong, Seung-Duk,Chang, Chung-Soon,Lee, Kang-Suk 생화학분자생물학회 1975 한국생화학회지 Vol.8 No.1

본 연구는 대장균 strain B와 B/r(Escherichia coli Band B/r)의 세포막 분획에의 해서 phosphatidyl glycerol이 3-sn-phosphatidyl-1'-(3'-acyl(-sn-glycerol(acyl phosphatidyl glycerol 로 전환되는 기작을 밝혔다. 이 과정에서 phosphatidyl glycerol은 더 간단한 화합물로 분해된 후 acyl phosphatidyl glycerol로 합성되는 것이 아니라 직접 acyl group이 옮겨져서 ester 결합을 하는 것으로 생각된다. Phosphatidyl glycerol이 acyl phosphatidyl glycerol로 전환되는 반응을 촉매하는 효소인 acyl phosphatidyl glycerol synthetase는 E. coli homogenate의 세포막 분획에 존재하는 것으로 밝혀졌다. Phosphatidyl glycerol이 acyl phosphatidyl glycerol로 전환됨에 있어서 두 개의 다른 반응 기작을 밝혔다. 두 분자의 phosphatidyl glycerol이 한 분자의 acyl phosphatidyl glycerol 을 합성하는 즉 phosphatidyl glycerol이 acyl group의 공여체와 수용체로 각각 작용하는 반응과 다른 반응은 phosphatidyl glycer이 이 수용체로 phosphatidyl ethanolamine이 acyl group 공여체로 작용하는 기작이다. Acyl phosphatidyl glycerol 생합성에 있어서 최적 pH 는 7.0이며 최적 calcium ion 농도는 6.0mM 이었다. 이 실험 결과는 대장균의 phosphatidyl glycerol의 새로운 대사과정을 밝혔다. The present study has shown that phosphatidyl glycerol was converted to 3-sn-phosphatidyl-1'-(3'-acyl)-sn-glycerol (acyl phosphatidyl glycerol) by cell free extracts of Escherichia coli Band B/r. In this process, phosphatidyl glycerol was esterified directly rather than degraded to simpler compounds which are subsequently incorporated into acyl phosphatidyl glycerol. The enzyme, "acyl phosphatidyl glycerol synthetase", which catalyzes the conversion of phosphatidyl glycerol to acyl phosphatidyl glycerol was found to reside solely in the praticulate fraction of E. coli homogenates. Two separate reactions were identified where one molecule of acyl phosphatidyl glycerol was synthesized from two molecules of phosphatidyl glycerol, in which phosphatidyl glycerol acted both as an acyl acceptor and a donor. In the other reaction, phosphatidyl ethanolamine appears to act as an acyl donor to synthesize acyl phosphatidyl glycerol. The formation of acyl phosphatidyl glycerol has an optimum pH value at pH 7.0 and calcium concentration of 6.0 mM. These results show a new pathway for the turnover of phosphatidyl glycerol in Escherichia coli.

대장균 Strain B 와 B / r 에 있어서 Acyl Phosphatidyl Glycerol 의 생합성 기작에 관한 연구

조기승,홍승덕,장정순,이강석 ( Key Seung Cho,Seung Duk Hong,Chung Soon Chang,Kang Suk Lee ) 생화학분자생물학회 1975 BMB Reports Vol.8 No.1

The present study has shown that phosphatidyl glycerol was converted to 3-sn-phosphatidyl-1`-(3`-acyl)-sn-glycerol(acyl phosphatidyl glycerol) by cell free extracts of Escherichia coli B and B/r. In this process, phosphatidyl glycerol was esterified directly rather than degraded to simpler compounds which are subsequently incorporated into acyl phosphatidyl glycerol. The enzyme, $quot;acyl phosphatidyl glycerol synthetase$quot;, which catalyzes the conversion of phosphatidyl glycerol to acyl phosphatidyl glycerol was found to reside solely in the praticulate fraction of E. coli homogenates. Two separate reactions were identified where one molecule of acyl phosphatidyl glycerol was synthesized from two molecules of phosphatidyl glycerol, in which phosphatidyl glycerol acted both as an acyl acceptor and a donor. In the other reaction, phosphatidyl ethanolamine appears to act as an acyl donor to synthesize acyl phosphatidyl glycerol. The formation of acyl phosphatidyl glycerol has an optimum pH value at pH 7.0 and calcium concentration of 6.0 mM. These results show a new pathway for the turnover of phosphatidyl glycerol in Escherichia coli.

사람의 적혈구막의 Palmitoylcarnitine 과 Palmitoyl - Coa Carnitine Palmitine Palmitoyltransferase

조기승,정진성 ( Key Seung Cho,Jin Sung Chung ) 생화학분자생물학회 1982 BMB Reports Vol.15 No.3

An enzyme, palmitoyl-CoA: carnitine palmitoyltransferase (E.C. 2. 3.1.21) was confirmed to catalyze reversively the formation and hydrolysis of ^(14)C-palmitoylcarnitine in human erythrocyte membrane. The optimum pH range of this enzyme was between from pH 7.2 to pH 7.4, and decreased rapidly outside of this pH range. In the several buffer systems tested, the highest enzyme activity was obtained with Tris-HCl buffer. As a cofactor, 5 μmoles of Mg^(2+) ion significantly stimulated the enzyme activity in the experimental conditions. Palmitoylcarnitine formed from this enzyme system or synthesized from other chemical method has activated significantly the membrane bound enzymes, such as adenosine triphosphatase (ATPase) and Glucose-6-Phosphatase (G-6-Pase).

생쥐에서 KCN의 독성과 해독제 평가에 관한 연구

이철영,조기승 漢陽大學校 環境科學硏究所 1992 環境科學論文集 Vol.13 No.-

시안화합물(CN­)의 독성에 대한 해독제 평가 실험에 앞서, 먼저 생쥐를 사용하여 구강, 복강 및 피하 주입에 의한 시안화 칼륨(KCN)의 반치사량(??)을 24시간후의 생존수에 의해 측정하여 보았더니, 각각 70.mg/kg, 8.6mg/kg 및 8.8mg/kg 등을 나타냈으며, 결과로 보아 구강투여가 다른 경로에 비해 독성이 심한 것으로 관찰되었다. 시안화합물의 독성에 대한 해독 효과를 보기위해 여러 가능한 Sulfur-공여체와 몇 몇 해독 효과가 알려진 화합물들을 생쥐에 투여하여 KCN의 ??에 대한 해독 배율을 측정하여 보았더니, 시험해 본 화합물중에서 NaNO₂, Na₂S₂O₃ 및 Cysteine 등이 2배 이상의 해독율을 나타냈으며, NaNo₂+Na₂S₂O₃ 혼용 투여에서는 5.4배율의 해독 효과를, NaNo₂+Na₂S₂O₃+Vit.?? 혼용투여에서는 8.6배의 해독 상승율을 보이므로 단독 투여보다는 혼용 복합 투여가 더 효과적임을 나타내 주었다. 한편 S-공여 화합물인 6-thioguanosine과 2-thioxanthine은 1.4배의 해독율을 보였고, thiodiethanol은 1.6배의 해독율을 보여 이들 화합물이 CN­ 독성 해독에 있어서 rhodanese에 대한 S-공여체로서 얼마간 작용하고 있음을 보여주었다. Before the evaluation of antidotal efficacy on cyanide poisoning in mice, fifth percent of lethality(??) determined on 24 hr mortality after administration of KCN through on oral, intraperitoneal cavity and subcutaneous injection was exhibited 7.0mg/kg, 8.6mg/kg, 8.8mg/kg respectively. It demonstrated that oral administration of KCN was more severe in toxicity than other routes Several Sulfur-donor and other konwn compounds were tried in order to examine the detoxication potency against ?? of KCN toxicity in mice. Among them, single pretreatment of each NaNo₂, Na₂S₂O₃and Cysteine showed the over two fold detoxication potency. On the other hand, complex pretreatments of two of three compounds, NaNo₂+Na₂S₂O₃ or NaNo₂+Na₂S₂O₃+Vit.B exhibited more effectiveness than single pretreatment as showing the potency ratio of 5.4 and 8.6, respectively. While, S-donor compounds, 6-thioguanosine and 2-thioxanthine exhibited 1.4 fold detoxication potency, and thiodiethanol showed 1.6 fold detoxication. From these results such thiol compounds were somethat active as S-donor to rhodanese reaction in CN-detoxication.

신경 세포에서 Ca-channel의 비활성에 관한 연구

이영식,조기승 漢陽大學校 基礎科學硏究所 1988 基礎科學論文集 Vol.7 No.-

신경세포의 bursting 기작을 설명하기 위하여 기존에 제안된 Ca-activated Potassium channel 대신 Ca channel을 사용하여 기존의 model과 유사한 결과를 얻었다. 이들의 Phase Plane에서의 행동도 유사함을 보여준다. We have modified slow oscillation dynamics in Plant Nerve cell model in order to incorperated the Ca chnnael incativation mechanism. The calcium activated potassium channel has been replcaed with leak and voltage dependent calcium channel with and calcium inactivated voltage gated calcium channel. The simulation results with our model resemble the experimental results and Plant model's. The phase plane behavior of our model is also similar to the Plant model's behavior. It suggest that the calcium channel inactivation mechainsm may be a possible mehcanism for the slow oscillation dynamics in membrane potential oscillation in neuron cell body.

사람 적혈구 막에 있어서 Carnitine acyltransferase 효소에 관한 연구

박중근,김응렬,조기승 漢陽大學校敎養學部 1976 硏究論文集 Vol.- No.1

사람 적혈구막에서 palmitoyl carnitine을 생성하는 효소계의 존재를 확인하였는데 이 효소계에 의해 palmitoyl coenzyme A와 DL-Carnitine(methyl-14C)으로부터 palmitoyl carnitine-14C이 생합성됨을 고찰하였고, 한편 이 효소계에 의해 화학적으로 합성한 palmitoyl-14C-carnitine이 palmitic acid-14C과 carnitine으로 가수분해됨을 확인하였다. 이 효소계에 의해서나 또는 화학적 방법에 의해 만들어진 palmitoyl carnitine은 적혈구막을 용해하며 이때 막에 부착된 효소계인 Adenosine Triphosphatase나 Glucose-6-phosphatase등이 활성화됨을 발견하였다. An enzyme system in human erythrocyte membrane was found to catalyze the formation of palmitoyl carnitine-14C from palmitoyl coenzyme A and carnitine-(methyl-14C). It was also confirmed that the same enzyme acts on the hydrolysis of palmitoyl-14C-carnitine into palmitic acid-14C and carnitine. Palmitoyl carnitine formed from this enzyme system or other chemical method solubilized the erythrocyte membrane and stimulated significantly the membrane bound enzymes, such as Adeno-sine Triphosphatase (ATPase) and Glucose-6-phosphatase (G-6-Pase) tried.