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박인국 생화학분자생물학회 2003 생화학분자생물학회 소식 Vol.23 No.1

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박인국 생화학분자생물학회 2002 생화학분자생물학회 소식 Vol.22 No.3

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Studies on the Effects of Niacin Deficiency on Nicotinamide Coenzyme Levels and Related Enzyme Activities

박인국,Park, In-Kook 생화학분자생물학회 1985 한국생화학회지 Vol.18 No.3

Niacin결핍이 일본산 메추리의 여러기관내 존재하는 nicotinamide coenzyme과 이조효소에 관련된 효소들에 미치는 영향에 관하여 연구 조사하였다. Niacin결핍은 성장에 현저한 저 하와 특히 pectoral muscle의 심각한 atrophy현상을 유발시켰다. Niacin결핍으로 인하여 pectoral muscle의 NAD와 NADPH의 양은 현저하게 감소하였으나 뇌, 심장 및 간조직의 NAD와 NADPH의 양에는 변화가 없었다. 동물체내 niacin status (즉 nicotinamide coenzyme의 농도)는 간 또는 pectoral muscle에서 nicotinamide coenzyme를 필요로 하는 효소 (tryptophan pyrrolase, lactic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutamic dehydrogenase 및 malic enzyme)와 그리고 이 coenzyme를 필요로 하지 않는 효소 (aldolase와 fructose diphosphatase)의 활성에는 아무런 영향을 주지 못하였다. The effects of niacin deficiency on the levels of nicotinamide coenzymes and related enzymes were studied in various organs of Japanese quail. Niacin deficiency led to a marked depression in growth and a remarkable atrophy of the pectoral muscle. Niacin deficiency created a dramatic reduction of NAD and NADPH in the pectoral muscle but not in other tissues such as brain, heart and liver. The niacin status of animal did not influence the activity levels of metabolically related enzymes such as tryptophan pyrrolase, lactic dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glutamic dehydrogenase and malic enzyme or unrelated enzymes such as aldolase and fructose bisphosphatase in liver or pectoral muscle.

Effect of Riboflavin Deficiency on D-amino Acid Oxidase Activity and Tryptophan Metabolism in Rat Tissues

박인국,Park, In-Kook 생화학분자생물학회 1988 한국생화학회지 Vol.21 No.1

The effects of riboflavin deficiency on the levels of flavin coenzymes and D-amino acid oxidase activity and metabolic fate of L- and D-tryptophan in rat tissues have been investigated. The riboflavin deficiency resulted in the marked reduction of FMN and FAD in liver and kidney but riboflavin level was not affected. In riboflavin deficiency the level of liver D-amino acid oxidase activity fell to approximately 25% that of the control. Unlike the liver the level of kidney D-amino acid oxidase activity was not influenced by a riboflavin status in the animal. The overall time course study on tryptophan metabolism demonstrated that the metabolic pattern of L- and D-trypophan turned out to be relatively similar in all tissues examined. 본 연구에서는 flavin coenzyme level에 따른 riboflavin 결핍과 쥐의 조직에서의 D-amino acid oxidase활성과 L-, D-tryptophan 대사의 변화에 관해 조사하였다. Riboflavin결핍은 간과 콩팥에서 FMN과 FAD 현저한 감소를 일으켰지만 riboflavin level은 변하지 않았다. Riboflavin 결핍은 간과 콩팥에서 FMN파 FAD은 변화가 없었다. riboflavin 결핍에서 간의 D-amino acid oxidase 활성 수준은 비교군에 비하여 대략 25%까지 감소되었다. 간에서 와는 달리 콩팥의 D-amino acid oxidase 활성수준이 실험동물에서의 riboflavin 상태변화에 의하여 영향을 받지 않았다. 시간에 따른 tryptophan 대사에 대한 연구는 L-, D-tryptophan의 metabolic pattern은 실험동물의 모든 조직에서 비교적 비슷한 것으로 나타났다.

Polyamine이 Spectinomycin에 의한 Group I Intron의 Splicing 억제에 미치는 영향

박인국,Park, In-Kook 한국미생물학회 1999 미생물학회지 Vol.35 No.4

Cadaverine, putrescine, spermidine과 spermine이 spectinomycin에 의한 T4 파지 thymidylate synthase 유전자(td) intron의 splicing 억제에 미치는 영향을 조사하였다. Polyamine이 존재하지 않는 상태에서 7mM spectinomycin은 splicing rate를 약 40% 감소시켰다. 사용한 농도 범위(0.1~5mM)에서 cadaverine은 splicing rate를 감소시켰으나, putrescine은 0.5mM 농도에서 약 13% 정도의 splicing rate를 증가시켰다. Spermidine은 0.5mM 농도에서 약 11% 정도의 splicing rate를 증가시켰으며, sperimine은 0.01mM 농도에서 약 16% 정도의 splicing rate을 증가시켰다. 시험한 polyamine 중에서 특히 sperimine은 가장 낮은 농도에서 spectinomycin에 의한 억제반응을 극복하는 최고의 활성효과를 나타냈다. 이와 같은 억제 회복 효과는 polyamine에 의한 td intron 리보자임의 구조적 안정성에 기인하는 것으로 추정된다. Effects of polyamines such as cadaverine, putrescine, spermidine and spermine on the self-splicig inhibition of the T4 phage thymidylate synthase(td) intron by spectinomycin have been investrigated. Without polyamine 7mM spectinomycin caused 40% reduction of the splicing rate. Cadaverine reduced the splicing rate over the concentrations of 0.1 to 5 mM. Putrescine at 0.5 mM increased the splicing rate by 13%. Spermidine at 0.5 mM enhanced the splicing rate by 11% while spermine at 0.01 mM enhanced the splicing rate by 16%. Of the all polyamines tested, spermine exhibited the maximum activation effect to counteract the splicing inhibition by spectinomycin. This effect appears to be due to the role of polyamine in stabilizing the conformation of td intron ribozyme essential for the catalytic function.

Determination of Free Flavins in Animal Tissues by Reverse-Phase HPLC with Fluorometric Detection

박인국,Park, In-Kook 생화학분자생물학회 1985 한국생화학회지 Vol.18 No.2

동물 조직내 존재하는 free rihoflavin, FMN 및 FAD를 pmole수준에서 동시에 측정할 수 있는 간단하고 신속한 방법을 연구 조사하였다. treverse-phase HPLC에다 flavins의 fluorescence성질을 이용하여 측정하였다. Flavins은 polarity가 높은 순서로 column으로부터 먼저 나오고 retention time은 FAD가 3.6 min, FMN이 5.4 min 그리고 ribofavin이 9.4 min였다. Retention time은 mobile phase 완충 용액의 methanol부분을 증가시키므로서 단축시킬 수 있었다. Flavins을 동물 간조직에 첨가시 recovery정도는 FAD가 92%, FMN 이 84% 그러고 riboflavin이 98%였다. Flavins 농도에 다른 fluorescence의 relative response를 보면 FAD는 90 pmole, FMN은 85 pmole 그리고 riboflavin은 65 pmole수준까지 직선의 반응관계를 나타내었다. 본 논문에 기술한 방법을 동물의 뇌, 신장, 간 및 심 장조직내 free flavins측정에 적용하였던 바 재래식 fluorometric method와 상응하는 결과를 얻었다. A rapid and simple procedure for the concurrent assay of riboflavin and its coenzyme forms at the picomole level is described. The method makes use of reverse-phase HPLC with fluorometric detection. Some characteristics of the assay of FAD, FMN and riboflavin, respectively, are as follows. Range of linear response, in picomoles: up to 93, 84, 66; mean retention time, in minutes: 3.6, 5.4, 9.4; recovery from standard solutions, in percent(means $\pm$ S.E.): $92{\pm}4.7$, $84{\pm}3.9$, $98{\pm}0.1$. The method has been applied to the determination of flavins in tissue samples such as brain, heart, kidney and liver. The results obtained are comparable to those reported for a conventional fluorometric method.

Effects of Divalent Cations on the Spicing of Phage T4 Thymidylate Synthase Intron RNA

박인국,성정숙,신숙,Park, In-Kook,Sung, Jung-Suk,Shin, Sook The Korean Society for Integrative Biology 1997 Korean journal of biological sciences Vol.1 No.1

Effects of divalent cations such as $Mg^{2+}$, $Mn^{2+}$, $Ca^{2+}$, and $Zn^2$ on splicing activity of phage T4 thymidylate synthase intron RNA have been investigated. At the concentration of 0.5 mM, $Mn^{2+}$ in the absence of $Mg^{2+}$, a very small amount of pre-RNA was cleaved into ligation products (El-E2) but no circular or linear intron was produced. As the concentration of $Mn^{2+}$ was increased from 1 to 5 mM the pre-RNA was completely hydrolyzed. In the presence of 5 mM $Mg^{2+}$, both the linear intron and circular intron were produced but no El-E2 ligation product was produced. At both 3 and 5 mM $Mn^{2+}$ the RNA was hydrolyzed completely as observed with no $Mg^2+$ being present. In the case of $Zn^{2+}$, even at 0.5 mM concentration, the pre-RNA was completely hydrolyzed. This observation suggested that $Zn^{2+}$ facilitates RNA hydrolysis more rapidly than $Mn^{2+}$ does. at 5mM $Ca^{2+}$, the RNA was not hydrolyzed and remained intact as a primary transcript.

Effect of 6-Aminonicotinamide on the Levels of Some Metabolites and Related Enzymes in Rabbit Serum

박인국,이철승,이승훈,송윤경,신숙,Park, In-Koo,Lee, Chul-Seung,Lee, Seung-Hoon,Song, Yoon-Kyung,Shin, Sook The Korean Society for Integrative Biology 1990 동물학회지 Vol.33 No.4

The effects of an antimetabolite, 6-aminonicotinamide (6-AN) on the levels of enzymes and metabolites in rabbit serum were investigated. The intraperitoneal administration of 6-AN (multiple doses of l5mg/kg body weight) gave tise to a remarkable increase in glucose and cholesterol levels but did not exert any appreciable influence on the concentration of albumin and total protein. Alkaline phosphatase activity was significantly reduced by administration of 6-AN, whereas creatine phophokinase, serum glutamic oxaloacetate transaminase and serum glutamic pyruvate transaminase activities were matkedly enhanced. Nevettheless, the levels of Ca, P, Na, K, Cl and Co were not affeded to any extent by 6-AN. Antimetabolited인 6-aminonicotinamide(6-AN)가 토끼의 혈청내 효소 및 대사 물질에 미치는 영향에 관하여 연구하였다. 복강투여시 (l5mg/kg의 체중) 포도당과 콜레스테놀농도는 현저이 증가하였으나 알부민고 총단백질량은 크게 변하지 않았다. Creatine phophokinase,glutamic oxaloacetate transaminase,glutamic pyruvate transaminase 및 alctate dehydrogensenase활성은 매우 증가하였으며 alkaline phosphatase와 Ca, P, Na, K, Cl 및 Co등의 수준은 영향을 받지 않았다.

Studies on Some Fluorescence Properties of Flavin Peptides Isolated from Rat Tissues and of Free Flavins

박인국,Park, In-Kook 생화학분자생물학회 1986 한국생화학회지 Vol.19 No.2

심장 및 간의 mitochondria에서 분리한 flavin peptide처럼 riboflavin이 결핍된 그리고 투여된 간에서도 fluorescence excitation spectra의 second peak에 hypsochromic shift현상을 볼 수 있었다. pH가 2-7범위내에서 riboflavin과 liver mitochondrial flavin peptide의 fluorescence는 아무런 영향을 받지 않았으나 heart mitochondrial flavin peptide는 pH에 의한 fluorescence quenching을 나타냈고 그때 $pK_a$ 값은 4.3이었다. 쥐의 간에서 riboflavin의 결핍시 fluorescence excitation spectra의 fluorescence intensity는 riboflavin과 투여시의 fluorescence intensity에 약 50%에 달하였다. The hypsochromic shift of the second peak of fluorescence excitation wavelength was observed with flavin peptides isolated from heart and liver mitochondria and from whole livers of riboflavin-deficient and riboflavin-supplemented rats. The fluorescence of riboflavin and liver mitochondrial flavin peptide is independent of pH in the range of 2 to 7 but heart mitochondrial flavin peptide shows a pH-dependent fluorescence quenching with $pK_a$ of 4.3. It is noteworthy that the relative fluorescence intensity of each peak of fluorescence excitation spectra of riboflavin-deficient rat liver corresponds to about 50% that of riboflavin-supplemented rat liver.

Alterations of Sedimentation Profiles of Ribosomes from T . novellus under the Nutritional Shift

박인국,신숙 생화학분자생물학회 1992 생화학분자생물학회 춘계학술발표논문집 Vol.- No.-