• BMB Reports
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• 제28권2호
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• pp.162-169
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• 1995

Rat brain succinic semialdehyde dehydrogenase (EC 1.2.1.24 SSADH) activity was detected in mitochondrial, cytosolic and microsomal fractions. Brain mitochondrial soluble SSADH was purified by ammonium sulfate precipitation, DEAE Sephacel, and 5'-AMP Sepharose 4B affinity chromatography. The purified enzyme was shown to consist of four identical subunits, and the molecular weight of a subunit was 55 kD. The $K_m$ for short chain aliphatic aldehydes and aromatic aldehydes were at the $10^{-3}M$ level but that for succinic semialdehyde was 2.2 ${\mu}M$. Either $NAD^+$ or $NADP^+$ can be used as a cofactor but the affinity for $NAD^+$ was 10 times higher than that for $NADP^+$. The brain cytosolic SSADH was also purified by ammonium sulfate precipitation, DEAE Sephacel, Blue Sepharose CL-6B and 5'-AMP Sepharose 4B affinity chromatography and its Km for short chain aliphatic aldehydes was at the $10^{-3}$ level but that for succinic semialdehyde was 3.3 ${\mu}M$. $NAD^+$ can be used as a cofactor for this enzyme. We suppose that both enzyme might participate in the oxidation of succinic semialdehyde, which is produced during GABA metabolism. The activity of both cytosolic and mitochondrial SSADH was markedly inhibited when the concentration of succinic semialdehyde was high. The reciprocal plot pattern of product inhibition and initial velocity indicated a sequential ordered mechanism for mitochondrial matrix SSADH. Chemical modification data suggested that amino acid residues such as cysteine, serine and lysine might participate in the SSADH reaction.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.668-673
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• 2012

Biohydrogen production from organic wastewater by anaerobically activated sludge fermentation has already been extensively investigated, and it is known that hydrogen can be produced by glucose fermentation through three metabolic pathways, including the oxidative decarboxylation of pyruvic acid to acetyl-CoA, oxidation of NADH to $NAD^+$, and acetogenesis by hydrogen-producing acetogens. However, the exact or dominant pathways of hydrogen production in the anaerobically activated sludge fermentation process have not yet been identified. Thus, a continuous stirred-tank reactor (CSTR) was introduced and a specifically acclimated acidogenic fermentative microflora obtained under certain operation conditions. The hydrogen production activity and potential hydrogen-producing pathways in the acidogenic fermentative microflora were then investigated using batch cultures in Erlenmeyer flasks with a working volume of 500 ml. Based on an initial glucose concentration of 10 g/l, pH 6.0, and a biomass of 1.01 g/l of a mixed liquid volatile suspended solid (MLVSS), 247.7 ml of hydrogen was obtained after a 68 h cultivation period at $35{\pm}1^{\circ}C$. Further tests indicated that 69% of the hydrogen was produced from the oxidative decarboxylation of pyruvic acid, whereas the remaining 31% was from the oxidation of NADH to $NAD^+$. There were no hydrogen-producing acetogens or they were unable to work effectively in the anaerobically activated sludge with a hydraulic retention time (HRT) of less than 8 h.

• KSBB Journal
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• 제19권6호
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• pp.467-470
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• 2004

해당 작용의 중간체를 에너지원으로 이용한 무세포 단백질 발현 반응에서의 낮은 재현성 및 단백질 생산성은 반응액의 pH 및 NAD의 존재에 의해 크게 영향을 받는다는 사실을 밝혀내었다. 기존의 PEP를 사용하는 표준반응 용액에서 PEP를 G-6-P로 대체하고 동시에 반응액의 pH 및 NAD 농도를 최적화 함으로써 반응액 1 mL당 약 $300{\mu}g$에 이르는 단백질을 회분식 반응으로 발현할 수 있었다. ATP 재생 방법의 개선을 통한 회분식 무세포 단백질 발현의 생산성 향상은 다종 유전자의 고속 번역을 통한 기능 규명에 있어서 유용한 도구로서 사용될 수 있을 것으로 기대된다.

• 한국임상약학회지
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• 제8권1호
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• pp.29-34
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• 1998

Murine CD38 is a 42 kDa type II glycoprotein expressed on cell surface of both B and T lymphocytes. CD38 is a multifunctional enzyme that catalyzes the formation and hydrolysis of cyclic adenosine diphosphoribose (cADPR): ADP-ribosyl cyclase activity of CD38 catalyzes the formation of cADPR from NAD and cADPR hydrolase activity of CD38 catalyzes the hydrolysis of cADPR to ADP-ribose (ADPR). And also, CD38 has the catalytic activity of NAD glycohydrolase (NADase) which catalyzes the hydrolysis of catalyzes the formation and hydrolysis of cyclic adenosine diphosphoribose (cADPR): ADP-ribosyl cyclase activity of CD38 catalyzes the formation of cADPR from NAD to ADPR. In this study, we attempted to purify CD38 from mouse lymphocytes by using the immobilized anti-CD38 monoclonal antibody. The single step immuno-affinity column chromatography resulted in homogeneous purification, showing a single protein of 42 kDa on a SDS polyacrylamide gel. We have investigated the effects of various inhibitors on the enzyme activities of the purified CD38. Cibacron blue (0.5 mM) inhibited all three enzyme activities of CD38, NADase, ADP-ribosyl cyclase and cADPR hydrolase activities. ADPR (2 mM) showed inhibitory effect on both cADPR hydrolase activity and NADase, but not on ADP-ribosyl cyclase activity. However, ATP (2 mM) inhibited only cADPR hydrolase activity. $Zn^{2+}$ (1 mM) showed similar inhibitory effect as that of ADPR, but activated cyclase activity These results suggest that CD38 has three different catalytic activity domains which might be differentially regulated by their specific inhibitors.

• 한국지형학회지
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• 제17권3호
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• pp.77-88
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• 2010

2010년 봄 서울 지역에서 포집된 황사 및 비황사 시료를 전처리를 달리하여 황사의 입도 특성을 밝혔다. 최소 확산으로 분석된 황사 시료의 평균 입경은 19~56㎛, 비황사 시료는 37~92㎛이다. 이와는 대조적으로 최대 확산으로 분석된 황사와 비황사 시료의 평균 입경은 차이가 작아 각각 13~20㎛, 14~30㎛의 범위이다. 본 연구에서는 황사 발생시 최소 확산의 경우 약 0.5㎛, 1.5㎛ 그리고 8.5㎛, 최대 확산시 0.5㎛와 7.5㎛ 크기의 입자를 중심으로 각각 약 20㎛와 40㎛ 크기의 입자까지 한반도 대기 중에 유입되는 것을 확인하였다. 또한 비황사 시료에 비해 황사 시료가 뢰스 시료와 유사한 입도 특성을 가지며, 공통적으로 중국 등으로부터 원거리 기원지임을 지시한다. 황사와 뢰스층 사이의 입도 특성의 차이는 풍화작용의 기간과 강도에 기인한다.

• Tuberculosis and Respiratory Diseases
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• 제41권5호
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• pp.489-493
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• 1994

연구배경: NAD glycohydrolase(NADase)는 세포 표면에 위치하며 glycosylphatidylinositol(GPI)로 세포표면에 부착되어 있으며 bacterial PI-specific phospholipase C(PI-PLC)에 의해 분리된다. 최근 결핵환자에서 NADase가 증가한다는 보고가 있었으나 결핵균자체가 NADase가 높기 때문에 절대적인 NADase치가 증가했는 지는 확실치 않다. 따라서 저자들은 정상 대조군과 결핵환자의 적혈구에서 순수한 NADase activity를 측정하였다. 방법: 19명의 정상 건강 대조군과 16명의 과거 결핵의 진단 및 치료를 받지 않은 결핵환자를 대상으로하여 NADase activity를 측정하였고 결핵환자는 결핵치료 3개월후 재 검사하였다. NADase activity는 [carbonyl-$^3H$] nicotinamide 동위원소를 사용하여 측정하였다. 결과: 건강 대조군에서 $2031{\pm}824.0pmol/min/10^6$ erythrocytes, 결핵 감염군에서 $3339{\pm}1568.0$, 그리고 isoniazide와 rifampin으로 치료한 3개월 후 $2238.6{\pm}1013.1$을 얻어 결핵 감염시 NADase activity가 유의한 차이를 가지고 증가하며(p<0.05), 치료전에 비하여 치료후 유의있게 감소하였다. 결론: 결핵감염시 NADase activity가 올라가고 결핵 치료시 NADase activity가 정상화 되어 NADase activity가 결핵감염의 진단 및 치료에 대한 새로운 지표가 될수 있을 것으로 사료된다.

• 한국자원식물학회지
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• 제25권2호
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• pp.184-192
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• 2012

본 연구는 췌장베타세포인 HIT-T15 세포를 이용하여 매실주정추출물(PME)의 alloxan에 의한 산화스트레스로부터의 세포보호, 인슐린 분비능 및 항산화 효소 활성을 평가하였다. PME는 alloxan에 의해 유발된 산화스트레스로부터 세포를 보호하여 세포생존율을 증가시켰다. PME는 세포막 손상지표인 LDH 방출을 억제하였고 $NAD^+$/NADH ratio를 유의적으로 증가시켜 세포사멸이 억제되어짐을 확인하였다. 또한 alloxan 단독처리군에 비해 250 ${\mu}g$/ml PME 처리군에서 인슐린 분비량이 유의성 있게 증가하였다. Alloxan과 PME를 동시에 처리하여 HIT-T15세포의 항산화효소 활성을 측정했을 때 산화스트레스에 의해 감소되었던 항산화효소 활성이 PME에 의해 보호되는 효과를 확인하였다. 이상의 연구결과로부터 PME는 세포괴사 및 DNA fragmentation을 억제하고 세포내 항산화효소 활성을 증가시켜 alloxan에 의해 유발된 산화스트레스로부터 췌장베타세포를 보호하고 이에 따른 인슐린 분비능 조절 효과가 있는 것으로 생각된다.

• Journal of Ginseng Research
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• 제44권2호
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• pp.341-349
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• 2020

Background: The replicative senescence of human dermal fibroblasts (HDFs) is accompanied by growth arrest. In our previous study, the treatment of senescent HDFs with Rg3(S) lowered the intrinsic reactive oxygen species (ROS) levels and reversed cellular senescence by inducing peroxiredoxin-3, an antioxidant enzyme. However, the signaling pathways involved in Rg3(S)-induced senescence reversal in HDFs and the relatedness of the stereoisomer Rg3(R) in corresponding signaling pathways are not known yet. Methods: We performed senescence-associated β-galactosidase and cell cycle assays in Rg3(S)-treated senescent HDFs. The levels of ROS, adenosine triphosphate (ATP), and cyclic adenosine monophosphate (cAMP) as well as the mitochondrial DNA copy number, nicotinamide adenine dinucleotide (NAD)⁺/1,4-dihydronicotinamide adenine dinucleotide (NADH) ratio, and NAD-dependent sirtuins expression were measured and compared among young, old, and Rg3(S)-pretreated old HDFs. Major signaling pathways of phosphatidylinositol 3-kinase/Akt, 5' adenosine monophosphate-activated protein kinase (AMPK), and sirtuin 1/3, including cell cycle regulatory proteins, were examined by immunoblot analysis. Results: Ginsenoside Rg3(S) reversed the replicative senescence of HDFs by restoring the ATP level and NAD⁺/NADH ratio in downregulated senescent HDFs. Rg3(S) recovered directly the cellular levels of ROS and the NAD⁺/NADH ratio in young HDFs inactivated by rotenone. Rg3(S) mainly downregulated phosphatidylinositol 3-kinase/Akt through the inhibition of mTOR by cell cycle regulators like p53/p21 in senescent HDFs, whereas Rg3(R) did not alter the corresponding signaling pathways. Rg3(S)-activated sirtuin 3/PGC1α to stimulate mitochondrial biogenesis. Conclusion: Cellular molecular analysis suggests that Rg3(S) specifically reverses the replicative senescence of HDFs by modulating Akt-mTOR-sirtuin signaling to promote the biogenesis of mitochondria.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2001년도 학술대회
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• pp.115-116
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• 2001

• Korean Journal of Acupuncture
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• 제18권1호
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• pp.21-26
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• 2001

발암물질을 무독화시키는 QR 생성 유도를 살펴보기 위하여 황기 약침액 및 열수추출액을 생쥐의 간암세포인 Hepa1c1c7에 처리하여 측정한 결과, 황기 약침액의 농도를 증가시킬수록 많은 QR 생성율을 보였으며, GSH 생성이 증가하였고, GST 생성 또한 증가하였다.