• Journal of Microbiology
• /
• 제44권2호
• /
• pp.185-191
• /
• 2006

The photosynthetic bacterium, Rhodospirillum rubrum S1, when grown under anaerobic conditions, generated three different types of catalases. In this study, we purified and characterized the highest molecular weight catalase from the three catalases. The total specific catalase activity of the crude cell extracts was 88 U/mg. After the completion of the final purification step, the specific activity of the purified catalase was 1,256 U/mg. The purified catalase evidenced an estimated molecular mass of 318 kDa, consisting of four identical subunits, each of 79 kDa. The purified enzyme exhibited an apparent Km value of 30.4 mM and a Vmax of 2,564 U against hydrogen peroxide. The enzyme also exhibited a broad optimal pH $(5.0{\sim}9.0)$, and remained stable over a broad temperature range $(20^{\circ}C{\sim}60^{\circ}C)$. It maintained 90% activity against organic solvents (ethanol/chloroform) known hydroperoxidase inhibitors, and exhibited no detectable peroxidase activity. The catalase activity of the purified enzyme was reduced to 19 % of full activity as the result of the administration of 10 mM 3-amino-1,2,4-triazole, a heme-containing catalase inhibitor. Sodium cyanide, sodium azide, and hydroxylamine, all of which are known heme protein inhibitors, inhibited catalase activity by 50 % at concentrations of $11.5{\mu}M,\;0.52{\mu}M,\;and\;0.11{\mu}M$, respectively. In accordance with these findings, the enzyme was identified as a type of monofunctional catalase.

• Journal of Plant Biotechnology
• /
• 제47권1호
• /
• pp.100-106
• /
• 2020

Coix lacryma-jobi (Hanjeli) is known to posses anti-microbial properties. Therefore, phytochemical compounds of C. lacryma-jobi have been studied to produce novel antimicrobial agents as treatments against antibiotic-resistant bacteria.The objective of this study was to determine the phytochemical composition and antibacterial activity of the C. lacryma-jobi oil against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The phytochemical composition of the oil was determined via gas chromatography mass spectrophotometry (GC-MS). Moreover, agar disk and agar well diffusion were employed to screen the antibacterial activity of the oil. An agar well diffusion test was implemented to determinate MIC's (minimum inhibitory concentrations). Dodecanoic acid, tetradecanoic acid, 2,3-dihydroxypropylester, 1,3-dioctanoin, N-methoxy-N-methyl-3,4-dihydro-2H-thiopyran6-carboxamide, propanamide, 5-Amino-1-(quinolin-8-yl)-1,2,3-triazole-4-carboxamide, and pyridine were identified in the C. lacryma-jobi oil. The MIC value of the oil was 0.031 g/L and the MBC of the oil was 0.125 g/L effective in all test bacteria. Dodecanoic acid displayed inhibitory activity against gram-positive and gram-negative bacteria. Therefore, our research demonstrated C. lacryma-jobi (Hanjeli) oil exhibited antibacterial activity against E. coli, S. aureus, and B. subtilis. These research suggest that C. lacryma-jobi root oil could be used for medicinal purposes; however clinical and in vivo tests must be performed to evaluate its potential as an antibacterial agent.

• Radiation Oncology Journal
• /
• 제23권4호
• /
• pp.211-216
• /
• 2005

목적: all-trans retinoic acid (ATRA)는 뇌종양 세포의 증식억제효과가 있으며, ATRA와 방사선의 병용은 악성 뇌종양의 치료 효과를 증진시키는 방법이 될 수 있다. 그러나 ATRA에 의해 항산화효소가 증가되며 이로 인해 방사선에 의해 생성된 reactive oxygen species (ROS)가 제거된다면 방사선의 효과는 낮아질 수 있다. 본 연구에서는 ATRA에 의해 유도되는 카탈라제(catalase)에 의한 방사선감수성의 변화를 보고자하였다. 대상 및 방법: 백서 교종세포(36B10)을 대상으로 ATRA 및 ATRA의 화학적 억제제인 3-amino-1, 2, 4-triazole (ATZ) 와 병용하여 카탈라제 활성도, 방사선감수성 및 ROS의 변화를 측정하였다. 카탈라제 활성도는 $H_2O_2$의 소멸을 자외선 분광광도계로 측정하는 방법을 이용해 정량하였으며, 방사선감수성은 단일집락군형성능력으로, ROS 는 2, 7-dichlorofluorescein diacetate 를 분광광도계로 측정하였다. 결과: 카탈라제 활성도는 ATRA의 농도(10, 25, $50{\mu}M$)에 따라 증가하였다. ATRA ($10{\mu}M$)와 방사선(4 Gy)의 병용에 의해 생존분획은 상승적(supra-auditive)으로 감소하였으며, 이 감소된 생존분획은 ATZ 동시 투여에 의해 증가하였다. ATRA $10{\mu}M$ 또는 $25{\mu}M$을 48시간 처리 후 ROS는 대조군에 비해 각각 1.5배, 2배 증가하였고, 4 Gy와 ATRA의 병용군에서는 2.5배 증가하였다. ATRA와 방사선의 병용에 의해 증가된 ROS는 ATZ에 의해 감소되었다. 결론: ATRA에 의해 유도되는 카탈라제는 방사선감수성을 감소시키지 않으며, 오히려 ROS의 증가에 의해 방사선감수성을 상승시켰다. 따라서 ATRA와 방사선의 병용은 뇌종양의 치료에 유용한 방법이 될 수 있을 것으로 보인다.

• 한국표면공학회지
• /
• 제57권3호
• /
• pp.140-154
• /
• 2024

As the trend towards miniaturization in semiconductor integration process, the limitations of interconnection metals such as copper, tungsten have become apparent, prompting research into the emergence of new materials like cobalt and emphasizing the importance of studying the corresponding process conditions. During the chemical mechanical polishing (CMP) process, corrosion inhibitors are added to the slurry, forming passivation layers on the cobalt surface, thereby playing a crucial role in controlling the dissolution rate of the metal surface, enhancing both removal rate and selectivity. This review investigates the understanding of the cobalt polishing process and examines the characteristics and behavior of corrosion inhibitors, a type of slurry additive, on the cobalt surface. Among the corrosion inhibitors examined, benzotriazole (BTA), 1,2,4-triazole (TAZ), and potassium oleate (PO) all improved surface characteristics through their interaction with cobalt. These findings provide important guidelines for selecting corrosion inhibitors to optimize CMP processes for cobalt-based semiconductor materials. Future research should explore combinations of various corrosion inhibitors and the development of new compounds to further enhance the efficiency of semiconductor processes.

• Journal of Chest Surgery
• /
• 제46권1호
• /
• pp.14-21
• /
• 2013

Background: Reactive oxygen species (ROS) are known to be related to cardiovascular diseases. Many studies have demonstrated that angiotensin-converting enzyme inhibitors have beneficial effects against ROS. We investigated the antioxidant effect of captopril and enalapril in nitric oxide mediated vascular endothelium-dependent relaxations. Materials and Methods: Isolated rabbit abdominal aorta ring segments were exposed to ROS by electrolysis of the organ bath medium (Krebs-Henseleit solution) after pretreatment with various concentrations (range, $10^{-5}$ to $3{\times}10^{-4}$ M) of captopril and enalapril. Before and after electrolysis, the endothelial function was measured by preconstricting the vessels with norepinephrine ($10^{-6}$ M) followed by the cumulative addition of acetylcholine (range, $3{\times}10^{-8}$ to $10^{-6}$ M). The relevance of the superoxide anion and hydrogen peroxide scavenging effect of captopril and enalapril was investigated using additional pretreatments of diethyldithiocarbamate (DETCA, 0.5 mM), an inhibitor of Cu/Zn superoxide dismutase, and 3-amino-1,2,4-triazole (3AT, 50 mM), an inhibitor of catalase. Results: Both captopril and enalapril preserved vascular endothelium-dependent relaxation after exposure to ROS in a dose-dependent manner (p<0.0001). Pretreatment with DETCA attenuated the antioxidant effect of captopril and enalapril (p<0.0001), but pretreatment with 3AT did not have an effect. Conclusion: Both captopril and enalapril protect endothelium against ROS in a dose-dependent fashion in isolated rabbit abdominal aortas. This protective effect is related to superoxide anion scavenging.

• 한국균학회지
• /
• 제47권3호
• /
• pp.219-232
• /
• 2019

Chemicals related to hydrogen peroxide ($H_2O_2$) and nitric oxide (NO) generations were exogenously applied to Fusarium oxysporum f. sp. fragariae (Fof) causing Fusarium wilt disease in strawberry plants, and regulations of in vitro conidial germination and mycelial growth of the fungus by the chemical treatments were evaluated. $H_2O_2$ drastically reduced the conidial germination of Fof in a dose-dependent manner, and treatment with 3-amino-1,2,4-triazole (3-AT) catalase inhibitor also led to dose-dependent inhibition of conidial germination but relatively moderately. Gradual decreases in mycelial growth of Fof were found by high concentrations of $H_2O_2$, whilst exogenous 3-AT slightly increased the mycelial growth. Increasing sodium nitroprusside (SNP) NO donor, $N^G$-nitro-l-arginine methyl ester (L-NAME) NO synthase (NOS)-inhibitor and tungstate nitrate reductase (NR) inhibitor led to dose-dependent reductions in conidial germination of Fof in quite different levels. SNP conversely increased the mycelial growth but increasing L-NAME moderately decreased the mycelial growth. Tungstate strongly enhanced mycelial growth. Differentially regulated in vitro mycelial growths of Fof were demonstrated by SNP, L-NAME and tungstate with or without $H_2O_2$ supplement. Superoxide anion production was also regulated during the mycelial growth of Fof by nitric oxide. These results show that $H_2O_2$ and NO-associated enzymes can be suggested as fungal growth regulators of Fof as well as eco-friendly disease-managing agents in strawberry production fields.

• 대한환경공학회지
• /
• 제27권6호
• /
• pp.606-613
• /
• 2005

본 연구에서는 실내공기 중 포름알데히드를 측정하기 위해 세 가지 다른 반응의 흡광광도법(비색분석)을 응용한 뱃지형 확산측정기를 평가하였다. 흡수여지의 세척방법을 비교한 결과 사용된 세척용액의 종류에 관계없이 세척하지 않은 경우 보다 양호한 세척효과가 나타났다. 각 측정방법에서 사용될 흡수액의 농도는 시료채취율을 기준으로 정하였다. 평가된 공시험 값은 측정방법별로 15% 이내의 편차를 가진 것으로 나타나 대체적으로 안정적인 것으로 나타났다. 확산측정기의 재현성은 MBTH법이 상대표준편차 10% 이내로 가장 양호하며, 채취된 포름알데히드 양과 시간가중평균농도와의 상관관계는 세 가지 측정방법 모두 양호한 것으로 나타났다. 검출한계 및 정량한계는 시료채취율이 가장 좋은 MBTH법이 다른 측정방법과 비교하여 가장 낮게 나타나 시료채취율이 가장 크고 정량한계가 낮은 측정방법일수록 포름알데히드 측정에 요구되는 측정시간이 감소되는 것으로 나타났다.

• Applied Biological Chemistry
• /
• 제47권1호
• /
• pp.113-119
• /
• 2004

시설재배 고추중 tiazole계 살균제 bitertanol과 tebuconazole에 대하여 안전사용기준의 추천량과 배량을 포장에 살포 후 잔류농약의 감소양상을 조사하였다. 고추중 bitertanol의 반감기는 $5.2{\sim}6.1$일 이었고, tebuconazole은 $4.6{\sim}5.2$일로 나타났다. 고추잎에서의 반감기는 bitertanol은 $19.1{\sim}22.5$일 이었고, tebuconazole은 $16.7{\sim}20.8$일로 나타나 고추에 비해 반감일수가 $3{\sim}5$배 증가하였다. 고추잎에서 약제살포 24일 경과후 bitertanol과 tebuconazole의 잔류량은 10.1 mg/kg, 17.5 mg/kg으로 나타났는데, 이는 고추잎에 대한 Maximum Residue Limit(MRL) 3.0 mg/kg, 5.0 mg/kg을 크게 넘는 수치로 조사되었다. 시설재배 고추와 고추잎에서의 경시변화는 1차 회귀방정식에 부합하였으며, 고추잎에서의 엽면잔류량(Dislodgeable Foliar Residues, DFRs)은 24일 경과후 각각 36%, 48%가 소실되는 것으로 나타났다. 세척방법에 의한 잔류농약의 감소량을 조사한 결과 세제 사용시의 평균제거율을 bitertanol은 72.4%, tebuconazole은 72.2%로 나타났고, 일반 수돗물 사용시에는 bitertanol 60.3%, tebuconazole 61.5%로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제17권9호
• /
• pp.1460-1468
• /
• 2007

In this study, an approx. 2.5-kb gene fragment including the catalase gene from Rhodospirillum rubrum S1 was cloned and characterized. The determination of the complete nucleotide sequence revealed that the cloned DNA fragment was organized into three open reading frames, designated as ORF1, catalase, and ORF3 in that order. The catalase gene consisted of 1,455 nucleotides and 484 amino acids, including the initiation and stop codons, and was located 326 bp upstream in the opposite direction of ORF1. The catalase was overproduced in Escherichia coli UM255, a catalase-deficient mutant, and then purified for the biochemical characterization of the enzyme. The purified catalase had an estimated molecular mass of 189 kDa, consisting of four identical subunits of 61 kDa. The enzyme exhibited activity over a broad pH range from pH 5.0 to pH 11.0 and temperature range from $20^{\circ}C$ to $60^{\circ}C$C. The catalase activity was inhibited by 3-amino-1,2,4-triazole, cyanide, azide, and hydroxylamine. The enzyme's $K_m$ value and $V_{max}$ of the catalase for $H_2O_2$ were 21.8 mM and 39,960 U/mg, respectively. Spectrophotometric analysis revealed that the ratio of $A_{406}$ to $A_{280}$ for the catalase was 0.97, indicating the presence of a ferric component. The absorption spectrum of catalase-4 exhibited a Soret band at 406 nm, which is typical of a heme-containing catalase. Treatment of the enzyme with dithionite did not alter the spectral shape and revealed no peroxidase activity. The combined results of the gene sequence and biochemical characterization proved that the catalase cloned from strain S1 in this study was a typical monofunctional catalase, which differed from the other types of catalases found in strain S1.

• Journal of Pharmaceutical Investigation
• /
• 제33권2호
• /
• pp.135-140
• /
• 2003

Fluconazole is an orally active bis-triazole antifungal agent, which is used in the treatment of superficial and systemic candidiasis and in the treatment of cryptococcal infections in patients with the acquired immuno deficiency syndrome (AIDS). The purpose of the present study was to evaluate the bioequivalence of two fluconazole capsules, Diflucan (Pfizer Pharmaceuticals Korea Inc.) and Flucona (Korean Drug Pharmaceuticals Co., Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). The fluconazole release from the two fluconazole capsules in vitro was tested using KP VII Apparatus II method at 0.1 M hydrochloride dissolution media. Twenty normal male volunteers, $23.60{\pm}1.88$ years in age and $63.57{\pm}6.17\;kg$ in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After three capsules containing 50 mg as fluconazole was orally administered, blood was taken at predetermined time intervals and the concentrations of fluconazole in serum were determined using HPLC method with UV detector. The dissolution profiles of two fluconazole capsules were very similar at 0.1 M hydrochloride dissolution media. Besides, the pharmacokinetic parameters such as $AUC_t,\;C_{max}\;and\;T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$ and $C_{max}$ and untransformed $T_{max}$. The results showed that the differences in $AUC_t,\;C_{max}\;and\;T_{max}$ between two capsules based on the Diflucan were 4.96%, 5.65% and -13.76%, respectively. There were no sequence effects between two capsules in these parameter. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log(0.8) to log(1.25) $(e.g.,\;log(1.01){\sim}log(1.08)\;and\;log(1.00){\sim}log(1.12)\;for\;AUC_t\;and\;C_{max},\;respectively)$, indicating that Flucona capsule is bioequivalent to Diflucan capsule.