• Journal of Microbiology and Biotechnology
• /
• 제1권2호
• /
• pp.136-141
• /
• 1991

Optimum culture conditions for the formation of nitrile hydratase by Brevibacterium sp. CH2 were investigated. Addition of ferric and ferrous ions greatly increased the nitrile hydratase formation. The effects of nitriles, amides, and acids as an inducer on the formation of nitrile hydratase were investigated. Isobutyramide was the best inducer among the tested compounds. When Brevibacterium sp. CH2 was cultivated for 23 h at $30^{\circ}C$ in a optimized medium containing 15 g of glucose, 5 g of bacto peptone, 3 g of yeast extract, 3 g of malt extract, 1 g of $KH_2$$PO_4$, 1 g of $K_2$$HPO_4$, 1 g of NaCl, 0.5 g of isobutyramide, 0.2 g of MgSO$_4$ㆍ7$H_2O$, and 0.02g of $FeSO_4$ㆍ$7H_2$O per liter of distilled water with pH controlled at 7.1, the maximum total activity was 665 units/ml of the culture broth and the specific activity was 70 units/mg of the dry cells. The medium optimization increased the specific activity of Brevibacterium sp. CH2 2.2 times.

• Journal of Crop Science and Biotechnology
• /
• 제10권1호
• /
• pp.19-26
• /
• 2007

Glutathione S-transferases(GSTs, EC 2.5.1.18), glyoxalase-I(EC 4.4.1.5) and alliin lyase(alliinase, EC 4.4.1.4) are important enzyme systems in plant bodies. The first two are mainly detoxifying enzymes that utilize glutathione(GSH) in the defense mechanism, and the last one is mainly involved in secondary metabolism and relevant to sulfur compounds derived from GSH. The activities of the three enzymes have been investigated in soluble extracts of vegetable crops, including pumpkin, cabbage, broccoli, radish, carrot, potato, sweet potato, mungbean, and onion. GST activities were detected in all of the vegetables, and the extract of onion bulb exhibited the highest specific activity(648 nmol/min/mgP). The putative GSTs of most of the vegetables were found to be induced by ethanol. The activities of GSTs in onion bulb were found to be markedly inhibited by S-hexyl glutathione and were also inhibited by S-butyl glutathione and S-propyl glutathione. The anti-CmGSTF1 antiserum recognized a thick band for putative onion GST. The estimated glyoxalase-I activity level was also high in onion bulb(4540 nmol/min/mgP), indicating that the thick band detected by Western blot analysis might result from partial recognition of glyoxalase-I by the antiserum. The specific activities for glyoxalase-I were moderate in radish and carrot, and the extracts of other vegetables had rather low levels of activities. The extract of onion also showed the highest specific activity level for alliinase(2069nmol pyruvate/mgP). The extracts of other vegetables also had alliinase activities, although the estimated values were much lower than that of onion.

• 한국식품과학회지
• /
• 제27권5호
• /
• pp.673-679
• /
• 1995

Valencia 오렌지로부터 추출한 펙틴에스테라제(pectinesterase, PE) 중에서 가열처리하지 않은 PE 조효소를 CM-Sephadex C-50, Phenyl Sepharose CL-4B와 CM-Biogel A의 chromatography를 차례로 수행하여 내열성이 약한 TLPE(thermolabile pectinesterase)와 내열성이 강한 TSPE(thermostable pectinesterase)를 분리 정제하였다. PE 중에서 가열처리한 PE 조효소에서는 위와 같은 정제과정으로 TSPE 만을 분리하였다. TLPE는 비활성 1,005 units/mg이고 35배로 정제된 것을 13.6% 회수할 수 있었으며, 반면에 가열하지 않고 분리한 TSPE는 비활성 3,115 units/mg이고 100.5배로 정제된 것을 1.5% 얻을 수 있었으나 가열하여 분리한 TSPE는 비활성 1,803 units/mg이고 가열처리한 조효소가 140배로 정제된 것을 15.4% 얻을 수 있었다.

• 대한한의진단학회지
• /
• 제11권2호
• /
• pp.13-26
• /
• 2007

Background: Neurofeedback is an electroencephalographic biofeedback technique for training individuals to alter their brain activity via operant conditioning. Also neurofeedback is a form of behavioural training aimed at developing skills for brain activity. Within the past decade, several neurofeedback studies have been published that tend to overcome the methodological shortcomings of earlier studies. This research describes the methodical basis of neurofeedback and reviews the evidence base for its clinical efficacy and effectiveness in attention-deficit hyperactivity disorder (ADHD). Methods: In neurofeedback training, self-regulation of specific aspects of electrical brain activity is acquired by means of immediate feedback and positive reinforcement. In frequency training, activity in different EEG frequency bands has to be decreased or increased. Slow cortical potentials (SCPs) training is focused on the regulation of cortical excitability. Results: Neurofeedback studies revealed training-specific effects on, for example, attention and memory processes and performance improvements in real-life conditions, in healthy subjects as well as in patients. In several studies it was shown that ADHD symptomatology was reduced after frequency training or SCP(Slow cortical potentials) training. Moreover a decrease of impulsivity errors and an increase of the contingent negative variation. Conclusions: This research provides evidence for both positive behavioural and specific neurophysiological effects of neurofeedback training. Also there is growing evidence for neurofeedback as a valuable module in neuropsychiatric disorders. Further, controlled studies are warranted.

• Journal of Microbiology and Biotechnology
• /
• 제29권9호
• /
• pp.1375-1382
• /
• 2019

Phenylalanine hydroxylase from Chromobacterium violaceum (CvPAH) is a monomeric enzyme that converts phenylalanine to tyrosine. It shares high amino acid identity and similar structure with a subunit of human phenylalanine hydroxylase that is a tetramer, resulting in the latent application in medications. In this study, semirational design was applied to CvPAH to improve the catalytic ability based on molecular dynamics simulation analyses. Four N-terminal truncated variants and one single point variant were constructed and characterized. The D267P variant showed a 2.1-fold increased thermal stability compared to the wild type, but lower specific activity was noted compared with the wild type. The specific activity of all truncated variants was a greater than 25% increase compared to the wild type, and these variants showed similar or slightly decreased thermostability with the exception of the $N-{\Delta}9$ variant. Notably, the $N-{\Delta}9$ variant exhibited a 1.2-fold increased specific activity, a 1.3-fold increased thermostability and considerably increased catalytic activity under the neutral environment compared with the wild type. These properties of the $N-{\Delta}9$ variant could advance medical and pharmaceutical applications of CvPAH. Our findings indicate that the N-terminus might modulate substrate binding, and are directives for further modification and functional research of PAH and other enzymes.

• Nutrition Research and Practice
• /
• 제17권1호
• /
• pp.13-31
• /
• 2023

BACKGROUND/OBJECTIVES: Epigenetic regulation by nutrients can influence the development of specific diseases. This study sought to examine the effect of individual nutrients and nutrient families in the context of preventing chronic metabolic diseases via epigenetic regulation. The inhibition of lipid accumulation and inflammation by nutrients including proteins, lipids, vitamins, and minerals were observed, and histone acetylation by histone acetyltransferase (HAT) was measured. Correlative analyses were also performed. MATERIALS/METHODS: Nutrients were selected according to information from the Korean Ministry of Food and Drug Safety. Selected nutrient functionalities, including the attenuation of fatty acid-induced lipid accumulation and lipopolysaccharide-mediated acute inflammation were evaluated in mouse macrophage Raw264.7 and mouse hepatocyte AML-12 cells. Effects of the selected nutrients on in vitro HAT inhibition were also evaluated. RESULTS: Nitric oxide (NO) production correlated with HAT activity, which was regulated by the amino acids group, suggesting that amino acids potentially contribute to the attenuation of NO production via the inhibition of HAT activity. Unsaturated fatty acids tended to attenuate inflammation by inhibiting NO production, which may be attributable to the inhibition of in vitro HAT activity. In contrast to water-soluble vitamins, the lipid-soluble vitamins significantly decreased NO production. Water- and lipid-soluble vitamins both exhibited significant inhibitory activities against HAT. In addition, calcium and manganese significantly inhibited lipid accumulation, NO production, and HAT activity. CONCLUSIONS: Several candidate nutrients and their family members may have roles in the prevention of diseases, including hepatic steatosis and inflammation-related diseases (i.e., nonalcoholic steatohepatitis) via epigenetic regulation. Further studies are warranted to determine which specific amino acids, unsaturated fatty acids and lipid-soluble vitamins or specific minerals influence the development of steatosis and inflammatory-related diseases.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2001년도 추계학술발표대회
• /
• pp.796-797
• /
• 2001

The $Ag^{2+}$ solution was constructed by supplying pure metal silver in filtrated distilled with constant voltage. The solution at the $Ag^{2+}$ concentration of 10 ppm showed specific activity against Gram positive and negative bacteria. More than 90% activity showed against Candida albicans ATCC 102321 at the same concentration. The addition of DASA, $Ag^{2+}$ and artemisia mixture, in the EVLN had same activity by comparison with chemical synthetic antiseptic.

• 한국미생물·생명공학회지
• /
• 제22권1호
• /
• pp.7-12
• /
• 1994

One bacterial strain, that had made the largest inhibition zone at the antagonism assay and also that lost the inhibition activity by the protease treatment, was isolated from raw milk. That strain was identified as Streptococcus salivarius subsp. thermophilus. The specific growht rate of this strain was maximum at 45$\circ $C. However, at this temperature the strain produced no bacteriocin. The bacteriocin activity was quite stable even at high temperature. Moreover, the activity of the vacteriocin was sensitive to proteases. but not to $\alpha $-amylase, DNase I, or RNase.

• Mycobiology
• /
• 제29권3호
• /
• pp.173-175
• /
• 2001

The fruit body of Ramaria botrytis DGUM 29001 was used to determine enzyme activities of fruit body. The specific activity of laccase was the highest(6.5 unit/mg$\cdot$protein) and that of $\alpha$-amylase and xylanase was relatively high. However, little or no enzyme activity of $\beta$-glucosidase, CMCase, exo-$\beta$-1,4-glucanase, chitinase, lipase and protease was found.

• 한국응용곤충학회지
• /
• 제32권3호
• /
• pp.291-299
• /
• 1993

네가지 종류의 곤충 중장에 있는 주요 해독효소인 cytochrome P-450 monooxygenases의 활성을 그들의 먹이종류 및 섭식여부와 연관시켜 분석하였다. 담배나방유충을 인공사료로 사육하였을 때 전반적으로 중장의 cytochrome P-450 monooxygtenases(MFO)활성이 지방체의 경우보다 3배가량 높게 나타났다. 고추열매나 인공사료를 공급하여 사육하였을 때보다 담배잎으로 사육하였을 때 담배나방유충의 중장 MFO는 훨씬 높게 나타났으며, 흰불나방의 경우염주나무잎이 MFO활성을 가장 높게 유기했다. 담배나방, 파밤나방, 희불나방, 담배거세미나방 등의 유충들을 각각의 인공사료로 사육하였을 때 광식성이며 동시에 살충제저항성을 보유하고 있는 파밤나방의 MFO활성이 가장 높게 나타났다.