• 제목/요약/키워드: aminotransferase activity

검색결과 441건 처리시간 0.023초

Co-expression of Gamma-Aminobutyrate Aminotransferase and Succinic Semialdehyde Dehydrogenase Genes for the Enzymatic Analysis of Gamma-Aminobutyric Acid in Escherichia Coli

  • So, Jai-Hyun;Lim, Yu-Mi;Kim, Sang-Jun;Kim, Hyun-Ho;Rhee, In-Koo
    • Journal of Applied Biological Chemistry
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    • 제56권2호
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    • pp.89-93
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    • 2013
  • Gamma-aminobutyric acid (GABA) aminotransferase (gabT) and succinic semialdehyde dehydrogenase (gabD) genes from Pseudomonas fluorescens KCCM 12537 were cloned into a single pETDuet-1 vector and co-expressed in Escherichia coli BL21(DE3) simultaneously. The mixture of both enzymes, called GABase, is the key enzyme for the enzymatic analysis of GABA. The molecular mass of the GABA aminotransferase and succinic semialdehyde dehydrogenase were determined to be 52.8 and 46.7 kDa following computations performed with the pI/Mw program, respectively. The GABase activity between pH 6.0 and 9.0 for 24 h at $4^{\circ}C$ remained over 75%, but under pH 6.0 decreased rapidly. The GABase activity between 25 and $35^{\circ}C$ by the treatment at pH 8.6 for 30 min remained over 80%, but over $35^{\circ}C$ decreased rapidly. When the activity against GABA was defined as 100%, the purified GABase activity against 5-aminovaleric acid having a similar structure to GABA showed 47.7% and GABase activity against ${\beta}$-alanine, ${\varepsilon}$-amino-n-caproic acid, $_L$-ornithine, $_L$-lysine, and $_L$-aspartic acid showed between 0.3 to 2.3%. The GABA content was analyzed with this co-expressed GABase, compared with the other GABase which was available commercially. As a result, the content of GABA extracted from brown rice, dark brown rice, and black rice were $26.4{\pm}3.5$, $40.5{\pm}4.7$ and $94.7{\pm}9.3{\mu}g/g$, which were similar data of other GABase in the error ranges.

Effects of Pyridoxine on Growth Performance and Plasma Aminotransferases and Homocysteine of White Pekin Ducks

  • Xie, Ming;Tang, Jing;Wen, Zhiguo;Huang, Wei;Hou, Shuisheng
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권12호
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    • pp.1744-1748
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    • 2014
  • A dose-response experiment with seven supplemental pyridoxine levels (0, 0.66, 1.32, 1.98, 2.64, 3.30, and 3.96 mg/kg) was conducted to investigate the effects of pyridoxine on growth performance and plasma aminotransferases and homocysteine of White Pekin ducks and to estimate pyridoxine requirement for these birds. A total of 336 one-day-old male White Pekin ducks were divided to 7 experimental treatments and each treatment contained 8 replicate pens with 6 birds per pen. Ducks were reared in raised wire-floor pens from hatch to 28 d of age. At 28 d of age, the weight gain, feed intake, feed/gain, and the aspartate aminotransferase, alanine aminotransferase, and homocysteine in plasma of ducks from each pen were all measured. In our study, the pyridoxine deficiency of ducks was characterized by growth depression, decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine. The ducks fed vitamin $B_6$-deficient basal diets had the worst weight gain and feed/gain among all birds and this growth depression was alleviated (p<0.05) when pyridoxine was supplemented to basal diets. On the other hand, plasma aspartate aminotransferase and homocysteine may be the sensitive indicators for vitamin $B_6$ status of ducks. The ducks fed basal diets had much lower aspartate aminotransferase activity and higher homocysteine level in plasma compared with other birds fed pyridoxine-supplemented diets (p<0.05). According to quadratic regression, the supplemental pyridoxine requirements of Pekin ducks from hatch to 28 days of age was 2.44 mg/kg for feed/gain and 2.08 mg/kg for plasma aspartate aminotransferase and the corresponding total requirements of this vitamin for these two criteria were 4.37 and 4.01 mg/kg when the pyridoxine concentration of basal diets was included, respectively. All data suggested that pyridoxine deficiency could cause growth retardation in ducks and the deficiency of this vitamin could be indicated by decreasing plasma aspartate aminotransferase activity and increasing plasma homocysteine.

Sodium Fluoride 함량이 흰쥐의 간 기능 효소활성에 미치는 영향 (Influences of Sodium Fluoride Contents on Hepatic Functional Enzyme Activities in Rats)

  • 김한수
    • 한국환경과학회지
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    • 제28권11호
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    • pp.943-950
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    • 2019
  • The purpose of this study was to probe the influences of NaF oral administration on a dose-effect relationship between fluoride levels of serum enzyme activity such as alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) in rats fed experimental diets for 5 weeks. All groups increased the activity of serum ALP, AST, ALT, and LDH levels with increasing NaF. In addition the fluoride levels of serum and organ tissues (liver, brain, heart, lung, kidney) in oral NaF groups (NF3~NF50) were significantly increased by adding sodium fluoride in comparison with normal diet group (ND) (p<0.05). These results, a high concentration of sodium fluoride was determined that the toxicity to various organ tissues.

Xanthomonas oryzae pv. oryzae로 부터 aspartate aminotransferase 유전자의 분리 및 생화학 특성 (Cloning and Biochemical Characterization of Aspartate Aminotransferase from Xanthomonas oryzae pv. oryzae)

  • 강한철;윤상홍;이창묵
    • Journal of Applied Biological Chemistry
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    • 제52권3호
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    • pp.109-115
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    • 2009
  • Xoo로 부터 aspartate aminotransferase로 추정되는 유전자를 분리한 다음 발현시켜 생화학 특성을 조사하였다. 분리된 유전자는 His6 pET-21(a) 운반체에 삽입시켰으며 E. coli BL21(DE3)에서 발현시켰다. 재조합된 Asp-AT는 affinity chromatography를 이용하여 분리하였으며 SDS-PAGE분석에서 43kDa의 단일 밴드를 나타내었다. 분리된 효소는 amino donor 로서 L-aspartate에 대하여 효소활성도가 가장 높았고, L-leucine 및 L-cysteine에 대하여서도 상당한 활성도를 나타내었다. 효소의 최적 pH는 약 7.5 근처에서 나타났고 효소의 안정성은 산성조건 보다는 알칼리 조건에서 훨씬 높았다. 최적 온도는 약 $35-40^{\circ}C$로 나타났고 $55^{\circ}C$에서 20분간 열처리한 이후의 잔여 활성도는 약 78%로 나타났다. 여러 중금속 중에서 망간 이온에 의해 효소활성이 촉진되었다.

Effects of Salts on the Conformation and Catalytic Properties of D-Amino Acid Aminotransferase

  • Ro, Hyeon-Su
    • BMB Reports
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    • 제35권3호
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    • pp.306-312
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    • 2002
  • The effects of salts on the biochemical properties of D-amino acid aminotransferase from Bacillus sp. YM-1 have been studied to elucidate both the inhibitory effects of salts on the activity and the protective effects of salts on the substrate-induced inactivation. The results from UV-visible spectroscopy studies on the reaction of the enzyme with D-serine revealed that salt significantly reduced the rate of the formation of the quinonoid intermediate and its accumulation. The kinetic and spectroscopy studies of the reaction with $\alpha$-[$^2H$]-DL-serine in different concentrations of NaCl provided evidence that the rate-limiting step was changed from the deprotonation of the external aldimine to another step(s), presumably to the hydrolysis of the ketimine. Gel filtration chromatography data in the presence of NaCl showed that the enzyme volume was reduced sharply with the increasing NaCl concentration, up to 100 mM. An additional increase of the NaCl concentration did not affect the elution volume, which suggests that the enzyme has a limited number of salt-binding groups. These results provide detailed mechanistic evidence for the way salts inhibit the catalytic activity of D-amino acid aminotransferase.

마우스에서 dibutyl phthalate 급성 투여가 간 지질과산화와 gamma-glutamyl transferase 활성에 미치는 효과 (Effects of acute dibutyl phthalate administration on hepatic lipid peroxidation and gamma-glutamyl transferase activity in mice)

  • 최달웅;김영환
    • 환경위생공학
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    • 제19권1호
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    • pp.50-56
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    • 2004
  • Dibutyl phthalate (DBP) is used extensively in the plastic industry and has been known as an endocrine disruptor. Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyl transferase (GGT) activity. The serum toxicity index, level of lipid peroxidation and triglyceride (TG), and activity of GGT were measured in male ICR mice after a single administration of DBP (5 g/kg, po). DBP did not alter serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, glucose and cholesterol level. However, the treatment with DBP was found to significantly increase the level of lipid peroxidation in liver and lung. The TG content and activity of GGT in the liver of DBP-exposed animals was also increased. These results indicate that DBP can induce mild oxidative stress in mice. The GGT activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

살균제 carbendazim이 랫드 간 해독체계에 미치는 영향 (The Effect of Fungicide Carbendazim on Hepatic detoxication systems of rat)

  • 이제봉;신진섭;정미혜;박연기;강규영
    • 농약과학회지
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    • 제9권4호
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    • pp.338-346
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    • 2005
  • Carbendazim의 랫드 간 해독체계에 대한 영향을 검색하기 위하여 간장독성의 지표 효소인 혈장 ALT(alanine aminotransferase) 및 AST(aspartate aminotransferase) 활성, 간에 대한 독성, 해독 및 대사에 대한 영향을 구명하기 위하여 간 GSH(glutathione), GST(glutathione-S-transferase), cytochrome P450 및 cytochrome P450 reductase 활성을 375, 750, 1,500 mg/kg 약량에서 측정한 결과 혈장 ALT 및 AST 활성이 120분 후에 약간의 증가가 있었으나 특이한 독성증상은 관찰되지 않았다. GSH는 고농도와 중농도 120분에서 20%의 함량증가가 있었고, GST는 120분까지 $36{\sim}50%$ 정도의 활성저해가 있었으나 240분에는 활성이 회복되었다. Cytochrome P450함량은 60분까지 $25{\sim}50%$까지 함량이 저하되었으나 120분에 70%이상 회복되었고, 240분 저농도에서는 거의 회복되었으며, cytochrome P450 reductase도 120분까지 $25{\sim}50%$ 활성저해가 있었으나, 240분에는 무처리 군의 활성과 유사하게 회복되어 대사관련 효소에 대한 손상은 크지 않을 것으로 판단되었다. 이상의 결과에서 benzimidazole 계 살균제인 carbendazim은 생체내 해독 및 대사관련 체계에 영향이 적은 농약으로 급성적인 중독은 일으키지 않을 것으로 판단되었다.

High-level Expression and Purification of Recombinant 4-Aminobutyrate Aminotransferases in Escherichia coli

  • Lee, Sung Gu;Tae Jin Choi;Young Tae Kim
    • Journal of Microbiology and Biotechnology
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    • 제6권3호
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    • pp.162-166
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    • 1996
  • The protein coding sequence of the 4-aminobutyrate aminotransferase was amplified by polymerase chain reaction (PCR) from a previously cloned cDNA of pig brain using a pair of primers based on the published sequence. The amplified DNA was introduced into a T7 expression vector. Recombinant 4-aminobutyrate aminotransferases were overexpressed in Escherichia coli. The inclusion bodies were formed when enzyme was overexpressed. The unfolded, overproduced proteins were purified by chromatography with hydroxyapatite and refolded by a sequential dialysis method. The renatured 4-aminobutyrate aminotransferase regained the catalytic activity. However, the purified mutant protein did not show the catalytic function of 4-aminobutyrate aminotransferase.

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Structural Arrangement for Functional Requirements of Brain Recombinant 4-Aminobutyrate Aminotransferase

  • Sung, Bo-Kyung;Kim, Young-Tae
    • BMB Reports
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    • 제33권1호
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    • pp.43-48
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    • 2000
  • 4-Aminobutyrate aminotransferase is a key enzyme of the 4-aminobutyric acid shunt. It converts the neurotransmitter 4-aminobutyric acid to succinic semialdehyde. In order to study the structural and functional aspects of catalytically active Cys residues of pig brain 4-aminobutyrate aminotransferase, we purified the active form in E. coli by coproduction of thioredoxin. The structural arrangement for functional requirements of a dimeric protein using a bifunctional sultbydryl reagent was then characterized, and the spatial proximity between the essential SH groups and a cofactor (pyridoxal-5'-phosphate) binding site was determined. The bifunctional sultbydryl reagent DMDS reacted with the enzyme at the ratio of one molecule per enzyme dimer. This resulted in an approximately 50% loss of enzymatic activity. The spatial proximity of the distance between the essential SH groups and the cofactor-binding site was determined by the energy transfer measurement technique. The result (approximate 20 ${\AA}$) suggested that cross-linking of two sulfhydryl groups with DMDS is not near a PLP binding site.

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사염화탄소로 유발된 간손상에서의 효소 활성도의 변화로 본 홍화자 분획물의 간손상 보호 작용 (Hepatoprotective Effect of Subfractions of Carthamus tinctorius L. Semen on the Reversal of Biotransformation Enzyme Activities in CCl4-induced Hepatotoxic Rats)

  • 정춘식;정기화;정정숙
    • 한국식품위생안전성학회지
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    • 제14권2호
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    • pp.172-178
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    • 1999
  • Previous studies have shown that methanol extract and its butanol fraction of Carthamus tinctorius L. Semen have the hepatoprotective effect on the CCl4-induced hepatotoxicity. The hepatoprotective effect of subfractions has been evaluated by analyzing blood and hepatocyte biochemical analyses and biotransformation enzyme analyses. Treatment of BS-5, subfraction has significantly decreased the activities of alanine aminotransferase and aspartate aminotransferase. In addition, the levels of cholesterol and triglyceride in liver have been decreased as compared with that of CCl4 treated rats. The hepatoprotective effect of BS-5, subfraction on the CCl4-induced hepatotoxicity would be mediated of the attenuation of the level of cytochrome P450 and the enhancement of the activity of glutathion S-transferase.

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