• Title/Summary/Keyword: Aspartate aminotransferases

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Crystal Structure of MJ0684 from Methanococcus jannaschii, a Novel Archaeal Homolog of Kynurenine Aminotransferase

  • Yang, Jin-Kuk
    • Bulletin of the Korean Chemical Society
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    • v.29 no.1
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    • pp.173-176
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    • 2008
  • MJ0684 from Methanococcus jannaschii is a hypothetical protein belonging to the subfamily Ig of amino acid aminotransferases. In the present study, the crystal structure of MJ0684 has been determined at 2.2 resolution. It reveals that MJ0684 has an overall structure similar to subfamily Ig aminotransferases and its active site architecture is most similar to that of kynurenine aminotransferases among several kinds of aminotransferases in the subfamily Ig?. It has two hydrophobic active site residues conserved in the kynurenine aminotransferases for recognizing hydrophobic substrates. In addition, the absence of any basic residue for recognizing the side chain carboxylic group of the aspartate in the active site rules out the possibility that MJ0684 would act as an aspartate aminotransferase. These structural observations collectively imply that MJ0684 is a novel archaeal homolog of the subfamily Ig kynurenine aminotransferase.

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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    • v.27 no.12
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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.

Clinical Study for Low Dose & Short-Term Therapy of Biphenyl Dimethyl Dicarboxylate(DDB) in the Chronic Hepatitis. Patients with Elevated Serum Aspartate Aminotransferase and Alanine Aminotransferase Levels (Biphenyl Dimethyl Dicarboxylate의 저용량 단기 투여가 만성 간염환자의 상승된 Aspartate Aminotransferase와 Alanine Aminotransferase의 저하 효과에 관한 임상적 연구)

  • Kim, Dong Woung;Kang, Byung Ki
    • Korean Journal of Clinical Pharmacy
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    • v.3 no.1
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    • pp.45-53
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    • 1993
  • Biphenyl Dimethyl dicarboxylate(DDB) has been regarded as a safe, effective drug for decreasing serum aminotransferase levels from elevated serum aminotransferase levels, which cause acute or chronic hepatitis and chronic liver diseases. This study was designed to low dose(22.5mg/day) & short-term therapy effectiveness for 4 weeks of DDB in 30 chronic hepatitis patients with elevated serum aminotransferases. The following results were observed. 1. Serum alanine aminotransferase(ALT) levels significantly decresed from 173. $97\pm130.62(U/L)$ of pretreatment level to $32.23\pm19.22(U/L)$ after treatment for 4 weeks(p<0.00l) and normalized patients by $73\%$ 2. Serum aspartate (AST) aminotransferase levels significantly decreased from $94.90\pm49.17(U/L)$ of pretreatment level to $45.30\pm23.25(U/L)4 after treatment(p0<0.01). 3. However, no significant effects in the serum AST & ALT changes by which cause hepatitis and hepatitis duration (p>0.05). 4. No significant adverse effects were observed except for mild epigastric discomfort in one patient during DDB treatment It is suggested that DDB small dosage administration can result effectively decreasing serum aminotransferase levels from chronic hepatitis patients with elevated serum aminotransferase levels.

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Association between extract from fruit of Opuntia ficus-indica and streptozotocin-induced diabetic rats

  • Jo, Hyunmu;Kim, Hyun Seok;Kim, Dae Joong;Sim, Sung Bo
    • Korean Journal of Veterinary Research
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    • v.61 no.1
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    • pp.6.1-6.6
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    • 2021
  • Opuntia ficus-indica has traditionally been used in prevention and treatment of various diseases such as diabetes mellitus. The current study was performed to determine whether Opuntia ficus-indica is associated with diabetes. Diabetic rat models were induced with streptozotocin (STZ). This study divided rats into 1 day (short-term) and 4 consecutive weeks (long-terms) of daily administration. These groups were subdivided into four groups each other for assessment of blood glucose level as follows: Group 1, untreated rats given distilled water; Group 2, untreated rats given Opuntia ficus-indica; Group 3, STZ-induced diabetic rats given distilled water; Group 4, STZ-induced diabetic rats given Opuntia ficus-indica. Blood glucose level was measured for one day and four weeks. In addition, serum markers of alanine aminotransferase (ALT), aspartate transaminase (AST), cholesterol, and creatinine were determined, and total protein triglycerides were measured at four weeks. Blood glucose level was highest in both groups (Group 3 and Group 4) at 30 minutes and two weeks and gradually decreased in a time-dependent manner. The difference in blood glucose among the four groups was significant (p < 0.05). Additionally, the levels of ALT, AST and triglycerides were significantly decreased by Opuntia ficus-indica.

A Stereochemical Aspect of Pyridoxal 5' -Phosphate Dependent Enzyme Reactions and Molecular Evolution

  • Jhee, Kwang-Hwan;Tohru, Yoshimura;Yoichi, Kurokawa;Nobuyoshi, Esaki;Kenji, Soda
    • Journal of Microbiology and Biotechnology
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    • v.9 no.6
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    • pp.695-703
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    • 1999
  • We have studied the stereospecificities of various pyridoxal 5'-phosphate (PLP) dependent enzymes for the hydrogen transfer between the C-4' of a bound coenzyme and the C-2 of a substrate in the transamination catalyzed by the enzymes. Stereospecificities reflect the structures of enzyme active-sites, in particular the geometrical relationship between the coenzyme-substrate Schiff base and the active site base participating in an $\alpha$-hydrogen abstraction. The PLP enzymes studied so far catalyze only a si-face specific (pro-S) hydrogen transfer. This stereochemical finding suggests that the PLP enzymes have the same topological active-site structures, and that the PLP enzymes have evolved divergently from a common ancestral protein. However, we found that o-amino acid aminotransferase, branched chain L-amino acid aminotransferase, and 4-amino-4-deoxychorismate lyase, which have significant sequence homology with one another, catalyze a re-face specific (pro-R) hydrogen transfer. We also showed that PLP-dependent amino acid racemases, which have no sequence homology with any aminotransferases, catalyze a non-stereospecific hydrogen transfer: the hydrogen transfer occurs on both faces of the planar intermediate. Crystallographical studies have shown that the catalytic base is situated on the re-face of the C-4' of the bound coenzyme in o-amino acid aminotransferase and branched chain L-amino acid aminotransferase, whereas the catalytic base is situated on the si-face in other aminotransferases (such as L-aspartate aminotransferase) catalyzing the si-face hydrogen transfer. Thus, we have clarified the stereospecificities of PLP enzymes in relation with the primary structures and three-dimensional structures of the enzymes. The characteristic stereospecificities of these enzymes for the hydrogen transfer suggest the convergent evolution of PLP enzymes.

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Mercury Exposure in Association With Decrease of Liver Function in Adults: A Longitudinal Study

  • Choi, Jonghyuk;Bae, Sanghyuk;Lim, Hyungryul;Lim, Ji-Ae;Lee, Yong-Han;Ha, Mina;Kwon, Ho-Jang
    • Journal of Preventive Medicine and Public Health
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    • v.50 no.6
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    • pp.377-385
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    • 2017
  • Objectives: Although mercury (Hg) exposure is known to be neurotoxic in humans, its effects on liver function have been less often reported. The aim of this study was to investigate whether total Hg exposure in Korean adults was associated with elevated serum levels of the liver enzymes aspartate aminotransferase (AST), alanine transaminase (ALT), and gamma-glutamyltransferase (GGT). Methods: We repeatedly examined the levels of total Hg and liver enzymes in the blood of 508 adults during 2010-2011 and 2014-2015. Cross-sectional associations between levels of blood Hg and liver enzymes were analyzed using a generalized linear model, and nonlinear relationships were analyzed using a generalized additive mixed model. Generalized estimating equations were applied to examine longitudinal associations, considering the correlations of individuals measured repeatedly. Results: GGT increased by 11.0% (95% confidence interval [CI], 4.5 to 18.0%) in women and 8.1% (95% CI, -0.5 to 17.4%) in men per doubling of Hg levels, but AST and ALT were not significantly associated with Hg in either men or women. In women who drank more than 2 or 3 times per week, AST, ALT, and GGT levels increased by 10.6% (95% CI, 4.2 to 17.5%), 7.7% (95% CI, 1.1 to 14.7%), and 37.5% (95% CI,15.2 to 64.3%) per doubling of Hg levels, respectively, showing an interaction between blood Hg levels and drinking. Conclusions: Hg exposure was associated with an elevated serum concentration of GGT. Especially in women who were frequent drinkers, AST, ALT, and GGT showed a significant increase, with a significant synergistic effect of Hg and alcohol consumption.

Healing and preventive effects of low-esterified pectin on liver injury induced by carbon tetrachloride in rats

  • Khotimchenko, Yuri S.;Kolenchenko, Elena A.;Khotimchenko, Maxim Y.;Kovalev, Valeri V.
    • Advances in Traditional Medicine
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    • v.4 no.1
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    • pp.28-36
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    • 2004
  • The purpose of this study was to investigate the pharmacological effects of low-esterified pectin on carbon tetrachloride $(CCL_4)-induced$ hepatotoxicity in rats. The study included two experiments. In the first experiment the animals were given daily $CCL_4$ through gavage for 7 days and then 10, 50, or 250 mg/kg b.w. of pectin for 21 days. At the end of experiment rats were killed within 24 hours. The increased bilirubin level, enhanced alanine aminotransferase and aspartate aminotransferase activity in plasma induced by $CCL_4$ were partly normalized by pectin administration in a dose-dependent manner. The pectin treatment also resulted in significant recovery of $CCL_4-induced$ decrease of the liver glycogen content. In addition, pectin significantly improved $CCL_4-induced$ alterations of pro-oxidant and antioxidant biochemical parameters in liver and plasma compared to those of rats administered $CCL_4$. In the second experiment the animals were given daily 10, 50 or 250 mg/ kg b.w. of pectin for 21 days before a 7-day administration of $CCL_4$. Rats were killed 24 hours after the end of experiment. Pretreatment with pectin before $CCL_4$ administration resulted in significantly inhibited increase of the blood enzymatic activities of alanine and aspartate aminotransferases and bilirubin level in a dose-dependent manner. Also, preliminary administration of pectin prevented elevation of malondialdehyde and conjugated diene levels in liver and plasma as well as a reduction of glutathione content in liver of rats given $CCL_4$. These results suggest that low-esterified pectin exert healing and preventive effects on $CCL_4-induced$ hepatotoxicity in rats.

Association Between Cadmium Exposure and Liver Function in Adults in the United States: A Cross-sectional Study

  • Hong, Dongui;Min, Jin-Young;Min, Kyoung-Bok
    • Journal of Preventive Medicine and Public Health
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    • v.54 no.6
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    • pp.471-480
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    • 2021
  • Objectives: Cadmium is widely used, leading to extensive environmental and occupational exposure. Unlike other organs, for which the harmful and carcinogenic effects of cadmium have been established, the hepatotoxicity of cadmium remains unclear. Some studies detected correlations between cadmium exposure and hepatotoxicity, but others concluded that they were not associated. Thus, we investigated the relationship between cadmium and liver damage in the general population. Methods: In total, 11 838 adult participants from National Health and Nutrition Examination Survey 1999-2015 were included. Urinary cadmium levels and the following liver function parameters were measured: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), total bilirubin (TB), and alkaline phosphatase (ALP). Linear and logistic regression analyses were performed to assess the associations between urinary cadmium concentrations and each liver function parameter after adjusting for age, sex, race/ethnicity, annual family income, smoking status, alcohol consumption status, physical activity, and body mass index. Results: The covariate-adjusted results of the linear regression analyses showed significant positive relationships between log-transformed urinary cadmium levels and each log-transformed liver function parameter, where beta±standard error of ALT, AST, GGT, TB, and ALP were 0.049±0.008 (p<0.001), 0.030±0.006 (p<0.001), 0.093±0.011 (p<0.001), 0.034±0.009 (p<0.001), and 0.040±0.005 (p<0.001), respectively. Logistic regression also revealed statistically significant results. The odds ratios (95% confidence intervals) of elevated ALT, AST, GGT, TB, and ALP per unit increase in log-transformed urinary cadmium concentration were 1.360 (1.210 to 1.528), 1.307 (1.149 to 1.486), 1.520 (1.357 to 1.704), 1.201 (1.003 to 1.438), and 1.568 (1.277 to 1.926), respectively. Conclusions: Chronic exposure to cadmium showed positive associations with liver damage.

The Therapeutic Effects of Korean Red Ginseng on Carbon Tetrachloride- and Galactosamine-induced Hepatotoxicity in Rats (홍삼의 사염화탄소 및 갈락토사민 유발 간독성에 대한 치료효과)

  • Lee, Chung-Kyu;Han, Yong-Nam;Kim, Na-Young;Choi, Jong-Won
    • Journal of Ginseng Research
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    • v.27 no.1
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    • pp.11-16
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    • 2003
  • In this study, we investgated the effect of Red Ginseng (KRG) on liver damage induced by carbon tetrachloride (CTC) and galactosamine (GalN) in rats using indicator enzymes such as serum alanine/aspartate aminotransferases, sorbital dehydrogenase, lactate dehydrogenase, and ${\gamma}$-glutamyltransferase. Treatment of KRG restored these enzyme activities to near normal level compared to CTC or GalN treatment alone. Treatment of KRG also enhanced hepatic microsomal enzyme system, malondialdehyde formation, and depletion of reduced glutathione content, which were reduced by CTC or GalN. We also found that the decreased activities of glutathione S-transferase and glutathine reductase but not ${\gamma}$-glutamycysteine synthetase after KRG treatment restored to normal level. These results indicate that KRG has potent therapeutic activity against CTC- and GalN-induced hepatotoxicity in rat.