• BMB Reports
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• 제28권1호
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• pp.12-16
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• 1995

The branched-chain ${\alpha}$-keto acid dehydrogenase (BCKAD) complex is a rate limiting enzyme which catalyzes the oxidative decarboxylation of branched-chain ${\alpha}$-keto acids. Numerous studies have suggested that BCKAD is subject to covalent modification in vitro via phosphorylation and dephosphorylation, which are catalyzed by a specific kinase and phosphatase, respectively. The biggest difficulty in the assay of BCKAD activity is to arrest the interconversion between the active and inactive forms. BCKAD activity was determined from fresh rat heart and liver tissues using homogenizing and assay buffers containing inhibitors of phosphatase and kinase. The results suggest that a radiochemical assay using ${\alpha}$-keto[1-$^{14}C$]-isovalerate as a substrate for the enzyme can be applied as a reliable method to determine in vitro enzyme activity with arrested interconversion between the active and inactive forms of the BCKAD complex.

• Advances in Traditional Medicine
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• 제9권4호
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• pp.303-306
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• 2009

The defatted methanol extract of Raphanus sativus Linn. (Cruciferae) seed (MERS) was evaluated for its antisteroidogenic potential in mature female Swiss albino mice. The methanol extract at the doses of 100 and 200 mg/kg body weight significantly elevated the levels of cholesterol and ascorbic acid contents which serve as a precursor for the synthesis of steroid hormones in ovaries. The extract also significantly inhibited glucose-6-phosphate dehydrogenase and ${\Delta}^5-3{\beta}$-hydroxy steroid dehydrogenase, the two key enzymes involved in ovarian steroidogenesis. Hence the extract (MERS) exhibited significant antisteroidogenic activity.

• 식물병연구
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• 제26권1호
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• pp.1-7
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• 2020

The succinate dehydrogenase inhibitor (SDHI) is a class of fungicides, which is widely and rapidly used to manage fungal pathogens in the agriculture field. Currently, fungicide resistance to SDHIs has been developed in many different plant pathogenic fungi, causing diseases on crops, fruits, vegetables, and turf. Understanding the molecular mechanisms of fungicide resistance is important for effective prevention and resistance management strategies. Two different mechanisms have currently been known in SDHI resistance. The SDHI target genes, SdhB, SdhC, and SdhD, mutation(s) confer resistance to SDHIs. In addition, overexpression of ABC transporters is involved in reduced sensitivity to SDHI fungicides. In this review, the current status of SDHI resistance mechanisms in phytopathogenic fungi is discussed.

• Asian-Australasian Journal of Animal Sciences
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• 제16권3호
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• pp.445-454
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• 2003

Concept and establishment of essential amino acids in animals and human beings rendered immeasurable contributions to animal production and human health. In ruminant animals, however, essential amino acids have never been completely established. The present review proposes a hypothesis that histidine may not be an essential amino acid for normal growing cattle (Japanese black) at least at the growing stage after about 450 kg of body weight on the basis of the experimental results of histidinol dehydrogenase activities in some tissues of the cattle together with hints from which the hypothesis was derived. At the same time, histidinol dehydrogenase activities in liver, kidney and muscle of swine, mouse, fowl and wild duck will be shown and the essentiality of histidine in these animals will be discussed. Finally, the essentiality of histidine for adult human will briefly be discussed.

• Journal of Microbiology and Biotechnology
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• 제18권12호
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• pp.1908-1914
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• 2008

An alkaliphilic bacterium, Bacillus clausii SKAL-16, was isolated from soil that had been contaminated with vegetable oil. The optimal pH and general pH range for bacterial growth was 8, and 7 to 10, respectively. The bacterium could grow on tributyrin and glycerol, but could not grow on acetate and butyrate. The SKAL-16 strain excreted butyric acid during growth on tributyrin, and selectively ingested glycerol during growth on a mixture of butyric acid and glycerol. The SKAL-16 generated intracellular lipase, but did not produce esterase and extracellular lipase. The DNA fragment amplified with the chromosomal DNA of SKAL-16 and primers designed on the basis of the esterase-coding gene of Bacillus clausii KSM-KI6 was not identical with the esterase-coding gene contained in the GenBank database. Pyruvate dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase activities were detected in the cell-free extract (crude enzyme).

• 한국가축번식학회지
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• 제17권3호
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• pp.257-262
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• 1993

Various tissue and follicular components were analyzed for the determination of lactate dehydrogenase(LDH) isozyme patterns by electrophoretic technique with chromogen reaction in the pig. Optimum conditions for the tissue homogenate and the storage were finally established. Small quantities of follicular components were analysed for typing of LDH isozymes by microelectrophoresis. Microelectrophoretic analysis showed that only LDH-1 was visible in the oocytes, all isozymes in cumulus masses, and LDH-1, 2 and 3 in follicular fluid. The results provide critical information on the LDH activity of various tissues and follicular components. Furthermore, t he developed methods should be useful the analysis of LDH in the small quantity of samples, especially in the oocyte, and easily applicable to the oocyte and early embryos of other domestic species.

• 한국동물학회지
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• 제34권1호
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• pp.123-130
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• 1991

Several parameters of u -glycerol-3-pholphate dehydrogenase (GPDH) such as activity, content and translatable mRNA levels were measured to elucidate mechanism underlving developmental and tissue specific regulation of 6PDH activity in Drosophila melonogastrr. In adult segments, most of total GPDH activity (62%1 Iwas detected in thorax where GPDH-1 resided, while 32% of total GPDH aUiviD was only detected in abdomen where GPDH-3 resided. The relative synthesis of GPDH was, however, similar in both tissues, although 58% of total GPDH was synthesized in abdomen. These results strongly suggest that the turnover rate of the abdominal enzyme (GPDH-3) was much more rapid than that of thoracic enzymes (GPDH-1). In nitro translation and immunoblotting experiments also indicate that GPDH-3 was arised by posttranslational modification from a single polypeptide (GPDH-1).

• Journal of Microbiology and Biotechnology
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• 제24권7호
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• pp.954-958
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• 2014

Succinic semialdehyde dehydrogenase (SSADH) catalyzes the oxidation of succinic semialdehyde (SSA) into succinic acid in the final step of ${\gamma}$-aminobutyric acid degradation. Here, we characterized Bacillus subtilis SSADH (BsSSADH) regarding its cofactor discrimination and substrate inhibition. BsSSADH showed similar values of the catalytic efficiency ($k_{ca}t/K_m$) in both $NAD^+$ and $NADP^+$ as cofactors, and exhibited complete uncompetitive substrate inhibition at higher SSA concentrations. Further analyses of the sequence alignment and homology modeling indicated that the residues of catalytic and cofactor-binding sites in other SSADHs were highly conserved in BsSSADH.

• Environmental Analysis Health and Toxicology
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• 제16권1호
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• pp.9-16
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• 2001

It is known that alcoholics have significantly lower mitochondrial aldehyde dehydrogenase (ALDH)s'activity than do normal subjects or nonalcoholics with liver disease. However, there are only few reports that explain the reasons behind this reduction of ALDHs'activities. In this study, ALDH activity is inhibited by acetaldehyde, a substrate for ALDH However, the addition of glutathione (GSH) protected ALDH activities against the inhibitory effects of acetaldehyde in vitro. Furthermore, when GSH depletion is induced using diethyl maleate (DEM) in rats by 24% in cytosol and 43% in mitochondria, ALDH activities were also depressed by 31% and 63%, respectively compared to non-treated rats without significant reductions in other hepatic enzymes. These results suggest that ALDHs'activities are closely related to the concentration of acetaldehyde and/or cellular GSH contents . Therefore in alcoholic liver disease, increased productions of acetaldehyde and decreased contents of mitochondrial GSH may involved in the depression of ALDHs'activities.

• 약학회지
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• 제36권5호
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• pp.469-473
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• 1992

Yeast alcohol dehydrogenase (YADH) has an acidic residue that interacts with the 2'- and 3'-hydroxyl groups of the adenosine ribose of the $NAD^+$ coenzyme. The acidic residue of Asp-223 (according to horse liver alcohol dehydrogenase amino acid sequence) is supposed to determine the coenzyme specificity for $NAD^+$ rather than $NADP^+$. We mutated Asp-223 to leucine and the mutant YADH was expressed in yeast and characterized for the coenzyme specificity. The turnover numbers of mutant enzyme for $NAD^+$ and ethanol were decreased 3.5- and 4.8-fold compared to wild-type enzyme, respectively. Contrastively, catalytic specificity for $NADP^+$ was increased 13-fold. As a result, the mutant YADH also employed $NADP^+$ as a coenzyme.