• Food Science of Animal Resources
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• v.24 no.2
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• pp.151-155
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• 2004

This study was performed to develop the method of differentiation fresh and frozen meat by using the measurement of mitochondrial malate dehydrogenase. The principle of this experiment is based on the fact the enzyme proteins associated with mitochondria membrane could be released by freezing. The methods were studied by measurements of protein concentration of meat press juice, WHC (water-holding capacity), drip loss and mitochondrial malate dehydrogenase enzyme activity. Samples were stored at 4$^{\circ}C$ and -18$^{\circ}C$ during storage period, respectively. Protein concentration of meat press juice was ranged from 8.5 mg/mL to 12.7 mg/mL and increased by freezing below at -18$^{\circ}C$(p<0.05). The WHC was not significantly different between fresh meat and frozen chicken meat (p＞0.05). The amount of drip loss of fresh and frozen chicken meat at 4$^{\circ}C$ and -18$^{\circ}C$ was not significantly different (p＞0.05). Mitochondrial malate dehydrogenase activity of frozen meat (-18$^{\circ}C$) was significantly higher (p＜0.05) than that of fresh meat. Also, enzyme activity of frozen meat was maintained at the same level after 3 minutes reaction. But fresh meat had not this reaction. From these results, it suggests that mitochondrial malate dehydrogenase can be used as a promising enzyme to differentiate between fresh and frozen meat.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.181-190
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• 1995

Malate dehydrogenase in the mosquito ovary after a blood meal, Aedes aegypti, was purified and characterized. MDH purification steps involved DEAE-Sepharose, S-Sepharose and Cibacron blue affinity chromatography. The purified MDH was 70,000 daltons in molecular weight and was a homodimer consisting of tow identical subunits. Optimal activity of purified MDH was obtained pH 9.0-9.2 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With obtained pH 9.0-92 in malate-oxaloacetate reaction and pH 9.8-10.2, in oxaloactate-malate reaction. With malate as substrate, purified mitochondrial MDH (1.28$\times$${10}^{-4}$ M) had lower Km value than cytoplasmic MDH (8.92x${10}^{-3}$ M). MDH activity was inhibited by citrate, $\alpha$-ketoglutarate, and ATP. Inhibition of MDH activity by ATP and citrate was less in malate-oxaloacetate reaction and in oxaloacetate-malate reaction. MDH activity was completely inhibited by ATP in oxaloacetate-malate reaction and not inhibited by citrate in malate-oxaloacetate reaction. Temporal activity change of MDH is similar to that of isocitrate dehydrogenase in the ovary after blood feeding; their activities in the ovary began to rise at 18 hours after a blood meal, and reached at the maximal level at 48 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.10
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• pp.1599-1605
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• 2005

The object of this study is to develop the method for differentiating fresh meat from frozen meat by using the measurement of the mitochondrial malate dehydrogenase in the Korean native cattle. The principle of this experiment is based on the fact that the enzyme proteins associated with mitochondrial membrane could be released by freezing. The methods of differentiating fresh meat from thawed, frozen meat were studied by measurements of mitochondrial malate dehydrogenase activity of meat press juice. Fresh and frozen beef were stored at 4, -4, -18 and -77$^{\circ}C$ for 15-day storage period. A meat press machine using air pressure was manufactured especially for these experiments, and sufficient amount of drip (about 0.15 mL/g) from 1.5 g of beef sample was efficiently obtained under a pressure of 8 kg/$cm^{2}$ generated by the meat pressing machine. The mitochondrial malate dehydrogenase activities of frozen meat drip i년ices stored at -18 and -77$^{\circ}C$ were significantly higher than those of fresh and frozen meat samples at -4$^{\circ}C$ (p < 0.05) during 10-min reaction period. However, the enzyme activities of the frozen meat drip juices (-18 and -77$^{\circ}C$) disappeared after 5 minutes of the reaction, which was not observed from the fresh and -4$^{\circ}C$ frozen meats. The enzyme activity maintained until 12 minutes for the fresh and -4$^{\circ}C$ frozen meats. From these results, the mitochondrial malate dehydrogenase could be considered as an indicator to differentiate fresh beef from frozen one.

• Korean Journal of Medicinal Crop Science
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• v.16 no.4
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• pp.261-267
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• 2008

Malate dehydrogenase is a ubiquitous enzyme in plants, involving in a range of metabolic processes depending on its subcellular location. A malate dehydrogenase (PgMDH) cDNA was isolated and characterized from the root of Panax ginseng C. A. Meyer. The deduced amino acid sequence of PgMDH showed high similarity with the NAD-dependent mitochondrial malate dehydrogenase from Glycinemax (P17783), Eucalyptus gunnii (P46487), and Lycopersicon esculentum (AAU29198). And the segment of a malate dehydrogenase gene was amplified through RT-PCR. The expression of PgMDH was increased after treatments of chilling, salt, UV, cadmium or copper treatment.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.23-29
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• 1989

Biochemical consequence of the accumulation in cells of superoxide $(O^{-}_{2})$ which was proposed to be probably a common chemical factor in the secondary process of the mechanism of chilling injury as well as in the visible light photodamage in cells of higher plants, has been investigated in the present work. Especially focused was the destructive effect of $O^{-}_{2}$ on the biochemical activity of mitochondria, as informations which support the suggestion that mitochondrial inner membrane is the major site of $O^{-}_{2}$ production have been collected. Mitochondria and submitochondrial particles (SMP) were prepared from soybean hypocotyls for this case study. When SMP were treated with the electrolytically produced $O^{-}_{2}$ they suffered not only inhibition of the membrane-bound enzymes as demonstrated by cytochrome c oxidase, but also lipid peroxidation of membrane as proved by malondialdehyde production. Malate dehydrogenase present in the protein extract from mitochondrial matrix was also inhibited by the $O^{-}_{2}$ treatment. These results exhibited the chaotic effect of the overproduction and accumulation of $O^{-}_{2}$ in cells under a certain abnormal circumstance such as environmental stress on the physiological function of mitochondrial; disruption of the cellular metabolic pathways and the structural integrity of membrane.

• Journal of Pharmacopuncture
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• v.18 no.3
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• pp.68-74
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• 2015

Objectives: The present study was undertaken to determine the modulatory effect of taurine on the liver mitochondrial enzyme system with reference to mitochondrial lipid peroxidation (LPO), antioxidants, major tricarboxylic acid cycle enzymes, and electron transport chain enzymes during 7,12-dimethyl benz[a]anthracene (DMBA) induced breast cancer in Sprague-Dawley rats. Methods: Animals in which breast cancer had been induced by using DMBA (25 mg/kg body weight) showed an increase in mitochondrial LPO together with decreases in enzymic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)), non-enzymic antioxidants (reduced glutathione (GSH), vitamin C, and vitamin E), in citric acid cycle enzymes (isocitrate dehydrogenase (ICDH), alpha ketoglutarate dehydrogenase (alpha KDH), succinate dehydrogenase (SDH) and malate dehydrogenase (MDH)), and in electron transport chain (ETC) complexes. Results: Taurine (100 mg/kg body weight) treatment decreased liver mitochondrial LPO and augmented the activities/levels of enzymic, and non-enzymic antioxidants, tricarboxylic acid cycle enzymes and ETC complexes. Conclusion: The results of our present study demonstrated the chemotherapeutic efficacy of taurine treatment for DMBA-induced breast carcinomas.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.331-340
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• 1995

Interstrain polymorphisms of isoenzyme profiles and mitochondrial (Mt) DNA fingerprints were observed among seven strains of Acnnthnmoeba isolated from different sources and morphologically assigned to A. polvphngn. Mt DNA ringerprints by eight restriction endonucleases (Bgl II, Sca I, Cla I, EcoR I, Xbo I, Kpn I, Sal I, and Sst I) revealed considerable interstrain polymorphisms . Isoenzyme profiles revealed considerable interstrain polymorphisms for acid phosphatase, lactate dehydrogenase, and glucose-6- phosphate dehydrogenase while those for glucose phosphate isomerase , leucine aminopeptidase , and malate dehydrogenase showed similarity Despite of the interstrain polymorphisms, the isoengyme profiles and Mt DNA fingerprints of the strain Ap were found to be identical with those of the strain .tones . Mt DNA fingerprinting was found to be highly applicable for the strain identification, characterization, and differentiation. Key words: Acanthnmoebn polyphcga, interstrain polymorphism, isoenzyme profiles , Mt DNA fingerprints, strain differentiation, strain identification.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.121-129
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• 2017

BACKGROUND/OBJECTIVES: The study was conducted to evaluate the effects of dietary leucine supplementation on mitochondrial biogenesis and energy metabolism in the liver of normal birth weight (NBW) and intrauterine growth-retarded (IUGR) weanling piglets. MATERIALS/METHODS: A total of sixteen pairs of NBW and IUGR piglets from sixteen sows were selected according to their birth weight. At postnatal day 14, all piglets were weaned and fed either a control diet or a leucine-supplemented diet for 21 d. Thereafter, a $2{\times}2$ factorial experimental design was used. Each treatment consisted of eight replications with one piglet per replication. RESULTS: Compared with NBW piglets, IUGR piglets had a decreased (P < 0.05) hepatic adenosine triphosphate (ATP) content. Also, IUGR piglets exhibited reductions (P < 0.05) in the activities of hepatic mitochondrial pyruvate dehydrogenase (PDH), citrate synthase (CS), ${\alpha}$-ketoglutarate dehydrogenase (${\alpha}$-KGDH), malate dehydrogenase (MDH), and complexes I and V, along with decreases (P < 0.05) in the concentration of mitochondrial DNA (mtDNA) and the protein expression of hepatic peroxisome proliferator-activated receptor-${\gamma}$ coactivator $1{\alpha}$ (PGC-$1{\alpha}$). Dietary leucine supplementation increased (P < 0.05) the content of ATP, and the activities of CS, ${\alpha}$-KGDH, MDH, and complex V in the liver of piglets. Furthermore, compared to those fed a control diet, piglets given a leucine-supplemented diet exhibited increases (P < 0.05) in the mtDNA content and in the mRNA expressions of sirtuin 1, PGC-$1{\alpha}$, nuclear respiratory factor 1, mitochondrial transcription factor A, and ATP synthase, $H^+$ transporting, mitochondrial F1 complex, ${\beta}$ polypeptide in liver. CONCLUSIONS: Dietary leucine supplementation may exert beneficial effects on mitochondrial biogenesis and energy metabolism in NBW and IUGR weanling piglets.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.4
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• pp.263-275
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• 2022

There is a paucity of detailed data related to the effect of senescence on the mitochondrial antioxidant capacity and redox state of senescent human cells. Activities of TCA cycle enzymes, respiratory chain complexes, hydrogen peroxide (H₂O₂), superoxide anions (SA), lipid peroxides (LPO), protein carbonyl content (PCC), thioredoxin reductase 2 (TrxR2), superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPx1), glutathione reductase (GR), reduced glutathione (GSH), and oxidized glutathione (GSSG), along with levels of nicotinamide cofactors and ATP content were measured in young and senescent human foreskin fibroblasts. Primary and senescent cultures were biochemically identified by monitoring the augmented cellular activities of key glycolytic enzymes including phosphofructokinase, lactate dehydrogenase, and glycogen phosphorylase, and accumulation of H₂O₂, SA, LPO, PCC, and GSSG. Citrate synthase, aconitase, α-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, and complex I-III, II-III, and IV activities were significantly diminished in P25 and P35 cells compared to P5 cells. This was accompanied by significant accumulation of mitochondrial H₂O₂, SA, LPO, and PCC, along with increased transcriptional and enzymatic activities of TrxR2, SOD2, GPx1, and GR. Notably, the GSH/GSSG ratio was significantly reduced whereas NAD⁺/NADH and NADP⁺/NADPH ratios were significantly elevated. Metabolic exhaustion was also evident in senescent cells underscored by the severely diminished ATP/ADP ratio. Profound oxidative stress may contribute, at least in part, to senescence pointing at a potential protective role of antioxidants in aging-associated disease.

• Journal of Ginseng Research
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• v.17 no.2
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• pp.114-122
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• 1993

0.5 mg of natural ginsenoside mixture and 0.8 $\mu$Ci of synthesized 14C-ginsenosides were administered orally to a rat and killed at one hour after the ginsenoside administration and the liver was fractionated into nuclear fraction, mitrochondria microsomes and cytosol fraction. Radioactivity distribu lion in subcellular fractions of the liver showed that 32o1c of total radioactivity absorbed in the liver was in cytosol fraction but a significant portion of the radioactivity was also found in mitochondria (26.6%) and microsomal fraction (18.l%). 5.8% of the total radioactivity was recovered from the nuclear fraction as well. This suggested that ginsenosides might be distributed into all subcellular fractions. Activities of mitochondrial aldehyde dehydrogenase, lactate dehydrogenase and malate dehydrogenase of the liver of rat at two hours after the ginsenoside administraion were found appreciably stimulated, suggesting that the ginsenoside concentration in the liver might be around 10-5%, since optimum concentrations for most enzyme catalyzed reactions in vitro were known to be 10-6% 10-4%. A significant portion of the radioactivity recovered from subcellular fractions of the liver was found in protein fractions, suggesting that proteins might interact with ginsenosides. Examination of protein-ginsenoside interation by gel filtration, equilibrium dialysis and amonium sulfate precipitation technique suggesting that proteins and ginsenosides do not bound covalently but weakl\ulcorner combined. When purified ginsenoside Rbl and Rgl were incubated with rat liver cytosolic enzymes for 20 min, the above ginsenosides were hydrolyzed quickly, suggesting that ginsenosides might be rapidly hydrolyzed and metabolized in the liver. It was also observed in vitro that the ginsenosides such as Rbl and Rgl were easily hydrolyzed by rat liver cytosol preparation suggesting that absorbed ginsenosides might be quickly hydrolyzed and metabolized in the liver.