• Biomolecules & Therapeutics
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• v.16 no.1
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• pp.1-8
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• 2008

Mitochondria are important sensor of apoptosis. $H_2O_2-induced$ cell death rate was enhanced by serum deprivation. In this study, we investigated whether serum deprivation using 0.5 or 3 % FBS induces apoptotic cell death through mitochondrial enzyme activation as compared to 10 % FBS. Apoptotic cell death was observed by chromosome condensation and the increase of sub-G0/G1 population. Serum deprivation reduced cell growth rate, which was confirmed by the decrease of S-phase population in cell cycle. Serum deprivation significantly increased caspase-9 activity and cytochrome c release from mitochondria into cytosol. Serum deprivation-induced mitochondrial changes were also indicated by the increase of ROS production and the activation of mitochondrial enzyme, succinate dehydrogenase. Mitochondrial enzyme activity increased by serum deprivation was reduced by the treatment with rotenone, mitochondrial electron transport inhibitor. In conclusion, serum deprivation induced mitochondrial apoptotic cell death through the elevation of mitochondrial changes such as ROS production, cytochrome c release and caspase-9 activation. It suggests that drug sensitivity could be enhanced by the increase of mitochondrial enzyme activity in serum-deprived condition.

• BMB Reports
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• v.28 no.2
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• pp.177-183
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• 1995

The activity of aldehyde dehydrogenase (ALDH) in the cerebrum, cerebellum, striatum, and medulla oblongata was examined and mitochondrial matrix ALDH was purified prior to immunohistochemical study on the localization of ALDH isozymes in pig brain. Relatively high enzyme activity was found in the striatum and medulla oblongata when using indole-3-acetaldehyde as substrate, and in the striatum when using 3,4-dihydroxyphenylacetaldehyde (DOPAL). The main part of mitochondrial ALDH activities with both acetaldehyde and DOPAL existed in the matrix fraction. The ratio of activity of the matrix to the membrane fraction in the cerebrum was higher than in the cerebellum, suggesting that the distribution pattern of ALDH isozymes was different according to the brain regions. The 276-fold purified mitochondrial matrix ALDH from pig brain was identified to be homologous tetramers with 53 KD subunits. The enzyme showed maximal activity at pH 9.0 and was stable in the temperature range from $25^{\circ}C$ to $37^{\circ}C$. The mitochondrial matrix ALDH activity was considerably inhibited by acetaldehyde in vitro. The $K_m$ values of the enzyme for acetaldehyde and propionaldehyde were 5.8 mM and 4.9 mM, respectively, whereas $K_m$ values for indole-3-acetaldehyde and DOPAL were 44 ${\mu}M$ and 1.6 ${\mu}M$, respectively. The $V_{max}/K_{m}$ ratio was the highest with DOPAL as compared with other substrates. These results suggested that mitochondrial matrix ALDH in the present work might be a low Km isozyme involved in biogenic aldehyde oxidation in pig brain.

• The Korean Journal of Mycology
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• v.22 no.2
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• pp.122-129
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• 1994

The role of metal ions for the activity of the mitochondrial $F_1-ATPase$ was studied. Removal of non-heme iron ion from the mitochondria by dialysis against chelating agents, 10 mM ethylenediaminetetraacetic acid(EDTA) and 10 mM o-phenanthroline(o-Phe), led to 56% and 49% inactivation of the enzyme, respectively. The enzyme dialyzed against EDTA was reactivated 81% by the addition of 0.5 mM $Fe^{3+}$ and 70% by 0.5 mM $Mg^{2+}$. But, $Fe^{2+}$ did not reactivate the enzyme. Coexistence of 0.5 mM $Fe^{2+}$ and 0.5 mM $Mg^{2+}$ resulted in 95% reactivation of the enzyme, while $Fe^{3+}$ with 0.5 mM $Mg^{2+}$ did not reactivate the enzyme like the effect of $Fe^{2+}$ alone. The enzyme dialyzed against o-Phe showed the similar results. These data showed that $Fe^{3+}$ is predominantly required for the activity of the mitochondrial $F_1-ATPase$ in Lentinus edodes and stimulated the activity of it by $Mg^{2+}$. $Fe^{3+}$ and $Mg^{2+}$ increased enzyme's affinity for substrate, decreasing the Km value 1.67 mM to 0.65 mM.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.165-171
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• 1993

The effects of the iron ions for the light-induced mitochondrial $F_0F_1-ATPase$ of Lentinus edodes was studied. The enzyme activity was stimulated up to 202% by 0.1 mM $Fe^{2-}$ ion, but was inhibited by $Fe^{3+}\;and\;Mg^{2+}$. In the presence of 0.5 mM $Mg^{2+}$, the activity also increased 32% by 0.1 mM $Fe^{2+}$ ion, and decreased to a similar extent by $Fe^{3+}$ ion than by only $Fe^{3+}$ ion. Also, the activity was inhibited 53% by 5.0 mM $Fe^{2-}$ ion in the presence of 0.5 mM $Mg^{2+}$ ion and various concentration of $Fe^{3+}$ ion(mM). These results showed that $Fe^{2+}$ strongly stimulated the enzyme activity and its role for the enzyme was independent of $Mg^{2+}$ ion, but was dependent of $Fe^{3+}$ ion. From inactivation of the enzyme by addition of metal chelating agent, EDTA, it is suggested that the enzyme is to be metalloenzyme. The optimal pH and temperature of the enzyme in the presence of 0.1 mM $Fe^{2+}$ was 7.6 and $63^{\circ}C$, respectively.

• The Korean Journal of Mycology
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• v.21 no.3
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• pp.157-164
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• 1993

The effects of the iron ions on the light-induced mitochondrial $F_1-ATPase$ in Lentinus edodes was studied. This enzyme activity was stimulated by each of the ferric, ferrous and magnesium ion. Especially, the activity of the enzyme by 5.0 mM ferric ion increased up to 107% in comparision with control group(100%). In the presence of magnesium ion, each of ferric and ferrous ion increased the activity of the enzyme, particulary, coexistence of 0.1 mM magnesium and 5.0 mM ferric ion increased the activity up to 270% with magnesium ion dependence. The activity of the enzyme was stimulated up to 268% by 5.0 mM ferric ion in the presence of 0.1 mM magnesium and 0.1 mM ferrous ion. Therefore, the coexistence of ferrous ion did not affect the activity. From the above, we propose that light-induced mitochondrial $F_1-ATPase$ in Lentinus edodes is a $Mg^{2+}{\cdot}Fe^{3+}{\;}F_1-ATPase.$ The optimal pH and temperature for the enzyme were 7.5 and $66^{\circ}C$ respectively.

• 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.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.199-204
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• 2002

It has been known that Ganoderma lucidum and Lentinus edodes have anticancer activity and immune enhancing activity. These two mushrooms were grown in liquid culture and harvested. From these mycelia, DNA was isolated and EtBr-CsCl density gradient ultracentrifugation was performed to purify it further. Then mitochondrial DNA was isolated by bisbenzimide-CsCl density ultracentrifugaton. Mitochondrial DNA of Ganoderma lucidum was digested by restriction enzymes, EcoR I, Hind Ⅲ, and Pst I, then electrophoresed. It showed 12, 22, 4 fragments. Mitochondrial DNA of Lentinus edodes was digested by EcoR I. Electric pattern showed 6 fragments. 4 fragments had appeared by Pst 1 digested mitochondrial DNA. Hind ill couldn't digest mitochondrial DNA of Lentinus edodes. Mitochondrial DNA of fusants was isolated to compare to those of parents. The results showed that fusant P₂S₄has new, recombined mitochondrial DNA. But P₂S₄had the same DNA that Ganoderma lucidum had.

• The Korean Journal of Mycology
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• v.17 no.4
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• pp.177-183
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• 1989

Mitochondria in Pleurotus ostreatus was purified by stepped sucrose density gradient centrifugation. The mitochondrial ATP synthase was investigated by various waveof the illumination at dark room for 30 min. The mitochondrial ATP synthase activity was stimulated 2.3 fold by 480 nm illumination compared with the broad wavelength group. The mitochondrial ATP synthase activity according to various times of illumination was stimulated 4.2 fold for 15 min at 480 nm compared with the broad wavelength group. The optimum pH and optimum temperature of the mitochondrial ATP synthase were 7.5 and $56^{\circ}C$, respectively. The activity of this enzyme was stimulated by 0.5 mmol $Fe^{2+}$, 1.0 mmol $Fe^{3+}$ and 5.0 mmol $k^+$ ion, but inhibited by 0.1 mmol $Na^+$ ion.

• Archives of Pharmacal Research
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• v.26 no.11
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• pp.951-959
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• 2003

A series of typical (chlorpromazine, haloperidol and thioridazine) and atypical (risperidone, quetiapine, clozapine and olanzapine) antipsychotics were tested for effects on integrated bioenergetic functions of isolated rat liver mitochondria. Polarographic measurement of oxygen consumption in freshly isolated mitochondria showed that electron transfer activity at respiratory complex I is inhibited by chlorpromazine, haloperidol, risperidone, and quetiapine, but not by clozapine, olanzapine, or thioridazine. Chlorpromazine and thioridazine act as modest uncouplers of oxidative phosphorylation. The typical neuroleptics inhibited NADH-coenzyme Q reductase in freeze-thawed mitochondria, which is a direct measure of complex I enzyme activity. The inhibition of NADH-coenzyme Q reductase activity by the atypicals risperidone and quetiapine was 2-4 fold less than that for the typical neuroleptics. Clozapine and olanzapine had only slight effects on NADH-coenzyme Q reductase activity, even at 200 $\mu$ M. The relative potencies of these neuroleptic drugs as inhibitors of mitochondrial bioenergetic function is similar to their relative potencies as risk factors in the reported incidence of extrapyramidal symptoms, including tardive dyskinesia (TD). This suggests that compromised bioenergetic function may be involved in the cellular pathology underlying TD.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.41-48
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• 1983

The activity and distribution of aspartate aminotransferase (EC 2.6. 1. 1) and alanine aminotransferase (EC 2.6.1.2) in adult Fascicle hepatica have been studied. Fasciola hepatica was fractionated by differential centrifugation into nuclear, mitochondrial and cytosolic fractions. The activity of GOT and GPT was measured by the method of Reitman and Frankel. Isozyme patterns of those enzyme were also examined by DEAE-cellulose column chromatography. The results obtained were as follows; 1. The activity of aspartate and alanine aminotransferase was about 0.55 unit and 0.92 unit per 1g of Fascicle hepatica, respectively. 2. The activity of those enzymes was relatively low compared with those in mammalian tissues. 3. The distribution of aspartate aminotransferase in the subcellular organelles showed that 71% of the activity was in cytosolic, 24% in mitochondrial and 5% was in nuclear fraction. 4. About 22% of the total alanine aminotransferase activity was found in the mitochondrial fratstion, about 66% in the cytosolic fraction. 5. Aspartate aminotransferase from cytosolic fraction was separated into two types of isozymes, whereas alanine aminotransferase from cytosolic fraction gave only one active peak on DEAE-cellulose column chromatography.