• BMB Reports
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• v.30 no.2
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• pp.138-143
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• 1997

In order to assess controversial' proposals concerning the fatty acid-induced uncoupling of mitochondrial oxidative phosphorylation, we investigated the interaction of stearic acid with key mitochondrial proteins and measured the effect of stearic acid on the respiration of cytochrome c oxidase vesicles. Electron paramagnetic resonance spectra of spin-labeled stearic acid clearly demonstrated that cytochrome c oxidase interacts strongly with stearic acid. However, the respiration of detergent-solubilized cytochrome c oxidase was not altered significantly by stearic acid. Surprisingly, adenine nucleotide carrier, which was assumed to bind and translocate fatty acid anions in the Skulachev model of uncoupling, did not bind stearic acid at all. The respiration rate of cytochrome c oxidase vesicles was increased by ~70% in the presence of $20{\mu}m$ stearic acid and this uncoupling was attributed to a simple protonophoric effect of stearic acid.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.97-103
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• 1991

Glutamine phosphoribosylpyrophosphate amidotransferase of Streptomyces tubercidicus was purified and characterized. Molecular weight of the isolated enzyme was determined to be approximately 230,000 and was composed foru identical subunits having a molecular weight of 58,000. This enzyme was strongly inhibited by AMP while considerably inhibited by ATP and GTP. Inhibition effect of enzyme activity by AMP was antagonized by increased concentration of substrate, PRPP, and metal ion (especially, $Mg^{++}$) was essential in both catalytic activity and nucleotide inhibition of this enzyme. Therefore, it was confirmed that end product inhibition of glutamine phosphoribosylpyrophosphate amidotransferase by adenine participated in the regulation of tubercidin biosynthesis from Streptomyces tubercidicus.s.

• BMB Reports
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• v.34 no.1
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• pp.39-42
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• 2001

Previous studies indicate that B. subtilis protoporphyrinogen oxidase is poorly inhibited by diphenyl ether herbicides. To better understand the basis of this insensitivity, the enzyme was overexpressed as a soluble protein in E. coli, purified and characterized. The mechanism of oxidation of B. subtilis protoporphyrinogen IX was studied and the enzyme kinetic parameters were determined for protoporpyrinogen IX; $K_m$, and $k_{cat}$ were $6.3\;{\mu}M$ and $0.028\;h-^1$, respectively. The enzyme required flavin adenine dinucleotide as a cofactor and its activity was enhanced by 1 mM n-octylglucopyranoside. The nonenzymatic oxidation rate was dependent on the concentration of protoporphyrinogen IX, suggesting that the reaction involves a pre-equilibrium step followed by a rate-limiting step.

• Natural Product Sciences
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• v.21 no.1
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• pp.25-29
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• 2015

In a continuation of our studies to discover bioactive secondary metabolites from marine sources, we further investigated samples from a tryptamine and phenyl-alkane producing sponge, which resulted in the isolation of four uncommon small molecules and five nucleosides. Their structures were determined to be 7,8-dihydroimidazo[1,5-c]pyrimidin-5(6H)-one (1), 5-chlorocavernicolin (2), maleimide-5-oxime (3), 3-methylmaleimide-5-oxime (4), uridine (5), 2'-deoxyuridine (6), thymidine (7), adenine (8), and adenosine (9) by spectroscopic analyses. The isolated compounds were evaluated for inhibitory activity against soluble epoxide hydrolase (sEH) as well as the Wnt/${\beta}$-catenine signaling pathway.

• Journal of Microbiology and Biotechnology
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• v.8 no.6
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• pp.625-630
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• 1998

Using a modified yeast secretory expression vector, $\alpha$-amylase of Schwanniomyces occidentalis was produced from Saccharomyces cerevisiae. The expression vector contains the a-amylase gene (AMY) harboring its own promoter without the regulatory region and the adenine base at the -3 position from the ATG start codon, its own signal sequence, CYC1 transcription terminator, and SV40 enhancer. The expressed $\alpha$-amylase activity from cells carrying the plasmid was approximately 26 times higher than that from the cells harboring an unmodified plasmid. When Saccharomyces diastaticus was transformed with this modified vector, a 2.5 times higher level of amylolytic activity than that from Sch. occidentalis was observed.

• Applied Biological Chemistry
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• v.1
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• pp.62-67
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• 1960

1) The variations of flavin adenine dinucleotide(FAD), flavin monomucleotide(FMN) and free riboflavin in control and 600r X-ray irradiated soybean sprout were estimated by the paper chromatographic method. 2) It was found that the formation of riboflavin in soybean sprout was mainly in FAD. 3) There were no great variation of FMN and free riboflavin in soybean sprout during the germination. 4) The moderate amount (600r) of X-ray irradiation accerelated the formation of FAD in soybean sprout during the germination.

• Journal of Microbiology and Biotechnology
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• v.5 no.1
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• pp.1-5
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• 1995

A genomic DNA of alkaliphilic bacterium, Micrococcus sp. Y-l, was analysed using the physical mapping method of pulsed-field gel electrophoresis (PFGE). Five restriction enzymes of Sspl, Hpal, Xbal, Ndel or EcoRI, which recognize the Adenine-Thymine-rich sequences of genomic DNA, were used for the generation of few (7 to 20) distinctly separate fragments, with average sizes in the range of 200～500 kb. However, the sites for Notl and SfiI, 8 base-recognizing enzymes, were highly frequent. The genome size of this strain was determined to be 4 mega base pairs (Mb) from restriction fragments separated by PFGE. This is the first case of restriction mapping in alkaliphilic bacterium.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.965-968
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• 2006

Exogenous S-adenosyl-L-methionine (AdoMet) enhances the production of actinorhodin in Streptomyces coelicolor. Thirty compounds related structurally with AdoMet were tested for their actinorhodin production. The relationships between the structures of the compounds tested and their actinorhodin production were analyzed using computational methods, and the molecules containing both bulky substituents at the C6 position of adenine and the long 5'-alkyl chain of adenosine were predicted to show high actinorhodin production.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.85-90
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• 2017

Mitochondria participate in various intracellular metabolic pathways such as generating intracellular ATP, synthesizing several essential molecules, regulating calcium homeostasis, and producing the cell's reactive oxygen species (ROS). Emerging studies have demonstrated newly discovered roles of mitochondria, which participate in the regulation of innate immune responses by modulating NLRP3 inflammasomes. Here, we review the recently proposed pathways to be involved in mitochondria-mediated regulation of inflammasome activation and inflammation: 1) mitochondrial ROS, 2) calcium mobilization, 3) nicotinamide adenine dinucleotide ($NAD^+$) reduction, 4) cardiolipin, 5) mitofusin, 6) mitochondrial DNA, 7) mitochondrial antiviral signaling protein. Furthermore, we highlight the significance of mitophagy as a negative regulator of mitochondrial damage and NLRP3 inflammasome activation, as potentially helpful therapeutic approaches which could potentially address uncontrolled inflammation.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2689-2694
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• 2011

Novel 5'-norcarbocyclic adenine and guanine phosphonic acid analogues with 6'-electronegative moiety such as unsaturated C-C bond were designed and synthesized from commercially available 2-methylene-propane-1,3-diol (4). Regioselective Mitsunobu reaction successfully proceeded from an allylic functional group (${\pm}$)-12b at low reaction temperature in polar cosolvent (DMF/1,4-dioxane) to give purine phosphonate analogues (${\pm}$)-13 and (${\pm}$)-20. The purine nucleoside phosphonate and phosphonic acid analogues were subjected to antiviral screening against HIV-1. Guanine analogue (${\pm}$)-23 shows significant anti-HIV activity in PBM cell lines ($EC_{50}=8.1\;{\mu}M$).