• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2485-2488
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• 2009

• Proceedings of the Zoological Society Korea Conference
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• 2003.08a
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• pp.162.2-162
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• 2003

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.301-305
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• 2002

The gene (ppaT) encoding Thermus caldophilus GK24 pyrophosphatase (Tca pyrophosphatase) was cloned and sequenced. The gene was found to contain an open reading frame encoding 175 amino acids with a calculated mass of 19,155 Da. The ppaT gene was expressed under the control of the tac promoter in Escherichia coli. The recombinant Tca pyrophosphatase was purified 21.4-fold with $56\%$ yield and specific activity of 25.7 U $mg^-1$, following a combination of heating (to denature the E. coli proteins) and one step of DEAE-Sephacel column chromatography. The native enzyme was found to have an approximate molecular mass of 110,000 Da and consisted of six subunits. The enzyme exhibited maximal activity at pH of 8.0-8.5 and was stable at $80-90^{\circ}C$. A divalent cation was absolutely required for the enzyme activity, with $Mg^2+$. being the most effective.

• BMB Reports
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• v.29 no.3
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• pp.253-260
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• 1996

An enzyme that hydrolyzes flavin-adenine dinucleotide (FAD) was found to be present in rat liver lysosomal membrane prepared from Triton WR-1339 filled lysosomes (tritosomes) purified by flotation on sucrose. This FAD phosphohydrolase (FADase) exhibited optimal activity at pH 8.5 and had an apparent Km of approximately 3.3 mM. The activity was decreased 50~70% by dialysis against EDTA and this was restored by $Zn^{2+}$, $Mg^{+2}$, $Hg^{+2}$, and $Ca^{+2}$ ions inhibited the enzyme, but $F^-$ and molybdate had no effect. The enzyme was also inhibited by p-chloromercuribenzoate (pCMB), reduced glutathione and other thiols, cyanide, and ascorbate. The presence of ATP, ADP, AMP. ${\alpha}-{\beta}-methylene$ ATP, AMP-p-nitrophenyl phosphate (PNP), GMP, and coenzyme A (CoA) decreased the activity on FAD, but pyrimidine nucleotides, adenosine, adenine, or $NAD^+$ were without effect. Phosphate stimulated the activity slightly. FAD phosphohydrolase activity was separated from ATPase and inorganic pyrophosphatase activities by solubilization with detergents and polyacrylamide gel electrophoresis and by linear sucrose density gradient centrifugation suggesting that the enzyme is different from ATPase, inorganic pyrophosphatase, and soluble lysosomal FAD pyrophosphatase. Paper chromatography showed that FAD was hydrolyzed to flavin mononucleotide (FMN) and AMP which were further hydrolyzed to riboflavin and AMP by phosphatases known to be present in lysosomal membranes. Incubation of the intact Iysosomes with pronase showed that the active site of FAD phosphohydrolase must be oriented to the cytosol. The FAD hydrolyzing activity was detected in Golgi, microsome, and plasma membrane, but not in mitochondria or soluble lysosomal preparations.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.237-244
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• 2002

To analyze proteins related to antifungal activity, SAR01 strain was isolated from seaweed and identified as Streptomyces sp. from the result of FAME (fatty acid methyl ester) analysis. The isolated strain had antifungal activities against T species of plant pathogenic fungi. Antifungal activity deficient mutant (SAR 535) of Streptomyces sp. SAR01 was induced by gamma radiation $(^{60}Co,\;5kGy)$. By 2 D electrophoresis analysis, 6 protein spots were found in wild strain (SAR01) but these spots disappeared in mutant strain (SAR535). Among them, 5 proteins showed similarities to heat shock protein 70(HSP70), Fe-containing superoxide dismutase II (Fe- SODII), ribosome recycling factor (RRF), 10 kDa chnperonin (GroES) and inorganic pyrophosphatase (PPAse), respectively. It suggested that the above 6 proteins could be closely related to the antifungal activity of Streptomyces sp. SAR01.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.4
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• pp.241-250
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• 1982

Time course of alkaline inorganic PPase activity with different parts of mung-bean sprout and some properties of partially purified enzyme from mung-bean leaves were investigated. The enzyme activity in leaf, root and cotyledon showed a tendency to increase at an early stage and then decrease gradually as germination continued. However, the crude homogenate of epicotyl showed the continuous decline of the enzyme activity but that of hypocotyl showed the continuous increase. In particular, the enzyme activity of leaf fraction was about 2-4 times as high as those of other fractions. The specific activity of the leaf enzyme was increased 86-fold, with a 23.9% yield, upon purification procedures. The purified enzyme from leaves had the Rm value of 0.35 and was not homogenous when judged by disc gel electrophoresis. Using tetrasodium pyrophosphate as a substrate, the apparent Km value for the partially purified enzyme was 0.89 mM. The enzyme was highly specific for $Mg^{2+}$ $CU^{2+}$ and $Fe^{2+}$ was also showed the activating effect of 56% and 55% with $Mg^{2+}$, respectively. However, $Ca^{2+}$), $Zn^{2+}$, $Mn^{2+}$, $Co^{2+}$ and $Ni^{2+}$ acted as inhibitors for the enzyme. The pH optimum for the enzyme shifted from 9.0 to 8.0 as the concentration of $Mg^{2+}$ was increased. The enzyme from mun-bean leaf was the most active at $50^{\circ}C$ and considerably stable on heat.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.219-222
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• 2000

Physiological changes of Escherichia coli during the fed-batch fermentation process were characterized in this study. Overall cellular protein samples prepared at the different stage of fermentation were separated by 2-dimensional gel electrophoresis (2-DE), and differently expressed 15 proteins, Phosphotransferase enzyme I, GroEL, Trigger factor, ${\beta}$ subunit of ATP synthase, Transcriptional regulator KDGR, Phosphoglycerate mutase 1, Inorganic pyrophosphatase, Serine Hydroxymethyl-transferase, ${\alpha}$ subunit of RNA polymerase, Elongation factor Tu, Elongation factor Ts, Tyrosine-tRNA ligase, DnaK suppressor protein, Transcriptional elongation factor, 30S ribosomal protein S6 were identified using matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOF MS). When bacterial cells grow to high cell density, and IPTG-inducible heterologous protein is produced, expression level of overall cellular proteins was decreased. According to their functions in the cell, identified proteins were classified into three groups, proteins involved in transport process, small-molecule metabolism, and synthesis and modification of macromolecules.