• 통합자연과학논문집
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• 제8권4호
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• pp.267-272
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• 2015

Galactosemia is a potentially lethal disorder caused by the deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT) within the Leloir pathway. Galactokinase (GALK) is the enzyme in Leloir pathway which converts ${\alpha}$-D galactose to galactose 1-phosphate. The elevated level of galactose-1-phosphate, the product of GALK plays a major role in Galactosemia. Therefore the inhibition of GALK is a novel therapy for this disorder. Hence in the present study, we performed molecular docking of twenty inhibitors with different activity against galactokinase into the active site of galactokinase enzyme. The binding mode of these inhibitors was obtained using Surflex dock program interfaced in Sybyl-X2.0. The residues such as SER141, TYR109, ARG105, ARG228, TYR106, GLY346, GLY136, ASP86, ASP186 and SER142 found to interact with inhibitors.

• 한국식품과학회지
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• 제48권6호
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• pp.542-547
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• 2016

The thermal properties of ramie leaf ${\beta}$-amylase (RBA) were examined to develop a novel process for enzyme purification. The thermostability of RBA extract prepared from ramie leaf powder was examined at various temperatures. RBA activity decreased slightly, whereas other carbohydrate-active enzymes, such as $\small{D}$-enzyme, were rapidly inactivated during 30 min incubation at $60^{\circ}C$. When the heat-treated extract was incubated with various substrates, maltose was produced exclusively as the major product, whereas the untreated crude extract produced maltose and other maltooligosaccharides. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, fewer protein bands were observed for the heat-treated extract than the untreated extract, indicating that the thermostable RBA was partially purified and other thermolabile enzymes were eliminated. Thus, the treatment of the RBA extract at $60^{\circ}C$ for 30 min resulted in 5.4-fold purification with a recovery yield of 90%.

• Mycobiology
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• 제36권3호
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• pp.148-151
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• 2008

A novel biomass was prepared from Pichia anomala KCCM 11473, which grew well in ginseng-steaming effluent (GSE), and its physiological functionalities and enzyme activities were determined. When the strain was cultured in the GSE (pH 6.0) at 30$^{\circ}C$ for 48 h, 1.6 mg of biomass per ml-cultures was produced. The cell-free extract of the biomass showed high antihypertensive angiotensin I-converting enzyme inhibitory activity of 72.0% and anticholesteromia HMG-CoA reductase inhibitory activity of 46.5%. The cell-free extract also showed 13.0 U per ml and 8.5 U per ml of neutral protease activity and alkaline protease, respectively.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.315.1-315.1
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• 2002

DNA topoisomerases I (topo I) and II are essential enzymes that relax DNA supercoiling and relieve torsional strain during DNA processing. including replication. transcription. and repair. Topo I relaxes DNA by cleaving one strand of DNA by attacking a backbone phosphale with a catalytic lyrosine (Tyr723. human topo I). This enzyme has recently been investigated as a new target for antineoplastic drugs. Inhibitors to the enzyme intercalate between the DNA base pairs. interfering religation of cleaved DNA, therefore inhibit the activity of topo I. (omitted)

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1097-1103
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• 2020

Bacterial surface display systems have been developed for various applications in biotechnology and industry. Particularly, the discovery and design of anchoring motifs is highly important for the successful display of a target protein or peptide on the surface of bacteria. In this study, an efficient display system on Escherichia coli was developed using novel anchoring motifs designed from the E. coli mipA gene. Using the C-terminal fusion system of an industrial enzyme, Pseudomonas fluorescens lipase, six possible fusion sites, V¹⁴⁰, V¹⁷⁶, K¹⁷⁹, V²²⁶, V²³², and K²³⁴, which were truncated from the C-terminal end of the mipA gene (MV¹⁴⁰, MV¹⁷⁶, MV¹⁷⁹, MV²²⁶, MV²³², and MV²³⁴) were examined. The whole-cell lipase activities showed that MV¹⁴⁰ was the best among the six anchoring motifs. Furthermore, the lipase activity obtained using MV¹⁴⁰ as the anchoring motif was approximately 20-fold higher than that of the previous anchoring motifs FadL and OprF but slightly higher than that of YiaTR232. Western blotting and confocal microscopy further confirmed the localization of the fusion lipase displayed on the E. coli surface using the truncated MV¹⁴⁰. Additionally the MV¹⁴⁰ motif could be used for successfully displaying another industrial enzyme, α-amylase from Bacillus subtilis. These results showed that the fusion proteins using the MV¹⁴⁰ motif had notably high enzyme activities and did not exert any adverse effects on either cell growth or outer membrane integrity. Thus, this study shows that MipA can be used as a novel anchoring motif for more efficient bacterial surface display in the biotechnological and industrial fields.

• Asian-Australasian Journal of Animal Sciences
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• 제12권6호
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• pp.988-1001
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• 1999

The rumen ecosystem is increasingly being recognized as a promising source of superior polysaccharide-degrading enzymes. They contain a wide array of novel enzymes at the levels of specific activities of 1,184, 1,069, 119, 390, 327 and $946{\mu}mol$ Reducing sugar release/min/mg protein for endoglucanase, xylanase, polygalactouronase, amylase, glucanase and arabinase, respectively. These enzymes are mainly located in the surface of rumen microbes. However, glycoside-degrading enzymes (e.g. glucosidase, fucosidase, xylosidase and arabinofuranosidase, etc.) are mainly located in the rumen fluid, when detected enzyme activities according to the ruminal compartments (e.g. enzymes in whole rumen contents, feed-associated enzymes, microbial cell-associated enzymes, and enzymes in the rumen fluid). Ruminal fungi are the primary contributors to high production of novel enzymes; the bacteria and protozoa also have important functions, but less central roles. The enzyme activities of bacteria, protozoa and fungi were detected 32.26, 19.21 and 47.60 mol glucose release/min/mL mediem for cellulose; 42.56, 14.96 and 64.93 mmol xylose release/min/mL medium after 48h incubation, respectively. The polysachharide-degrading enzyme activity of ruminal anaerobic fungi (e.g. Neocallimastix patriciarum and Piromyces communis, etc.) was much higher approximately 3~6 times than that of aerobic fungi (e.g. Tricoderma reesei, T. viridae and Aspergillus oryzae, etc.) used widely in industrial process. Therefore, the rumen ecosystem could be a growing source of novel enzymes having a tremendous potential for industrial applications.

• BMB Reports
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• 제28권2호
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• pp.100-106
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• 1995

S-adenosylmethionine (SAM) synthetase was purified to homogeneity from soybean (Glycine max) axes. The enzyme was purified 216-fold with a 1.5% yield by ammonium sulfate fractionation, acetone fractionation, ion exchange chromatography with DEAE-sephacel, gel filtration with Sephacryl S-300, and afffinity chromatography with ATP-agarose. The enzyme activity reached a maximum 3 days after germination. SAM synthetase had a subunit molecular weight of 57,000 daltons from a silver stained single band on SDS-PAGE. The molecular weight of the enzyme was 110,000 daltons from Sephacryl S-300 gel filtration. The enzyme was composed of two identical subunits. The $K_m$ values of the enzyme for L-methionine and ATP were 1.81 and 1.53 mM, respectively. The enzymatic activity was not affected by polyamines, agmatine, or SAM analogues, but was inhibited by SAM. The inhibition pattern was showed non-competitive for L-methionine and uncompetitive for ATP. The activity of SAM synthetase was inhibited by thiol-blocking reagents. The enzyme was induced by treatment with $10^{-3}$ M putrescine at germination. Experimental data revealed a possible novel regulation mechanism of polyamine biosynthesis through several endogenous intermediates.

• BMB Reports
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• 제28권5호
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• pp.408-413
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• 1995

Decrease in the amount of cotyledonary spermidine in Glycine max under anaerobic conditions related to an increase in spermidine dehydrogenase. Under the same conditions, no enzymatic activity of diamine oxidase was observed. Exposure of Glycine max both to spermidine and 1,3-diaminopropane under anaerobic conditions resulted in a decrease in spermidine contents. Correlated with the decrease in spermidine contents, there was a drastic increase in spermidine dehydrogenase. The molecular weight of the purified enzyme estimated by Sephacryl S-300 gel column and SDS gel electrophoresis were 130,000 dalton and 65,000 dalton, respectively, indicating that the enzyme is a dimer. The optimal pH for activity was 9.3. The $K_m$ value for spermidine was 0.61 mM. Neither metal ions nor polyamine and derivatives affected enzymatic activity, but the enzyme was inhibited by DTNB, NEM and PCMB, suggesting that a cysteine residue of the enzyme is associated with or involved in enzyme activity. To our knowledge, this is the first report describing properties of the enzyme from plants. Considered together, the data in this paper indicate that both spermidine and 1,3-diaminopropane, novel activators, enhance the spermidine dehydrogenase activity and control the intracellular spermidine contents.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.245-253
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• 2014

A fibrinolytic enzyme was produced by an edible mushroom of Pleurotus ostreatus using submerged culture fermentation. The enzyme was purified from the culture supernatant by applying a combination of freeze-thaw treatment, ammonium sulfate precipitation, hydrophobic interaction, and gel filtration chromatographies. The enzyme was purified by a 147-fold, with a yield of 7.54%. The molecular masses of the enzyme an determined by gel filtration and SDS-PAGE were 13.6 and 18.2 kDa, respectively. The isoelectric point of the enzyme was 8.52. It hydrolyzed fibrinogen by cleaving the ${\alpha}$ and ${\beta}$ chains of fibrinogen followed by the ${\gamma}$ chains, and also activated plasminogen into plasmin. The enzyme was optimally active at $45^{\circ}C$ and pH 7.4. The enzyme activity was completely inhibited by EDTA, whereas protease inhibitors of TPCK, SBTI, PMSF, aprotinin and pepstatin showed no inhibition on its activity. The partial amino acid sequences of the enzyme as determined by Q-TOF2 were ATFVGCSATR, GGTLIHESSHFTR, and YTTWFGTFVTSR. These sequences showed a high degree of homology with those of metallo-endopeptidases from P. ostreatus and Armillaria mellea. The purified enzyme can also be applied as a natural agent for oral fibrinolytic therapy or prevention of thrombosis.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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• pp.35-36
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• 2001

Nutrition influences cancer incidence and offers a variety of preventive dietary factors including non-nutritive plant metabolites. To identify novel potential chemopreventive agents, we have set up cell- and enzyme-based in vitro marker systems relevant for prevention of carcinogenesis in vivo. This experimental approach led to the identification of Xanthohumol (Xn), a prenylated chalcone from hop (Humulus lupulus L.) as a most promising broad-spectrum chemopreventive agent.(omitted)