• Proceedings of the Microbiological Society of Korea Conference
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• 1991.04a
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• pp.225-236
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• 1991

The genes encoding the thermostable $\alpha$-amylase and maltogenic amylase from Bacillus lichenciformis were cloned and expressed in E. coli. The recombinant plasmid pTA322 was found to contain a 3.1kb EcoRI genomic DNA fragment of the thermostable $\alpha$-amylase. The cloned $\alpha$-amylase was compared with the B. licheniformis native $\alpha$-amylase. Both $\alpha$-amylase have the same optimal temperature of $70^{\circ}C$ and are stable in the pH range of 6 and 9. The complete nucleotide sequences of the thermostable $\alpha$-amylase gene were determined. It was composed of one open reading rame of 1,536 bp. Start and stop codons are ATG and TAG. From the amino acid sequence deduced from the nucleotide sequence, the cloned thermostable $\alpha$-amylase is composed of 483 amino acid residues and its molecular weight is 55,200 daltons. The content of guanine and cytosine is $47.46mol\%$ and that of third base codon was $53_41mol\%$. The recombinant plasmid, pIJ322 encoding the maltogenic amylase contains a 3.5kb EcoRI-BamHI genomic DNA fragment. The optimal reaction temperature and pH of the maltogenci amylase were $50^{\circ}C$ and 7, respectively. The maltogenic amylase was capable of hydrolysing pullulan, starch and cyclodextrin to produce maltose from starch and panose from pullulan. The maltogenic amylase also showed the transferring activity. The maltogenic amylase gene is composed of one open reading frame of 1,734bp. Start and stop codons are ATG and ATG. At 2bp upstream from start codon, the nucleotide sequence AAAGGGGGAA seems to be the ribosome-binding site(RBS, Shine-Dalgarno sequence). A putative promoter(-35 and-10 regions) was found to be GTTAACA and TGATAAT. From deduced amino acid sequence from the nucleotide srquence, this enzyme was comosed of 578 amino acid residues and its molecular weight was 77,233 daltons. The content of guanine and cytosine was $48.1mol\%$. The new recombinant plasmid, pTMA322 constructed by inserting the thermostable $\alpha$-amylase gene in the EcoRI site of pIJ322 to produce both the thermostable $\alpha$-amylase and the maltogenic amylase were expressed in the E. coli. The two enzymes expressed from E. coli containing pTMA322 was reacted with the $15\%$ starch slurry at $40^{\circ}C$ for 24hours. The distribution of the branched oligosaccharides produced by the single-step process was of the ratio 50 : 50 between small oligosaccharide up DP3 and large oligosaccharide above DP3.

• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.193-213
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• 1995

The purpose of this study is to investigate a possible contribution of nonspecific esterases, which occur in the oral cavity, to the degradation of ester bonds in polymethacrylates. One of the problems connected with the use of composite resins for restorations is their inadequate resistance to wear. It has been shown that methacrylate hydrolysis can be catalyzed by enzymes and that a carboxylic hydrolase (porcine liver esterase) catalyzed the hydrolysis of several mono - and dimethacrylates. The softening effect on a BISGMA/TEGDMA polymer induced by hydrolase will accelerate the in vivo wear of the polymer. Porcine liver esterase (EC 3.1.1.1) 3.2 mol/L $(NH_4)_2$ $SO_4$ was obtained from Sigma Chemical Company. The esterase activity of one unit is defined as the amount of enzyme capable of hydrolyzing $l{\mu}mol$ ethyl butyrate per min at pH 8.0 AT $25^{\circ}C$. Phosphate buffer, 10mmol/L, pH 7.0, was made by adjustment of a solution of $Na_2HPO_4$ with $H_3PO_4$. Composite resins used in this study are Silux Plus, Z-100, Durafil VS, and Prisma APH. Cylindrical specimens, 14mm in diameter and 3mm thick, of Silux Plus, Z-100, Durafil VS, Prisma APH were polymerized under the celluloid strip. 60 specimens were divided into 2 groups. One group was emersed only in buffer solution, the other group was emersed in buffer and enzyme solution. Silux Plus and Z-100 were divided into 2 subgroups, one subgroup was cured only Visilux 2. And the other subgroup was cured Visilux 2 and Triaid II. Thereafter, specimens were polished to its best achievable surface according to manufacture's directions. The Vickers hardness of the specimens was measured after 1, 2, 4, 7, 9, 15, 50 days. The solutions were changed after each measurement. Composite resin surfaces were evaluated for the surface roughness with profilometer (${\alpha}$-step 200, Tencor instruments, USA) after 1 and 50 days. And then surfaces of specimens were pictured with stereosopy after 1 and 50 days. The results were as follows. 1. The surface hardness of Silux plus, durafil VS, and Prisma APH were decreased with time. But, the surface hardness of Z-100 was not decreased. 2. The surface hardness of all composite resins was decreased by esterase. 3. Composite resins, which were light-cured by Visilux 2 and concomitantly baked by oven, showed more hardened surface than light-cured by Visilux 2 only. 4. Significant surface changes were occured in Silux plus after esterase treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.228-233
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• 2001

This study was carried out to characterize the enzymatic properties and effectiveness on the firmness of pectinesterase(PE) and polygalacturonase(PG) which are present in carrot cell wall, and to determine the blanching condition of raw carrot. Crude enzyme was extracted from carrots and used as PE and PG. The optimum pH of PE and PG activity were 7.0 and 5.0, respectively. NaCl enhanced PE and PG activities, particularly at 0.15 M and 0.10 M, respectively. Although the optimum temperature of PG ($70^{\circ}C$) was higher than that of PE ($50^{\circ}C$), PE ($Z-value=8.76^{\circ}C$) was more heat-stable than PG($Z-value=6.67^{\circ}C$). Blanching condition was determined as at $55^{\circ}C$ for 60 min in 0.03 M $CaCl_2$, 0.1 M NaCl and pH 7.0 from measuring firmness after blanching at various temperature ($50~70^{\circ}C$) and time (5~60 min).

• Toxicological Research
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• v.34 no.3
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• pp.231-239
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• 2018

Bisphenol A, an everywhere chemical, is applied as a plasticizer in polycarbonate plastics, which often used in our everyday products and in epoxy resins as protective coatings and linings for food and beverage cans for decades. Human exposure to BPA may lead to adverse effects by interfering with oestrogen receptors. Our present study was conducted to investigate the protective effects of selenium (Se) and vitamin E (Vit E) on BPA-induced damage in the liver of male rats. Animals were randomly divided into four groups: the first group received olive oil and served as control. The second group received both (Se + Vit E) (0.5 mg/kg diet; 100 mg/kg of diet). The third one treated orally by (10 mg/kg b.w.) of BPA. The last group received (Se + Vit E) (0.5 mg/kg diet; 100 mg/kg of diet) concomitantly with (10 mg/kg b.w.) BPA. Exposure to BPA for three weeks engendered a hepatic disorder. An increased AST and ALT enzymatic activity was noticed in BPA-treated group as compared to other groups. Furthermore, a change in glucose, cholesterol, LDL-C, HDL-C, albumin, and bilirubin level was remarkable. Moreover, exposure to BPA increased malondialdehyde levels while reduced gluthatione content was decreased in the liver homogenate. A decrease in glutathione peroxidase, glutathione s-transferase and catalase activities was observed in the same group. Administration of selenium and vitamin E through the diet in BPA treated rats ameliorated the biochemical parameters cited above. In addition, an improvement in activities of liver enzymes was recorded. The histological findings confirmed the biochemical results. The model of this study that we employed characterized the relationships between BPA-induced hepatotoxicity and its alleviation by natural antioxidants like selenium and vitamin E.

• Journal of Life Science
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• v.21 no.6
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• pp.893-900
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• 2011

Prostatic acid phosphatase (PAP) is one of the widely used biomarkers in the diagnosis of prostate cancer. It was initially identified in 1935 and is the most abundant phosphatase in the human prostate. PAP is a prostate-specific enzyme that is synthesized in prostate epithelial cells. It belongs to the acid phosphatase group that shows enzymatic activity in acidic conditions. PAP is abundant in prostatic fluid and is thought to have a role in fertilization and oligospermia. It also has a potential role in reducing chronic pain. But one of the most apparent functions of PAP is the dephosphorylation of macromolecules such as HER-2 and PI3P that are involved in the ERK1/2 and MAPK pathways, which in turn leads to inhibition of cell growth and tumorigenesis. Currently, clinical trials using PAP DNA vaccine are underway and FDA-approved immunotherapy using PAP is commercially available. Despite these clinically important aspects, molecular mechanisms underlying PAP regulation are not fully understood. The promoter region of PAP was reported to be regulated by NF-${\kappa}B$, TNF-${\alpha}$, IL-1, androgen and androgen receptors. Here, the features of PAP gene and protein structures together with the function, regulation and roles of PAP in prostate cancer are discussed.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.166-174
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• 2007

To know the effect of enzymatic pre-treatment on softwood Kraft pulp, two xylanse-encoding genes, named xynl and xynll were isolated from Thrichoderma ressei. Structural genes of xylanase (XYNI, XYNII) and cellulase (EGIV-CBDII) were isolated from T. ressei and Rumicoccus albus respectively, and expressed in E. coli. bacterial culture. The specific activity of purified recombinant XYNI is higher than XYNII. The brightness of XYNI treated softwood Kraft pulp increased to 29.9%. On further sequential treatment with EGIV-CBDII and XYNI the brightness of softwood Kraft pulp were improved to 9.1 and 73% respectively. As expected the Kappa number of softwood Kraft pulp also decreased 8.1, 4.6 and 3.2% respectively. Results further indicate that this sequential combination of enzyme treatment has synergic effect for improving bleaching of softwood Kraft pulp.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.13 no.1
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• pp.37-42
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• 2013

Gaucher disease is a lysosomal storage disease caused by deficiency of glucocerebrosidase (GBA). This condition is characterized by accumulation of glucocerebrosidase in liver, spleen, lung, skeletal system, and central nervous system. Gaucher disease is the prototype of disease in which efficacy of enzyme replacement therapy has been established. However, because recombinant enzyme is not able to enter the central nervous system, its efficacy is limited to the non-neurological manifestations of Gaucher disease. Importantly, approximately a half of Korean patients with Gaucher disease suffer from neurological manifestations. In addition, Korean Gaucher disease patients exhibit distinct mutation spectrum from those in other populations. Common mutations in Korean patients with Gaucher disease are also associated with neurological phenotype. Therefore, therapeutic strategies tailored to Korean patients were necessary. Interestingly, a chemical chaperone, ambroxol, has been known to increase residual enzymatic activities of the select mutant GBAs encoded by mutations prevalent in Korean patients. One promising aspect of this drug is that it can cross blood-brain barrier, and enhance the enzyme activity in the brain. In vitro study suggested this chemical chaperone as one of new therapeutic agents in Gaucher disease, and a well-designed human trial is required to confirm its efficacy.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.18 no.1
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• pp.23-29
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• 2018

Carbamoyl phosphate synthetase 1 deficiency (CPS1D) is a rare autosomal recessive urea cycle disorder characterized by hyperammonemia. CPS1D is caused by mutations in the CPS1 gene on chromosome 2q35. Based on the age of onset, there are two phenotypes: the neonatal type and the delayed-onset type. The severity of clinical manifestation depends on the degree of CPS1 residual enzymatic activity, and can result in hyperammonemia and neurological dysfunction. We report a case of CPS1D in a neonate who developed vomiting, decreased consciousness and hyperammonemia at 25th day after birth. She showed excellent response to treatment including hydration, ammonia-lowering drugs and a low-protein diet without hemodialysis. Her growth, development and neurological outcomes were fair at the last follow-up at 17 months of age.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.379-383
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• 2004

For the elucidation of substrate specificity to the brown copra meal by Bacillus sp. ${\beta}-mannanase.$, the enzymatic hydrolysate after 24 hr of reaction was heated in a boiling water bath for 10 min, and then centrifuged to remove the insoluble materials from hydrolysates. The major hydrolysates composed of D.P 5 and 7 galactosyl mannooligosaccharides. For the separate of galactosyl mannooligosaccharides, the supernatant solution of 150 ml was put on a first activated carbon column. The column was then washed with 5 l of water to remove mannose and salts. The oligosaccharides in the column were eluted by a liner gradient of $0{\sim}30%$ ethanol, at the flow rate of 250 ml per hour. The sugar composition in each fraction tubes was examined by TLC and FACE analysis. The combined fraction from F3 was concentrated to 30 ml by vacuum evaporator. Then put on a second activated carbon column. The oligosaccharides in the column were eluted by a liner gradient of $0{\sim}30%$ ethanol (total volume: 5 l), at the flow rate of 250 ml per hour. The eluent was collected in 8 ml fraction tubes, and the total sugar concentration was measured by method of phenol-sulfuric acid. The major component of F2 separated by 2nd activated carbon column chromatography were identified $Gal^3Man_4(6^3-mono-{\alpha}-D-galactopyranosyl-{\beta}-mannotetraose)$. To investigate the effects of brown copra meal galactomannooligosaccharides on growth of Bifidobacterium longum, B. bifidum were cultivated individually on the modified-MRS medium containing carbon source such as $Gal^3Man_4$, compared to those of standard MRS medium.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.317-322
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• 2005

The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans was subcloned into an E. coli-yeast shuttle vector, pYES2.0, resulting in pYGECFTN. The plasmid pYGECFTN (8.6 kb) was introduced into Saccharomyces cerevisiae SEY2102 cells and then the transformants were selected on the synthetic defined media lacking uracil. The cft gene expression in yeast transformant was demonstrated by the analyses cyclofructan (CF) spots on thin-layer chromatogram. The recombinant CFTase was not secreted into the medium and localized in the periplasmic space. The production of CF was observed after 5 min of the enzymatic reaction with inulin. The optimun pH and temperature for CF production were found to be at pH 8.0 and $45^{\circ}C$, respectively. Enzyme activity was stably maintained up to $55^{\circ}C$. The CF was produced from all inulin sources and was most efficiently produced from dahlia tubers and Jerusalem artichokes.