• Title/Summary/Keyword: $A{\beta}1-42$

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$^{1}$H-NMR spectroscopic evidence on the glycosidic linkages of the transglycosylated products of low-molecular-weight $\beta$-D-glucosidase from trichoderma koningii (Trichoderma koningii에서 분비되는 .$\beta$-D-glucosidase의 반응산물에 대한 핵자기공명분석)

  • 이헌주;정춘수;강사욱;하영칠
    • Korean Journal of Microbiology
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    • v.27 no.1
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    • pp.35-42
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    • 1989
  • The mode of transglycosylation reaction observed during the action of low-molecular-weigh $\beta$-D-glucosidase ($\beta$-D-glucoside glucohydrolase, EC3.2.1.21) purified from Trichoderma koningii ATCC 26113 was investigated using $^{1}H$-NMR spectroscopy. The enzyme was purified by the series of procedures including ammonium sulfate precipitation, and fractionations by column chromatographies on Bio-Gel P-150, DEAE-Sephadex A-50, and SP-Sephadex C-50. The final purification was performed by the band eluation after preparative polyacrylamide gel electrophoresis. The enzyme showed its molecular size of 78,000 through the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and its isoelectric point of 5.80 through the analysis of analytical isoelectric focusing. The H-1 proton resonances were analyzed. After the reaction of the enzyme with cellobiose, the reaction products were separated by high performance liquid chromatography using refractive index detector. H-1 resonances of the products were consisted with those of gentiobiose [$\beta$-D-glucopyranosyl--(1,6)-D-glucopyranose], and cellotriose [$\beta$-D glucopyranosyl-(1,4)-$\beta$-D-glucopyranosyl]-(1,4)-D-glucopyranose] with minor resonances of sophorose [$\beta$-D-glucopyranosyl-(1,2)-D-glucopyranose], respectively.

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A Study of the Cholesterol and Lipoprotein in the Maternal and Fetal Serum (산모(産母)와 태아(胎兒)의 혈청 Cholesterol 및 Lipoprotein에 관한 연구)

  • Yi, Kui-Nyung
    • Journal of Nutrition and Health
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    • v.5 no.2
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    • pp.75-82
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    • 1972
  • Fifteen cases of primiparas and their offsprings (fetal cord) were investigated with regard their serum total, free and esterified cholesterol by means of Liberman Buchard reaction. The serum ${\alpha}-and\;{\beta}-lipoprotein$ were analyzed by cellulose acetate electrophoresis, and the serum atherolipid numbers were calculated on the bases of the serum total cholesterol and ${\beta}-/{\alpha}-$ lipoprotein ratio, with the following conclusion. 1.Total, free and esterified cholesterol are $178.9{\pm}25.3$, $45.1{\pm}12.6$ and $133.7{\pm}20.6\;mg.%$ in the normal control women, $201.5{\pm}29.5,\;58.7{\pm}42.1$ and $157.1{\pm}26.2\;mg.%$ in the maternal blood, showing hypercholesterolemia in the latter as compared to the former. 2. The serum total, free and esterified cholesterol in the cord blood are $94.5{\pm}20.4$, $32.9{\pm}1.5$ and $61.2{\pm}18.9mg.%$, showing hypocholesterolemia as compared to the control women and maternal blood. 3. The serum ${\alpha}-$, $pre-{\beta}$, ${\beta}-lipoprotein$ and chylomicron are $24.2{\pm}4.2$, $17.3{\pm}3.4$, $51.8{\pm}4.8$ and $6.0{\pm}1.6%$ in the normal women, whereas $14.9{\pm}2.1$, $22.2{\pm}5.1$, $58.7{\pm}3.3 and 3.1{\pm}1.2%$ in the maternal serum, $32.4{\pm}8.1$, $28.8{\pm}2.4$, $25.8{\pm}7.0$ and $3.1{\pm}0.9%$ in the cord serum, showing $hyper-{\beta}-lipoproteinemia$ in the former and $hypo-{\beta}-lipoproteinemia$ in the latter. 4. The serum atherolipid number of the normal control women, maternal cord blood are $4.21{\pm}1.24$, $8.02{\pm}1.42$ and $1.12{\pm}0.37$, showing hyperlipemia in the former and hypolipemia in latter. 5. The relative ratio of the serum free and esterified cholestrol of both normal control women and maternal blood is about 1 : 3, while that of the fetal blood about 1 : 2. 6. The relative ratioes of the serum ${\alpha}-and$ ${\beta}-lipoprotein$ in the control women is about 1 : 2, that of materna blood about 1 : 3 and that of the fetal blood about equal magnitude. 7. The serum esterified cholesterol, ${\alpha}-lipoprotein,\;{\beta}-/{\alpha}-lipoprotein$ ratio and atherolipid number fluctuates are proportionally between the maternal and fetal blood, while the serum free, total cholesterol and ${\beta}-lipoprotein$ between the two vary inversely with statistically significant corelations. 8. It is apparent from the above results that the fetal nutritional demand for lipids resulted from hypocholesterolemia and hypo ${\beta}-lipoproteinemia$ seems to be met satisfactorily by maternal hypercholesterolemia and hyper ${\beta}-lipoproteinemia$, which seems to pose a significant maternal-infant nutritional relationship. A brief ciscussion was made on these conciusion in the light of biochemistry and endocrinology.

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Characterization of $\beta$-1,4-D-arabinogalactanase from Alkalophilic Bacillus sp. HJ-12 (호알칼리성 Bacillus sp. HJ-12 유래 $\beta$-1,4-D-arabinogalactanase의 특성)

  • 신해헌;변유량
    • Microbiology and Biotechnology Letters
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    • v.23 no.6
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    • pp.710-716
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    • 1995
  • $\beta $-1, 4-D-arabinogalactanase isolated from alkalophilic Bacillus sp. HJ-12, approximate Mw 42 kDa, was generally stable in the range of pH 6-10 and below 50$\circ$C and its highest activity was observed at 60$\circ$C with pH 7-9. The isolated $\beta $-1, 4-D-arabinogalactanase specifically hydrolyzed $\beta $-1, 4-galactosyl linkage that is the major structure of soybean arabinogalactan (SAG) but not $\beta $-1, 3-galactosyl linkage of the other polysaccharides. K. was estimated as 0.67 mg/ml by the method of Hanes-Woolf plot. No metals and chemical reagents inhibited the enzyme activity but urea did. The active site of this enzyme assumed to be tryptophan residue. The hydrolysis products from SAG, assayed by gel chromatography, TLC and HPLC, were predominantly galactotetraose (Gal$_{4}$) and triose (Gal$_{3}$) with a small portion. $\beta $-1, 4-D-arabinogalactanase hydrolyzed ONPG as well as SAG, and the degree of hydrolysis of SAG was 15% which is lower than that by the other $\beta $-1, 4-galactanases from different sources. SAG treated with this enzyme resulted in the reduction of specific viscosity up to 70%.

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High-level Secretory Expression of Recombinant $\beta$-Agarase from Zobellia galactanivorans in Pichia pastoris (Pichia pastoris에서 Zobellia galactanivorans 유래 재조합 $\beta$-Agarase의 고효율 분비생산)

  • Seok, Ji-Hwan;Park, Hee-Gyun;Lee, Sang-Hyeon;Nam, Soo-Wan;Jeon, Sung-Jong;Kim, Jong-Hyun;Kim, Yeon-Hee
    • Microbiology and Biotechnology Letters
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    • v.38 no.1
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    • pp.40-45
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    • 2010
  • The gene encoding $\beta$-agarase (agaB) which hydrolyzes $\beta$-1,4 linkages of agarose from Zobellia galactanivorans was cloned and fused to Saccharomyces cerevisiae mating factor alpha-1 secretion signal ($MF{\alpha}1$), in which the transcription of $MF{\alpha}1$-AgaB was under the control of AOX1 (alcohol oxidase 1, methanol inducible) promoter. The constructed plasmid pPIC-AgaB (9 kb) was integrated into HIS4 gene locus of Pichia pastoris genome. Successful integration was confirmed by performing colony PCR. The transformed cells showed red halos around its colonies in methanol agar plate by adding iodine solution, indicating the active expression of agaB in P.pastoris. By SDS-PAGE and zymographic analysis, the molecular weight of $\beta$-agarase was estimated to be a 53 kDa and about 15% N-linked glycosylation was occurred. The activity of extracellular $\beta$-agarase reached 1.34, 1.42 and 1.53 units/mL by inducing 0.1, 0.5, and 1% methanol, respectively, at baffled flask culture of P.pastoris GS115/pPIC-AgaB for 48 hr. Most of the enzyme activity was found in the extacellular fraction and the secretion efficiency showed 98%. Thermostability of recombinant $\beta$-agarase was also increased by glycosylation.

Separation of $H_2$/$N_2$ Gas Mixture by PTMSP-PEI and PDMS-PEI Composite Membranes (PTMSP-PEI와 PDMS-PEI 복합막에 의한 수소/질소 혼합기체 분리)

  • 강태범;조성혜;이현경
    • Membrane Journal
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    • v.13 no.4
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    • pp.291-299
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    • 2003
  • Polymer membranes such as poly(1-trimethylsilyl-1-propyne)-polyetherimide (PTMSP-PEI) and poly(dimethylsiloxane)- polyetherimide (PDMS-PEI) composite membrane were prepared by solution casting method. To investigate the characteristics of these membranes, the analytical methods such as FT-IR, $^1H-NMR,$ DSC, TGA, GPC, and SEM have been utilized. The number-average (equation omitted) and weight-average (equation omitted) molecular weight of PTMSP were 477,920 and 673,329 respectively. The glass transition temperature ($T_g$) of PTMSP was $224^{\circ}C.$ The separation of the gas mixture ($H_2/N_2$) through the composite membranes were studied as a function of pressure. The separation factor (${\alpha}, {\beta},$ quation omitted) of the composite membranes used in this work increased as the pressure of permeation cell increased. The real separation factor (${\alpha}$), head separation factor (${\beta}$), and tail separation factor (equation omitted) of PTMSP-PEI composite membrane were 2.28, 1.17, and 1.96 respectively at ${\Delta}P$ 30psi and $25^{\circ}C.$ (${\alpha}, {\beta}$ and equation omitted of PDMS-PEI composite membrane were 3.70, 1.53, and 2.42 respectively at ${\Delta}P$ 30psi and $25^{\circ}C$.

Cytotoxic Effects of 1, 2-Hexanediol and 1, 2-Hexanediol Galactoside on HaCaT Cell (1, 2-Hexanediol과 1, 2-Hexanediol Galactoside의 HaCaT Cell에 대한 세포독성)

  • Kim, Jun-Sub;Jung, Kyung-Hwan
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.3
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    • pp.343-347
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    • 2018
  • We synthesized 1, 2-hexanediol galactoside (HD-Gal) from HD using Escherichia coli (E. coli) ${\beta}-galactosidase$ (${\beta}-gal$), in which the reaction is generally called as transgalactosylation (reverse hydrolysis). In this study, we investigated how much HD-Gal and HD had a cytotoxic effect on HaCaT cell, in order to compare HD-Gal with HD in terms of the cytotoxicity of human skin cell. Cell proliferation assay and phase-contrast microscope observation were used for investigating the cytotoxicity. As a result, HD-Gal had not cytotoxic effect on HaCaT cell in the concentration range from 42.2 to 211 mM. In addition, when we observed the cells using microscopy, there was no change in the cell morphology. Meanwhile, when 42.2 mM and 84.4 mM HD were treated on HaCaT cell, we did not observe the cytotoxicity; however, when 168.8 mM and 211 mM HD were on HaCaT cell, HD had a higher cytotoxic effect on HaCaT cell. In addition, when HD was treated on the cells regardless of the concentration of HD, there were obvious changes in cell morphology and cell number. It was expected hopefully that HD-Gal would be applicable as a substitute for HD as a less toxic preservative in views of safety, health, and well-being.

Molecular Epidemiology of Metallo-β-lactamase Producing Pseudomonas aeruginosa Clinical Isolates (임상에서 분리된 Metallo-β-lactamase 생성 Pseudomonas aeruginosa의 분자역학)

  • Choi, Myung-Won
    • Journal of Life Science
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    • v.22 no.9
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    • pp.1268-1276
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    • 2012
  • The emergence and dissemination of carbapenem-resistant bacteria have resulted in limitations of antibiotic treatment and potential outbreaks of metallo-${\beta}$-lactamase (MBL) producing Pseudomonas aeruginosa resistant to carbapenems. In this study, we conducted molecular characterization of the MBL genes of the ${\beta}$-lactam drug-resistant P. aeruginosa and prepared basic data for treatment and prevention of proliferation of antimicrobial-resistant bacterial infections. Forty-two P. aeruginosa isolates of 254 were resistant to imipenem or meropenem. Among the 42 isolates, 28 isolates were positive for the Hodge test, and 23 isolates were positive for the EDTA-disk synergy test (EDST). MBLs were detected in 59.5% (25/42) of P. aeruginosa isolates. Eight isolates harbored $bla_{IMP-6}$, whereas 17 isolates harbored $bla_{VIM-2}$. The $bla_{IMP-6}$ gene was in a class 1 integron containing five gene cassettes: $bla_{IMP-6}$, qac, aacA4, $bla_{OXA-1}$, and aadA1. Some strains that produce IMP-6 and VIM-2 showed epidemiological relationships. The $bla_{IMP-6}$ gene in carbapenem-resistant P. aeruginosa showed an identical pattern to a gene cassette that was reported at a hospital in Daegu, Korea. Therefore, MBL-producing P. aeruginosa is already endemic in the community. We are concerned that the existence of carbapenem-resistant bacteria containing the blaMBL gene may increase pressure on antibiotic selection when treating infections. We believe that we should select appropriate antibiotics based on the antibiotic susceptibility test and continue the research to prohibit the emergence and spread of antibiotics resistant bacteria.

Synthesis of Functionalized Benzoxazoles and Their Binding Affinities to A β42 Fibrils

  • Chun, Young-Shin;Lim, Soo-Jeong;Oh, Seung-Jun;Moon, Dae-Hyuk;Kim, Dong-Jin;Cho, Cheon-Gyu;Yoo, Kyung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.29 no.9
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    • pp.1765-1768
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    • 2008
  • Functionalized benzoxazole derivatives were designed and synthesized based on the structural features of PIB and FDDNP, which show excellent binding affinities to aggregated A$\beta$ 42 fibrils. All the synthesized compounds were evaluated by competitive binding assay against aggregated A$\beta$ 42 fibrils using [$^{125}$I]TZDM and displayed good in vitro binding affinities with Ki values (0.47-15.3 nM) from subnanomolar to nanomolar range. Among them, benzoxazoles 1f and 1a having malononitrile and ester moieties at C-6 exhibited superior binding affinities ($K_i$ = 0.47 and 0.61 nM, respectively) to PIB ($K_i$ = 0.77 nM).

Influence of Feeding β-Cyclodextrin on Reducing the Content of Cholesterol in Pork (돼지고기의 콜레스테롤 함량 감소에 관한 β-Cyclodextrin의 급여효과)

  • Park, Byung-Sung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.3
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    • pp.328-334
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    • 2006
  • The main objective of the present study was to determine the effect of dietary ${\beta}-cyclodextrin\;({\beta}CD)$ on reducing the cholesterol content of pork. Twelve swine of 50 kg body weight were randomly distributed into four groups of three heads each and fed experimental diets for 9 weeks until they reached a market weight of 110 kg. They were assigned to the four experimental diets containing 0% (control), 1.5%, 3.0% or 5.0% pure ${\beta}CD$. Daily feed intake, body weight gain and feed efficiency were not significantly different between any of the four group. The plasma total lipid, triacylglycerol and total cholesterol content of the swine in the three ${\beta}CD$-fed groups were significantly (p<0.05) decreased when compared to those in the control group, and were significantly (p<0.05) reduced by 21.80%,55.58% and 27.69%, respectively, in the swine fed on 5% ${\beta}CD$. The cholesterol content of pork belly (mg/100g) was significantly (p<0.05) decreased by 5.33 mg, 12.70 mg and 15.23 mg in the swine maintained on 1.5%, 3.0% and 5.0% ${\beta}CD$, respectively. The cholesterol content of pork belly, when expressed as the rate of reduced cholesterol, was significantly (p<0.05) decreased by 6.44%, 15.36% and 18.42% in groups of 1.5%, 3.0% and 5.0% ${\beta}CD$, respectively, when compared to that of the control group. These results suggest that dietary ${\beta}CD$ may be classified as dietary fiber which can modulate cholesterol metabolism in swine.