Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NADH-dichlorophenol-indophenol oxidoreductases (PMOs) were purified from synaptic plasma membranes or synaptic vesicles (small recycling vesicles) from both bovine and rat brains and from a neuroblastoma cell line, NB41A3. Several isoforms could be identified in purified plasma membranes and vesicles. Purification of the enzyme activity involved protein extraction with detergents, (NH4)2SO4 precipitation, chromatography under stringent conditions and native PAGE. PMO activity could be attributed to a very tight complex of several proteins that could not be separated except by SDS/PAGE. SDS/PAGE resolved the purified complex into at least five proteins, which could be micro-sequenced and identified unambiguously as hsc70, TOAD64 and glyceraldehyde-3-phosphate dehydrogenase tightly associated with the brain-specific proteins aldolase C and enolase-gamma. Enzyme activity could be purified from both synaptic plasma membranes and recycling vesicles, yields being much greater from the latter source. Highly purified plasma membranes (prepared from a neuroblastoma cell line NB41A3 by iminobiotinylation of intact cells and affinity purification with avidin and anti-avidin antibodies under very stringent conditions) also displayed PMO activity tightly associated with TOAD64. The association of PMO in a tight complex was confirmed by its immunoprecipitation from cellular and membrane extracts of NB41A3 using antibodies directed against any component protein of the complex followed by immunodetection with antibodies directed against the other members. Antibodies also inhibited the enzyme activity synergistically. In addition, induction of the different components of the complex during dichlorophenol-indophenol stress was demonstrated by the S1 RNase-protection assay in synchronized NB41A3 cells. The role of the complex in membrane fusion and cellular response to extracellular oxidative stress during growth and development is discussed.
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PMID:Purification of a dichlorophenol-indophenol oxidoreductase from rat and bovine synaptic membranes: tight complex association of a glyceraldehyde-3-phosphate dehydrogenase isoform, TOAD64, enolase-gamma and aldolase C. 918 18

beta-N-Acetylhexosaminidase was purified from the extract of cabbage by sequential steps of ammonium sulfate fractionation, chromatofocusing, DEAE-Sepharose CL-6B ion exchange chromatography and Sephacryl S-200 HR gel filtration. By these steps, the purity of the enzyme increased by 256 fold with a recovery of 8%. The purified enzyme was homogeneous as examined by native PAGE. It showed an optimal pH of 4, an optimal temperature of 60 degrees C and a Km of 0.94 mM for hydrolysis of pNp-beta-GlcNAc. The molecular mass of the enzyme determined from filtration through Sephacryl S-200 was 150 kDa. Three subunits with molecular mass of 64, 57 and 51 kDa were observed as determined by SDS-PAGE. NBS (0.025 mM), DEPC (3 mM) and WRK (30 mM) significantly inhibited the activity of the enzyme. The enzyme also showed activity toward pNp-beta-GalNAc, N,N'-diacetylchitobiose, N,N',N"-triacetylchitotriose and N,N',N",N"'-tetraacetyl chitotetraose but showed no activity toward pNp-alpha-GlcNAc, chitin and ethylene glycol chitin.
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PMID:Purification and properties of beta-N-Acetylhexosaminidase from cabbage. 967 59

Cationic lipid formulations consisting of 3beta [N-(N', N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the helper lipid dioleoylphosphatidylethanolamine (DOPE) (1.5: 1 molar ratio) were prepared by solvent evaporation and sized by high pressure extrusion. Liposomes made of 1:1 molar ratio 1 ,2-dioleoyl-3-trimethyl-ammonium-propane (DOTAP)/DOPE were used as controls in the study. The two formulations were characterized and evaluated for their efficiency in transfecting SKnSH (neuroblastoma) and primary rat neuronal cell lines. DC-Chol/DOPE liposomes were more efficient at transfecting both the SKnSH and the primary rat neuronal cells and also less toxic compared to the DOTAP/DOPE liposomes. The cellular-associated signal of rhodamine-labeled DC-Chol/DOPE liposomes into SKnSH and primary rat neuronal cells was higher than the rhodamine-labeled DOTAP/DOPE liposomes. These results demonstrate that DC-Chol/DOPE cationic liposomes provide an efficient vehicle for the delivery of plasmids into SKnSH and primary neuronal cells compared to DOTAP/DOPE liposomes. DC-Chol/DOPE liposomes may provide a good non-viral candidate for transfecting primary rat neuronal cells.
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PMID:3Beta [N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol)-mediated gene delivery to primary rat neurons: characterization and mechanism. 1034

In prion diseases the endogenous prion protein (PrPC) is converted into an abnormally folded isoform, denoted PrPSc, which represents the major component of infectious scrapie prions. The mechanism of the conversion is largely unknown, but the conversion is thought to occur after PrPC has reached the plasma membrane. Here we show that exogenous administration of the cationic lipopolyamine DOSPA interfered with the accumulation of PrPSc in scrapie-infected neuroblastoma cells. Structural analysis of the compounds tested revealed that inhibition of PrPSc was specific for lipids with a headgroup composed of the polyamine spermine and a quarternary ammonium ion between the headgroup and the lipophilic tail. The cationic lipopolyamine DOSPA induced the cellular degradation of preexisting PrPSc aggregates within 12 hours and interfered with the de novo synthesis of PrPSc. Biosynthesis of PrPC, or the assembly of sphingolipid-cholesterol microdomains (rafts) on the plasma membrane, were not affected by this inhibitor. After removal of DOSPA and replating into normal medium propagation of PrPSc commenced, although initially at a reduced rate. Incubation of ScN2a cells in free spermidine had no inhibitory effect on the accumulation of PrPSc. Our results indicate that membrane targeting of a small polyamine molecule creates a potent inhibitor of PrPSc propagation and offers the possibility to degrade preexisting PrPSc aggregates in living cells.
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PMID:Cationic lipopolyamines induce degradation of PrPSc in scrapie-infected mouse neuroblastoma cells. 1093 79

The study of down-stream techniques of recombinant Aeromonas punctata prolyl endopeptidase (apPEP) was presented here. High cell-density fermentation of E. coli BL21/pKKH-PEP in NBS BioFlo 3000 5 L fermentor was achieved, the final cell density was 22.5 g (DCW)/L after 14 h cultivation, the yield of apPEP expressed in soluble protein was 3.0 g per litter broth. After sonication, the supernatant of free cell extract was purified by ammonium sulfate fractionation, High performance Q sepharose FF, Phenyl sepharose 6 FF, the purity of apPEP reached 96%, enzyme specific activity was 65.5 u/mg, apPEP yield reached 0.86 g/L broth. Total recovery of enzyme protein was 8.2%, actviity recovery was 24.4%. The molecular weight of apPEP was 76,464 +/- 30 Da measured by MS, N terminus amino acids sequence consistent with that deduced from DNA sequence. pI 6.0, which was similar with PEP from Aeromonas hydrophila.
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PMID:[Purification and characterization of recombinant Aeromonas punctata prolyl endopeptidase]. 1105 78

Oxidative stress and mitochondrial dysfunction have been implicated in Parkinson's disease (PD) pathology. NADH:ubiquinone oxidoreductase (complex I) (EC 1.6.99.3) enzyme activity is aberrant in both PD and 1-methyl-4-phenylpyridinium (MPP(+)) models of PD. Reverse transcription polymerase chain reaction of RNA isolated from MPP(+)-treated human neuroblastoma SH-SY5Y cells identified changes in steady-state mRNA levels of the mitochondrial transcript for subunit 4 of complex I (ND4). Expression of ND4 decreased to nearly 50% after 72 h of MPP(+) (1 mM) exposure. The expression of other mitochondrial transcripts did not change significantly under the same conditions. Pre-incubation of cells with the free-radical spin-trap, N-tert-butyl-alpha-(2-sulfophenyl)-nitrone prior to MPP(+) exposure, prevented decreases in cell viability and ND4 expression. This suggests that functional defects in complex I enzyme activity in PD and MPP(+) toxicity may result from changes in steady-state mRNA levels and that free radicals may be important in this process.
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PMID:Decreased expression of the NADH:ubiquinone oxidoreductase (complex I) subunit 4 in 1-methyl-4-phenylpyridinium -treated human neuroblastoma SH-SY5Y cells. 1140 16

Analytical grade L-glutamic acid is chemically stable and has a C/N mole ratio of 5, which is close to that of many of natural biological materials, such as blood and animal tissue. Two L-glutamic acid reference materials with substantially different 13C and 15N abundances have been prepared for use as organic reference materials for C and N isotopic measurements. USGS40 is analytical grade L-glutamic acid and has a delta13C value of -26.24 per thousand relative to VPDB and a delta15N value of -4.52 per thousand relative to N2 in air. USGS41 was prepared by dissolving analytical grade L-glutamic acid with L-glutamic acid enriched in 13C and 15N. USGS41 has a delta13C value of +37.76 per thousand and a delta15N value of +47.57 per thousand. The delta13C and delta15N values of both materials were measured against the international reference materials NBS 19 calcium carbonate (delta13C=+1.95 per thousand ), L-SVEC lithium carbonate (delta13C=-46.48 per thousand ), IAEA-N-1 ammonium sulfate (delta15N=0.43 per thousand ), and USGS32 potassium nitrate (delta15N=180 per thousand ) by on-line combustion continuous-flow and off-line dual-inlet isotope-ratio mass spectrometry. Both USGS40 and USGS41 are isotopically homogeneous; reproducibility of delta13C is better than 0.13 per thousand, and that of delta15N is better than 0.13 per thousand in 100-microg amounts. These two isotopic reference materials can be used for (i) calibrating local laboratory reference materials, and (ii) quantifying drift with time, mass-dependent fractionations, and isotope-ratio-scale contraction in the isotopic analysis of various biological materials. Isotopic results presented in this paper yield a delta13C value for NBS 22 oil of -29.91 per thousand, in contrast to the commonly accepted value of -29.78 per thousand for which off-line blank corrections probably have not been quantified satisfactorily.
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PMID:Two new organic reference materials for delta13C and delta15N measurements and a new value for the delta13C of NBS 22 oil. 1460 17

The cytotoxicity of a new platinum compound Pt1 [2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinedichloroplatin(II)] and six polyoxometalates (POM1-6) on two neuroblastoma cell lines (SHEP-SF and KCN) and an Ewing's Sarcoma cell line (CADO-ES-1) was studied. Cisplatin [cis-diamminedichloroplatinum(II)] and carboplatin [cis-diammine(cyclobutanedicarboxylato)platinum(II)] were used as reference agents. Using MTT tests, the cytotoxicity (LD50: lethal doses 50%) of the compounds were measured at different concentrations. After 72 h exposure, the LD50 data for the platinum-containing substances ranged between 4.47 x 10(-6) and 1.91 x 10(-4) M. The SHEP-SF cell line displayed the highest sensitivity to cisplatin. The novel platinum agent Pt1 had a similar cytotoxic effect to the reference agent cisplatin. Both cisplatin and Pt1 were more cytotoxic than carboplatin. The POMs reduced cell viability compared to untreated cells at concentrations between 8.4 x 10(-7) and 3.47 x 10(-5) M. POM1 ([(CH3)4N]2Na6.5(NH4)2[SnII1.5(WO2(OH))0.5(WO2)2(SbW9O33)2] x 32H2O) was the most effective polyoxoanion with a mean LD50 value of 8.83 x 10(-6) M in the three cell lines tested. With CADO-ES-1 and KCN cells, POM1 was found to be more effective than the platinum compounds cisplatin, carboplatin and Pt1.
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PMID:Cytotoxic effects of novel polyoxotungstates and a platinum compound on human cancer cell lines. 1561 12

The mechanisms behind the pathology of prion diseases are still unknown, but accumulating evidence suggests oxidative impairment along with metal imbalances in scrapie-infected brains. In this study, we have investigated iron-induced oxidative stress in scrapie-infected mouse neuroblastoma N2a (ScN2a) cells. Uninfected N2a and ScN2a cells were treated with ferric ammonium citrate (FAC) for 1-16 h, and the levels of labile iron pool (LIP), the formation of reactive oxygen species (ROS), cell viability and ferritin protein levels were measured. The increase in LIP in N2a cells was transient with a quick recovery to normal levels within 4h accompanied by a moderate increase of formation of ROS after 3h followed by the decrease to the basal level. In ScN2a cells, the increase in LIP was lower, but the process of recovery was prolonged and accompanied by high ROS formation and decreased cell viability. Ferritin protein levels were significantly lower in ScN2a cells than in wild-type cells in all iron treatments. These results suggest that ScN2a cells are more sensitive to iron treatment as compared to wild-type cells with respect to ROS formation and cell viability, and that ferritin deficiency in infected cells may contribute to iron-induced oxidative stress in scrapie-infected cells.
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PMID:Increased iron-induced oxidative stress and toxicity in scrapie-infected neuroblastoma cells. 1592 93

Xylanase of low molecular weight (K II) was isolated from the fungus Aspergillus niger IBT-90 cultivated in medium with wheat bran. K II was purified by precipitation with ammonium sulphate (20-80% saturation) and gel filtration on Biogel P-10. This enzyme is most active in hydrolysis of birchwood xylan at 50 degrees C and pH 5.5. Xylanase K II has an ability to degrade 1,4-beta-bonds and to debranch substrates. It degrades not only xylans but also cellulose, an important factor for its application in bakery. Ag+, Fe3+ and NBS are strong inhibitors of the enzyme. DTT and Na+ activate xylanase K II by 24 and 13%, respectively. Enzyme K II used as additive to flour improves dough properties, increases the volume of wheat-rye and whole meal bread, and increases the porosity of crumb and the moisture of the final product, consequently extending the shelf life of bread.
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PMID:Isolation and properties of Aspergillus niger IBT-90 xylanase for bakery. 1601 37


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