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)

Pollution from the Kjeldahl method for crude protein has been reduced by substituting a low level of copper (0.04 g CuSO4) for the mercury (0.7 g HgO) specified in the AOAC official method, 2.049. Adjustments were made in the salt-acid ratio so the new system could handle hard-to-digest samples in a reasonable time. The new method was rugged for lysine. HCl. It is designed to be used for crude protein in feeds or similar Kjeldahl work. Precision and accuracy were equal to or better than that for the official method in a study of 17 samples analyzed in duplicate on 3 different days. The following samples were used in the study: lysine. HCl, tryptophan, NBS standards, urea, meals, mixed feeds, grains, and forage. The average per cent nitrogen found was 9.52 by the official method and 9.53 by the copper method. The average standard deviation was 0.038 by the official method and 0.033 by the copper method, giving the corresponding relative standard deviations of 0.40 and 0.35%.
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PMID:Pollution-reduced Kjeldahl method for crude protein. 103 79

The cleavage of dynorphin and three analogs containing paired basic residues by several proteases was investigated. The cysteine protease of neuroblastoma cells cleaved only the bond between Arg-Arg residues. Submandibular arginyl-endopeptidase, however, cleaved bonds between both Arg-Arg and Arg-Lys residues, and pancreatic trypsin at the carboxyl sides of both arginine and lysine residues. This shows that the cysteine protease is highly specific for paired arginine residues.
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PMID:Dynorphin-degrading cysteine protease is highly specific for paired arginine residues. 134 63

The beta-amyloid precursor protein (APP) is a membrane-bound glycoprotein which has been proposed to play a role both as a growth factor and a mediator of cell adhesion. Using the Neuro-2A neuroblastoma cell line, we have investigated the capacity of APP to mediate neural cell adhesion. The cells express the protein at a high level, the immunohistochemical staining pattern at the level of the membrane having a punctate pattern. Fab' fragments of antibodies to the extracellular portion of the molecule were found to inhibit cell binding to a collagen substrate, but not to laminin, fibronectin, or poly-l-lysine. Fab' fragments of antibodies to the nerve cell adhesion molecule N-CAM also inhibited binding of Neuro-2A cells specifically to collagen. This inhibition of cell-surface binding was accompanied by a repression of neurite outgrowth in differentiating cells in the presence of antibodies. APP antibodies also inhibited neuron-neuron and neuron-glial binding, but not glial-glial cell adhesion. These data suggest that the APP, which is expressed primarily on differentiated neuronal cells, may play a role in the mediation of both cell-cell and cell-substrate adhesion.
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PMID:Beta amyloid precursor protein mediates neuronal cell-cell and cell-surface adhesion. 164 74

The heparin-binding p30 protein amphoterin is proposed to mediate adhesive interactions of the advancing plasma membrane in migrating and differentiating cells. Since the NH2-terminal part of amphoterin is exceptionally rich in lysine residues, we have studied its interactions with plasminogen and tissue plasminogen activator (t-PA). On immunostaining of N18 neuroblastoma cells, amphoterin and t-PA showed a close co-localization in the filopodia of the leading membrane and in the substrate-attached material. In purified systems, both t-PA and plasminogen bound to immobilized amphoterin, and their binding was inhibited by the lysine analogue epsilon-aminocaproic acid. Plasminogen bound to immobilized amphoterin was activated by t-PA, and this resulted in effective degradation of the immobilized amphoterin. Correspondingly, amphoterin-bound t-PA activated plasminogen. In solution amphoterin accelerated t-PA-catalyzed plasminogen activation maximally 46-fold. The results indicate that t-PA and plasminogen form through their lysine-binding sites a complex with amphoterin, which results in acceleration of plasminogen activation and effective degradation of amphoterin. We suggest that local acceleration of t-PA-catalyzed plasminogen activation by amphoterin at the leading membrane enhances the penetration of growing cytoplasmic processes through extracellular materials during cell migration, differentiation and regeneration. The amphoterin-mediated adhesion at the leading membrane may be transient in nature, because the protein also enhances its own breakdown by accelerating t-PA-catalyzed plasminogen activation.
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PMID:Interactions of plasminogen and tissue plasminogen activator (t-PA) with amphoterin. Enhancement of t-PA-catalyzed plasminogen activation by amphoterin. 190 31

Earlier studies in our laboratory have shown that C-6 glial cells in culture exhibit astrocytic properties with increasing cell passage. In this study, we tested the responsiveness of early and late passage C-6 glial cells to various cultures conditions: culture substrata (collagen, poly-L-lysine, plastic), or supplements for the culture medium, DMEM, [fetal calf, or heat inactivated (HI) serum, or media conditioned from mouse neuroblastoma cells (NBCM) or primary chick embryo cultured neurons (NCM)]. Glutamine synthetase (GS) and cyclic nucleotide phosphohydrolase (CNP), astrocytic and oligodendrocytic glial markers, were used. Cell number and protein content increased exponentially with days in culture regardless of the type of the substratum or cell passage. Differences in cell morphology among the three types of substratum were also reflected on GS activity, which rose by three-fold on culture day 3 for cells grown on collagen; thereafter, GS profiles were similar for all substrata. This early rise in GS is interpreted to reflect differential cell adhesion processes on the substrata; specifically, cell adhesion on the collagen stimulated differentiation into "astrocytic phenotype". Analogous to immature glia cells in primary cultures, early passage C-6 glial cells responded to neuronal factors supplied either from NCM or NBCM by expressing reduced GS activity, the astrocytic marker and enhanced CNP activity, the oligodendrocytic marker. Thus, early passage cells can be induced to express either astrocytic or oligodendrocytic phenotype. In accordance with our previous reports on primary glial cells, late passage C-6 cells exhibit their usual astrocytic behavior, responding to serum factors with GS activity. Moreover, whereas NCM or NBCM alone markedly lowered GS activity, a combination with serum restored activity. The present findings confirm our previous observations and further establish the C-6 glial cells as a reliable model to study immature glia.
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PMID:Early and late passage C-6 glial cell growth: similarities with primary glial cells in culture. 257 33

A trypsin-like enzyme has been purified to apparent homogeneity from neuroblastoma cell membranes by a procedure including extraction with Triton X-100, soybean trypsin inhibitor-immobilized Sepharose 4B affinity chromatography, and gel filtration. SDS-polyacrylamide gel electrophoresis under reducing conditions of the purified enzyme gave a single band corresponding to a molecular weight of 28,000. The molecular weight of the enzyme was also estimated to be 32,000 by gel filtration. The pH optimum of the activity was 8.5-9.0. The purified enzyme was inhibited by diisopropylphosphorofluoridate, p-aminobenzamidine, and leupeptin, and moderately by chymostatin, but not, or only scarcely, by bestatin, phosphoramidon, p-chloromercuribenzoate, and N-ethylmaleimide. The substrate subsite specificity of the purified enzyme was broad toward various peptidyl-arginine (or lysine) 4-methylcoumaryl-7-amides, but it cleaved dynorphin(1-17) only at two sites, i.e., between the Arg6-Arg7 and Lys11-Leu12 bonds, both of which correspond to the initial cleavage sites of dynorphin with a membrane preparation of neuroblastoma cells. A trypsin-like enzyme was also purified from a synaptic membrane preparation of rat brain, which shows almost the same properties as those of the enzyme from the neuroblastoma cell membrane. Thus, the trypsin-like enzyme present in the synaptic membrane would participate in the degradation of dynorphin.
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PMID:Membrane-bound trypsin-like enzyme functioning in degradation of dynorphin in neuroblastoma cells. Purification and characterization. 289 72

A dynorphin A 1-13 amide (DYN) derivative biotinylated in position lysine 13 (B-DYN) has been prepared by automated solid-phase peptide synthesis. The derivative retained its ability to bind to avidin, and B-DYN-avidin complex showed a dissociated half-life of 10 hr at 37 degrees C. Opioid receptor binding was measured in membrane preparations of rat brain (mu), NG-108-15 neuroblastoma-glioma hybrid cells (delta), and guinea pig cerebellum (kappa). Biotinyl substitution of DYN either did not effect receptor binding (delta) or slightly reduced binding affinity (mu and kappa). Binding of B-DYN to the kappa receptor was very tight, with an IC50 value in the low picomolar range, while binding to mu and delta sites was over two orders of magnitude lower. Preassociation of B-DYN with avidin resulted in a reduction of the affinities to the investigated opioid receptors by 100- to 1000-fold. However, the apparent affinity of B-DYN-avidin for the kappa-opioid receptor is sufficient to suggest that B-DYN may be a useful tool for kappa-opioid receptor assay, localization, and purification.
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PMID:[Biocytin13]dynorphin A 1-13 amide: a potential probe for the kappa-opioid receptor. 290 85

When incubated with cultured mouse neuroblastoma cells under growth stimulatory condition, [3H]putrescine or [3H]spermidine can metabolically label a cellular protein of apparent molecular mass 18 kDa. The labeling, which leads to hypusine formation, is due to a covalent linkage between a lysine residue and the butylamino group derived from spermidine. This reaction can be demonstrated in the cytosolic fractions obtained from cells whose spermidine pool was depleted by prior treatment with alpha-difluoromethylornithine. In an effort to characterize the enzyme system involved in this unique post-translational modification, we found that NAD+ at 0.1 mM stimulated labeling more than 150-fold. Other nucleotides such as NADP+, ATP and GTP were ineffective. The fact that NAD+ dramatically stimulated labeling of the 18 kDa protein indicated that the enzyme involved in hypusine formation may be an NAD+-requiring enzyme.
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PMID:NAD+ stimulated the spermidine-dependent hypusine formation on the 18 kDa protein in cytosolic lysates derived from NB-15 mouse neuroblastoma cells. 312 83

Non-saturable penetration and the V and Km constants of saturable influx of leucine, lysine and glycine were always greater in cultured neuroblastoma (C1300) than in glioma (C6) cells. Aspartate uptake was detected only in glioma cells. Unstimulated efflux of the amino acids was initially fast in both cell types but soon slowed down. The efflux of glycine and aspartate exhibited no heteroexchange, the efflux of lysine was stimulated by extracellular leucine and that of leucine slightly by lysine and glycine but only in glioma cells.
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PMID:Transport of leucine, lysine, glycine and aspartate in neuroblastoma C1300 and glioma C6 cells. 312 24

An 18 kDa protein can be metabolically labeled by [3H]putrescine or [3H]spermidine in various mammalian cells. The labeling is due to a post-translational modification of one lysine residue to hypusine using the aminobutyl moiety derived from spermidine. In view of the lack of knowledge of the function of this spermidine-modified protein, we decided to use the radioactivity associated with the [3H]spermidine-labeled 18 kDa protein as a tracer to develop a simple procedure for purifying this protein from cultured cells. We first screened more than 15 different affinity adsorbents for their ability to bind the labeled 18 kDa protein. This approach enabled us to develop a four-step procedure to purify the labeled 18 kDa protein from NB-15 mouse neuroblastoma cells. The procedure, including a Cibacron Blue column, an omega-aminooctyl-agarose, a Sepharose G-50, and a Mono Q column, resulted in an 800-fold purification of the labeled 18 kDa protein. Two-dimensional gel analysis of fractions enriched in the labeled 18 kDa protein revealed (i) the presence of isoforms of hypusine-containing 18 kDa protein, with pI values ranging from 4.7 to 5.2, and (ii) the presence of an additional labeled protein with an apparent molecular mass of 22 kDa and a pI value of 5.0. The labeling intensity of the 22 kDa protein, however, was less than 5% of that of the 18 kDa protein. Peptide map analysis, using the V-8 proteinase digestion method, indicated that the 18 kDa hypusine-containing protein obtained from NB-15 cells was similar to eukaryotic initiation factor 4D isolated from rabbit reticulocytes.
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PMID:Isolation and characterization of an 18 kDa hypusine-containing protein from cultured NB-15 mouse neuroblastoma cells. 313 4


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