Some properties of cytoplasmic RNA fractions of the mouse Ehrlich ascites carcinoma

1968 ◽  
Vol 46 (2) ◽  
pp. 155-166 ◽  
Author(s):  
K. Hosokawa ◽  
M. J. Fraser
Keyword(s):  
Amino Acid ◽  
Ribosomal Rna ◽  
Gradient Centrifugation ◽  
Heterogeneous Material ◽  
Ehrlich Ascites Carcinoma ◽  
Molar Ratio ◽  
5S Rna ◽  
Sucrose Density Gradient Centrifugation ◽  
Ehrlich Ascites ◽  
Amino Acid Acceptor

Two RNA subfractions from mouse Ehrlich ascites carcinoma 105 000 × g supernatant and three RNA subfractions from the tumor microsomal fraction have been resolved by chromatography on methylated albumin–kieselguhr. The five subfractions have been examined for their amino acid acceptor capacities and nucleotide compositions and by sucrose density-gradient centrifugation. One of the 105 000 × g supernatant fractions has been identified as amino acid acceptor or transfer RNA (tRNA) and the three microsomal components have been identified as tRNA, 5S RNA, and ribosomal RNA. The microsomal tRNA and 5S RNA appear to be associated with ribosomal RNA in a molar ratio approaching 2:1 and together make up about 6–8% of the total microsomal RNA. The second 105 000 × g supernatant RNA fraction has not been identified. It is recovered in widely varying amounts and behaves like heterogeneous material in chromatographic and sedimentation procedures.

THE BIOSYNTHESIS OF AMINO ACID ACCEPTOR RNA

1964 ◽  
Vol 42 (6) ◽  
pp. 859-870 ◽  
Author(s):  
R. A. Cook ◽  
J. P. Bouchard ◽  
M. J. Fraser
Keyword(s):  
Amino Acid ◽  
Tumor Cells ◽  
Actinomycin D ◽  
Ehrlich Ascites Carcinoma ◽  
Ehrlich Ascites ◽  
Specific Activities ◽  
Dna Template ◽  
Acceptor Capacity ◽  
Amino Acid Acceptor

Preliminary observations have been made on the biosynthesis of amino acid acceptor RNA in the mouse Ehrlich ascites carcinoma. Measurements have been made of the incorporation of radioactivity from either14C-CH3-methionine or uridine-2-14C into the RNA of nuclear and cytoplasmic fractions which precipitate at pH 5.0 from 105,000 × g supernatants of broken nuclei preparations and of cell homogenates ("soluble" RNA or sRNA). With either labelled precursor higher specific activities were found in the nuclear than in the cytoplasmic sRNA fractions. Whereas actinomycin D and DNase inhibited the incorporation of radioactivity from uridine-2-14C into nuclear sRNA, these agents stimulated significantly the incorporation of radioactivity from14C-CH3-methionine. The glycine acceptor capacity of nuclear sRNA was found to be greater than that of cytoplasmic sRNA. The base ratios of the amino acid acceptor RNA fractions derived from nuclear sRNA and from cytoplasmic sRNA by chromatography on methylated albumin columns were very similar. The results are consistent with the hypothesis that the amino acid acceptor RNA is made on a DNA-template in the nucleus of the tumor cells, is subsequently released from the template, methylated, and then transferred to the cytoplasm.

scholarly journals Molecular heterogeneity of mouse duodenal alkaline phosphatase. Association of lipids and peptides

1974 ◽  
Vol 141 (1) ◽  
pp. 93-101 ◽  
Author(s):  
P. R. V. Nayudu ◽  
Fraser B. Hercus
Keyword(s):  
Alkaline Phosphatase ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Sucrose Density Gradient ◽  
Molar Ratio ◽  
Molecular Forms ◽  
Partial Specific Volume ◽  
Molecular Heterogeneity ◽  
Sucrose Density Gradient Centrifugation

Polyacrylamide-gel electrophoresis and Bio-Gel P-300 molecular-sieve chromatography of mouse duodenal alkaline phosphatase demonstrates its molecular heterogeneity, which, in a kinetic sense, is manifest also in the differential relative velocities of the heterogeneous forms of the enzyme with two substrates, phenylphosphate and β-glycerophosphate. Different treatments that eliminate most of the electrophoretic and chromatographic variability of the enzyme also decrease the velocities with both substrates so that the molar ratio of hydrolysis of one substrate relative to the other is also altered to a low but stable value. Concomitant with these changes, lipids and peptides are dissociated from the enzyme. The lipids are tentatively identified as a sterol and phospholipids. The peptides have an average composition of four to six amino acids and appear to be strongly electropositive. The conditions of dissociation suggest that their binding to the enzyme is non-covalent and predominantly based on hydrophobic and ionic bonding. The concept of lipid and peptide association would suggest prima facie differential molecular weights as a factor in the observed electrophoretic and chromatographic heterogeneity. However, the molecular forms of the enzyme with differences in elution volume equivalent to more than one-half the void volume of the Bio-Gel P-300 column, or even enzyme fractions dissociated from the lipids and peptides compared with undissociated portions, do not show any differences in sedimentation on sucrose-density-gradient centrifugation. This may be because the alterations in molecular weight owing to binding of small molecules are too small to be detected by this method. Alternatively, since lipids are involved, the binding may alter the partial specific volume in such a way that the buoyant density is not significantly altered.

THE TERMINAL GROUPS OF RIBONUCLEATE CHAINS IN EACH OF THE 16S AND 23S COMPONENTS OF ESCHERICHIA COLI RIBOSOMAL RNA

1967 ◽  
Vol 45 (6) ◽  
pp. 937-948 ◽  
Author(s):  
J. L. Nichols ◽  
B. G. Lane
Keyword(s):  
Escherichia Coli ◽  
Chain Length ◽  
Ribosomal Rna ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Quantitative Estimates ◽  
16S Rna ◽  
The Mean ◽  
End Group

Ribosomal ribonucleates from Escherichia coli have been resolved into 16S and 28S components by sucrose density-gradient centrifugation, and the chain termini in each of the 16S and 23S RNA components have been analyzed by hydrolysis with alkali. The principal 5′-linked end group of 16S RNA was found to be adenosine, and the principal 5′-linked end group of 23S RNA was found to be uridine. The principal 3′-linked end group of 16S RNA was also found to be adenosine, whereas the principal 3′-linked end group of 23S RNA was found to be guanosine. Quantitative estimates of chain length based on analyses for 5′-iinked terminals indicate that the mean chain length for 16S RNA is about 1.3 × 103nucleotide residues and the mean chain length for 23S RNA is about 2.1 × 103nucleotide residues.

COMPETITION BETWEEN AMINO ACIDS FOR TRANSPORT INTO EHRLICH ASCITES CARCINOMA CELLS

1961 ◽  
Vol 39 (11) ◽  
pp. 1717-1735 ◽  
Author(s):  
P. G. Scholefield
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Amino Acid ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Transport Systems ◽  
Radioactive Carbon ◽  
Ehrlich Ascites ◽  
Competitive Inhibitors ◽  
Amino Acid Analogues

The cumulative entry of amino acids into Ehrlich ascites carcinoma cells is due to the presence of active transport systems, each with its own specific range of substrates. Several amino acids and amino acid analogues may have an affinity for the same transport system and thus may inhibit transport of other amino acids by acting as competitive inhibitors or competitive substrates. Loss of methionine from ascites cells takes place by a diffusion process which obeys Fick's law. Leucine accumulation by ascites cells is small and is increased on addition of certain other amino acids. The increase is not due to inhibition of leucine oxidation as increase in the rate of production of radioactive carbon dioxide from labeled leucine also occurs. Kinetic aspects of these results are discussed.

A SENSITIVE METHOD FOR MEASUREMENT OF AMINO ACYL RIBONUCLEIC ACID SYNTHETASE ACTIVITIES

1962 ◽  
Vol 40 (1) ◽  
pp. 653-666 ◽  
Author(s):  
Murray J. Fraser
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rat Liver ◽  
Ribonucleic Acid ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Ehrlich Ascites ◽  
Sensitive Method

A sensitive method for the measurement of amino acyl RNA synthetase activities (amino acid activating enzymes) is described. The method is based on measurements of the rates of labelling of soluble ribonucleic acid with14C-amino acids. Determinations of α-glutamyl-RNA, glutaminyl-RNA, and glycyl-RNA synthetase activities in the "pH 5 enzymes" fractions from rat liver and mouse Ehrlich ascites carcinoma cells have been made.

A SENSITIVE METHOD FOR MEASUREMENT OF AMINO ACYL RIBONUCLEIC ACID SYNTHETASE ACTIVITIES

1962 ◽  
Vol 40 (5) ◽  
pp. 653-666 ◽  
Author(s):  
Murray J. Fraser
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Rat Liver ◽  
Ribonucleic Acid ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Ehrlich Ascites ◽  
Sensitive Method

A sensitive method for the measurement of amino acyl RNA synthetase activities (amino acid activating enzymes) is described. The method is based on measurements of the rates of labelling of soluble ribonucleic acid with14C-amino acids. Determinations of α-glutamyl-RNA, glutaminyl-RNA, and glycyl-RNA synthetase activities in the "pH 5 enzymes" fractions from rat liver and mouse Ehrlich ascites carcinoma cells have been made.

scholarly journals Isolation of 10-nm filaments from astrocytes in the mouse optic nerve.

1981 ◽  
Vol 88 (1) ◽  
pp. 245-250 ◽  
Author(s):  
S Tsukita ◽  
H Ishikawa ◽  
M Kurokawa
Keyword(s):  
Optic Nerve ◽  
Peptide Mapping ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sucrose Density Gradient ◽  
Molar Ratio ◽  
Sucrose Density Gradient Centrifugation ◽  
Optic Nerves ◽  
10 Nm Filaments

Astroglial filaments approximately 10 nm in diameter were isolated from degenerated mouse optic nerves by Triton X-100 and DNase I treatments followed by sucrose density gradient centrifugation. 2-4 wk after bilateral enucleation, optic nerves contained virtually a single population of 10-nm filaments (astroglial filaments), free from neurofilaments. In negative-staining and thin-section electron microscopy, the isolated filaments were seen as nonbranching linear structures with smooth contour, and were morphologically identical to those in situ. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed the isolated filaments to be composed of two major polypeptides with molecular weights of 45,000 and 55,000, present in an approximate molar ratio of 1:1. These findings, together with the results of one-dimensional peptide mapping and solubility study, indicate that the astroglial filaments in the mouse optic nerve are primarily composed of these two polypeptides.

Ribonucleic acids of differentiating and non-differentiating uredosporelings of wheat stem rust

1974 ◽  
Vol 52 (6) ◽  
pp. 1309-1317 ◽  
Author(s):  
W. K. Kim ◽  
R. Rohringer
Keyword(s):  
Ribosomal Rna ◽  
Stem Rust ◽  
Gel Electrophoresis ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Wheat Stem Rust ◽  
Sucrose Density Gradient Centrifugation ◽  
Ribonucleic Acids ◽  
Molecular Weights ◽  
Germ Tubes

Uredospores of wheat stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) were deposited onto Millipore membranes and allowed to germinate. Those remaining continuously at 20° formed germ tubes only (non-differentiated), but those exposed to 30° for 90 min after the first 2 h of germination developed infection structures corresponding to appressoria and substomatal vesicles (differentiated).Nucleic acids were extracted with a phenol method from resting uredospores and from differentiated and non-differentiated sporelings. The amount of extractable RNA decreased as germination progressed, but no RNA was detected in the germination medium. The decrease in extractable RNA (up to 40%) occurred in both differentiated and non-differentiated sporelings.Acrylamide gel electrophoresis was used to separate RNA species and to determine their approximate molecular weights (in daltons): sporelings contained 25-S (1.65 × 106) and 18-S (0.80 × 106) ribosomal RNA (rRNA), 5-S (3.6 × 104) rRNA, and 4.5-S (2.4 × 104) transfer RNA (tRNA). Radioactive uridine, fed to sporelings, was incorporated mostly into 5-S rRNA and (or) tRNA.Acrylamide gel electrophoresis and sucrose density gradient centrifugation revealed that differentiated sporelings contained a type of RNA that was not detected in non-differentiated sporelings. It was heterogeneous and migrated in the 16-S to 5-S interval on polyacrylamide gels. Some of the RNA present in this fraction may have been preformed in resting spores and released from more complex material during the process of differentiation.

BIOCHEMICAL STUDIES ON 1-AMINOCYCLOPENTANE CARBOXYLIC ACID

1962 ◽  
Vol 40 (1) ◽  
pp. 1101-1110 ◽  
Author(s):  
K. Ahmed ◽  
P. G. Scholefield
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acid ◽  
Brain Cortex ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Inhibitory Effects ◽  
Synthetic Amino Acid ◽  
Ehrlich Ascites ◽  
Biochemical Studies

The synthetic amino acid 1-aminocyclopentane carboxylic acid does not seem to be metabolized but is actively concentrated by slices of rat brain cortex and Ehrlich ascites carcinoma cells. Its transport into the ascites cells has much in common with that of methionine since they are both inhibited by similar groups of amino acids. Kinetic analysis of the inhibitory effects of glycine, D- and L-methionine, allyl glycine, and thienyl glycine on the transport of 1-aminocyclopentane carboxylic acid confirms the suggestion that this amino acid and methionine enter ascites cells as the result of the action of a common transport system.

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