Ribonucleic acid extraction

MONTAGNIER, L. and SANDERS, F.K. Sedimentation properties of infective ribonucleic acid extracted from encephalomyocarditis virus. Nature (London), (I963), 197, II78-II8I. 

Extracts from 152 plant species, representing 46 different families, were screened for effects on tobacco mosaic virus (TMV) replication in cucumber cotyledons. Twenty species have shown enough activity to warrant further study. Several members of the Caprifoliaceae family increased virus replication. An extract of Lonicera involucrata enlarged the virus lesions in local lesion hosts and produced a thirty fold increase in virus titer, but had no effect on virus replication in systemic hosts. The active material appears to affect the virus defense mechanism of local lesion hosts. An extract of common geranium is an active virus inhibitor. It inactivates TMV and TMV-RNA (ribonucleic acid) in vitro by forming non-infectious complexes. In vivo, it also inhibited starch lesion formation in cucumber cotyledons incited by TMV infection. 

In a number of methods, isolation of the nucleoprotein complex (stage 2) is avoided. In the isolation of ribonucleic acid from beef pancreas,1241 nuclear material and cell debris are removed from a normal-saline extract of the minced tissue, which is then brought to half-saturation with sodium chloride (to dissociate the protein from the nucleic acid). After removal of the protein, the nucleic acid is precipitated with alcohol. However, the suggestion has been made126 that it is more satisfactory to isolate the nucleoprotein first, and this has been carried out, for instance, in the extraction of the ribonucleic acid from fowl sarcoma GRCH 15.126 Nucleoprotein complexes have also been isolated from baker s yeast127 and have been separated into various fractions, the nucleic acids from which differ slightly in composition. In addition, nucleoproteins have been isolated by complex formation with cetyltrimethylammonium bromide.128... 

Our studies have shown that cotton dust extracts contain deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) (27). DNA is present in varying concentrations in cardroom cotton dust (28) and emanates from bacteria, fungi, protozoa and plant cells. DNA might be important in the pathogenesis of byssinosis, as minute amounts can cause complement conversion. 

The aminoacyl transfer reaction, one of the latter stages in protein synthesis, involves incorporation of amino acids from soluble ribonucleic acid-amino acid into ribosomal protein. This reaction requires guanosine triphosphate and a soluble portion of the cell. Evidence has been obtained with rat liver preparations that aminoacyl transfer is catalyzed by two protein factors, aminoacyl transferases (or polymerases) I and n, which have been resolved and partially purified from the soluble fraction. Transferase n activity has also been obtained from deoxycholate-soluble extracts of microsomes. With purified transferases I and n, incorporation is observed with relatively low levels of GTP its sulfhy-dryl requirement is met by a variety of compounds. The characteristics of this purified amino acid incorporating system, in terms of dependency on the concentration of its components, are described. 

Two major metabolites were isolated by paper chromatography (from trichloroacetic acid extracts of the cells) and were identified as 8-azaguano-sine 5-phosphate and 8-azaguanosine, respectively. The two compounds were present in the ratio of 4 1. The structure of the 8-azaguanosine 5-phosphate was indicated by chromatographic and electrophoretic comparison of it with (a) the 5-nucleotide prepared by the action of snake venom on the bacterial ribonucleic acid containing 8-azaguanine, and (b) the 3-nucleotide prepared by alkaline hydrolysis. 

Derivation By extraction from tea by synthesis from uric acid prepared from yeast ribonucleic acid. 

Rabbit-muscle extracts contain the enzyme amylose isomerase, which also catalyzes the degradation of (1—>6)-interchain linkages. i -i i This reaction is not hydrolytic, but appears to be a reversible transglucosylation. Amylose isomerase preparations are heterogeneous, and, on electrophoresis, four components of various activity and ribonucleic acid content are obtained. The in vivo significance of this enzyme is not yet established. 

Nagasawa, T., H. Oura, S. Hiai, and K. Nishinaga Effect of Ginseng Extract on Ribonucleic Acid and Protein Synthesis in Rat Kidney. Chem. Pharm. Bull. (Japan) 25, 1665 (1977). 

Enzymes, as you probably know, are proteins that can make chemical reactions happen in a more selective and faster way. At the end of each reaction cycle the enzymes remain unchanged so they act as catalysts. Since they occur in the living world we call them biocatalysts. Aside from proteins, ribonucleic acids and their fragments can act as catalysts and are called ribozymes, by analogy to enzymes. Enzymes are extracted from living tissues, for example, milk, saliva, liver, muscle have to be stored under carefully maintained conditions and, once outside living tissue, lose their activity fast. Isolation and purification of enzymes and assaying their activity have been major operations in biochemical and biomedical laboratories. Today,... 

EGGER, K.L. and SHATKIR, A.J. In vitro translation of caxdiovirus ribonucleic acid by mammalian cell-free extracts. 

Mononucleotides in alkaline hydrolysates of ribonucleic acids are best separated on PEI-cellulose and quantitatively determined after elution. In a recommended procedure, the individual fractions are eluted with M lithium chloride on to a narrow paper strip, the strip is dried, the nucleotides are eluted from it with water and the concentrations of the aqueous solutions determined by spectrophoto-metric measurements in the UV [57] considerably more accurate analyses are possible with this procedure than by direct extraction from the adsorbent [57] (see also Fig. 54, p. 104). 

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