Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new route for the synthesis of 1-(beta-D-allofuranosyl)uracil ("allo-uridine") and the corresponding 6'-deoxy-derivative ("6'-deoxy-allo-uridine") as well as for 1-(beta-D-altrofuranosyl) uracil ("altro-uridine") is described. NMR studies of allo-uridine revealed a preferred conformation with the base in anti-position, C-2'-endo-pucker of the sugar moiety, the 5'-OH-group above the furanose ring and the 5'-CH2OH-group in a gt position with the OH-group in the plane of the furanose ring. The same conformation is found for the 5'- and 6'-phosphate, indicated by the influence of the phosphate group on the H-6 signal. Allo-uridine is phosphorylated by the phosphotransferases from carrot and from malt sprouts only in the 6'-position. The phosphate ester is hydrolysed by unspecific phosphatases but not by 5'-nucleotidase. A (3' leads to 6')-dinucleoside phosphate is formed by pancreatic ribonuclease with 2',3'-cyclic cytidylic acid and allo-uridine. It is split by nuclease S1, but not by snake-venom phosphodiesterase. It has no primer activity for polynucleotide phosphorylase. All-uridine 6'-diphosphate could not be prepared enzymatically by nucleotide kinase or by chemical methods, where 5',6'-cyclic phosphates are formed, which are hydrolysed exclusively to 6'-monophosphates.
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PMID:Synthesis, conformation and enzymatic properties of 1-(beta-D-allofuranosyl)uracil and some derivatives. 631 65

The incorporation of the cytokinin N(6)-benzyladenine into tobacco (Nicotiana tabacum) callus tRNA and rRNA preparations isolated from tissue grown on medium containing either N(6)-benzyladenine-8-(14)C or N(6)-benzyladenine-8-(14)C: benzene-(3)H(G) has been examined. N(6)-benzyladenine was incorporated into both the tRNA and rRNA preparations as the intact base. Over 90% of the radioactive N(6)-benzyladenosine recovered from the RNA preparations was associated with the rRNA. Purification of the crude rRNA by either MAK chromatography or Sephadex G-200 gel filtration had no effect on the N(6)-benzyladenosine content of the RNA preparation. The distribution of N(6)-benzyladenosine moieties in tobacco callus tRNA fractionated by BD-cellulose chromatography did not correspond to the distribution of ribosylzeatin activity. N(6)-benzyladenosine was released from the rRNA preparation by treatment with venom phosphodiesterase and phosphatase, ribonuclease T(2) and phosphatase, or ribonuclease T(2) and a 3'-nucleotidase. N(6)-benzyladenosine was not released from the RNA preparation by treatment with either ribonuclease T(2) or phosphatase alone or by successive treatment with ribonuclease T(2) and a 5'-nucleotidase. Brief treatment of the rRNA preparation with ribonuclease T(1) and pancreatic ribonuclease converted the N(6)-benzyladenosine moieties into an ethyl alcohol soluble form. On the basis of these and earlier results, the N(6)-benzyladenosine recovered from the tobacco callus RNA preparations appears to be present as a constituent of RNA and not as a nonpolynucleotide contaminant.
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PMID:Incorporation of cytokinin N-benzyladenine into tobacco callus transfer ribonucleic Acid and ribosomal ribonucleic Acid preparations. 1665 17