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Biomedical subjects

M Saneyoshi

Publications and source records attributed to M Saneyoshi.

At least 127 records · Page 7Linked to original sources
PubMed1980

Utilization of 5-alkyl UTPs by DNA-dependent RNA polymerase I and II purified from cherry salmon (Onchorhynchus masou) liver.

DNA dependent RNA polymerase II was purified to approximately 8300 fold from sonicated nuclear extract of cherry salmon (Onchorhynchus masou) liver by the following purification steps: polyethylene glycol treatment, DEAE=Sephadex A-25 column chromatography, heparin-Sepharose column chromatography, and affinity chromatography on DNA-cellulose. Final preparation of this enzyme has a specific activity of 157 nmole UMP incorporation into RNA per mg of protein per 10 min at 25 degrees. RNA polymerase I was also purified to approx. 3800 fold in a similar manner. Its specific activity was calculated as 26.2 nmole/mg/10 min. Utilization of various UTPs of these enzymes was studied by substitution experiments under the condition of limited synthesis. 5-Methyl UTP (rTTP) could be utilized by the RNA polymerase I 1.7 fold more efficiently compared with UTP. In contrast, the RNA polymerase II recognized rTTP as a substrate as efficiently as UTP. Similar experiments using other alkyl UTPs have been performed.

Alkylation↗
PubMed1979

In vitro antiherpesviral activity of 5-alkyl derivatives of 1-beta-D-arabinofuranosyluracil.

Several 5-alkyl derivatives of 1-beta-d-arabinofuranosyluracil (araU) were tested for antiherpesviral activity and inhibitory action on cell growth in human embryonic lung fibroblasts. 1-beta-d-Arabinofuranosylcytosine, 9-beta-d-arabinofuranosyladenine, and 5-iododeoxyuridine (IUdR) were included as reference materials. Among the 5-alkyl derivatives of araU, arabinosylthymine was the most active, followed by 5-ethyl- and 5-propyl-araU. 5-Ethyl-araU was as active as IUdR and more active than 9-beta-d-arabinofuranosyladenine against herpes simplex virus (HSV) type 1 and did not inhibit cell growth at a concentration as high as 1,000 mug/ml. 5-Butyl- and 5-methoxymethyl-araU, as well as araU, exhibited relatively low activity. The araU derivatives tested were as active against HSV WT-34, an isolate from a patient with keratitis, as against HSV type 1. Against an IUdR-resistant isolate, HSV WT-20, arabinosylthymine was less inhibitory than IUdR. Deoxyribonucleic acid synthesis in HSV type 1-infected cells was markedly inhibited by arabinosylthymine, IUdR, and 5-ethyl-araU, whereas cellular deoxyribonucleic acid synthesis in uninfected cells was significantly inhibited by IUdR but not by arabinosylthymine or 5-ethyl-araU.

Arabinofuranosyluracil↗
PubMed1979

Utilization of 2'-deoxy-6-thioguanosine 5'-triphosphate in DNA synthesis in vitro by DNA polymerase alpha from calf thymus.

Chemically synthesized beta-2'-deoxy-6-thioguanosine 5'-triphosphate, a putative active form of beta-2'-deoxy-6-thioguanosine, was used efficiently as a substrate for DNA synthesis catalyzed by DNA polymerase alpha from calf thymus. The deoxythioguanylate was incorporated into DNA by replacing deoxyguanylate and supported the further elongation of DNA chains on activated calf thymus DNA. In contrast, DNA polymerase beta used beta-2'-deoxy-6-thioguanosine 5'-triphosphate at a much lower rate. The reaction product of DNA polymerase alpha, i.e., 6-thioguanine-containing DNA, adsorbed specifically to the organomercurial agarose column, and showed a peak of UV absorption at 342 nm, which is characteristic of thioguanine.

Animals↗
PubMed1979

Recognition of various arginine transfer ribonucleic acids with arginyl-tRNA synthetase purified from human placenta.

Arginyl-tRNA synthetase has been purified approximately 550 fold from crude extract of human placenta by the following purification steps: Ammonium sulfate fractionation, chromatographies of DEAE-cellulose and CM-Sephadex and Sephadex G-100 gel filtration. Final preparation of this enzyme has specific activity of 123 nmole of arginyl-tRNA formed per mg of protein and was free from other aminoacyl-tRNA synthetase activities. Recognition of various arginine tRNAs with this enzyme was studied using kinetic analysis of arginylation of arginine tRNA and also arginine tRNA dependent ATP-PPi exchange reaction. Affinity of this enzyme with arginine tRNA was determine from Vmas/Km values and it was in the order of rabbit, Chum salmon, B. subtilis, E. coli and yeast in both systems.

Amino Acyl-tRNA Synthetases↗
PubMed1979

Inhibitory effects of 9-beta-D-arabinofuranosylguanine 5'-triphosphate and 9-beta-D-arabinofuranosyladenine 5'-triphosphate on DNA polymerases from murine cells and oncornavirus.

The effects of the newly synthesized compound 9-beta-D-arabinofuranosylguanine 5'-triphosphate (ara-GTP) on the activity of DNA polymerases from mouse cells and oncornavirus were compared with those of 9-beta-D-arabinofuranosyladenine 5'-triphosphate. Ara-GTP did not replace deoxyguanosine 5'- triphosphate as substrate for these DNA polymerases but inhibited the activities of DNA polymerase alpha, beta, and gamma and viral DNA polymerase. DNA polymerase alpha was more sensitive than DNA polymerases beta and gamma and viral DNA polymerase to inhibition by ara-GTP. The inhibitions by ara-GTP and 9-beta-D-arabinofuranosyladenine 5'-triphosphate were due to competition or partial competition 5'-triphosphate were due to competition or partial competition with deoxynucleoside triphosphate with the same base. The inhibition constant (Ki) and the mode of inhibition of nucleotide incorporation varied depending on the combination of inhibitor, substrate(s), and enzyme species.

Animals↗
PubMed1979

Recognition of structure of 5-halogenated derivatives of ara-UTP by DNA polymerase gamma and reverse transcriptase.

This report deals with the test of a series of 5-halogenated derivatives of ara-UTP for the inhibition of DNA polymerase gamma and viral reverse transcriptase. The compounds newly synthesized and tested were; ara5-FUTP, ara5-C1UTP, ara5-BrUTP and ara5-IUTP. The results were: 1) All these compounds were inhibitory to DNA polymerase gamma and reverse transcriptase. The mode of inhibitions was, in all cases, competitive against dTTP. 2) Ki values for these inhibitors with DNA polymerase gamma were lower than those with reverse transcriptase. 3) Ara5-ClUTP was less inhibitory to reverse transcriptase than other derivatives.

Animals↗
PubMed1978

Inhibition of mouse myeloma DNA polymerase alpha by 5-triphosphates of 1-beta-D-arabinofuranosylthymine and 1-beta-D-arabinofuranosylcytosine.

This is the first report dealing with the effect of 1-beta-D-arabinofuranosylthymine 5'-triphosphate (araTTP), synthesized by a new method, on eukaryotic DNA polymerase [EC 2.7.7.7]. AraTTP was tested for the inhibition of DNA synthesis in vitro using highly purified mouse myeloma DNA polymerase alpha in comparison with 1-beta-D-arabinofuranosylcytosine 5'-triphosphate (araCTP). AraTTP was found to inhibit competitively the incorporation of [3H]dTTP into DNA and non-competitively the incorporation of [3H]dCTP, while the mode of the inhibition by araCTP was non-competitive with respect to dTTP and competitive with respect to dCTP. Neither araTTP nor araCTP was utilized as a substrate in place of dTTP or dCTP in DNA synthesis by DNA polymerase alpha.

Animals↗
PubMed1978

Inhibitory effect of 1-beta-D-arabinofuranosylthymine 5'-triphosphate and 1-beta-D-arabinofuranosylcytosine 5'-triphosphate on DNA polymerases from murine cells and oncornavirus.

This report compares the effect of the newly synthesized 1-beta-D-arabinofuranosylthymine 5'-triphosphate with 1-beta-D-arabinofuranosylcytosine 5'-triphosphate on the activity of DNA polymerases from mouse cells and oncornavirus. 1-beta-D-Arabinofuranosylthymine 5'-triphosphate inhibited all the activities of DNA polymerase alpha, beta, and gamma and viral DNA polymerase. The mode of inhibition of 1-beta-D-arabinofuranosylthymine 5'-triphosphate as well as 1-beta-D-arabinofuranosylcytosine 5'-triphosphate was competitive to the deoxynucleoside triphosphate with the same base. The inhibition constant (Ki) and the mode of inhibition of nucleotide incorporation varied with changes in the combination of the inhibitor, substrate(s), and enzyme species.

Animals↗