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Your search keyword '"H. Akiyoshi"' showing total 8 results
Start Over Author "H. Akiyoshi" Publication Year Range More than 50 years ago
8 results on '"H. Akiyoshi"'

1. Isolation and purification of calcium and magnesium dependent endonuclease from rat liver nuclei

Author

T. Takahashi, H. Akiyoshi, and R. Ishida

Subjects
DNA, Bacterial, inorganic chemicals, Size-exclusion chromatography, Biophysics, chemistry.chemical_element, Calcium, Nucleic Acid Denaturation, Tritium, Biochemistry, Endonuclease, chemistry.chemical_compound, Centrifugation, Density Gradient, Escherichia coli, Animals, Magnesium, Molecular Biology, Cell Nucleus, chemistry.chemical_classification, Manganese, Deoxyribonucleases, biology, Cell Biology, Hydrogen-Ion Concentration, Endonucleases, Chromatin, Enzyme assay, Rats, Molecular Weight, Enzyme, Liver, chemistry, Sephadex, Chromatography, Gel, biology.protein, Spectrophotometry, Ultraviolet, DNA, Thymidine
Abstract

An endonuclease associated with rat liver chromatin was extracted with 0.6 M NaCl and purified by ammonium sulfate fractionation and Sephadex G-100 gel filtration. The enzyme produces single strand scissions on native DNA at neutral pH in the presence of 1 mM CaCl2 and 5 mM MgCl2. Alkali-denatured DNA was not nicked by the enzyme. Omission of Ca2+ reduced the enzyme activity to about one seventh. Without Ca2+, however, Mn2+ was more effective than Mg2+. The molecular weight of the enzyme is about 27,000.

Published
1974
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3. Isolation and characterization of substance in yeast extract which inhibits growth of thymine-less strains of Escherichia coli

Author

H. Akiyoshi, N. Kinoshita, and H. Endo

Subjects
Guanine, Nucleosides, Biology, medicine.disease_cause, Microbiology, Molecular biology, Adenosine, Thymine, Culture Media, chemistry.chemical_compound, chemistry, Biochemistry, Yeasts, Mutation, medicine, Escherichia coli, Yeast extract, Chromatography, Thin Layer, Thymidine, Inosine, Hypoxanthine, medicine.drug
Abstract

SUMMARY: Yeast extract which promotes the growth of wild-type strains of Escherichia coli had a potent bactericidal action on thymine-less mutants. The active principle in the yeast extract was found to be adenosine. All of the other nucleosides and their bases tested except guanine, hypoxanthine and inosine also showed various degrees of bactericidal activity. The activity of adenosine was competitively annulled by the addition of excess thymidine to the medium, but thymine showed practically no anti-adenosine effect.

Published
1969

4. Isolation and purification of calcium and magnesium dependent endonuclease from rat liver nuclei.

Author

Ishida R, Akiyoshi H, and Takahashi T

Subjects
Animals, Calcium pharmacology, Centrifugation, Density Gradient, Chromatin enzymology, Chromatography, Gel, DNA, Bacterial, Deoxyribonucleases metabolism, Endonucleases metabolism, Escherichia coli, Hydrogen-Ion Concentration, Liver cytology, Magnesium pharmacology, Manganese pharmacology, Molecular Weight, Nucleic Acid Denaturation, Rats, Spectrophotometry, Ultraviolet, Thymidine, Tritium, Cell Nucleus enzymology, Deoxyribonucleases isolation & purification, Endonucleases isolation & purification, Liver enzymology
Published
1974
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6. Genetic evolution of bacteriophage. II. Physical length of the homologous region in a hybrid between serologically and morphologically unrelated phages.

Author

Akiyoshi H and Yamamoto N

Subjects
Carbon Isotopes, Centrifugation, Density Gradient, Salmonella typhimurium, Thymidine, Thymine pharmacology, Tritium, DNA, Viral isolation & purification, Genetics, Microbial, Hybridization, Genetic, Salmonella Phages
Abstract

P22 and P221 DNA were labeled with (3)H-thymidine and hybridized with P22 DNA, P221 DNA, or Fels 1 DNA immobilized on Millipore membrane filters. With this technique, 31% of the P22 genome was computed to be homologous to the P221 genome. Since the molecular weight of P22 DNA is 2.65 x 10(7) daltons, the homologous region between P22 and P221 should be equivalent to about 8.2 x 10(6) daltons and contain 13,300 nucleotide pairs or about 4400 triplets. Moreover, 46% of the P221 genome was computed to be homologous to the P22 genome. Therefore, the molecular weight of P221 DNA was calculated to be about 1.80 x 10(7) daltons. Sucrose gradient centrifugation showed that the molecular weight of P221 DNA was 2.01 x 10(7) daltons. Thus, the P221 genome is about 25 to 30% smaller than the P22 genome. Further-more, 54% of the P221 genome was found to be homologous to the Fels 1 genome. However, the labeled P22 DNA hybridized with Fels 1 DNA was about 2% of the labeled P22 DNA hybridized with P22 DNA.

Published
1970
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