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Biomedical subjects

F Egami

Publications and source records attributed to F Egami.

At least 91 records · Page 5Linked to original sources
PubMed1968

Studies on extracellular ribonucleases of Ustilago sphaerogena. Purification and properties.

1. Four ribonucleases were isolated from culture media of Ustilago sphaerogena. They were designated ribonucleases U(1), U(2), U(3) and U(4). 2. They were purified about 1600-, 3700-, 1100- and 16-fold respectively. 3. It was shown by gel filtration that ribonucleases U(1), U(2) and U(3) have molecular weights about 10000 like ribonuclease T(1), and that ribonuclease U(4) is much larger. 4. Ribonucleases U(1), U(2) and U(3) are thermostable, but ribonuclease U(4) is not. 5. The pH optimum of ribonucleases U(1) and U(4) is pH8.0-8.5, and that of ribonucleases U(2) and U(3) is pH4.5.

Basidiomycota↗
PubMed1968

Studies on extracellular ribonucleases of Ustilago sphaerogena. Characterization of substrate specificity with special reference to purine-specific ribonucleases.

1. Ribonuclease U(1) splits only the phosphodiester bonds of guanosine 3'-phosphates in RNA. It may be regarded as a guanyloribonuclease [ribonucleate (guanine nucleotide)-2'-transferase (cyclizing), EC 2.7.7.26] similar to ribonuclease T(1) (Egami, Takahashi & Uchida, 1964). It seems to be identical with the extracellular ribonuclease described by Glitz & Dekker (1963, 1964a,b). 2. Ribonucleases U(2) and U(3) are novel enzymes with a strict specificity. They split the internucleotide bonds between purine 3'-nucleotides and 5'-hydroxy groups of adjacent nucleotides in RNA with the intermediary formation of purine nucleoside 2',3'-(cyclic)-phosphates, which are slowly hydrolysed to purine 3'-nucleotides. So they may be classified as ;puryloribonucleases [ribonucleate (purine nucleotide)-2'-transferase (cyclizing)]'. Double-stranded RNA is scarcely split by ribonucleases U(2) and U(3). 3. Ribonuclease U(4) has no absolute base specificity, and produces the mononucleotides 3'-adenylate, 3'-guanylate, 3'-cytidylate and 3'-uridylate from RNA.

Adenine Nucleotides↗