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R M DAWSON

Publications and source records attributed to R M DAWSON.

At least 19 recordsLinked to original sources
PubMed1965

THE ADENOSINE-TRIPHOSPHATASE SYSTEM RESPONSIBLE FOR CATION TRANSPORT IN ELECTRIC ORGAN: EXCLUSION OF PHOSPHOLIPIDS AS INTERMEDIATES.

1. Subcellular fractions were prepared from the electric organs of Electrophorus and Torpedo and assayed for adenosine-triphosphatase activity. 2. Treatment of the ;low-speed' fraction from Torpedo with m-urea gave an adenosine-triphosphatase preparation that was almost completely (98%) inhibited by ouabain (0.1mg./ml.) and dependent on the simultaneous presence of Na(+) and K(+). 3. The adenosine-triphosphatase preparations were exposed to [gamma-(32)P]ATP for 30sec. in the presence of (i) Na(+), (ii) K(+), (iii) Na(+)+K(+) and (iv) Na(+)+K(+)+ouabain. No significant labelling of phosphatidic acid, triphosphoinositide or any other phospholipid was observed. 4. The results suggest that phospholipids do not act as phosphorylated intermediates in the ;transport adenosine-triphosphatase' system of electric organ.

Adenosine↗
PubMed1965

THE PREPARATION OF ADENOSINE 5'-PYROPHOSPHATE BY A NON-ENZYMIC METHOD.

1. A non-enzymic method for the preparation of adenosine 5'-diphosphate is described, in which the terminal phosphate of adenosine 5'-triphosphate is transferred to methanol in the presence of hydrochloric acid. The final purified product can be obtained in 60% yield. 2. Experiments with [(14)C]methanol showed that no methylation of the adenosine diphosphate occurs during the reaction. 3. Confirmation that the pyrophosphate moiety of the adenosine diphosphate produced was in the 5'-position was obtained by: (a) periodate oxidation; (b) treatment with apyrase and examination of the resulting adenylic acid isomer by paper chromatography. 4. The method appears to be generally applicable to the preparation of nucleoside 5'-diphosphates from the corresponding nucleoside 5'-triphosphates.

Adenine Nucleotides↗