Synthesis in vitro of Novel Nucleic‐Acid‐Like Polymers of Ehrlich Ascites Tumor Cells

Abstract

1. When cytoplasmic particles isolated from Ehrlich ascites tumor cells were incubated with [14C]ribose, bases and inorganic phosphate in the presence of MgC12 and Tris/HCl (pH 7.0), radioactivity was incorporated into trichloroacetic-acid-insoluble materials.2. Radioactive products, extracted and purified by DEAE-cellulose column chromatography, were hydrolyzed in 1 M HCl at 100°C for 1 h and the resultant radioactive neutral sugar components were purified and identified as ribose, glucose and rhamnose by gas chromatography and mass spectrometry.3. When [14C]glucose was incubated in the same reaction system, radioactivity was also incorporated into trichloroacetic-acid-insoluble materials. Purified radioactive products were hydrolyzed in 1 M HCl at 100 "C for 1 h and the resultant radioactive neutral sugar components were also shown to be ribose, glucose and a little rhamnose, as was the case with the products synthesized from [14C]ribose.4. When ['4C]deoxyribose was incubated in the same reaction system, little incorporation was observed. 5.The radioactive products were incubated with venom phosphodiesterase and the digests were analyzed by Dowex 1 x 4 column chromatography. The results suggest that the radioactive products contained ribonucleotides and 'nucleotides' containing glucose (glucose 'nucleotides').6. When the radioactive products were incubated with both venom phosphodiesterase and alkaline phosphatase, ribonucleosides and glucose 'nucleosides' were detected. In Dowex 1x4 (borate form) chromatography, ribonucleosides were eluted coincidentally with ribonucleoside markers (Cyd, Ado, Urd and Guo), whereas the elution profiles of glucose 'nucleosides' were totally different from those of ribonucleosides.