[Preparative isolation of deoxyriboadenylic acids from hydrolysates of oxidized herring-sperm DNA using...

The alkaline hydrolysis of oxidized DNA from herring sperm yields a complex mixture of deoxyriboadenylic acids. After the removal of the fragments containing 1-3 monomer units by column chromatography, approximately 10% of the partial hydrolysate remains. This remaining fraction which contains the fragments of higher molecular weight is separated into two fractions by the base-pairing mechanism on a PV(pT)n-DEAE-Cellulose column with a two-step temperature gradient. The first fraction eluted at -4 degrees, contains the substances (approximately equal to 95% of the sample) that undergo no base-pairing with the immobilised oligothymidylic acid units. The remaining 5% of the sample that hybridizes with PV(pT)n-DEAE-Cellulose at -4 degrees, is eluted at 30 degrees (fraction 2). After enzymatic dephosphorylation, homologues of deoxyriboadenylic acid containing up to 8 monomer units are isolated on a preparative scale in chromatographically pure form from fraction 2 using column chromatography. Purity and structure of the isolated adenylic acids are determined by paper chromatography and by enzymatic hydrolysis.