The effect of polyanion on the enzymatic degradation of modified deoxyribonucleoprotein samples.

The degradation of DNA in modified deoxyribonucleoprotein samples by DNase II in the presence of a polyanion (polypentose sulphate) was studied. The behaviour of DNP samples partially depleted of histone and treated with acetic anhydride is characterized by an increased accessibility of their DNA to DNase II, by a decreased polyanion amount needed for the maximum enzymatic degradation of their DNA, and, finally, by a more profound inhibitory effect of higher polyanion amounts on the DNase II-catalyzed degradation. On the other hand, the behaviour of DNP samples treated with formaldehyde is characterized by a decreased accessibility of their DNA to DNase II, by a limited increase in the enzymatic degradation of their DNA in the presence of the polyanion, and finally by a less profound inhibitory effect of higher polyanion amounts on the DNase II-catalyzed degradation.