Preparation of some deoxyribonucleic acid–protein complexes from rat-liver homogenates

Abstract

Deoxyribonucleic acid was prepared from rat liver by the action of a number of salts in con-juction with phenol. The amount of residual protein attached to the deoxyribonucleic acid depends upon the salt used. p-Aminosalicylate and diethyldithiocarbamate have been the only salts to produce a deoxyribonucleic acid nearly free from protein. The ability to complex with metals, in addition to the power to interact with proteins, is required to liberate deoxyribonucleic acid with very little protein from rat liver. Neither naphthalene-2-sulfonate nor ethylenediamine-NNN''N tetra-acetate separately liberates any appreciable quantity of deoxyribonucleic acid but the two salts will do so when used together. No protein was taken up on deoxyribonucleic acid which was mixed with a rat-liver homogenate in the presence of 0.14 M benzoate. The relevance of these experiments to the nature of the deoxyribonucleic acid-protein bonding is discussed.