NUCLEIC ACIDS AND OTHER PROTEIN-BOUND PHOSPHORUS COMPOUNDS OF CAT BRAIN

Methods have been investigated for purifying the phosphorus compounds of brain for the determination of specific activities after the administration of radioactive phosphate. The specific activities of the nucleic acids obtained by the method of Hammarsten (8) were much lower than those obtained by the Schmidt and Thannhauser procedure (18). There was a considerable incorporation of radioactive phosphate into the phosphorous compounds of cat brain following an intracisternal injection of P32. The determination of the relative specific activities for a number of phosphorus fractions showed that the incorporation was most rapid into the acid-soluble phosphorus followed, in descending order, by “phosphoprotein”, “diphosphoinositide”, pentosenucleic acid, acid-insoluble residue, phospholipid, and desoxypentosenucleic acid.