The action of nitric acid on the phosphorus of nucleoproteids and paranucleoproteids

Abstract

The manner in which phosphorus is combined in the true nucleoproteids and in those known as the psuedo (para) nucleo-compounds or phospho-proteins has not as yet been definitely ascertained nor has it been determined that the phosphorus in both classes of compounds is similarly or otherwise combined. Burian 1 has, it is true, suggested that in true nucleic acids phosphorus is the bond between the No. 7 nitrogen of the purin bases and the remainder of the nucleic acid molecule, but this view is founded on the fact that the nucleic acids do not give the diazo reaction which he regards as characteristic of those purins in which there is no substitution of the imide hydrogen of nitrogen No. 7 of the purin skeleton, an explanation of the reaction that is rejected by Steudel who has pointed out that thymin gives the diazo reaction of Burian although it does not contain nitrogen in the No. 7 position. 2

If Burian's suggestion were accepted it would establish a radical distinction between the manner in which phosphorus is held in nucleic acids and that obtaining in paranucleic acids, for in the latter there are no purin bases.

Whether we do or do not accept Burian's view, it is possible on other grounds to establish a distinction between the two classes of compounds in regard to the manner in which the phosphorus is combined in them. For this purpose nitric acid may be allowed to act for periods of varying length on pure preparations of the compounds.

In the observations of which the present paper is the result, nucleic acid from yeast and Hammarsten's nucleoproteid of the pancreas were employed as representatives of the true nucleoproteids while caseinogen exemplified the para compounds.