Differentiation of ribonucleic acids by inhibition of streptococcal deoxyribonuclease

Abstract

A study was made of the depolymerizing action of group A streptococcal desoxyribonuclease on thymus desoxyribonucleic acid as affected by ribonucleic acids of diverse origin. Crude and purified prepns. of ribonucleic acids derived from a variety of bacteria partially inhibited the desoxyribonuclease. In contrast, ribonucleic acids from mammalian pancreas and liver, tobacco leaves, wheat germ and yeast failed to show inhibition. Two prepns. of tobacco mosaic virus nucleic acid resembled the bacterial ribonucleic acids in causing inhibition, but they were effective only in relatively high concn. The results are interpreted as indicating the possible existence in living matter of 2 qualitatively different types of ribonucleic acid: (a) an inhibitory form which is present in bacteria and possibly in some viruses, and (b) a non-inhibitory form which is present in mammalian tissue and in plants.