Influence of Deoxyribonucleic Acid Content on the Proteolysis of Sputum and Pus

Abstract

DEOXYRIBOSE nucleoprotein (DNP) has been identified as an important constituent of purulent exudates, constituting 30–70 per cent of the total solids¹. The action of deoxyribonuclease (DNase) in liquefying such exudates has been largely ascribed to the depolymerization of DNA^2–6. Sherry, Johnson and Tillett⁴ observed that acid-soluble nitrogen was progressively liberated into solution following the addition of DNase to the exudate. Similarly, liberation of trichloroacetic acid (TCA) soluble tyrosine was noted during our investigation of DNase action on purulent sputum. It is possible that this liberation of TCA soluble tyrosine resulted from the digestion of protein by an intrinsic proteolytic enzyme which requires depolymerization of interfering DNA. This communication is concerned with the testing of the hypothesis: (a) that a nucleoprotein, resistant to proteolysis, exists in sputum and pus; (b) that the protein becomes susceptible to a native proteolytic enzyme after the nucleoprotein complex has been split.