Purification of oligonucleotides with streptolysin S inducer activity and de Novo synthesis of the hemolysin

The oligoribonucleotide fraction containing the Streptolysin S inducer activity from the RNase digest of yeast RNA (active fraction; A. W. Bernheimer and M. J. Rodbart, 1948, J. Exp. Med., 80, 149–168) was purified by the oligo(dC)-cellulose affinity chromatography based on its high guanine content. A 20-fold purification of the inducer activity over that of AF the active fraction, and approximately 2000-fold over that of yeast RNA has been obtained. The purification oligonucleotide was found to contain several molecular species with 7–10 nucleotide residues, all apparently with inducer activity. Streptolysin S induced with this oligonucleotide preparation and gel filtered has a specific activity comparable to the highest value reported previously. Incorporation of amino acids into streptolysin S was observed upon induction with the purified oligonucleotide and paralleled the increase in the hemolysin activity. This and experiments with chloramphenicol indicated that streptolysin was synthesized de novo on stimulation with the oligonucleotide inducer. The pattern of amino acid incorporation was in good agreement with the amino acid composition of purified streptolysin reported earlier. No incorporation of glucose or mannose was observed.