Release of the Hemolytic Component of Streptolysin S by ATP and Magnesium Ion from a Protoplast Membrane Fraction of Streptococci

Abstract

1. A protoplast membrane fraction of Streptococcus pyogenes S 8 was prepared.
2. A hemolysin of streptolysin S nature was released from the membrane fraction by ATP and Mg⁺⁺ in the presence of oligonu-cleotide or Tween 40.
3. Contrary to the net synthesis by resting cells, the release was not inhibited by chloramphenicol, puromycin and strepto-mycin.
4. The system consisting of the mem-brane fraction, ATP and Mg⁺⁺ could lyse the rabbit erythrocytes. The hemolysis was not inhibited by cholesterol.
5. From these observations, it was con-cluded that the hemolytic component of streptolysin S was released from the mem-brane fraction by ATP and Mg⁺⁺. The hemolysin of streptolysin S nature obtained in the presence of oligonucleotide or Tween 40 is a complex of a hemolytic component (polypeptide) and a stabilizing component (oligonucleotide or Tween 40).
6. For the release of hemolytic compo-nent from the membrane fraction, GTP, UTP, CTP, ADP and creatine phosphate-creatine kinase system were as effective as ATP. GDP, UDP, CDP, AMP, GMP, UMP, CMP, mal-tose and glucose were ineffective.
7. For the release, Mg⁺⁺ could be re-placed by Mn⁺⁺, but not by Ca⁺⁺. The latter was rather inhibitory for the reaction.
8. The release of the hemolytic compo-nent by ATP and Mg⁺⁺ could not be observed in the presence of trypsin. No inhibitory effect on the release of the hemolytic com-ponent was observed with RNases and several enzyme poisons such as PCMB et al.
9. The hemolytic component was still retained in the membrane fraction prepared from resting cells preincubated in the presence of maltose. Chloramphenicol, puromycin and streptomycin inhibited the synthesis of the hemolytic component by resting cells. Peni-cilline G and mitomycin C had no effect.
The present authors wish to express their sincere thanks to Dr. J. Koyama for his useful discussions.